DESCON ENGINEERING LIMITED

ASME Project

American Society of Mechanical Engineering, UET Lahore chapter this year, like every year, organised a team for the Thermodynamic Section and assigned a project, ‘Design Analysis and Fabricate of Water Tube Boiler’. The team comprises of 18 members working as a unit to put forth their immense effort in reaching a new milestone. The Water Tube Boiler that is being worked on is to be forwarded in various project exhibitions to demonstrate the calliper of ASME UET Lahore chapter.

Some Specifications and Details of the Boiler

What is a water tube boiler?

A water-tube boiler is a type of boiler in which water circulates in tubes which are heated externally by the fire. Water-tube boilers are used for high-pressure boilers. Fuel (coal) is burned inside the furnace, creating hot gas which heats up water in the steam-generating tubes. In smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely on the water-filled tubes that make up the walls of the furnace to generate steam.

A water tube boiler is more geared towards the latter setting than the former though, since water tube boilers can create large amounts of steam and recycle water for use again and again if kept in a closed system. There are several, important pieces that make up a water tube boiler, though.

In water tube boilers, water is circulated though the tubes and hot flue gases flow outside the tubes, e.g. Bob cock & Wilcox, Admiralty three drum, Y-160 and Foster wheeler D-type. The water tube boiler is employed for high pressure, high temperature, high capacity steam applications, e.g. providing steam for main propulsion turbines of cargo pump turbines.

Parts of a water tube boiler

Furnace - Furnace is usually membrane walled and gas tight. Most of the heat transfer occurs in the furnace in the form of direct radiation.

Super Heater - Inverted 'U' is most widely used. There are other types like vertical 'S' type drainable. Super heater is usually embedded in the boiler bank. When superheat temperature is high, part of the super heater section is directly place in the furnace to increase direct radiation and reduce size.

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Boiler Bank - Boiler bank connects both the drums. Natural circulation occurs without the aid of any external down comers

Economisers - Economizer is used downstream of Boiler bank to preheat the feed water absorbing heat from hot exhaust gases

Pipes- In a water tube boiler, water runs through pipes. The pipes are heated by surrounding fire or hot gases, and the more the water is heated, the higher it goes until it becomes steam. The pipes then allow the steam to escape into the upper drum.

Upper Drum- The upper drum is where the steam goes once it's travelled the length of the pipes. The steam collects in the upper drum, away from the heated pipe, and begins to condense back into water. As the steam once more becomes liquid it drips down from the upper drum and is collected in a lower drum, or the mud drum.

Lower Drum- The lower drum is set at the bottom of the water tube boiler beneath the upper drum. The condensed steam collects here and from the mud drum it goes back into the pipes. The more pressure from built-up water, the more water that will be turned back into steam and passed through the pipes yet again.

Re-heater- The function of Re-heater is to reheat the steam coming out from high pressure turbine. The Re-heater is composed of two sections.

Burners- As evident from the name, these are used for burning pulverized coal or oil.

Working Principle of a Water Tube Boiler

In the water-tube boiler, water flowed through tubes heated externally by combustion gases, and steam was collected above in a drum. Water tube boilers are very huge and their water holding capacity is enormous. The water-tube boiler became the standard for all large boilers as they allowed for higher pressures than earlier boilers, higher than 30 b. Example, Babcock & Wilcox boiler manufactured at Thermax Boilers Limited. It is a horizontal, externally fired, stationary, high pressure, and water tube boiler with a super heater

The coal is fed from hopper on to the grate where it is burnt. The flue gases are deflected by the fire brick baffles so that they pass across the left side of the tubes in a beneficial path transferring heat to water in the tubes and to the steam in the super heater and finally they escape into the atmosphere through the chimney. The drought is regulated by a damper placed at the back chamber.

