lethabo power station units no. 1 to 6 particulate ......no. 1 to 6 at lethabo power station during...

Lethabo Power Station

Units No. 1 to 6 Particulate

Emission Monitor

Correlations,

Unit No. 4 Start-up &

Unit No. 6 Shutdown Report

1st July 2016

Report No. RSL222

P.O. Box 2459 Noordheuwel ext 4 Krugersdorp 1756 Vat No. 4670254459

10 Chisel Street Boltonia

Krugersdorp 1739

Tel: +27 (011) 660 9432 Tel: +27 (011) 954 6652 Fax:+27 (086) 689 4572

www.stacklabs.co.za

Eskom Holdings SOC Limited

Lethabo Power Station

Private Bag X415

Vereeniging

1930

Attention: Yaseen Waja

Tel: 0164575062

Cell: 0837864988

Date

Order No. Report No. Enquiries

1st July 2016 PO: 4501942164

RSL222 Tel: 011 954 6652

Cell: 082 458 7438

e-mail: [email protected]

REPORT No.: RSL222

LETHABO POWER STATION UNITS NO. 1 TO 6 PARTICULATE EMISSION MONITOR

CORRELATIONS, UNIT NO. 4 START-UP & UNIT NO. 6 SHUTDOWN REPORT

Sir

Herewith the finalised report for the particulate emission monitor correlations conducted on Units No. 1 to 6 at Lethabo Power Station during the period from December 2015 to July 2016, Unit No. 4

Start-up Measurements and Unit No. 6 Shutdown Measurements.

We thank you for the opportunity to be of service. We trust that your requirements were interpreted correctly. Should you however have any queries, please contact us at the above numbers, we will

gladly assist.

PH Pretorius

Stacklabs

ISO 9096, 12141 & 10155

STACKLABS ISO #:825268/:2007-05-23 © ISO 2003

II

Source Information

Source Location: Lethabo Power Station

Private Bag X415

Vereeniging 1930

South Africa

Permit No. TBA Contact: Yaseen Waja

Title: System Engineer

Telephone: (016) 457 5062

Listed Activity Category: 1.1 Solid Combustion Installation

Survey Date: December 2015 to July 2016

Pollutants: Total Particulate Matter (TPM) Negotiated Limit: 100 mg/Nm

3 dry 10% O2

Method: ISO 9096, 12141 & 10155

Plant: Unit No. 1

Survey Date: 9th to 18

th March 2016

Measured Concentration: 12.6 to 58.1 mg/Nm3 dry 10 % O2

Compliance: Yes – All Measurements No. 1 to 11

Plant: Unit No. 2


rd December 2015


Compliance: Yes – Measurements No. 1 to 12

Measurement No. 9- plant malfunction

Plant: Unit No. 4


th June 2016


Compliance: Yes – Measurements No. 3 to 12

No – Measurements No. 1 & 2 (618.37 MW SB)

Plant: Unit No. 5


th December 2015

Measured Concentration: 65.8 to 144 mg/Nm3 dry 10 % O2

Compliance: Yes – Measurements No. 7, 8, 9, 10, 12, 14 & 15 No – Measurements No. 1 to 6, 11 & 13

Plant: Unit No. 6 Survey Date: 12

th to 7

th December 2015


Compliance: Yes – Measurements No. 7 to 12, 14 & 15 No – Measurements No. 1 to 6 & 13

Testing Laboratory

Laboratory: Stacklabs 10 Chisel Street Boltonia Krugersdorp 1739

Contact: Mr PH Pretorius Title: Managing Member

Telephone: (011) 954 6652

E Mail: [email protected]

III

Report No. RSL222 Reference

Revision

SLOP019

0

Title: Units No. 1 to 6 Particulate Emission Monitor

Correlations, Unit No. 4 Start-up & Unit No. 6 Shutdown

Date 2012/05/25

Revision Date No Revision

Compiled by Functional representative Authorised by

………………… …………………... …………………….. WJ Bronkhorst

Team Leader

P Buell

Quality Representative

PH Pretorius

Managing Member

Review and Certification

All work, activities and tasks performed for this report were carried out under my direction and

supervision. All work was conducted in compliance with listed standards

I have reviewed the details, calculations, results, conclusions and all written material contained within

this report, and hereby certify that the presented material is authentic and accurate.

Name: PH Pretorius

Title: Managing Member

2016/07/01

Sign:___________________________ Date:______________________

IV

Table of Contents

Section Page

Source Information............................................................................................................ II

Review and Certification...................................................................................................... III Report Summary.................................................................................................................. V

1. Monitoring Objective........................................................................................................... 1 2. Plant Description and General Operating Procedures.......................................................... 1 3. Methods and procedures....................................................................................................... 3 4. Results.................................................................................................................................. 5 5. Discussion............................................................................................................................ 17 6. Monitor Deviations............................................................................................................ 47 7. Recommendations.............................................................................................................. 47 8. Acknowledgements............................................................................................................. 47 9. References............................................................................................................................ 47 10. Distribution.......................................................................................................................... 47

Appendix No. 1 .................................................................Detailed Measurement Results 48

Appendix No. 2 .......................................................................................Plant parameters 67

Appendix No. 3 ...................................................................................Correlations Graphs 95 Appendix No. 4.................................................Water Vapour Concentration Calculation 112

Appendix No. 5............................................................................... Outlines of Procedures 114

Appendix No. 6............................... Particulate Emission Monitor Calibration Certificate 117

Appendix No. 7.................................................................................Particle Size Analysis 120 Appendix No. 8.................................................................................... Filter Mass Sheets 124

