project report on chloro caustic group
TRANSCRIPT
Project Report on Chloro Caustic Group
Tata Chemicals Ltd. Mithapur
Gujrat India
Submitted to:- Submitted by:-
Mr. Rajnish Vadgama (HOD) Pintu Jain
Mr. Anil Modi (Deputy Manager) 3rd year chemical engineering
MNIT Jaipur
Email id- [email protected]
PREFACE Theory on any subject is very important but without knowing and witnessing its practical application it becomes useless. The principle activity of plant training is to get details about unit operations unit processes which are carried out in chemical industry and also about the equipment used in industry. Another attractive feature to learn about industrial management and discipline which are equally important in life. During the period of training students get acclimatized to the industry atmosphere and also come face to face with the various problems occurring and ways to solve them, this helps him tremendously to face, the different challenges when he actually becomes an employee of industry. Thus, industry exposure is really mandatory for every technical student.
ACKNOWLEDGEMENT
It will be a great experience to be part of this organization. I have received
encouragement and support from various persons who have directly or
indirectly contributed towards the completion of this project.
I am thankful to the management of Tata Chemical Limited who permitted me
for doing the project training within an exposure of functioning of big
corporate for the period of 45 days.
I would like to show my greatest appreciation to Mr. PARAG BADIYANI SIR
& Mr. UPENDRA BHAYANI who gave me a golden chance to become part
of Tata chemicals. I feel motivated and encouraged every time I met them.
I would also like to specially thank Mr. RAJNISH VADGAMA SIR Mr. ANIL
MODI SIR and entire CHLORO AND CAUSTIC Department for their
constant help and critical evaluation.
Last but not least, I would like to thank the whole staffs of Tata Chemical Ltd.,
Who support me in my research and data collection.
Index
S. no. Content
History
CHLORO –CAUSTIC GROUP • Product of C. C. Group • CCG management
HISTORICAL EVALUATION of PROCESS • Non - Electrolytic Process • Electrolytic Process • Review of Technology
INTRODUCTION TO C. C. Group • Process Flow Chart of the CC Group
PRIMARY BRINE REFINING • Flow sheet • Material balance
SECONDARY BRINE REFINING • Process Flow Chart for Filtration • Filtration • Process flow chart for resin tower • Resin tower • Equipment details
CELL HOUSE • Theory regarding the electrolysis • Brief Description of Plant • Brine Dechlorination & Chlorate decomposition • Chlorine Cooling & Blowing • Electrolysis PROCESS • Equipment deatils • Material balance and energy balance
HYDROCHLORIC ACID PLANT • HCl Plant flow sheet • Process • Hydrogen handling before processing in HCL Plant
• Handling of equipment’s • M.O.C. of Equipment • Safety & Good House keeping
CHLORINE PLANT
Chlorine Drying
Plant flow sheet
Chlorine Compression
Plant flow sheet
Liquefaction and storage of chlorine gas
Filling of liquid chlorine cylinder
CL2 neutralizer Hypo plant
Equipment details
Properties of Chlorine
Degree of Hazards and their Effects
First Aid
DO’S & DON’T For Chlorine
Safe Handling of Liquid chlorine Tonner:
Receipt of Empty Tonner Returned From The Party:
Filling operation NICKLE BRINE BODY EVAPORATOR
Brief Description of Plant
Plant flow sheet
Material balance and energy balance
M.O.C. Of Equipment UTILITY SECTION
Cooling Water System
Chilled Water System
Raw Water System
D. M. Water System CRITICAL PROCESS PARAMETERS IN THE CC GROUP PLANT
GENERAL SAFETY INFORMATION
Lab Safety Equipment:
Chemical Hazards and Symbols
Chemical Hazard Symbols and Definitions
Selection of PPE According To Body Part
Selection of Material of Construction of PPE
Material Safety Data Sheet
Safety data for different chemicals WORK PERMIT PROCEDURE
Purpose
Scope
Work Permit
Procedure for obtaining the Work Permit
History
Mithapur is located in the Dwarka Taluka of the Jamnagar District of
Gujarat state on the western coast of India. Started as a small trading firm
by Jamsedji Nusserwanji Tata in 1868, from a small private trading firm to
one of the largest conglomerates in India; the Tata Group has come a long
way Starting in 1939 with a capacity of 33,000 tons per annum of Soda
Ash, the plant at Mithapur has since grown into a chemicals behemoth
with an installed capacity of 8,75,000 Tons Per Annum, about 34 per cent
of the country’s capacity, making it one of the largest producers of
synthetic soda ash in the world.
The Mithapur plant is the largest integrated salt works and inorganic
chemicals complex in this part of the world. Its salt works are spread over
60 sq km and can produce over 2 million tones of solar salt, the base raw
material for almost all the 27 basic chemicals that the company produces.
Beginning with a soda ash capacity of 80 Tones per day, the chemical
complex has grown into a vast operations site manufacturing 2,400 Tones
per day of Soda Ash, 1500 Tonnes per day of vacuum evaporated salt and
33 other products. Tata Chemicals pioneered the production and marketing
of high-quality iodized salt from Mithapur. With the turnover of Rs.4107
cores (2006-07), Tata Chemicals Limited was India's leading manufacturer
and marketer of inorganic chemicals and fertilizers.
Tata Chemicals is also one of India's leading manufacturers of urea and
phosphatic fertilizers. The urea plant, located at Babrala in the state of
Uttar Pradesh in Northern India, is the country's most energy efficient
fertilizer unit, and produces 12% of the country's urea output in the private
sector.
TCL is also a pioneer and market leader in the branded, iodized salt
segment. Its salt has a purity percentage of 99.8 per cent, the highest in the
country. In 2006, TCL introduced i-shakti, a high iodine based salt for
growing kids.
Headquartered in Mumbai, TCL has a regional presence in Ahmadabad,
Mumbai, Chennai, Kolkata and Noida. TCL offices are also located at
Chandigarh, Agra, Bareilly and Lucknow.
An ISO-9001/14001 certified company, TCL has a varied user industry
base comprising glass, paper, textiles, food additives, petroleum, refining,
chemicals, dyes, pesticides, direct farm application etc. With an export
presence in South and Southeast Asia, the Middle East and Africa, it has
set itself the objective of achieving global cost competitiveness in soda ash.
The Company has outperformed its competitors to maintain
leadership not only in the market share but also in providing
innovative product and service offerings. The Company, the first
synthetic soda ash manufacturer in the country, has been the market
leader since its inception. Tata Chemicals pioneered the sale of
packaged iodized edible branded salt in India. The Tata Kisan
Kendras are at the forefront of transforming the face of rural India.
CHLORO –CAUSTIC GROUP
• Product of C. C. Group
50 % Caustic Soda Lye
Liquid Chlorine
Hydrochloric Acid
Sodium Hypo Chlorite
• CCG management
HISTORICAL EVALUATION of PROCESS
• Non - Electrolytic Process
The production of caustic soda by non - electrolytic process ( i.e. Lime
Soda process - Solvay Process ) dates back to early years of the chemical
industry.
• Electrolytic Process
1) 1800 : First ever electrochemical production of caustic soda & chlorine
by CRUICK-SHANK.
2) 1885 : Introduction of Diaphragm Technology - the Grieshem cell. 1930
: Mercury - Amalgam cell process gained importance as rapid growth of
Rayon industry increased the demand for pure chloride free caustic soda.
Actually this technology was introduced by Castner Kellner in 1892.
3) 1928 : Kenneth Stewart of Hooker Chemicals of U.S.A. introduced
deposited diaphragm cell.
4) 1930 : Mercury - Amalgam cell process gained importance as rapid
growth of Rayon industry increased the demand for pure chloride free
caustic soda. Actually this technology was introduced by Castner Kellner in
1892.
5) 1970 : Du Pont - USA and Asahi - Japan, developed Bi - layer
membrane , which had higher conversion efficiency and had prolonged life.
6) 1970 : Introduction of membrane cell .
7) 1971 : Oxy Tech developed the Modified Diaphragm. Modified
Diaphragm is a mixture of asbestos and fibrous fluorocarbon polymer.
Review of Technology:
1. Diaphragm Technology
• Advantages:
Use of well brine.
Lower Power consumption.
• Disadvantages:
Use of Asbestos.
Lower purity of Caustic & chlorine
Cell outlet caustic is of only 15%.
2. Mercury Amalgam Technology
Advantages:
Cell outlet caustic is of direct 50%.
High Purity of Caustic & Chlorine
Brine Purification is simple.
Disadvantages:
Use of Mercury, a lethal pollutant.
Large floor space. High power consumption
Costly environmental protection.
3. Membrane cell Technology
Advantages:
Lower power consumption.
High Purity of Caustic & Chlorine.
High concentration of Caustic i.e 32%
Environment friendly
Disadvantages:
Brine processing cost is high.
Sensitive to Shut Down.
Spare replacement is highly costly.
INTRODUCTION TO C. C. Group:
• We have Switched over from DIAPHRAGM CELL technology to
MEMBRANE CELL technology in July - 1995.
• Capacity enhancement done from 30 TPD to 100 TPD production rate
of Caustic Soda.
Process Flow Chart of the CC Group
BRINE REFINING
PRIMARY BRINE REFINING
To remove brine impurities
PROCESS:
The saturated brine from SSD is coming to the reaction tan where
soda solution and caustic is added to it. And finally it goes to the
thickener.
The impurities like Ca++ & Mg++ are precipitates in the form of
Calcium carbonate (CaCO3) & Magnesium Hydroxide (Mg (OH)2)
using soda solution (Na2CO3) & caustic solution (NaOH).
The precipitates are settled in clarifier. The precipitates which are
settled in clarifier (sludge) are sending to S.B.R.