The position of water tubes near the furnace is heated to a higher temper than the rest. Owing to higher temperature, the density of water decreases and hence the water rises through the

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uptake header and short tube to the drum. The water at the back end, which is at a lesser temperature, now travels down through the long tube and the ‘downcomer header’. Thus, a continuous circulation of water called as natural circulations established between the water tubes and the drum. The steam produced gets collected above the water in the drum. Here, saturated steam is drawn off the top of the drum Since water droplets can severely damage turbine blades, dry steam from the steam-drum is again heated to generate superheated steam at 730°F (390°C) or higher in order to ensure that there is no water entrained in the steam. Cool water at the bottom of the steam drum returns to the feed-water drum via large-bore 'down comer tubes', where it helps pre-heat the feed-water supply. To increase the economy of the boiler, the exhaust gasses are also used to pre-heat the air blown into the furnace and warm the feedwater supply. Such water-tube boilers in thermal power station are also called steam generating unit

Visit to Descon Engineering Private Limited

The ASME, Student body of UET Lahore chapter, Thermodynamic Section organized an educational and field trip to ‘Descon Engineering Private Limited’(Lahore Manufacturing Works )for all ASME members to aid them in the learning of the working of Boiler and its manufacturing process. The feedback from all the Thermodynamic Section members, the executive body members and the faculty of Descon was appreciable. A delegation was sent from UET Lahore to Descon prior to the visit to asking for permission to visit them during their working hours so that students could visually see and learn the various processes carried out in the industry and workshops.

A bus was arranged to take the members from UET to Descon and bring them back to UET. The visit timings were from 12-3 pm. After we reached there, all members were first given a brief introduction of Descon by a presentation on multimedia in a hall, by Descon employees followed by a tea break. A short question- answering session was also conducted and all the queries of members were appropriately answered by the Descon faculty. Later on we were allowed to explore the industry on foot and observe all the processes being carried out that could be relevant and useful for our boiler manufacturing. Some of the relevant processes included welding, forging, casting and operations of a lathe machine. After a knowledge – filled visit to all the workshops the members were offered lunch at their local restaurant.

The Descon representatives later on the day handed out their brochures and a hardcopy of their productive data to the executive body members of the Thermody-namic ASME section which was intended to allow students to boost their knowledge about Descon and later on assist them in job interviews.

Thus a successful and informative field trip came to an end with executive members briefing the section members of the

DESCON ENGINEERING LIMITED

manufacturing processes with appropriate sequence to be used for boiler construction. A technical discussion session was carried out eventually to clarify any further queries regarding the manufacturing.

As a result of the field trip new dates, deadlines and revised tasks were then planned to propagate the fabrication process.

DESCON ENGINEERIG

Descon Engineering Limited is an integrated engineering services and manufacturing company operating in Pakistan, South East Asia and the Middle East since its inception in 1977. It has evolved into a leading engineering company serving various sectors. With major operations in Pakistan, Qatar, Kuwait, Saudi Arabia, and the United Arab Emirates, a workforce of over 38,000 extensive equipment resources, and a history of executing large-scale construction and manufacturing projects. The integrated package of services encompasses engineering, procurement, manufacturing, construction, commissioning and maintenance. With over 30 years of engineering, procurement, construction, manufacturing and project management experience, alliances with the world’s leading process equipment technology developers and multiple state-of-the-art fabrication facilities. Descon delivers high quality process equipment solutions at the most competitive prices.

PROJECTS

Descon has executed major projects in the sectors of oil and gas, chemical, petrochemical, fertilizer, power, cement and infrastructure. These projects have been delivered to clients who are investors, operators or themselves EPC contractors. Major international exploration and production companies, oil marketing companies and owners/operators have had their investments secured by entrusting Descon to implement their projects according to their budgets and time schedules while adhering to international quality standards and with zero tolerance towards unsafe practices and damage to the environment. The combination of an experienced human resource pool and well established project management systems have enabled us to succeed and grow in a competitive environment. From compact process plants to large civil infrastructure projects we have delivered a wide variety of projects of national importance.