Appendix No. 9............................................................................... Calibration Certificate 130

V

REPORT SUMMARY

In order to meet the requirements of the South African Air Quality Act No. 39 of 2004

(Reference 9.1), all Solid Fuel Combustion Installations (Category 1.1) such as Lethabo Power Station, are obligated to monitor several listed pollutants during operation. These pollutants

include particulate matter, Sulphur Dioxide and Oxides of Nitrogen. The Act further specifies

that all particulate monitoring programs are required to meet international standards such as ISO 9096 & 12141 (Reference 9.2 & 9.3) and therewith ISO 10155 (Reference 9.4). To this

end and in keeping with the ESKOM Standard for Emission Monitoring and Reporting (420-

56242363) (Reference 9.5) Eskom’s scheduled particulate emission monitor correlations on

five Units at its Lethabo Power Station situated near Vereeniging in the Northern Free State. The risks areas included Units No. 1, 2, 4, 5 & 6’s electrostatic precipitators and the only

pollutant considered was particulate matter (particulate emission monitors correlations).

Continuous particulate emission monitors generally operate on a principle of passing a light

beam through a dust-laden gas stream. The dust concentration is then determined by measuring

the degree of light attenuation resulting from the dust within the gas stream. However the

degree of light attenuation is dependent on more than just the quantity of dust. Dust characteristics such as colour, size, shape and distribution of the dust within a duct, will all

impact on the amount of light that is attenuated. In addition, these characteristics will change

over time as the plant’s electrostatic precipitator or bag filters performances change. In order to compensate for these characteristic changes and to facilitate the determination of mass

emissions from the light attenuation, a correlation of light attenuation and measured mass

emissions must be conducted at regular intervals. The correlation of the light attenuation and mass emission requires the determination of the actual mass emission emitted from a particular

plant by means of isokinetic or Gravimetric dust sampling. This procedure must be conducted

over a range of plant operating conditions representative of the plant’s general operating

conditions and is referred to as a particulate emission monitor correlation or a dynamic calibration.

Stacklabs, an environmental testing laboratory, was contracted by Eskom to complete the required particulate emission monitor correlations on Units No. 1, 2, 4, 5 & 6. In addition to

the five particulate emissions monitor correlations, Stacklabs was also contracted to conduct

particulate emission measurements during a light up period on Unit No. 4 and a shutdown period on Unit No. 6.

All required site measurements for the five correlations, the light up and shutdown

measurements were carried out during the period from December 2015 to July 2016. The relevant results and correlation graphs have been presented in this report and may be

summarised as follows:

VI

Report Summary

Units No. 1, 2, 4, 5 & 6 Particulate Emission Monitor Correlations

Unit No. 1

The following table presents the results of the particulate emission monitor’s indications from

Outputs No. 1 & 2 as well as the measured particulate emissions in mg/Nm3 (dry) @ 10% O2.

The measurements listed below were all included in the final correlations for Unit No. 1.

Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

March 2016

Correlation

Measured Dust Mass

Test No. mA mA mg/Nm3 (dry) @ 10% O2

1 10.3 5.0 32.8

2 10.3 4.9 38.5

3 13.8 5.5 45.5

4 14.5 5.6 58.1

5 12.5 5.3 39.7

6 6.5 4.4 12.9

7 10.9 5.0 43.8

8 8.3 4.6 25.7

9 6.5 4.4 12.6

10 7.9 4.6 29.6

11 7.3 4.5 22.9

All particulate emissions reported as mg/Nm3 Dry corrected to 10% O2. The final correlation includes three zero points as described in ISO 10155.

Unit No. 1 Particulate Emission Monitor Correlation Equations

Lethabo Power Station Unit No. 1

March 2016 Correlations

Issued Date Function Correlation *MME Monitor

Output

No. yyyy/mm/dd

mg/Nm3(d) @ 10% O2

= m * mA + c Coefficient

mg/Nm3(d)

@ 10% O2

Range

Extinction

1 2016/04/26 5.1455 * mA – 18.5028 0.97 58.1 0 to 0.3

2 2016/04/26 34.3035 * mA – 135.1348 0.97 58.1 0 to 2.0

VII

Unit No. 1 Air flow to gas flow correlation

The following table presents the results of the plant recorded total Air Flow indication (kg/s)

as well as the measured Gas Flow results (Nm3 (dry) @ 10% O2).

Recorded Total Air Flow

Measured Gas Flow

Test No. kg/s Nm3 (dry) @ 10% O2

1 611.5 719.3

2 621.9 725.3

3 619.2 697.8

4 622.5 702.0

5 622.5 705.9

6 532.6 567.3

7 521.4 566.0

8 525.4 585.6

9 427.5 472.3

10 440.4 478.8

11 438.0 476.2

Gas Flow reported as Nm3/ s Dry corrected to 10% O2



March 2016 Correlation

Issued Date Function Correlation *MMGF Monitor

Output

No. yyyy/mm/dd

Nm3/s (d) @ 10% O2

= m * kg/s Air Flow + c Coefficient

Nm3/s (d)

@ 10% O2

Range

n/a 2014/04/26 1.1331 * Air Flow (kg/s)

– 5.9209 0.998 725.3 n/a


*MMGF: Maximum Measured Gas Flow during correlation period

VIII

Unit No. 2



The measurements listed below were all included in the final correlations for Unit No. 2

except where indicated.

Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

Dec 2015

Correlation

Measured Dust Mass


1 18.9 6.2 83.3

2 >20.0* 6.6 77.7

3 14.5 5.6 63.0

4 18.4 6.2 79.0

5 >20.0* 6.6 89.8

6 16.3 5.8 67.3

7 19.3 6.3 79.7

8 >20.0* 6.7 91.2

10 6.4 4.4 15.5

11 6.3 4.3 13.7

12 7.7 4.6 15.2

13 6.0 4.3 11.6


*Measurements No. 5 & 8 were excluded from the Correlation on Output No. 1 due to signal

saturation. Measurement No. 9 was excluded from Output No. 1 & 2 Correlations due to burst filter.



December 2015 Correlations


Output

No. yyyy/mm/dd

mg/Nm3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2

Range

Extinction

1 2016/02/23 5.4767 * mA – 21.7274 0.99 83.3 0 to 0.3

2 2016/02/23 34.3566 * mA – 136.2854 0.99 91.2 0 to 2.0

IX





Measured Gas Flow


1 651.4 736.4

2 657.8 766.9

3 661.7 759.9

4 652.7 773.2

5 649.7 784.1

6 649.3 735.1

7 653.7 774.7

8 650.4 772.1

9 541.3 592.1

10 538.1 536.1

11 543.4 540.4

12 540.3 545.2

13 546.7 547.4

14 536.6 548.1



December 2015 Correlation


Output

No. yyyy/mm/dd

Nm3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2

Range

n/a 2016/02/23 1.1457 * Air Flow (kg/s)

– 17.4328 0.99 784.1 n/a



X

Unit No. 4




Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

June 2016

Correlation

Measured Dust Mass


1 29.0* 7.8 126.3

2 28.2* 7.6 110.9

3 18.7 6.2 67.1

4 21.1* 6.6 61.5

5 20.8* 6.5 90.1

6 18.4 6.2 58.4

7 20.9* 6.5 72.9

8 13.7 5.4 37.9

9 15.0 5.7 53.3

10 14.2 5.5 52.3

11 15.1 5.7 54.8

12 22.3* 6.7 96.8


*mA on Output 1 for Measurements No. 1, 2, 4, 5, 7 & 12 were extrapolated from Output 2’s results on request of customer.



June 2016 Correlations


Output No.

yyyy/mm/dd mg/Nm

3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2 Range

Extinction

1 2016/07/01 4.4949 * mA – 17.4959 0.99 67.1 0 to 0.3

2 2016/07/01 31.7272 * mA – 128.2120 0.98 126.3 0 to 2.0

XI





Measured Gas Flow


1 616.5 747.9

2 618.8 766.4

3 618.7 804.8

4 601.0 799.6

5 605.9 817.8

6 608.2 822.6

7 608.8 783.6

8 514.7 652.0

9 532.5 640.0

10 452.7 494.2

11 435.1 492.1

12 434.2 491.7



June 2016 Correlation


Output No.

yyyy/mm/dd Nm

3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2 Range

n/a 2016/07/01 1.2879 * Air Flow (kg/s)

– 16.5418 0.99 822.6 n/a



XII

Unit No. 5




except where indicated.

Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

Dec 2015

Correlation

Measured Dust Mass


1 >20.0* 8.3 113.4

2 >20.0* 8.3 114.7

3 >20.0* 8.4 120.4

4 >20.0* 8.0 110.3

5 >20.0* 9.1 144.0

6 >20.0* 8.9 135.7

7 18.2 6.1 77.3

8 >20.0* 6.9 88.2

9 >20.0* 7.0 97.4

10 >20.0* 6.5 80.4

11 >20.0* 8.0 109.6

12 19.1 6.3 65.8

13 >20.0* 8.0 123.1

14 >20.0* 6.7 80.9

15 19.8 6.4 71.6

All particulate emissions reported as mg/Nm3 Dry corrected to 10% O2. The final correlation includes three zero points as described in ISO 10155. *Measurements No. 1 to 6, 8 to 11, 13 & 14 were excluded from the Correlation on Output No. 1 due

to signal saturation.



Dec 2015 Correlations


Output No.

yyyy/mm/dd mg/Nm

3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2 Range

Extinction

1 2016/02/23 4.7217 * mA – 18.6368 0.90 77.3 0 to 0.3

2 2016/02/23 27.1495 * mA – 103.0318 0.99 144 0 to 2.0

XIII





Measured Gas Flow


1 609.1 638.8

2 610.4 637.9

3 603.8 650.2

4 605.4 668.0

5 606.6 644.7

6 599.1 673.6

7 532.3 581.9

8 520.7 593.2

9 516.8 571.8

10 498.0 626.8

11 474.9 569.2

12 500.5 617.0

13 450.9 548.1

14 447.1 552.6

15 491.6 593.2





Output No.

yyyy/mm/dd Nm

3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2 Range

n/a 2016/02/23 1.0984 * Air Flow (kg/s)

– 17.0016 0.99 673.6 n/a



XIV

Unit No. 6




except as indicated.

Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

Dec 2015

Correlation

Measured Dust Mass


1 >20.0* 9.4 155.6

2 >20.0* 9.8 165.7

3 >20.0* 9.5 141.3

4 >20.0* 8.5 120.4

5 >20.0* 9.2 137.1

6 >20.0* 10.5 172.3

7 10.6 5.0 23.0

8 11.6 5.1 25.1

9 9.9 4.9 18.7

10 16.6 5.9 44.8

11 13.8 5.5 30.6

12 15.8 5.8 42.0

13 >20.0* 8.0 121.4

14 10.6 5.0 23.4

15 12.3 5.2 25.8

All particulate emissions reported as mg/Nm3 Dry corrected to 10% O2. The final correlation includes three zero points as described in ISO 10155. *Measurements No. 1 to 6 & 13 were excluded from the Correlation on Output No. 1 due to signal

saturation.