CHEMICAL REACTIONS:
• Ca++ + Na2CO3 = CaCO3 + 2Na+
• Mg++ + 2 NaOH = Mg (OH)2 + 2Na+
PRIMARY BRINE REFINING FLOW SHEET
MATERIAL BALANCE
• Ca++ + Na2CO3 = CaCO3 + 2Na+
• Mg++ + 2 NaOH = Mg (OH)2 + 2Na+
Inlet brine composition
Ca+2=2.5 gpl
Mg+2=0.5gpl
Equivalent mole of Ca+2 = 2.5/40=0.0625 mole/l
Equivalent mole of Mg+2= 0.5/23=0.0217 mole/l
Output Brine composition
Ca+2= 2 ppm
Mg+2=3 ppm
Equivalent mole of Ca+2 = 2/40=0.5*10^-4 mole/l
Equivalent mole of Mg+2= 3/23=1.2295*10^-4 mole/l
Required weight of Na2Co3 = (0.0625-0.5*10^-4)*96= 5.9952 g/l
Required weight of NaOH= 2*(0.0217-1.2295*10^-4)*40=1.726 g/l
SECONDARY BRINE REFINING
• OBJECTIVE:
To produce ultra-pure brine produced in two steps.
SECONDARY BRINE REFINIERY FLOW SHEET
FILTRATION:
• Using three precoat type leaf filter (Pressure Filters) having 16 leaf in each
unit. Which removes the fine sludge particles, which are not settled in the
Clarifier?
• Material used, as a precoat is cellulose When filter reaches the maximum
operating pressure (2.5 Kg / cm2) or outlet brine to filter laboratory
analysis exceeds 1 N.T.U., the filter must be cleaned. Before going to
storage tank brine passed through Safety filter, which stops the cellulose
fibers eventually released by pressure leaf filters. To E - 507 (heat
exchanger) low pressure steam & cooling water connection are provided to
warm or cooled the brine temperature in order to control Resin Operating
Temperature & thermic balance of electrolysis.
RESIN TOWER:
• Before entering in the electrolyzer brine passes through two ion -
exchange resin tower placed in series in order to absorb Calcium,
Magnesium & Strontium ions contained in the brine.
• The resin utilized has a very high selectivity for metal ions so that
Calcium and Magnesium content can be reduced to below 20 ppb.
• When the resin in a tower reaches the maximum absorbing capacity the
resin must be regenerated
• Absorption capacity - 6 gms / liters of resin.
• The resin volume in the towers is 4000 liters. Washing the resin with
demiwater, 4% hydrochloric acid solution, 5 % caustic solution & brine
performs the regeneration.
• The operation and regeneration of the resin tower is completely atomized
and controlled by DCS.
Process Flow Chart for Resin tower
EQUIPMENTS DETAILS
TAG NO. EQUIPMENT CAPACITY MOC
P-536 PUMP 15M3/Hr,3.7kw SS-316
P-537 “ 40m3/hr,3.75kw SS-316
P-538 Sludge pump “ “ P-504 “ “ “ P-525 “ 3 “ 5.5 “ Pp
P-506 Pump 55m3/hr,18.5 Kw Titanium
p-507 “ “ “
P-508 “ 60” PP
p-509 “ 42” Pp
p-510 “ 30”11kw Pp
p-511 “ 0.11m3/hr.0.38kw SS-410
p-515 “ 5m3/hr,5.5kw PP
D-536 Soda solution tank 21m3 Ms
D-537 “ 22m3 “
D_537 Reactor 36m3 MSRL
D-504 Clarified brine tank 24m3 “
D-525 A Na2So3 5m3 MSRL
D-526 NaoH 1m3 “
D-527 A Flocculent tank 7m3 MS
D-527 B “ 0.56m3 “
D-535 Stand pipe 7m3 MSRL
p-516 Pump 55m3/hr,18.5kw Titanium
P-505 “ 5m3/hr, 5.5kw “
D-511 Agitators 0.75kw
D-506 Clarified brine tank 55m3 MSRL
D-507 Filtered brine tank 55m3 “
D-510 Alpha cellulose tank 2m3 “
D-515 Effluent tank 100m3 “
D-516 B Pure brine tank 55m3 “
CELL HOUSE
Theory regarding the electrolysis
Electrolysis process is characteristic quqntatily by laws established by
M.FARADAY
FARADAY’S LAW OF ELECTROLYSIS
1). the mass of a substance formed in electrolysis is proportional to the
amount of electricity that has passed through the electrode.
2) In the electrolysis of different chemical components equal amount of
electricity result in the electrochemical transformation of equivalent
amounts of substance.
The following equation expresses faraday’s law:
M= Meq I*t/F
Where,
M=mass of substance that has been formed or transfer
I=current
T=time
F=96500C/mol
There are two types of membrane available for cation exchange
1. Sulfonate base
- A thin cathodes side carboxylic layer
- A thick core sulphonic layer with embedded reinforcement cloth
2. Carboxyl ate base
-A very thin layer of anodic sulphonic
-A thick core carboxylic layer with embedded reinforcement cloth
-A thin cathodic side carboxylic layer
CELL VOLTAGE
- Current density is defined the electrical load per unit of membrane area
- A minimum theoretical D.C. potential must (2.3 v) be impressed between
the anode and the cathode to run the reaction.
VCR= Vm +voltage drop
CURRENT EFFICIENCY
• Theoretical caustic production in Mton NaOH (100%) =0.0358*I (kA)
• Cathodic current effin. = Real caustic production/theoretical production
• The.CL2 production=0.0318*I
• As a cathodic current efficiency we can calculate the cathodic current
efficiency.
• Power in KWh/Mtcs =670.1*Vc/C.E *100
• Power in KWH / Mtcl2=756*Vc/A.E. *100
Brief Description of Plant
32% Caustic soda is used as a R.M. in CCG, it is also supplied to
Marine Chemicals & rest is evaporated to 50% Caustic Soda.
Cl2 gas is cooled and further processed in Chlorine Processing Plant
(CPP).
H2 gas is cooled and then used in HBR plant of Marine Chemicals &
HCl plant of CCG.
Depleted Brine free-chlorine content is removed in Cell House section &
sent to DeMag pant of Soda Ash.
Brine Dechlorination & Chlorate decomposition
Depleted Brine coming out from Electrolyser contains dissolved
chlorine of 1.5 to 3 gpl & Chlorate of 1.5 to 3 gpl that must be
removed in the brine dechlorination section.
Depleted brine is bifurcated into two streams, approximately 30%
quantity is diverted to chlorate decomposer & 70% quantity is
diverted to vacuum dechlorination tower.
The chlorate decomposition is done with the help of HCl addition.
The overall reaction for chlorate & hypochlorite ion decomposition
takes place is :
NaClO3 + 6HCl = NaCl + 3Cl2 + 3H2O
HOCl + HCl = Cl2 + H2O
In chlorate decomposer steam is diffused through the brine to strip
out the Cl2 & to maintain the temperature about 90° C for chlorate
decomposition.
The brine leaving the Electrolyser contains some available / free Cl2,
i.e. Chlorine molecules physically absorbed in brine & in the form of
Hypo-chlorous ions.
Hypo-chlorous ions are converted to Cl2 by HCl addition.
Brine dechlorination is done by passing the brine through packed
tower where vacuum is created with help of steam jet ejector.
If it required, sometime brine dechlorination is done by addition of
Na2SO3.
Cl2 + Na2SO3 + H2O = 2HCl + Na2SO4.
The available / free chlorine contents reduced from 3 gpl to 0.5 gpl
level.
After dechlorination, dechlorinated brine is sent to DeMag plant of
Soda Ash.
Cl2 gas comes out from Electrolyser is having temperature of
about 85 - 90 ° C , it is saturated with water vapors and it carries
NaCl mist.
In this section Cl2 gas is cooled to 20 °C temperature by passing
through 3 nos. of shell & tube type Cl2 cooler so water vapor is
condensed & moisture content is Cl2 gas is reduced.
This cool Cl2 gas is supplied to HCl & Chlorine Processing plant
by chlorine Blower.
Chlorine Cooling & Blowing
Cl2 leaves from electrolyser has a very high temperature (< 75 oC)
This Cl2 first passes counter current with Feed Brine from P-516
delivery through heat exchanger E-518 where brine heights up & Cl2
Cooled down.
Then Cl2 goes to E-601 where cooling water cooled it up to 30 oC
Then it goes to Cl2 blower suction, where blower blow it in such a
way that header suction always remain -50 mmwc & discharge
pressure ~ 1300 to 2300 mmwc.
From Cl2 blower it goes to Z-601 which is a desuperhighter & from
here it goes to E-602 where chilled water cooled it to 20 oC
And from E-602 Cl2 goes to CPP section.
PROCESS
• There are 8 nos. of ELECTROLYSER. Each Electrolyser is having 30
nos. of elementary membrane cell.
• Each elementary cell is made up of two compartments, Anodic and
Cathodic, separated by cation exchange membrane The specially designed
cation exchange membrane, separating the Anodic & Cathodic
compartments, in electric field, permits the passage of sodium ion & water
from Anodic to Cathodic side and strongly rejects the passage of anions.
By passing the Direct Current through the Electrolyser fed with ultra pure
brine, as an outcome of electrochemical reaction it gives three products
(1) 32% Caustic Soda
(2) Cl2 gas
(3) H2 gas and the following overall reaction take place:
• DM water is fed to the cathodic compartment in order to keep the
concentration of caustic soda allowed by membrane (30% to 33%).32%
Caustic soda is used as a R.M. in CCG, it is also supplied to Marine
Chemicals & rest is evaporated to 50% Caustic Soda.
• Cl2 gas is cooled and further processed in Chlorine Processing Plant
(CPP).