Descon has executed power projects with a total capacity of approximately 10,000 MW. Descon has to a large extent helped shape the fertilizer sector in the region. The fertilizer complexes include Ammonia, Urea, DAP and NP Plants as well as CO2 recovery units. In chemical and petrochemical industry a wide range of plants, such as; PTA, Ethylene, Polyethylene, Polypropylene, PDH, Hydrogen, Nitrogen Peroxide etc. Descon manufacturing facilities have delivered a wide range of cement plant equipment, including kilns, silos, hoppers/bins and conveying equipment in middle-east. Descon has rapidly established itself as a key player in infrastructure projects and successfully execute large-scale projects like dams, barrages, canals, highways and hydro-electric units. Heavy lifts and rigging expertise is based on a demonstrated track record and an extensive fleet of cranes, the largest of which is of 1200 tons capacity.

MANUFACTURING

Descon has seven manufacturing/fabrication facilities strategically located in Pakistan and the Gulf Cooperation Countries. Each shop specializes in producing a specific type of product. In general the product range spans industrial process equipment and fabricated items. Complete packages such as boilers, process skids, tanks, heat transfer equipment are tailored to the client requirements and delivered on a turnkey basis.

DESCON ENGINEERING LIMITED

Descon has provided over 134 boilers, with cumulative steam production of more than 5000 tons per hour, over 1100 pressure vessels (columns, drums, separators etc), 500 heat exchangers, 450 storage tanks and over 100,000 tons of steel structure. Descon is authorized to produce ASME certified equipment (A, PP, S, U and U2 stamps). Additional certifications include “R Stamp” issued by National Board of Boiler and Pressure vessel inspectors and CE marking (specifically for European Region). Manufacturing strength is complemented with global technological alliances for specialized equipment. Integrated customized management systems ensure cross functional monitoring of the processes and timely delivery of the goods. Use of quality management system assures quality at each step of planning, design, fabrication & production.

PRODUCTS

Process Equipment

Pressure Vessels

Columns

Separators

Knock-out Drums

Slug Catchers

Heat Transfer Equipment

Heat Exchangers

Air Fin Coolers

Furnaces

Heaters

Boilers

Heat Recovery Steam Generators (HRSGs)

Once Through Steam Generators (OTSG)

Direct Fired

Process

Fossil or Non-Fossil Fuel Fired

Pre-Engineered Skids

Amine / TEG Units

Dew Point Control Units

Separator Packages

Glycol Dehydration

Chemical Injection LPG Road Tankers

Rigid bobtail delivery truck

Articulated

Field Erected Storage Tanks

Flare Stacks

Steel Structure

Piping Spools

Wind Tower Salt Heaters Cement Plants

MILESTONES IN MANUFACTURING WORKS

It all started in a small one room office in Lahore. The pioneers of the company came from a fertilizer plant. It was the entrepreneurial spirit of four people who had a vision of building a lasting institution prominent for its professionalism and distinguished by the desire of creating a world-class engineering powerhouse. 1977 Company established 1980 Olayan Descon JV formed in Olayan Saudi Arabia 1982 Descon Manufacturing Works commissioned 1982 Office established in Abu Dhabi 2000 JV engineering company formed with JGC Corporation 2000 Presson Descon (PDIL) formed, a JV with Presson Canada 2001 Fabrication shop established in Ruwais, Abu Dhabi 2002 Yanbu workshop commissioned 2004 Descon Engineering Qatar, LLC established 2005 Hamriyah Manufacturing Works in Sharjah commissioned

DESCON ENGINEERING LIMITED

2006 Rousch Power Plant and Altern Energy acquired by Descon 2007 Karachi Manufacturing Works commissioned 2007 First major EPC contract acquired from Fertil, Abu Dhabi 2008 Descon Oxychem commissioned 2010 JGC-Descon becomes Descon Integrated Projects., Limited 2010 Fabrication shop commissioned in Qatar

DESIGN AND ENGINEERING

There are three distinct groups for engineering and the total number exceeds 600 design engineers:

Plant design

Product design

Infrastructure design A strong in-house design and engineering capability exists to support proposal generation and project exhibition. The design and engineering team has extensive experience of working to international industry codes, standards, software and the best practices. The in-house capability to perform the following:

Basic Engineering

Detailed Engineering

Preparation of equipment specification and data sheets

Preparation of operation and maintenance manuals.