Output

No. yyyy/mm/dd

mg/Nm3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2

Range

Extinction

1 2016/02/23 3.4385 * mA – 14.1750 0.99 44.8 0 to 0.3

2 2016/02/23 28.0913 * mA – 116.7179 0.99 172.3 0 to 2.0

XV





Measured Gas Flow


1 609.1 638.8

2 610.4 637.9

3 603.8 650.2

4 605.4 668.0

5 606.6 644.7

6 599.1 673.6

7 532.3 581.9

8 520.7 593.2

9 516.8 571.8

10 498.0 626.8

11 474.9 569.2

12 500.5 617.0

13 450.9 548.1

14 447.1 552.6

15 491.6 593.2





Output No.

yyyy/mm/dd Nm

3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2 Range

n/a 2016/02/23 1.0984 * Air Flow (kg/s)

– 17.0016 0.99 673.6 n/a



XVI

Unit No. 4 Start-up Measurements

The following table presents the conditions as captured during the boiler Light up on Unit No.

4 on the 16th of March 2016. The table presents the boiler load in MW, particulate emission

monitor’s indications from Output No. 2 and the measured particulate emissions in mg/Nm3

(dry) @ 10% O2.

Boiler

Load

Stack

Oxygen

Monitor Output

(0 to 2 Ext)

Output No.2

2015

Correlation

Measured Dust

Mass

2015

Correlation

Measured Dust

Mass

Test No. MW % mA mg/Nm3 (dry)

@ 10% O2 mg/Nm3 (dry) @ Stack O2

1 0.0 12.2 >20.0* 828.1 638.0

2 0.0 11.7 >20.0* 3841.9 3242.9

3 370.0 7.9 >20.0* 2557.2 3043.5

Unit No. 6 Shutdown Measurement Results

The following table presents the conditions as captured during the boiler shutdown on Unit No. 6 on the 27

th & 28

th of June 2016. The table presents the boiler load in MW, stack gas

oxygen concentration in % v/v, particulate emission monitor’s indications from Output No. 2

and the measured particulate emissions in mg/Nm3 (dry) @ 10% O2 & mg/Nm

3 (dry) @ the

actual stack gas oxygen concentrations.

Boiler

Load

Stack

Oxygen

Monitor Output

(0 to 2 Ext)

Output No.2

2015

Correlation

Measured Dust

Mass

2015

Correlation

Measured Dust

Mass


@ 10% O2

mg/Nm3 (dry)

@ Stack O2

1 0.0 13.6 >20.0* 11353.1* 7608.3

2 0.0 20.6 >20.0* 173 559.6* 6311.3

The particulate emissions reported as mg/Nm3 Dry corrected to 10% O2 are not a true representation of

the concentrations due to the high stack gas oxygen concentrations.

Report Recommendations

It is recommended that:

The particulate emissions from Units No. 1 to 6 reported to the authorities, are according to the correlation function presented in Figures No. 1 & 2 of this report.

The next compliant correlation is conducted on Unit No 3 during the first quarter of 2016.

Lethabo Power Station Units No 1, 2, 4, 5 & 6 Emissions Dec 2015 to June 2016 Report No. RSL222 Page 1 of 131

1. Monitoring Objective

The primary objective of the particulate emission monitor correlations presented in this report

is to quantify the concentrations of all particulate matter released into the atmosphere during the

operations of Units No. 1, 2, 4, 5 & 6 at Lethabo Power Station.

The requirement for conducting the particulate emission monitor correlations is to demonstrate

compliance with the requirements of the National Environmental Management: Air Quality Act

(39/2004), Listed Activities and Associated Minimum Emission Standards in terms of Section 21, Category 1.1. The substance applicable under Category 1.1 is Particulate Matter which is

capped at 100 mg/Nm3 dry @ 10% O2. This cap limit however, in the case of Lethabo Power

Station, was negotiated to 100 mg/Nm3 dry @ 10% O2.

The objective of the particulate emission measurements surveys that were conducted during the

unit light up and shutdown periods on Units No. 4 & 6 respectively, was to quantify the concentrations of all particulate matter released into the atmosphere during the unit light up and

shutdown periods.

The requirement for conducting the particulate emission survey during the light up and shutdown periods has been set in the Stations Atmospheric Licence.

2. Plant Description & General Operating Procedure

2.1. The pulverised fuel steam generating boilers on which the particulate emission monitor correlations, light up and shutdown measurements were conducted, were originally designed

for a maximum steam flow of 600 MW. These units were originally equipped with four

parallel Brandt / Babcock electrostatic precipitators with a design capacity of 997 Am3/s gas

flow and a performance collecting efficiency of 99.88%. The electrostatic precipitators were later retro-fitted with sulphur trioxide flue gas conditioning and recently upgraded with high

frequency transformers on the first five fields.

Electrostatic Precipitator Design Data for Unit under Test (original Design)

Description @ 97 % MCR

Number of ESPs in use 4

Gas Volume Flow Rate Worst Coal 997 m3/s

Gas Temperature 132°C

Inlet Dust Burden 34.9 g/Nm3

Outlet Dust Burden n/a mg/Nm3

Carbon in Dust 2%

Sulphur in Coal n/a%

Pressure Drop 0.25Kpa

Temperature Drop 11°C


2.2. During the emission surveys, the particulate emission measurements were conducted through purpose built ports situated on the unit’s stacks at a level approximately 150m above ground

level. For a diagrammatic representation of the test positions, see the following sketch.