• H2 gas is cooled and then used in HBR plant of Marine Chemicals & HCl
plant of CCG.
• Depleted Brine free-chlorine content is removed in Cell House section &
sent to DeMag pant of Soda ash depleted Brine coming out from
Electrolyser contains dissolved chlorine of 1.5 to 3 gpl & Chlorate of 1.5 to
3 gpl that must be removed in the brine dechlorination section.
• Depleted brine is bifurcated into two streams, approximately 30%
quantity is • diverted to chlorate decomposer & 70% quantity is diverted to
vacuum dechlorination tower.
The chlorate decomposition is done with the help of HCl addition.
• In chlorate decomposer steam is diffused through the brine to strip out
the Cl2 & to maintain the temperature about 90° C for chlorate
decomposition
• De Nora electrolyser 30 DD 350 consists of 30 elementary membrane
cells with 84 sqmt of total membrane area. (3.5sqmt / elementary
cell.)Electrolyser is made of 29 intermediate bipolar elements (with an
anodic & cathodic side) and 30 membrane sheets assembled in a typical
filter press (zero gaps) configuration.
• The elementary cell of electrolyser is in a series electrical connection.
Current is carried by copper bus-bar to the end elements of of each
electrolyser & reaches sequentially all the elementary cell passing through
the metallic body of bipolar element Pure brine feed in to Decarbonisation
tower C - 507 through a heat exchanger E - 518.
Heat exchanger exchange heat with the produced chlorine, in order to
preheat the brine, recovering some heat from chlorine, by its partial cooling
and dehumidification. From C - 507 pure brine is feed directly by gravity to
each electrolyser.
• For filling and startup of single electrolyser brine goes through E- 517
heat exchanger In the electrolysis room the electrolysis of NaCl (Brine) is
operated by 8 electrolyser De-Nora, type 30 DD 350 at a rated load of 12.5
kA.
Effect of different impurity ions on membrane Components Effect on membrane Control
Acidity Neutralize the carboxylic
group so increase
electrical resists &so cell
voltage &over heating to
membrane &may cause
permemanent demage to
membrane
PH is controlled
Sulphate Depress the solubility &
difficult to maintain the
desired salt concentration.
Decrease hydroxyl ion
rejection capability
Sulphate con. Must be
taken in the range of the
specification limit
Calcium Physical disruption of
membrane
Brine specification limit
Sr,ba,fe,I,Al,Si All these element cause
the any way cause the
precipitate and increase in
current
Weekly checked at a out
let f resin tower
CHEMICAL REACTION
The overall reaction takes place is:
2NaCl + 2H2O = 2NaOH + Cl2 + H2
The overall reaction for chlorate & hypochlorite ion decomposition takes
place is
NaClO3 + 6HCl = NaCl + 3Cl2 + 3H2O
HOCl + HCl = Cl2 + H2
EQUIPMENTS DETAILS TAGNO. EQUIPMENT CAPACITY MOC
P-201 Pump 25m3/hr,7.5kw Cf-8m
P-202 “ 15”5.5kw Cf-8m
P-501 “ 55”15kw Ti
P-502 “ 55”,15kw “
k-601 “ 1900”,55kw “
D-501 32%caustic tank 15m3 SS-316-l
d-202 “ 6m3 MSRL
D-402 DM water tank 2m3 PP/FRP
D-501 Depleted brine
tank
55m3 FRP
D-502 “ 55m3 FRP
D-505 C Na2 SO3 1m3 MSRL
DM-505 Acidic brine tank 0.6m3 FRP
DM-506 “ 1.4m3 “
E-501 Heat exchanger 295744kcal/hr
no.tubes-109
Shell-MSRL
Tubes-SB-338 GR-2
E-518 “ 252746Kcal/hr
no. of tubes -217
Shell-SB-265 GR-2
Tube SB –338 GR-2
E-601 Heat exchanger 266421 k.cal/hr
no.tubes=343
Shell-MSRL
Tube-SB-338 GR-2
E-602 CL2 COOLER 90278 kcal/hr
no.of tubes=157,
shell-chilled water
Shell SS 516 GR-60
TUBE-SB-338 GR-2
E-2101 H2 COOLER 199012 kcal/hr
no.of tubes-232
shell-H2
Shell-SA-516 GR-60
Tube- SA-312 TP-
316
E-201 32%NaOHcooler,
plate heat
exchanger
456901kcal/hr Plate hast-c-276
Gasket –EPDM
E-202 “ 476784 kcal/hr “
E-516 Pure brine heater 1127136kcal/hr Plate- titanium
Gasket –EPDM
E-517 Start up brine
heater
188100kcal/hr Plate-titanium
Gasket –EPDM
MATERIAL AND ENERGY BALANCE
Let Basic brine flowrate is 59m3/hr.
Assuming 100% yield.
Input brine solution composition:-
Nacl= 300gpl
Na2So4=5.5 gpl
Output depleted brine composition:-
Nacl= 230 gpl
Na2So4=6.5 gpl
Here Na2So4 is not taking part in reaction so its mass will remain same in
both streams input and output.
Now Na2So4 mass flowrate in brine=5.5*59000=324.5 kg/hr
Therefore depleted brine flowrate=324.5*1000/6.5=49.923 m3/hr
Nacl in inlet brine=300*59000=17700kg/hr
Nacl in depleted brine=230*49923.077=11482.31kg/hr
Nacl reacted=17700-11482.31=6217.69kg/hr
Overall reaction around the cell
2NaCl + 2H2O = 2NaOH + Cl2 + H2
117 36 80 71 2
117 kg Nacl 80 kg Naoh
6217.69 kg Nacl 80*6217.69/117=4250.41 kg/hr NaOh
NaOh product rate= 4250.41 kg/hr= 102.033 ton/day
DM water requirement
6217.69 kg 2Nacl react with 2H2O=6217.69*36/117=1913.13 kg/hr
H2O required for reaction=1913.13 kg/hr
S.g. of brine at 80.7oc=1.181
Density of water at 80.7oc=974.8 kg/m3
Density of brine=1151.24 kg/m3
Density of depleted brine by same manner= 1094.46 kg/m3
Mass flowrate of brine= 59*1151.24=67923.16 kg/hr
Mass flowrate of water in brine= mass flow rate of brine-(mass flow rate of
Nacl + mass flowrate of Na2So4
=67923.16-(17700+324.3)
=49898.66 kg/hr
Mass flow rate of depleted brine=49.923*1094.46=54638.73 kg/hr
Mass flow rate of water in depleted brine=54638.73-(11452.31+324.5)
= 42831.91 kg/hr
Mass flow rate of water will go with products=47898.66-42831.91
=7066.74 kg/hr
Now NaOH produced from the cell is 32% w/w
Total NaOH solution= 4250.41/0.32= 13285.66 kg/hr
Water in NaOH=13285.66-4251.41=9034.25 kg/hr
Assuming H2 and Cl2 having 0% moisture content
Additional water required to 32% NaOH solution=9034.55-7066.74
= 1967.61 kg/hr
Total water required= additional + Water required for rxn
= 1967.61+1913.13=3880.74 kg/hr
Volume floe rate of DM water=3880.79/974.8=3.9810 m3/hr
H2 and Cl2 product rate
6217.69 kg Nacl- ? H2? Cl2
H2 produced=6217.69*2/117=106.28 kg/hr=2.55 ton/day
Cl2 produced= 3217*71/117=90.55 ton/day
ENERGY BALANCE:-
Electric current supplied = 12 kA =12000 coulomb per second.
Now according to, Faraday’s 2nd law of electrolysis,
“For a given quantity of electricity (electric charge), the mass of an
elemental material altered at an electrode is directly proportional to the
equivalent weight of elemental material.”
“The Equivalent weight of a substance is its molar mass divided by an
integer that depends on reaction undergone by the material.”
So,
m = e ×q ; production of 1 ton of 100% NaOH.
1000= 40×q
96500
So, q =2912500 coloumb
Now,
q = I×t
2912500=12000×t
So,
t =210.041 second.
Cell voltage =3.412 volt.
To calculate ton per hour of 100% caustic per cell:-
M =z×i = (40×12000) kg/sec
96500
M = (40×12000×3600) ton/ hr
96500×1000
M = 17.906 Tonnes/ hr .
η = (Tones/hour of NaOH produced per cell) ×100
1.651 × Circuit current
Here, tones /hr of 100% NaOH produced per cell = 17.906 ton
η = 17.906×100
1.651 × 12000
η = 90.33%
nsumption in kw/hr per ton of 100% = 608×volt×100
Caustic produced % current efficiency
= 608×3.412×100
90.
Power consumption in kw/hr per ton of 100% = 2297.3 kw/hr
Caustic produced
HYDROCHLORIC ACID PLANT
HCl Plant flow sheet
Sample Point
( For Analysis )
Vent Gas Blower
D.M.Water I/L
Chlorine I/L
HCl Recycle to
chamber
Hydrogen I/L
HCL
32%
Unabsorbed
HCl
vapour to tail
tower
Vent Line to Scrubber
Acid Circulation Pump
Combustion
Chamber
Cooler
TAIL
TOWER
Acid
circulati
on
Tank
(P900A/B)D900A
CT-2779
FI911A
PC911A
K902A/B
FC915A
TT913A
Moist.
Separ.HC912A
PI918A
FC918A
Moist.
Separ.
F601
FC919A
PI919A
PL9123
HV911A
HV912
F2101
7101
PI922 PC923
N2
PROCESS
Hydrogen handling before processing in HCL Plant
The scope of Hydrogen handling section are:-
To maintain positive hydrogen pressure in cell house header
To increase hydrogen pressure for suitable use in HCL plant.