DESIGN CODES AND STANDARDS

ASME

EN

API

TEMA

ASTM

ANS

AISC

AWS

ADR

TRD

SOFTWARE

Civil

STAAD Pro

STAAD Foundation

SAP-2000Piping

CADPipe

CASESAR II Mechanical

TANK

ASPEN B-JAC

DISASU

Electrical

ETAP

LUXICON

Smart Plant

Electrical

Process

Chempro

PRO II

FLARENET

HYSIS

PIPESIM

HTRI

ASPEN Plus / ASPEN ZYQAD

Tray 2000

Best Pipe

Paula

ASPEN (HTFS)

ESTPRO

DESCON ENGINEERING LIMITED

FABRICATION

Fabrication resources include:

Overhead Mobile Cranes

Fork Lifters

Shearing Machines

Radial Drilling

Magnetic Base Drill Machine

Column and Boom Welding Machi

QUALITY CONTROL AND ASSURANCE

A strong commitment to quality assurance and quality control (QA/QC) is inherent throughout the manufacturing business process and is governed by a comprehensive ISO: 9001:2000 Quality Management Systems. Salient functions of QA/QC include the following:

Design verification

Inspection of incoming materials

Stage inspections

Non-destructive inspections

Visual and dimensional examination

Pressure testing

Liaising with third party inspection agencies

Preparation of inspection data manuals

DESCON ENGINEERING LIMITED

DESCON ENGINEERING LIMITED

DESCON ENGINEERING LIMITED

DESCON ENGINEERING LIMITED

QUESTION SESSION BY STUDENTS

The students of ASME, UET Lahore Chapter, were given a reception in conference room and Production and Marketing engineer of Descon Mr. Umar khan delivered a presentation about the Descon. At the end and during presentation, the students asked him questions.

Rizwan Ail asked about the industrial softwares. Mr. Umar khan Answered that Industry has its own software’s that are purchased by that Company. The Engineers are specially trained to work on these software’s. The duration of training is specific. These software’s are very productive and advance.

Another question asked by student was what type of Engineers do you hire? Mr. Umar Khan replied him that here we hire l the engineers of all the departments but mostly are those of Mechanical and Metallurgical.

The students asked what sorts of projects you do? Mr. Umar Khan replied we have different sectors, oil and Gas, electricity Generation, Boilers, cement, Chemical power plant and in these sectors we are doing various sorts of projects like designing and fabrication of boiler, Generation of Electricity of 100MW and we are selling this electricity to Wapda. He also told us that recently a group of students of UET had a project with us.

Another student also asked him about the working hours. He replied that we work in different shifts. Generally, we have three shifts in a complete day and employees are being changed after each shift.

After this we visited the whole working area. The students asked the questions about milling, rolling, forging and honing. Then we also visited Boiler section. There the fabrication of Boiler was in Operation. We asked about maintenance, designing, operation, different technical terms to the Engineers. He briefed us well. The students also visited welding section and also asked about different questions about types of welding SMAW, GMAW, TIG, MIG and others as well.

STUDENT’S AND COMPANY’S RESPONSE

All the students enjoyed this marvellous Study tour. All the ASME student members appreciated Manager,

Assistance Manager and the whole management who arranged this tour. We found it very useful for our

studies. We had an opportunity to see the things practically and visualize the things. We also got an

opportunity to see the Engineers who are working in industry. Most of them were UETIANZ. We were also

encouraged to see them at main posts of the industry. The students were very satisfied and encouraged

the management to arrange such tours more and more. The company’s response was credible. They

treated us in a very nice way. They answered our questions, honoured us, serve us with tea .They had

already done these arrangements before our arrival. During our visit all the employees of Descon helped

and encouraged us. After the visit, they also served us lunch. After this they said us good-Bye with well

wishes.

DESCON ENGINEERING LIMITED

CONCLUSION

It was a very credible Industrial tour. All the students enjoyed this and from learning point of view it was

too much productive for all juniors and seniors members. The students of different departments also got

an opportunity to see each other. All appreciated the management and expected more such tours to

different multinational industries all over the Pakistan.

Rizwan Ali Bsc. Mechanical Engineering Student

Assistant Manager Thermodynamics Section

ASME UET Lahore, Pakistan rizwanali976@gmail.com

+92-300-4094863