Measurements were conducted along sections Q—Q.

2.3. The operating regime followed during the survey periods included all significant activities that arise during normal production as well as some fault conditions. The correlation included measurements at the following Boiler Loads:

Measurement

No. Unit No. 1 Unit No. 2 Unit No. 4 Unit No. 5 Unit No. 6

Load (MW) Load (MW) Load (MW) Load (MW) Load (MW)

1 609.4 561.4 618.7 601.5 614.6

2 609.3 561.7 618.8 601.4 614.9

3 609.7 561.5 618.7 601.5 614.8

4 609.8 561.7 618.1 602.3 615.1

5 609.5 562.0 618.1 601.2 615.1

6 500.3 562.4 618.6 601.0 614.9

7 500.3 562.5 605.0 502.7 421.2

8 500.1 562.5 500.2 502.7 421.3

9 400.6 401.9 500.0 490.3 373.6

10 400.5 401.9 375.1 494.7 491.8

11 400.7 401.8 375.2 452.0 491.9

12 - 398.7 375.1 495.4 491.9

13 - 398.6 - 450.3 448.0

14 - 398.5 - 450.4 448.0

15 - - - 487.0 485.1

S/S 1 - - 0.0 - 330.0 to 0.0

S/S 2 - - 0.0 - 0

S/S 3 - - 0 to 378.0 - -

S/S Start-up & Shutdown Measurements

For additional information of the plant parameters please see Appendix No. 2.


3. Methods & Procedures The method selected for the determination of the particulate emission concentration on Units

No. 1, 2, 4, 5 & 6 was in compliance with ISO 12141 Stationary source emissions -

Determination of concentration of particulate matter (dust) at low concentrations – Manual gravimetric method.

This general method can be briefly described as follows:

A sharp-edged nozzle is positioned in the duct facing into the moving gas stream and a sample

flow of the gas is extracted isokinetically for a measured period of time. To allow for non-

uniformity of the distribution of particulate concentration in the duct, samples are taken at a pre-selected number of stated positions in the duct cross-section. The particulate matter

entrapped in the gas sample is separated by a filter medium, then dried and weighed. The

particulate concentration is calculated from the weighed particulate mass and the gas sample volume. The particulate mass flow rate is calculated from the particulate concentration and

the duct gas volumetric flow rate. The particulate mass flow rate can also be calculated from

the weighed particulate matter, the sample time, the area of the sample plane and the nozzle

opening.

The degree to which this sample represents the total gas flow depends on

Homogeneity of the gas velocity within the sampling plane;

A sufficient number of sampling points in the sampling plane;

Isokinetic withdrawal of the plane

As stated above, the gas has to be sampled at more than one sampling point in the sampling

plane, dependant on the sampling plane area. This plane is normally divided into equal areas, at the centres of which gas is withdrawn. To determine the particle concentration in the plane,

the nozzle is moved from one sampling point to the other, extracting gas isokinetically at each

point. Sampling periods should be equal for each sampling point, resulting in a composite

sample. If equal sampling areas cannot be chosen, the sampling period shall be proportional to the sampling area. The sample is extracted through a sampling train, which principally

consists of:

A sampling probe tube with entry nozzle;

A particle separator;

A gas metering system, in-stack or external;

A suction system

The particle separator and / or the gas metering system may be located either in the duct, or

placed outside the duct.

It is necessary to avoid condensation of vapour in the sampling train during gas sampling,

because it will interfere with particle separation, particulate condition and flow measurements.

To this end, the probe tube, the particle separator and the gas flow-measuring device may be heated above the relevant dew point where necessary. The water vapour may intentionally be

removed downstream of the particle separator, to make use of a dry gas meter for the

measurement of sampled gas volume.

For isokinetic sampling, the gas velocity at the sampling point in the duct has to be measured,

and the corresponding sample gas flow has to be calculated and adjusted.

Normally a Pitot static tube is used for the measurement of duct gas velocity. If the sample gas

flow-measuring device is used within the duct, the relationship between the measured pressure

drop and the pitot static tube differential pressure is simple, facilitating the adjustment to


isokinetic conditions. If the gas meter device is situated outside the duct, the calculation of the

isokinetic sample gas flow rate is more complicated. The calculation may also include the duct gas density under standard conditions (which may be derived from the dry gas composition and

the moisture content), the temperature, static pressure of the gas in the duct, the gas meter

device, and the water vapour content of the duct gas, if the sample gas flow is measured after water removal.

After sampling, the collected particulate matter is completely recovered, dried and weighed and

the concentrations are determined.

All Stacklabs isokinetic sampling is carried out employing procedures and equipment that

comply with the requirements of ISO 9096 12141 1992 (Reference 1). All Stacklabs sampling equipment is calibrated by SANAS accredited laboratories.

Lethabo personnel were responsible for the setting of the plant prior to the test period. Stacklabs was contracted to provide the service of particulate emission monitors correlation

through isokinetic dust sampling only.

The broad outlines of filter weighing, pre-test preparations, sampling system integrity checks and sampling procedures are discussed in Appendix No 3.


4. Results 4.1. Unit No. 1

The following table presents the results of the particulate emission monitor’s indications from Outputs No. 1 & 2 as well as the measured particulate emissions in mg/Nm

3 (dry) @ 10% O2.

The measurements listed below were all included in the final particulate emission monitor

correlations for Unit No. 1.

Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

March 2016

Correlation

Measured Dust Mass


1 10.3 5.0 32.8

2 10.3 4.9 38.5

3 13.8 5.5 45.5

4 14.5 5.6 58.1

5 12.5 5.3 39.7

6 6.5 4.4 12.9

7 10.9 5.0 43.8

8 8.3 4.6 25.7

9 6.5 4.4 12.6

10 7.9 4.6 29.6

11 7.3 4.5 22.9






Output

No. yyyy/mm/dd

Nm3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2

Range

n/a 2014/04/26 1.1331 * Air Flow (kg/s)

– 5.9209 0.998 725.3 n/a





The following table presents the results of the plant recorded total Air Flow indication (kg/s) as

well as the measured Gas Flow results (Nm3 (dry) @ 10% O2).


Measured Gas Flow


1 611.5 719.3

2 621.9 725.3

3 619.2 697.8

4 622.5 702.0

5 622.5 705.9

6 532.6 567.3

7 521.4 566.0

8 525.4 585.6

9 427.5 472.3

10 440.4 478.8

11 438.0 476.2





Output

No. yyyy/mm/dd

Nm3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2

Range

n/a 2014/04/26 1.1331 * Air Flow (kg/s)

– 5.9209 0.998 725.3 n/a




4.2. Unit No. 2



The measurements listed below were all included in the final correlations for Unit No. 2 except where indicated.

Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

Dec 2015

Correlation

Measured Dust Mass


1 18.9 6.2 83.3

2 >20.0* 6.6 77.7

3 14.5 5.6 63.0

4 18.4 6.2 79.0

5 >20.0* 6.6 89.8

6 16.3 5.8 67.3

7 19.3 6.3 79.7

8 >20.0* 6.7 91.2

10 6.4 4.4 15.5

11 6.3 4.3 13.7

12 7.7 4.6 15.2

13 6.0 4.3 11.6


*Measurements No. 5 & 8 were excluded from the Correlation on Output No. 1 due to signal

saturation. Measurement No. 9 was excluded from Output No. 1 & 2 Correlations due to burst filter.





Output

No. yyyy/mm/dd

mg/Nm3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2

Range

Extinction

1 2016/02/23 5.4767 * mA – 21.7274 0.99 83.3 0 to 0.3

2 2016/02/23 34.3566 * mA – 136.2854 0.99 91.2 0 to 2.0






Measured Gas Flow


1 651.4 736.4

2 657.8 766.9

3 661.7 759.9

4 652.7 773.2

5 649.7 784.1

6 649.3 735.1

7 653.7 774.7

8 650.4 772.1

9 541.3 592.1

10 538.1 536.1

11 543.4 540.4

12 540.3 545.2

13 546.7 547.4

14 536.6 548.1





Output No.

yyyy/mm/dd Nm

3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2 Range

n/a 2016/02/23 1.1457 * Air Flow (kg/s)

– 17.4328 0.99 784.1 n/a




4.3. Unit No. 4




Monitor Output

(0 to 0.3 Ext)

Output No. 1

Monitor Output

(0 to 2 Ext)

Output No.2

June 2016

Correlation

Measured Dust Mass


1 29.0* 7.8 126.3

2 28.2* 7.6 110.9

3 18.7 6.2 67.1

4 21.1* 6.6 61.5

5 20.8* 6.5 90.1

6 18.4 6.2 58.4

7 20.9* 6.5 72.9

8 13.7 5.4 37.9

9 15.0 5.7 53.3

10 14.2 5.5 52.3

11 15.1 5.7 54.8

12 22.3* 6.7 96.8


*mA on Output 1 for Measurements No. 1, 2, 4, 5, 7 & 12 were extrapolated from Output 2’s results on

request of customer.



June 2016 Correlations


Output

No. yyyy/mm/dd

mg/Nm3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2

Range

Extinction

1 2016/07/01 4.4949 * mA – 17.4959 0.99 67.1 0 to 0.3

2 2016/07/01 31.7272 * mA – 128.2120 0.98 126.3 0 to 2.0






Measured Gas Flow


1 616.5 747.9

2 618.8 766.4

3 618.7 804.8

4 601.0 799.6

5 605.9 817.8

6 608.2 822.6

7 608.8 783.6

8 514.7 652.0

9 532.5 640.0

10 452.7 494.2

11 435.1 492.1

12 434.2 491.7



June 2016 Correlation


Output

No. yyyy/mm/dd

Nm3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2

Range

n/a 2016/07/01 1.2879 * Air Flow (kg/s)

– 16.5418 0.99 822.6 n/a




4.4. Unit No. 5



The measurements listed below were all included in the final correlations for Unit No. 5 except

where indicated.

Monitor Output (0 to 0.3 Ext)

Output No. 1

Monitor Output (0 to 2 Ext)

Output No.2

Dec 2015 Correlation

Measured Dust Mass


1 >20.0* 8.3 113.4

2 >20.0* 8.3 114.7

3 >20.0* 8.4 120.4

4 >20.0* 8.0 110.3

5 >20.0* 9.1 144.0

6 >20.0* 8.9 135.7

7 18.2 6.1 77.3

8 >20.0* 6.9 88.2

9 >20.0* 7.0 97.4

10 >20.0* 6.5 80.4

11 >20.0* 8.0 109.6

12 19.1 6.3 65.8

13 >20.0* 8.0 123.1

14 >20.0* 6.7 80.9

15 19.8 6.4 71.6


*Measurements No. 1 to 6, 8 to 11, 13 & 14 were excluded from the Correlation on Output No. 1 due

to signal saturation.