To cool the hydrogen gas from 85 to 20 deg. C
To remove excess moisture ( NaOH mist )
Hydrogen handling section consist two shell & tube heat exchanger , two
mist eliminators, two hydrogen blower and seal pots.
Startup Operation of Hydrogen Handling
As rectifier load reaches to 2 -2.5 KA, HCL operator will Open H2
blower suction filter inlet valves per instruction of CCR
HCL operator shall check following valves are open.
Suction & Delivery v/v of blower
Hydrogen chiller’s chilled water I/L & O/L v/v
Hydrogen line I/L & O/L valve.
Isolation v/v of all control valves
D.M. water I/L valve to suction & discharge filter & main D.M.
water valve.
Suction & delivery filter drain valve.
Make up water I/L valve to H2 seal pot
HCL operator will inform CCR that H2 blower at field
is ready for startup.
CCR operator will open H2 blower suction pressure control
Valve 100 % on manual mode.
As rectifier current reaches to > 4 KA, CCR operator will
Start H2 blower & make announcement that H2 blower is
Started
CCR operator shall put H2 blower vent pressure cont.r on
‘Auto mode’ with fully shut position ( PC - 2102 ) & slowly
Closing suction pressure cont.r on manual mode.( PC- 2101)
As H2 blower suction pressure becomes 80 - 200 mmwc, CCR
Operator shall put suction pressure controller on ‘Auto mode’
by giving set point of 80 - 200 mmwc.
Startup Operation of HCL Furnace
First of all HCL operator make ready the cooling water circuit of
individual furnace in which
start cooling water fan
open cooling water i/l & o/l v/v of cooler absorber & combustion
chamber
start cooling water pump p - 276
open i/l valve of sea water to cooling tower
Cooling water flow to cooler absorber shall be more than 150 m3/hr
unless furnace will be tripped.
HCL operator shall open CL2 & H2 moisture separator i/l valve
Make ready the D.M. water circuit in which
open i/l D.M water v/v to D- 906 ( D.M. water storae tank )
put D- 906 level controller on auto mode
start P- 906 to fill overhead tank
HCL operator shall check D.M. water flow contr. isolation v/v open
& fill the acid circulation tank D – 900
Start P - 900 acid circulation pump
HCL operator open acid circulation v/v,isolation v/v of tank D -900
level controller & acid production v/v to HCL storage tank D - 902
Start vent blower K - 902 after ensuring that chamber suction
control v/v is open from CCR.
Chamber suction should be > 150 mmwc
CCR operator shall make all condition ready to start furnace such
as
make furnace interlock healthy
H2 safety v/v 25 % open,H2 flow controller 6-20 % open CL2 flow
controller 20-30 % open & chamber suction controller on auto mode
to maintain -50 to -90 mmwc suction
As furnace is ready for start-up Shift Engineer shall inform CCR
operator to make announcement of plant start up condition.
HCl operator shall open N2 purging valve manually for
approximately one minute.
HCl operator shall light up pilot burner after opening pilot burner H2
valve and operator shall put pilot burner with H2 flame into the
combustion chamber through pilot window, Shift Engineer shall
observe flame through chamber sight glass.
HCl operator shall manually open hydrogen valve (after the hydrogen
control valve).
Shift Engineer shall first open 1 “Ø H2 line valve fully and open 1”
Ø control valve slowly till H2 flame is visible through combustion
chamber burner block by keeping furnace under suction.
After assuring stable H2 flame through burner, Shift Engineer shall
ask HCl operator to close pilot burner valve.
Now operator shall remove pilot burner & close pilot window
properly.
HCl operator shall open 1” Ø H2 valve till H2 flow reaches to 8 - 20
Kg/hr. by keeping chamber under suction.
Shift Engineer shall ask HCl operator to open Cl2 wheel valve slowly.
As H2 flame colour changes to whitish Shift Engineer shall ask
operator to close air intake valve to Cl2 line.
Operator shall open more 1” Ø H2 wheel valve to increase H2 flow.
As this valve gets fully open operator shall start slowly opening valve
before H2 flow control valve.
As valve in H2 line before H2 flow control valve gets fully opened,
operator shall close H2 line both 1” Ø valve completely.
As H2 flow reaches to 22 - 25 kg/hr. and Cl2 flow reaches to 330 -
380 kg/hr. Shift Engineer shall ask C.C.R operator to put H2 flow
controller and D.M. water flow on “ CASCADE MODE “ and to
give chamber suction set pilot – 30 to - 90 MMWC.
After observing plant condition, Shift Engineer shall instruct CCR
and HCl operator to increase Cl2 flow if it is required.
HAND OVER OF EQUIPMENT TO MAINTENANCE DEPT.
Any equipment shall be handed over to maintenance dept. by issuing
safety work permit ( QSF-730-12-01 / QSF-730-12-02 ).
Before issuing safety work permit shift engineer shall check that
equipment is isolated as mentioned below.
Tank like D-203, D- 900 & D-902 shall be completely emptied out /
drained, isolated from all inlet & out let pipeline. Washed with water.
Pump shall be isolated by closing suction, delivery & sealing valve.
EED shall be asked to remove its motor fuse.
Heat Exchanger shall be isolated by closing its all inlet & out let
valves.
M.O.C. of Equipment
P- 900 • Capacity of pump 44
m3/hr • M.O.C of pump PP • KW of pump 7.5
P - 901 • Capacity of pump 20
m3/hr • M.O.C of pump PP • KW OF pump 7.5
P – 902 • Capacity of pump 15
m3/hr • M.O.C of pump PP • KW of pump 2.2
P – 906 • Capacity of pump 7
m3/hr • M.O.C of pump SS-316 • KW OF pump 2.2
P - 276 • Capacity of pump 200
m3/hr • M.O.C of pump CF-8M • KW of pump 37
P – 904 • Capacity of pump 44 m3/hr • M.O.C. of pump PP • KW of pump 7.5
K - 2101 • Capacity of pump 1697
m3/hr • M.O.C of pump • KW of pump 22.5
D- 906 • DM water storage tank
Capacity 5 m3 • M.O.C. of tank MSRL
D - 900 • Acid circulation tank • Capacity 3.5 m3 • M.O.C of tank FRP
D - 902 • Acid storage tank • Capacity 150 m3 • M.O.C. of tank FRP
Safety & Good House keeping
Always insured Nitrogen purging before starting & shut down the
plant.
Use safety equipment such as hand gloves, gogles etc whenever
work with HCl acid leakage at plant.
Always ensure sufficient overflow of sea water at H2/Cl2 seal to
prevent any harmful effect of Cl2/H2 prss.
Always maintain N2 cylinder ready to use with proper connection.
Use plenty of sea water & soda powder at leakage of Hcl acid for
neutralization.
CHLORINE PLANT
This section mainly comprises of
1) Drying of Chlorine gas.
2) Compression of Chlorine gas.
3) Liquefaction of Chlorine gas & Storage.
4) Filling of Liquid Chlorine toners / cylinder.
5) Cl2 neutralization (Hypo) Plant.
Chlorine Drying
As Cl2 gas having a small amount of water is highly corrosive, in this
section Wet Cl2 received from C/H is passed through packed tower
having H2SO4 circulation in counter current direction.
As Cl2 gas comes in contact with Concentrated H2SO4, H2SO4
absorbs the moisture from Cl2 gas to give Dry Cl2 as a product.
Dilute waste H2SO4 is discharged to malara effluent.
PROCESS FLOW DIAGRAM
Chlorine Compression
Dry Cl2 is compressed to 3 - 5 Kg. / Cm2 pressure by liquid ring
type compressor & then supplied to Marine Chemicals and Liquid
Chlorine Plant.
Here H2SO4 is used as liquid for formation of ring in Chlorine
compressor.
PROCESS FLOW DIAGRAM
LIQUEFACTION AND STORAGE OF CHLORINE GAS
The chlorine gas coming from cells which after cooling, drying and
compression enters the tubes of the chlorine condenser, where it is
cooled down and liquefied by means of Freon - 22 evaporation.
Liquid chlorine flows by gravity into the storage tanks.
All the sniff gas, uncondensed chlorine & incondensable gases leaves
the liquefier tube side and goes to the either in HCl plant or Cold
process plant of Marine chemicals dept.
The liquefaction section is composed by :-
Freon compressors
Freon condenser, shell & tube heat exchanger, with chilled water as
cooling medium circulating in the tubes.
Condensed Freon receiver.
Chlorine condenser – shell & tube heat exchanger, where chlorine is
condensed by means of evaporating Freon.
Freon compressor:-Compressor, compressed the refrigerant at high
pressure, thereby increasing temperature. This high pressure &
temperature convert vapor into liquid.
FILLING OF LIQUID CHLORINE CYLINDER
There are four nos. of Liquid Cl2 storage tank, each having the storage
capacity of 76.0 T.
As per statutory requirement one storage tank always remains empty
for any emergency use.
As one storage tank gets filled it is isolated from liquifier &
pressurized to 170# psig.
At 170psig. Pressure liquid Cl2 is transferred from storage tank to
Tonner / Cylinder.
Tonners / Cylinders are stored in Godown & then dispatched.
CL2 NEUTRALIZATION (HYPO) PLANT
All section Cl2 equipments / pipelines are connected to “Cl2
Neutralization Section”.
During any emergency (i.e. leakages of any Cl2 carrying pipeline /
equipment) Cl2 gas from any section is released to this section.
In this section Cl2 gas is absorbed in 16% Caustic Soda in packed tower.
As a result of chemical reaction it gives Sodium Hypochlorite as a product.
Sodium Hypochlorite is supplied to internal as well as external customer by
road truck.
EQUIPMENTS DETAILS
Tag no. Equipments Capacity MOC
D-602 98%H2so4 tank 20m3 Cs
D-603 Dil.h2so4 tank 3.5m3
D-605 98%H2so4 tank 2m3 Ms
D-801-A/B Hypo tower tak 55 m3 Pvc/frp
D-802 “ “ “
Cl2 ST1 Cl2 storage
tank
76T MS
Cl2 ST2 " “ “
CL2 ST3 “ “ “
CL2 ST4 “ “ “
Properties of Chlorine:
Threshold Limit Value:
Definition:
TLV is average concentration of substance in ambient air for a normal 8
hours working or 40 hours work week to which nearly all workers may be
repeatedly exposed, dry after day without adverse effects:
Degree of Hazards and their Effects
Sr. No Chlorine Concentration
In Air (PPM)
Degree of Hazards
1 3.5 Least detectable odor.
2 15.1 Least amount required to
cause imitation of throat.
3 30.2 Least amount required to
cause coughing.
4 1.0 TLV-Least amount which
can be in haled safely –
shown workdays for a life
time.
5 4.0 Maximum amount that can
be breathed for one hour
without serious effect.
6 40 to 60 Amount dangerous in ½-1
hour.
7 1000 Amount likely to be fatal
after a few deep breathes.
First Aid
Treatment:
In all cases, immediately remove the patient from the contaminated
area, immediately begin appropriate treatment. Never give anything
by mouth to an unconscious patient.
Inhalation:
If the patient is breathing, place him in comfortable position, keep
him warm and at rest until a physician arrives. It breathing is difficult,
administer oxygen if equipment and trained personnel are available.
Automatic artificial respiration is considered preferable to manual, but only
when administered by an experienced operator.
1) Eyes: If even small quantities of Chlorine have entered in the eyes, flush
eyes immediately with copious amounts of lukewarm running water for at
least 15 minutes. Hold the eyelids apart forcibly to insure complete
irritation of all eye and lid tissues.
Never attempt chemical neutralization. Do not give any medication except
under specific I intimation from a physician.
2) Skin: Get patient under a shower immediately remove clothes while the
shower is running wash the skin with large quantities of soap and water.
Do not attempt to neutralize Chlorine with chemicals. Do not apply salves
or ointment except as directed by a physician.
3) Throat Irritation: Drinking milk may help relieve the discomforts of
throat irritation from Chlorine exposure.
4) Coughing: A mild stimulant such a hot coffee or hot tea is often used
for relief.
DO’S & DON’T For Chlorine
DO’S:
Use required PPE’s during Chlorine handling.
Chlorine is 1.8 times heavier than air so, when Chlorine will leak you
should leave place perpendicular or opposite direction of air in
respect of working place.
One liter liquid Chlorine = 456.8 liter Chlorine gas so, when liquid
Chlorine will leak
You must immediately arrest leakage.
Keep away flammable material from Chlorine
When Chlorine will spillage Chlorine should neutralize with Caustic
soda after it should wash with water
When Chlorine will spray on any parts of body you have to wash
with water up to minimum 15 minute
When Chlorine come in respiratory system then affected person shift
toward open place and give artificial respiratory
On above situation immediately give medical treatment.
DON’T:
Flammable material should not burnt near to Chlorine.
When liquid Chlorine will spray on any parts of body then skin will affect with cold burn so, you must not direct contact with liquid Chlorine.
Wet Chlorine is highly corrosive so, dry chlorine never keep in contact with water.
Chlorine and Petroleum product can form some compound with Hydrogen, Turpentine, Alcohol, Acetylene, Ammonia and Sulphur etc. and by this compound it can blast so, it must always keep away from chemicals.
Effect of Temperature on Volume:
• With increase of temperature of container the volume of liquid increased
rapidly and at 70oC it crosses the capacity of container and damage of
container is possible causing SERIOUS HAZARDS.
Effect of Temperature On Vapor pressure:
Safe Handling of Liquid chlorine Tonner:
Caustic soda and chlorine - one of the most important inorganic chemicals
- are used by almost all industries for one thing or the other. The
consumption of liquid chlorine in various sectors is increasing day by day.
Although chlorine is highly toxic and hazardous in nature, at the same time
it is very useful to mankind and has become indispensable. There are many
hazards inherent in the manufacture, handling and use of chlorine like
many other industrial chemicals. But with proper design and sound
operating practices, costly injuries and damage can be reduced and in many
cases eliminated.
For safer handling of chlorine, it is either transported by pipe lines or by
big tanker. In India, tonners are widely used for transportation of liquid
chlorine.
Handling of chlorine needs experience and skill staff as well as it also
requires to be managed by proper design of plant for handling due to its
hazardous nature.
One should know the physical and chemical properties of gaseous and
liquid chlorine before handling it. Before going in detail about the handling
of chlorine, knowledge of following top ten hazards is highly useful while
handling the chlorine tonner.
Contamination of chlorine tonner with other chemical.
Exposure of chlorine tonner / storage to high temperature or fire
Lifting of the chlorine tonner by its valve protection hood.
Chlorine tonner valve leakage
Transportation of chlorine tonners without valve cap.
Keeping the tonners in stack (More than one layer).
Using chlorine tonners as pressure vessel or intermediate tank.
Using other method for loading and unloading tonners other than
EOT crane / mobile crane.
Moisture in chlorine will cause corrosion in the storage and tonner.
Hence chlorine drying and padding air quality is important
keeping the tonner in wet & muddy surface
Apart from the knowledge of long list of physical and chemicals
properties of chlorine, understanding of following properties of
chlorine, helps to handle the liquid chlorine tonner in a safer way.
The vapor pressure of liquid chlorine rises steeply with respect to
increase of temperature. At 200C., the vapor pressure is 5.6 atm.. So
chlorine tonner should always be kept away from heat source.
Also, the liquid chlorine has high coefficient of thermal expansion
leading to rapid increase in volume, with rising in temperature. Due
to this property, no container is completely filled completely.
The solubility of chlorine in water is very less. It is about 1% at
9.40C. It forms below crystalline chlorine hydrate when it is cooled
below 9.40C. This property is utilized by spilling the chilled water
below 9.40C while the chlorine is heavily leaking.
AT 00C and 1 atm. 1 volume of liquid chlorine = 457.6 volume of
gaseous chlorine. This property is utilized in case of leakage of liquid
chlorine through lower valve of the tonner. In this case, the tonner is
rolled immediately in order to position the leakage valve at top side
to allow only the gas leakage. This is also because the quantity of
chlorine that escape from gas leak is only about 1/15 th of what
would escape from a liquid leak through a hole of the same size.
Knowledge of following point is preferable to avoid any emergency
situation in chlorine handling area.
Manually operated chain pulley block as a standby for EOT crane
during power failure for lifting leaky chlorine tonners.
DG set power supply, as an alternative should be given to hypo
system and EOT carne.
Padding air compressor auto tripping and restarting at 180 - 150 psig
pressure to avoid over pressurizing the chlorine storage.
Always one liquid chlorine storage tank should be kept empty as a
“dump tank” for any emergency. This is also a statutory requirement.
Cl2 leak detectors should be installed at Chlorine storage and tonner
filling area. It is to be monitored on continuous basis and periodical
testing of sensors to be carried out.
Monitor compressed dry air quality - Dew Point to assure the dryness
of padding air (- 400C).
NRVs are to be provided in padding airline to liquid chlorine storage
to prevent the back flow. The NRV should be checked periodically.
Handling of chlorine tonner is done with utmost care with a
systematic procedure. At our site in Tata Chemicals Ltd, the entire
processes are divided into three steps in order to explain each activity
for safer operation.
Handling of liquid chlorine in tonner is done in three stages a)
Receipt of empty tonner returned from the party b) Filling operation
c) Storing the tonner and finally dispatching to the end user.
Receipt of Empty Tonner Returned From The Party:
On receipt of the tonner, its identification No, it’s physical condition,
valve condition, valve cap, and valve guard and hydraulic test date are
checked.
In case of tonner own by the party, evidence of paper for CCE
approval, manufacturer’s certificate and last hydraulic test is required
before unloading the tonner at site.
Proper segregation of tonners is necessary with display board in order
to avoid any confusion. Toner which is due for hydraulic test ,
tonners which is ready for filling, tonners which is kept for washing
etc – all are properly segregated.
All the tonners are checked and verified by the Engineer/Supervisor
for giving green signal for filling the liquid chlorine. The checklist
include following.
Test date.
Valve condition.
Checking of foreign materials- Checking of empty chlorine tonner
for possibility of any foreign chemicals is really a big and challenging
task. So following measures are taken
Information about all the chemicals used by the end users are
kept in our record. It is essential to have a knowledge of what
type of chemicals, the end user is using in the reactor or vessel
where the chlorine from the toner is emptied out and whether
it can form an explosive reaction or not.
Visit is done to the user end to check the methods of emptying
out the tonner.
Knowledge sharing with the user is encouraged for creating
awareness of possible consequence. Apart from the above
measure, it is also recommended to check the empty tonner by
inserting small bulb with camera by removing the plug from the
tonner.
If tonner does not contain any foreign matter, air pressure inside the
tonner is taken to check the valve and plug leakage with ammonia
torch.
If any foreign matter is found or suspected, tonner is shifted to
washing area for inspection.
In order to check the brass valve threads, seat and gland, air pressure
of 170Psig is taken inside the empty tonner. The leakage is detected
with the help of soap solution.
Stickers are affixed on the tonner’s duly signed, in order to ensure
that the tonner’s are checked by a responsible person to ensure ready
for filling.
FILLING OPERATION
Every day, the weighing machines are calibrated by standard weight
and recorded.
The tare weight are checked and are compared with the last record in
order to get the trend for loss of weight for analyzing. It is required
to find out the reason of major loss of weight.