Dec 2015 Correlations


Output

No. yyyy/mm/dd

mg/Nm3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2

Range

Extinction

1 2016/02/23 4.7217 * mA – 18.6368 0.90 77.3 0 to 0.3

2 2016/02/23 27.1495 * mA – 103.0318 0.99 144 0 to 2.0



The following table presents the results of the plant recorded total Air Flow indication (k/s) as



Measured Gas Flow


1 609.1 638.8

2 610.4 637.9

3 603.8 650.2

4 605.4 668.0

5 606.6 644.7

6 599.1 673.6

7 532.3 581.9

8 520.7 593.2

9 516.8 571.8

10 498.0 626.8

11 474.9 569.2

12 500.5 617.0

13 450.9 548.1

14 447.1 552.6

15 491.6 593.2





Output

No. yyyy/mm/dd

Nm3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2

Range

n/a 2016/02/23 1.0984 * Air Flow (kg/s)

– 17.0016 0.99 673.6 n/a




4.5. Unit No. 6



The measurements listed below were all included in the final correlations for Unit No. 6 except

as indicated.

Monitor Output (0 to 0.3 Ext)

Output No. 1

Monitor Output (0 to 2 Ext)

Output No.2

Dec 2015 Correlation

Measured Dust Mass


1 >20.0* 9.4 155.6

2 >20.0* 9.8 165.7

3 >20.0* 9.5 141.3

4 >20.0* 8.5 120.4

5 >20.0* 9.2 137.1

6 >20.0* 10.5 172.3

7 10.6 5.0 23.0

8 11.6 5.1 25.1

9 9.9 4.9 18.7

10 16.6 5.9 44.8

11 13.8 5.5 30.6

12 15.8 5.8 42.0

13 >20.0* 8.0 121.4

14 10.6 5.0 23.4

15 12.3 5.2 25.8


*Measurements No. 1 to 6 & 13 were excluded from the Correlation on Output No. 1 due to signal

saturation.





Output

No. yyyy/mm/dd

mg/Nm3(d) @ 10% O2


mg/Nm3(d)

@ 10% O2

Range

Extinction

1 2016/02/23 3.4385 * mA – 14.1750 0.99 44.8 0 to 0.3

2 2016/02/23 28.0913 * mA – 116.7179 0.99 172.3 0 to 2.0



The following table presents the results of the plant recorded total Air Flow indication (k/s) as



Measured Gas Flow


1 609.1 638.8

2 610.4 637.9

3 603.8 650.2

4 605.4 668.0

5 606.6 644.7

6 599.1 673.6

7 532.3 581.9

8 520.7 593.2

9 516.8 571.8

10 498.0 626.8

11 474.9 569.2

12 500.5 617.0

13 450.9 548.1

14 447.1 552.6

15 491.6 593.2





Output

No. yyyy/mm/dd

Nm3/s (d) @ 10% O2


Nm3/s (d)

@ 10% O2

Range

n/a 2016/02/23 1.0984 * Air Flow (kg/s)

– 17.0016 0.99 673.6 n/a




4.6. Unit No. 4 Light up Measurement Results

The following table presents the conditions as captured during the boiler Light up on Unit No. 4

on the 16th

of March 2016. The table presents the boiler load in MW, particulate emission monitor’s indications from Output No. 2 and the measured particulate emissions in mg/Nm

3

(dry) @ 10% O2.

Boiler

Load

Stack

Oxygen

Monitor Output

(0 to 2 Ext)

Output No.2

2015 Correlation

Measured Dust

Mass

2015 Correlation

Measured Dust

Mass


@ 10% O2

mg/Nm3 (dry)

@ Stack O2

1 0.0 12.2 >20.0* 828.1 638.0

2 0.0 11.7 >20.0* 3841.9 3242.9

3 370.0 7.9 >20.0* 2557.2 3043.5

4.7. Unit No. 6 Shutdown Measurement Results

The following table presents the conditions as captured during the boiler shutdown on Unit No.

6 on the 27th & 28

th of June 2016. The table presents the boiler load in MW, stack gas oxygen

concentration in % v/v, particulate emission monitor’s indications from Output No. 2 and the measured particulate emissions in mg/Nm

3 (dry) @ 10% O2 & mg/Nm

3 (dry) @ the actual stack

gas oxygen concentrations.

Boiler

Load

Stack

Oxygen

Monitor Output

(0 to 2 Ext)

Output No.2

2015 Correlation

Measured Dust

Mass

2015 Correlation

Measured Dust

Mass


@ 10% O2

mg/Nm3 (dry)

@ Stack O2

1 0.0 13.6 >20.0* 11353.1* 7608.3

2 0.0 20.6 >20.0* 173 559.6* 6311.3

The particulate emissions reported as mg/Nm3 Dry corrected to 10% O2 are not a true representation of

the concentrations due to the high stack gas oxygen concentrations.

The detailed results of the correlation measurements for Units No 1, 2, 4, 5 & 6 have been

presented in the following Tables:

Appendix No. 1 Detailed Measurement Results

Appendix No. 2 Plant parameters

Appendix No. 3 Correlations Graphs

Appendix No. 7 Particle Size Analysis Appendix No. 8 Filter Mass Sheets


The following abbreviations were used in the text, tables and figures:

MCR Maximum Continuous Rating °C Degrees Celsius

% v/v Percentage on a Volume-by-Volume basis

Am3 Actual Cubic Metres

Nm3 Normal Cubic Metres

g/s Grams per second

mg/s Milligrams per second

Fo Fields out ESP Electrostatic Precipitator

FFP Fabric Filter Plant

ext. Extinction mg/Nm

3 (d) @ 10% O2 Milligrams per Normal cubic meters dry corrected to 10% Oxygen

• ‘Actual’ refers to the measured temperature and pressure conditions of the gases in the duct

• ‘Normal’ refers to the actual conditions being normalised to 0 °C and 101,325 kPa.