During the tonner filling, the initial filling rate is kept low enough to
check any rise of temperature on the surface of tonner. A pyrometer
(a temperature measuring device) has been installed to monitor the
surface temperature of the tonner continuously. The temperature is
displayed on the DCS control room and in case of sudden rise of
temperature; immediate announcement is done for stopping the
filling operation. Recently, we have put interlock system for closing
the auto-filling valve when the temperature rises beyond a certain
limit.
In case of any rise in temperature is observed, following actions are
taken a) Filling operation is stopped immediately. b) Release the
chlorine gas from the tonner to hypo system. c) All senior staff is to
be informed. d) After releasing, the tonner is to be shifted for
washing. e) It is very-very important to get the name of the party who
has returned this tonner. This helps to find out the root cause
analysis for the reason of rise of temperature.
The weight of the liquid chlorine being filled in the tonner is
displayed at site. An auto filling system has been provided which
allows the auto filling valve, mounted in the chlorine filling line,
immediately shut off when net weight of liquid chlorine in the tonner
reaches to 900 Kg. Hooter starts buzzing to draw the attention of the
operator.
Sometimes, icing is observed on the vent line of the copper tube
connected to the tonner during filling operation. At this point, filling
operation is stopped immediately. Although it is very rare case but it
indicates either overfilling or any puncture on gas reduction pipe.
The filling line filter is clean in every fifteen days to ensure no
escaping of foreign particles with the liquid chlorine.
After filling is completed, the copper tubes are disconnected and
brass valve is covered with guard
The filled tonner / cylinder should be kept in the storage area (kept
under shade).
Storing the tonner and finally dispatching to the end user:
The filled tonners are kept under the shade.
Time and date of filling are be recorded and written on the tonner so
as to dispatch the tonner 24-hours after filling. This is required to
check any abnormal rise of temperature in 24 hrs. For this, the
operator checks the surface temperature of the tonner in every 4 hrs
and record the temperature in logbook for every tonner. The tonner
is dispatched after 24 hrs, after ensuring that there is no rise of
temperature in last 24 hrs.
Keep enough space between the tonners so that it can be accessed
easily.
Filled chlorine tonners should not be exposed to sunlight.
Chlorine tonners should not be stacked one above the other
Following necessary care are taken during the transportation.
Valid License / Certificate of fitness of driver.
Roadworthiness checks prior to loading.
Routes are properly identified and explained.
Drivers are made aware of the bad weather condition.
Drivers are trained for Emergency procedures.
Material Safety Data Sheet are provided to the drivers.
Apart from the above mentioned practices at our site, it is also ensured to
follow following practices by the end use for safe handling of chlorine
toner. All the following information are shared with them during customer
visit.
The Tonner or Cylinders should not be used as intermediate or
process vessel.
The Tonner or Cylinder valve should not be used for controlling the
flow of chlorine. A separate regulating valve on the process side
should be used for purpose of controlling the flow. Avoid frequent
operations as it can damage the valve.
Tonner should not be heated with hot water, steam or direct flame.
Increase in temperature will increase vapor pressure of the chlorine
inside the tonner which may lead to bursting of container.
A pressure gauge between the chlorine container valve and regulating
valve should be provided. Withdrawal of Chlorine must be stopped
when the gas pressure inside the container drops to 0.5 Kg/cm2.
Emergency absorption system should be provided to neutralize
chlorine from a tonner in case of emergency.
Consumer must provide an inverted barometric loop for connecting
the chlorine tonner to the process piping, particularly one containing
process liquid. This will prevent the back flow of liquid from process
to the tonner.
Emergency kit should be available at nearby location for arresting
leakage from the valve.
Do not spray water on leak chlorine tonner as it will make situation
worse due to corrosive action of chlorine and water.
In case of fire at nearby area it is allowed to spray cold water on the
surface of the tonner to keep them cool.
In case of the chlorine leakage, roll the tonners and bring the leaky
point up to prevent liquid chlorine from escaping as leak rate of
liquid chlorine is much higher than the leak rate of gas chlorine.
Roller type arrangement can be made for the usage of chlorine
tonners.
Tonners should not be unloaded directly throwing from road truck.
It is recommended that customer should send operators to the
supplier’s works for taking training on handling the tonners.
As it is mentioned above that handling of liquid chlorine in tonner requires
experience and trained personnel, but at the same time, there should not be
any gap while following the procedure. In spite of documented procedure,
people sometime bypassed the procedure which leads to the disastrous
incidence. So it is also necessary to have a frequent training to the same
experience personnel and conducting a mock drill at a regular interval. It
helps to keep them ready all the time.
Various safety measures related to CL2 Tonner Design & usage:
900 Kg liquid Cl2 filling in tonner the quantity of liquid CL2 to be
filled in a tonner is dependent on its water capacity.
Qty. of Liquid Cl2 = Water capacity * Filling ratio (1.19).
Generally water capacity in our country is 760 Liters corresponding
to 915 kg or more Liquid Cl2.
Both Cl2 Cylinder & tonner valves are conforming to IS 3224
approved by chief controller of explosives.
Barometric Leg: With emptying of container, the pressure inside
steadily drops & vacuum develops. Consequently there is a possibility
of suck-back into container from process line. This suck in back of
liquid results in internal corrosion of tonner. This can be prevented
by installing a suitably designed barometric leg. In system working at
atm pressure, the height of barometric leg should be:
H = 34/D ft
Where D is density of liquid in g/cc.
Protective Equipment’s For Cl2 Leak:
Air Line continuous respirator
Self-contained breathing apparatus
Industrial canister type gas mask
Emergency escape breathing apparatus: EEBA from ISI is a proven
line of emergency escape breathing devices. These are not used for
use as emergency response SCBA but as a means for personnel to
escape hazardous environments in workplace.
Tips To Get Protection Against Chlorine:
Tips for Public:
Do not panic. Chlorine does not burn or explodes.
Avoid deep breathing when Chlorine is present in the atmosphere.
Go indoors and close the doors and windows of the house and
switch off the ventilation system.
Move to the upper floor if in a multi store building.
Cover the face with a wet towel for additional protection.
Tips for Chlorine Consumers:
Use tonners on “first come first used” basis.
Do not heat the Chlorine Containers. This may lead to serious
accidents and even rupture of containers.
Use tonner key for operating the tonner valves.
Never use plastic tubing for Chlorine service. Use copper tubing with stand fittings.
Install a BAROMETRIC LEG in the system.
Keep a solution of Caustic Soda/Soda Ash/Hydrated Lime Slurry in a tank ready for neutralization of Chlorine in emergency,
Keep a tonner/cylinder safety kit always handy.
Pressure in a Chlorine Container is not a measure of quantity in the container. At a given temperature, the pressure in a container will be the same whether the quantity is 1 Kg. Or 900 Kgs.
Send your operators for training at your supplier’s works.
Education on Chlorine Safety:
NICKLE BRINE BODY EVAPORATOR
Brief Description of Plant
Scope of this section is production of Pure Salt Slurry & 50%
Caustic Soda.
In this section there are two evaporator bodies. Body no. 1 is used
for production of Pure Salt Slurry & Body no. 2 is used for
production of 50% Caustic Soda.
As per requirement & facility available we can run both the bodies
as either single effect or double effect.
Pure Brine received from SABR is evaporated with help of 50#
steam in BODY NO. - 1 & gives Pure Salt Slurry as a product
which is supplied to MUW plant.
32% Caustic Soda received from C/H is evaporated with help of
50# steam in BODY NO. - 2 & gives 32% Caustic Soda as a
product.
50 % Caustic Soda is supplied to customer by Road Tanker.
PROCESS FLOW DIAGRAM
MATERIAL BALANCE AND ENERGY BALANCE FOR NBE2
Let we are producing 1 ton 50% caustic
L=F+1000
Caustic balance
L*0.32=1000*0.5
L=1.562 ton
Water balance
L*(1-0.32)=F+500
F=562.5kg=0.562 ton
Energy balance
stream Caustic(kg/sec) Water(kg/sec) Total kg/sec
feed 0.1388 0.2951 0.4339
product 0.1388 0.1388 0.2776
Water vapor -------- 0.15625 0.15625
Data
Feed temperature of 32% caustic=358k=85oc
Steam pressure=50 psig
Latent heat of saturated steam=2118 KJ/kg
Outlet temperature of 50% caustic and water vapor=368k
Specific heat of feed=3.68 KJ/kg K
Specific heat of outlet 50% caustic=3.22 KJ/kg K
Heat entering at feed=mcpdt
=0.4339*3.68*(358-298)
=95.805 kW
Heat leaving at product=0.276*3.22*(368-298)
=62.2104 KW
Heat leaving at Product from water vapor
=Latent heat of vaporization + mcpdt
=0.15625*[2260+4.18*(373-298)]
=402.109 KW
Total heat Balance
Heat supplied by superheated steam= Output-input
M*lf=468.109+62.201-95.805
M=368.514/2079.21
M=0.177 kg/sec steam will be required for 1 ton/hr 50% caustic
M.O.C. Of Equipment
P -1400 :- • Capacity of this pump is 3578
M3/Hr • M.O.C. of this pump is Ni. +
Cr. • Power consumed is 75 kW
P -1401:- • Capacity of this pump is 60
M3/Hr • M.O.C. of this pump is SS-
316 • Power consumed is 15 kW
P -1402 :- • Capacity of this pump is 30
M3/Hr • M.O.C. of this pump is SS-
316 • Power consumed is 9.5 kW
P -1403 :- • M.O.C. of this pump is SS-
316 • Power consumed is 12.7 kW
P -1404 :- • Capacity of this pump is 60
M3/Hr
P -1405 :- • Capacity of this pump is 16
M3/Hr • M.O.C. of this pump is SS-
316. • Power consumed is 7.5 kW
P -1407:- • Capacity of this pump is 16
M3/Hr • M.O.C. of this pump is SS-
316 • Power consumed is 7.5 kW
P -1409 :- • Capacity of this pump is 60
M3/Hr • M.O.C. of this pump is SS-
316 • Power consumed is 11 kW
P -1410 :- • Capacity of this pump is 60
M3/Hr • M.O.C. of this pump is SS-
316 • Power consumed is 11 kW
• M.O.C. of this pump is SS-316
• Power consumed is 22.5 kW P - 2701 :-
• Capacity of this pump is 550 M3/Hr
• Power consumed is 75 kW K - 2701:-
• Power consumed is 22 kW P - 203 :-
• Capacity of this pump is 15 M3/Hr
• Power consumed is 5.5 kW P -1305 :-
• Capacity of this pump is 20 M3/Hr
• Power consumed is 2.2 kW
P/BRINE P :- • Power consumed is 22.5 kW • D-1401(RAW WAETR
TANK):-Capacity of this tank is 21.2 M3
• M.O.C. of this tank is SS-316 D-1403(RAW WAETR TANK)
• Capacity of this tank is 9.42 M3
• M.O.C. of this tank is MSRL • D-1404 (SLURRY TANK) :-
Capacity of this TANK is 21.2 M3
• M.O.C. of this tank is SS-3016
If rubber lined vassal is not used, then there is a possibility that Slurry carry over Iron content.
UTILITY SECTION
Sub sections
Low Pressure Steam (1.0 Kg / Cm2)
Cooling Water (Sea Water of 5.5 pH)
Raw Water
Chilled Water (NH3 Refrigeration System)
D. M. Water
Cooling Water System
Sea water comes from Talao header is fed to Mixing Tank where HCl
addition is being done to reduce pH up to 5.5 to 6.0.
The reaction takes place is:
CaCO3 + 2HCl = CaCl2 + CO2 + H2O
CO2 is liberated by Air Stripping in Degasifier.
By this way CaCO3 content in sea water is reduced to prevent any scaling
in any process equipment.
Chilled Water System
In this section Raw Water temperature is reduced to 8 - 15 ° C by NH3
refrigeration system.
There three nos. of (150 TR capacity for each) NH3 compressors in this
system.
Chilled water is supplied to various sub section of CCG & to Br2 plant.
Raw Water System
Raw Water is received from Water Softening plant to CCG - Utility section
& then supplied to various sub section of CCG.
D. M. Water System
D. M. Water is received from Water Softening plant to CCG - Utility
section & then supplied to various sub section of CCG.
CRITICAL PROCESS PARAMETERS IN THE CC GROUP
PLANT
SECTION PARAMETERS VALUES
PBR Brine density
NaCl Concentration in
clarified Brine
Ca+Mg ions
Concentration in clarified
brine
Free chlorine in clarified
brine
Clarity
Net Flow Turbidity Units
(NTU)
Racker load (For more
sludge settling)
23 Baume
300 -305gpl
(4-6) ppm
0.36 ppm
36 inches
12
1.5 Amp
Soda solution
Concentration (Soda
ash)
Sodium Sulphite
concentration in the
clarified Brine
170 gpl
2.8 gpl
SBR 3 Vertical
Leaf type
Pressure filters
are provided
-- Pressure
Drop
depends on
the thickness
of the filter
cake formed
inside
Pressure drop Across
each filter
Solids ratio
Quantity of Cellulose
used per square meter of
filtering surface
Pre-coat
Concentration
Outlet pressure for Safety
Filter
HCl Concentration
Temperature Control of
Filtered
Brine to Resin Tower
Calcium+ Magnesium
ions
NaCl (Gpl)
PH
Free- Chlorine(To Resin
Tower)
Pressure Drop across
Resin bed
(Ca+Mg) ions
Concentration
Caustic: DMWRatio
HCl: DMWRatio
0.55Kg/sq.cm
1:1
0.6 kg
20 gpl
0.15 kg/sq.cm
32%
60-65. C
6 ppm
(306-308)
(8.3 - 8.5)
Suitable for resin towers Nil
0.6
16-17 ppb
6.2
5.6
Cell house Composition of inlet brine
Temp.
Cl2 header pressure
NaOH con.
Rectifier load
Depleted brine
concentration
Individual cell voltage
306-308 gpl
65-75c
-40 to -80 mmwc
29.5 to 32 %
6.0 KA
210 - 250 GPL
2.5 - 4.5 volt
CCD Cl2 pressure at outlet of
compressor
Hypo
concentration(NaOH)
4 - 5 Kg. / Cm2
10-18 % of NaOH.
NaOH concentration reduced to
0.5 to 2% & F – Cl2 becomes > 110
gpl then iso late hypo tank
HCL Chamber suction
H2 safety
H2 flow controller
CL2 flow controller
chamber suction
H2 flow
Cl2 flow
should be > 150 mmwc
v/v 25 % open,
6-20 % open
20-30 % open &
-50 to -90 mmwc
8 - 20 Kg/hr
330 - 380 kg/hr
GENERAL SAFETY INFORMATION
Lab Safety Equipment:
Chemical Hazards and Symbols:
Chemical Hazard Symbols and Definitions:
Selection of PPE According To Body Part:
Body Part Hazard PPE Necessary
Head Falling object, shock,
chemical spurting
Safety helmet, hard hats,
safety caps, headgear
Eye Chemical splash, dust
flying, particles, gas
welding ,radiation
Spectacles, lenses & goggles
for chemical welding,
grinding, furnace, dust etc
Ear High level noise( more
than 90 db-A)
Earplugs, plugs, inserts
Nose Dust, Toxic gases Dust masks, cloth mask,
rubber mask, fume mask,
respirator for dust, gas,&
vapor, breathing apparatus,
Canister gas mask, air line
respirators,
chemical/mechanical filters
Selection of Material of Construction of PPE:
No Material For the protection from
1 Metal Flying particles, falling
body, sharp edge,
abrasion
2 Fiber Metal Sparks, falling body, flying
particles, sharp edge,
abrasion, machinery
3 Metal Screen Sharp edge & abrasion
4 Plastic, PVC Hot liquid, moisture, water,
petroleum product, acid
,alkali, spark, falling body,
flying particles, electric
shock, sharp edge,
abrasion, skin protection
5 Rubber Hot liquid, moisture, water,
acid, alkali, electric shock,
machinery, skin protection
6 Conductive Rubber Explosive Substance
CHLORINE, HYDROGEN, CAUSTIC are comes into hazard
product so we have to care for safety especially human safety and
equipment’s safety. Here different plant wise required safety
provisions taken to be mention below.
PBR SECTION
In this section there are no particular hazard apart from Na2CO3 and
CAUSTIC solution.
Here we should avoid soda ash spillage.
SBR SECTION
We have to take care of alpha -cellouse powder and alkali, HCL used for
regeneration of resin bed.
CELL HOUSE, CCD, Chlorine storage
In cell house we have to take care from the DC current .avoid touch
to the bus bar. Hydrogen line always should be in pressure which
ensures that air cannot enter and make explosive mixture.
Chlorine line always should be in pressure, which avoid the chlorine
gas to the atmospheric.
Time to time we should check the all joints and line of cl2 by
ammonia
We have to know the properties of chlorine, hydrogen, HCL, caustic
to avoid any danger regarding safety.
Apart from all this breakage glass alarm provided at several point in
plant and emergency shower is also provided with 24-hr water
facility. cell house and ccd is equipped with chlorine detector
alarm.(23 cl2 dectors)
All chlorine gas vent line is opened in the hypo tower so at the
changeover in hypo tower and storage tank we have to take care.
In chlorine storage area without gas mask no one should enter. And
in other area especially like NaOH storage, H2SO4 handling all the
PPE must be used. Like goggles with radiation shield, PVC coat, gum
boot, gloves etc.
Here from safety data sheet of chlorine, bromine and hydrogen gas
we can have a proper idea of the properties of same.
Material Safety Data Sheet
It is the best source of information the industrial hygienist can have
regarding any chemical hazards.
Manufacturers, Importers, Exporters, Users, Employers, workers
must have a copy of M.S.D.S. for each hazardous chemical.
M.S.D.S. should contain following information:-
Identity of the chemical --- common and chemical name of the
substance.
Physical & chemical characteristic of the substance. e.g. vapor
pressure , flash point etc.
Physical hazards. e.g. reactivity for explosion , potential extinguishing
data .
Health hazards with signs & symptoms of exposure, route of entry,
toxicity etc.
O.S.H.A. --- PEL & ACGIH – T.L.V, STEL etc.
Disclosure of information of any carcinogenic property.
Safe handling procedures, precautions, procedures for safe clearing
up on spills & leakages.
Emergency First Aid measures with possible Antidotes if available.
Revision of data of M.S.D.S. & Date of its preparation
Name, Address, emergency contact numbers of chemical
manufacturers, importers, distributors, who can provide additional
information on chemical.
Reactivity data – stability, incompatibility, corrosiveness, avoidable
conditions etc.
Waste disposal --- storage handling, transfer, transport precautions.
• Under the “ Right to Information “ Act , every worker involved in a
factory , has fundamental right to know actual potential exposure to
Hazards , it’s consequences and hence use of M.S.D.S. has become familiar
along with Specific Hazard Communication Specific employee training
program is required .
Important Points for F.M.O. & Hygienist Regarding M.S.D.S.
Potential risk from hazard exposure.
Practicable control measures e.g. elimination, substitution, enclosure
etc.
Compare effectiveness of different control measures.
Relative cost of implementation.
Maintenance & testing procedures for control.
User acceptability for long periods.
Social impact of implementation. ( Work force orientation)
Safety data for different chemicals:-
CHLORINE
General
Synonyms: berth lite, Molecular formula: Cl2
Physical data
Appearance:
Light greenish-yellow gas with an irritating odor
Melting point: -101 °C
Boiling point: -34 °C
Vapor density: 2.98 g/l
Vapor pressure: 5.8 bar at 20 ˚C
Specific gravity: 1.47 g/ml at 0 ˚C
Critical temperature: 144 ˚C
Auto ignition temperature: n/a
Stability
Stable. Incompatible with reducing agents, alcohols.
Toxicology
Toxic by inhalation, ingestion and through skin contact. Inhalation can
cause serious lung damage and may be fatal. 1000ppm (0.1%) is likely to be
fatal after a few deep breaths, and half that concentration fatal after a few
minutes. May irritate or burn skin. OEL (8hr TWA) 1 ppm.
Environmental information
Very toxic to aquatic organisms.
Personal protection
Safety glasses, gloves and good ventilation.
Sodium Hydroxide:
General
Synonyms:
caustic soda, soda lye, lye, white caustic, aetznatron, ascarite, Collo-
Grillrein, Collo-Tapetta, sodium hydrate, fotofoil etchant, NAOH, STCC
4935235, sodium hydroxide pellets, Lewis red devil lye, stamperprep, tosoh
pearl
Molecular formula: NaOH
Physical data
Appearance: odor less white solid (often sold as pellets)
Melting point: 318 ˚C
Boiling point: 1390 ˚C
Vapor density:
Vapor pressure: 1 mm Hg at 739 C
Specific gravity: 2.12
Flash point: n/a
Explosion limits: n/a
Water solubility: High (Note: dissolution in water is highly exothermic)
Stability
Stable. Incompatible with a wide variety of materials including many
metals, ammonium compounds, cyanides, acids, nitro compounds,
phenols, combustible organics. Hygroscopic. Heat of solution is very high
and may lead to a dangerously hot solution if small amounts of water are
used. Absorbs carbon dioxide from the air.
Toxicology
Very corrosive. Causes severe burns. May cause serious permanent eye
damage. Very harmful by ingestion. Harmful by skin contact or by
inhalation of dust. Typical STEL 2 mg m-1.
Hydrochloric acid
GENERAL
Synonyms: muriatic acid, chlorohydric acid. [Data for dilute Hydrochloric
acid can be found here.] Molecular formula: HCl
PHYSICAL DATA
Appearance: clear colorless or slightly yellow liquid with pungent odor.
Concentrated acid is fuming.
Melting point: -25 C
Boiling point: 109 C
Specific gravity: 1.19
STABILITY
Stable. Avoid heat, flames. Incompatible with most common metals,
amines, metal oxides, acetic anhydride, propiolactone, vinyl acetate,
mercuric sulfate, calcium phosphate, formaldehyde, alkalis, carbonates,
strong bases, sulfuric acid, chloro sulfonic acid.
TOXICOLOGY
Extremely corrosive. Inhalation of vapor can cause serious injury.
Ingestion may be fatal. Liquid can cause severe damage to skin and eyes.
TLV 5 PPM.
ENVIRONMENTAL INFORMATION
Lethal to fish from 25 mg/l up. Toxic for aquatic organisms due to pH
shift.
PERSONAL PROTECTION
Safety glasses or face mask, gloves. Effective ventilation.
WORK PERMIT PROCEDURE
Purpose:
The permit to work procedure is a formal written system used to
control certain types of potentially hazardous work. It is also a means
of establishing an effective means of communication and
understanding between personnel requiring the work to be done and
the personnel or contractors who are going to do the work.
• The issue of a permit does not in itself make a job safe. It also does not
constitute permission to do dangerous work and therefore should not be
seen as an easy way of eliminating a hazard or reducing risk.
• This procedure has been written for the benefit of all parties involved in
the Production, maintenance and services, and closure of a Permit to Work
for the Isolation or Interruption of Systems or Services or specific
Hazardous Activities.
• Safe working permit systems enable employees to enhance safety
procedures provides information on the requirements associated with safe
work permit systems including:
The authority to issue safe work permits
The situations where a permit is required
Things to be considered prior to the issue of a permit
The conduct of the work in accordance with the permit
The closure of the permit.
Scope:
• This procedural guidance applies to all work permit procedure in the
complex and complies with Gujarat Factory Rules. This procedure covers
provisions to prevent loss of life and property from incident, fire or
explosion as a result of cold /hot work in complex.
• The permit-to-work system covers all on-site including Routine non-
routine work, which may create potential hazards.
• Non-routine is that work normally requiring initiation of work orders
such as maintenance work on equipment, installation or modification of
equipment, painting, repair, working on a moving equipment of machinery
and equipment.
• This procedure includes Lockout/Tag out of equipment’s, piping and
valve etc.
Work Permit Procedure:
Five Categories of work permits are existing for the entire complex as
1. Category-1
2. Category-II
3. Category-III
4. Category-IV
Category-1
Each permit will have work permit No. and Book No. printed on it
• The work permit book will be available in the control room and custody
owner of the plant area.
• The issuer shall be a person in the grade of G from the operation Dept.
• If the job is to be carried out from the same dept. the issuer will be the
dept./section head to the job in charge of the area and the acceptor shall
be a person in the Grade G.
In normal circumstances the acceptor shall be a person from the
maintenance department not less than the G level.
Category – I permit will be applicable for
• Welding, cutting, grinding, drilling, soldering activity in the atmosphere of
Hydrogen, NH3, Cl2, Br2, CH3OH, C2H5OH, Kerosene, Diesel, Lignite
(Bag filter, crusher, vibrator, bin and ESP) and Highly flammable
chemicals. Other Hazardous jobs where the high risk are involved as
working on chimneys, lifting and shifting of heavy objects more than (05
tons) inside plant, Working at a height of more than 20ft, arresting of
steam leakage from running line where the steam pressure is more than
450#.
• Vessel entry, Entry of personnel into confined spaces for the purpose of
maintenance / inspection works containing or having contaminated gas,
hydrocarbons or toxic / corrosive chemicals or which is or has been
deficient in oxygen for normal breathing.
Procedure for obtaining the Work Permit
This permit will be prepared in three copies.
First Copy - The acceptor & display at site
Second copy - Electrical Dept.
Third copy - As the book copy of the issuer.
Appropriate marking has also been done on top left of each copy about the
distribution pattern as mentioned above
Explanatory Notes to Work Permit Forms
The check-listed items in the work permit forms are elaborated
below to amplify the underlying concepts and highlight their
significance.
Issuer:
The person shall be from operation / owner of the area not below the
‘Management’ cadre.
Authorization:
Only ‘F’ level staffs / Dept. Heads are the ‘Authorized Person’ to sign in
the work permits. In case the F level staff is not available / absent, the
person immediately below him can be the ‘Authorized Person’
Acceptor:
An engineer from the maintenance / service department shall accept the
permit. In case the permit is to be issued within the process/ operations
department itself (say for inspection of a vessel) the issuer shall be one
engineer and the acceptor shall be a different engineer.
Permit Receiver:
The person who is directly responsible for doing the job at site.
Department:
The name of the issuing department / section.
Location:
Exact location of the job (Area / floor / equipment name Description of
the job:
The actual work like cutting, welding, cleaning of vessel etc to be carried
out at site.
In case emergency alarm is sounded after permit is issued, the permit
becomes void.
Category I Work Permit – Work Flow:
Category-II
General
This is applicable for all activities other than those, which does not cover in
class I permit and will cover the following activities
Hot work which are not flammable in nature
Maintenance of pumps, equipments, vessels and structural jobs.
Civil and construction in running plants.
Laying and rerouting of piping.
Insulation, whitewashing and painting jobs.
Braking and opening of pipelines containing ammonia, sulphuric acid
steam, Hydrochloric acid, caustic soda and chlorine.
Vessel entry where toxic and flammable chemicals are not involved.
Cutting and welding near belt conveyors.
Any other specific activity as decided by the issuing authority
No permit is required for routine welding/cutting and similar jobs carried
out in the main fabrication shops and central workshops as well as for
torches, furnaces, sparking equipment etc. located in designated locations
of central laboratory. These jobs shall be done as per their work
instructions for respective activities.
Each permit will have work permit No. and Book No. printed on it
The work permit book will be available in the control room and
custody owner of the plant area.
The issuer shall be a person in the grade of G or Any authorized
person from the operation Dept.
If the job is to be carried out from the same dept. the issuer will be
the dept./section head to the job in charge of the area and the
acceptor shall be a person in the Grade G or any authorized person
Procedure for obtaining the Work Permit
This permit will be prepared in triplicate.
First Copy - The acceptor & display at site.
Second copy - Electrical Dept.
Third copy- as the book copy of the issuer.
Each copy is duly marked on top left as per the above distribution pattern.
All permits must be issued only from the respective control room
and shall be received by the concerned plant engineer or authorized
person.
On completion of the jobs the permits should be handed over by the
permit issuer after certifying the completion of job and the issuing
authority will accept the permit back and file the same in the control
room.
After completion of the job, the display copy shall be returned to the
issuer duly signed by the acceptor and shall be retained for one
month.
Explanatory Notes to Work Permit Forms
The check-listed items in the work permit forms are elaborated below to
appraise the underlying concepts and highlight their significance.
Issuer:
The person shall be from operation / owner of the area not below the
supervisory grade.
Acceptor:
An engineer / supervisor from the maintenance / service department shall
accept the permit. In case the permit is to be issued within the process/
operations department itself (say for cleaning/ inspection of a vessel) the
issuer shall be one of the engineers controlling the activity and the acceptor
another engineer in charge of job execution.
Department:
The departments issuing or accepting the work permits.
Location:
Exact location of the job (Area / floor / equipment name)
Description of the job:
The actual work like cutting, welding, cleaning of vessel etc to be carried
out at site.