5. Discussion

5.1. Unit No. 1 Particulate Emission Correlation

The correlation on Unit No 1 was completed form the 9th to the 19

th of March 2016. A total of

eleven measurements were conducted of which all eleven measurements were included in the

final particulate emission monitor correlations. The following trends indicate the particulate

emission monitor signals captured during Measurement No. 1 on the 9th of March with 609

MW boiler loading and the Measurement No. 10 on the 19th

of March with 400 MW boiler loading.


The outputs settings of all the particulate emission monitors included in this report have been

set for 0 to 0.03 extinction on Output No. 1 and 0 to 2.0 extinction on Output No. 2.

The measured particulate emission concentrations on Unit No. 1 ranged from 12.6 to 58.1 mg/Nm

3 Dry @ 10% O2, well below the negotiated cap value of 100 mg/Nm

3 Dry @ 10% O2.

The corresponding particulate emission monitor signals, recorded from Output No. 1, ranged

from 6.5 to 14.5 mA. The resulting co-ordinates produced the following correlation with a correlation coefficient of 0.974, which falls within the standards tolerance of 0.95 to 1.05.

4

6

8

10

12

14

16

18

20

Mo

nit

or

Ou

tpu

t (m

A)

Lethabo Unit No. 1 TPM Monitor Output Data (mA) Measurement No. 10 Output No. 2


A correlation derived for Output No. 2 based on the monitor settings of 0 to 2.0 extinction is

presented in the following Figure. This correlation also complies with the requirements of the ISO 10155, and includes the cap limit of 100 mg/Nm

3 Dry @ 10% O2.


5.2. Unit No. 1 Airflow to Gas Flow Correlation In addition to the measurement of the particulate emissions, gas volume flow rates were also

determined during this correlation period. The measured gas volume flow rates, which ranged

from 472.3 to 725.3 Nm3/s Dry @ 10% O2, were correlated against the plants corresponding

Total Air flow Rates to produce the following correlation with a coefficient of 0.998.

The following trends indicate Boiler load and Total Air Flow captured during Measurement No. 1 and demonstrates the typical load and air flow stability experienced during the correlation

period.


Plant parameters and trends for each measurement have been presented in Appendix No. 3.

The corresponding stack gas velocity data captured during Measurement No. 1 produced the

following profile.

The minimum, maximum and average gas velocity for this measurement was recorded as 27.8,

34.6 and 31.8 m/s respectively. The minimum and maximum deviation from the Average

velocity is therefore 12.7 & 8.8 % respectively.



The correlation on Unit No 2 was completed from the 19th to the 23

rd of December 2015. A

total of thirteen measurements were conducted of which only eight measurements were included in the final particulate emission monitor correlation for Output No. 1 and twelve for

the correlation for Output No. 2. Measurements No. 2, 5, 8 & 9 were excluded from the

correlation for Output No. 1 as a result of monitor signal saturation on the first output.

Measurement No. 9 was excluded from the correlations for Outputs No. 1 & 2 as a result of a burst filter.

The following trends indicate the particulate emission monitor signals captured during Measurement No. 5 on the 20

th of December with 562 MW boiler loading. The trends show the

saturated signal on Output No. 1 and the normal trend from Output No. 2.

The outputs settings have been set to 0 to 0.03 extinction on Output No. 1 and 0 to 2.0

extinction on Output No. 2.

4

6

8

10

12

14

16

18

20

Par

ticu

late

Em

issi

on

(mA

)

Lethabo Power Station Units No. 2 Measurement No. 5 Stack Emission Dust Emission mA Output 1


The measured particulate emission concentrations on Unit No. 2, included in the correlation for

Output No. 1, ranged from 11.6 to 83.3 mg/Nm3 Dry @ 10% O2 and for output No. 2 ranged

from 11.6 to 91.2 mg/Nm3 Dry @ 10% O2. The maximum measured emission of 91.2 mg/Nm

3

Dry @ 10% O2 was below the negotiated cap value of 100 mg/Nm3 Dry @ 10% O2. The

corresponding particulate emission monitor signals, recorded from Output No. 1, ranged from 6.0 to 19.3 mA. The resulting co-ordinates produced the following correlation with a

correlation coefficient of 0.997, which falls within the standards tolerance of 0.95 to 1.05.



3 Dry @ 10% O2.


5.4. Unit No. 2 Airflow to Gas Flow Correlation

In addition to the measurement of the particulate emissions, gas volume flow rates were also

determined during this correlation period. The measured gas volume flow rates, which ranged from 536.1 to 784.1 Nm

3/s Dry @ 10% O2, were correlated against the plants corresponding


The following trends indicate Boiler load and Total Air Flow captured during Measurement No.

1 and demonstrates the typical load and air flow stability experienced during the correlation

period.




following profile.

The minimum, maximum and average gas velocity for this measurement was recorded as 29.0

33.6 and 31.8 m/s respectively. The minimum and maximum deviation from the Average




The correlation on Unit No 4 was completed form the 13th to the 17

th of June 2016. A total of

twelve measurements were conducted of which six measurements were included in the final particulate emission monitor correlation for Output No. 1 and twelve for the correlation for

Output No. 2. Measurements No. 1, 2, 4, 5, 7 &12 were excluded from the correlation for

Output No. 1 as a result of monitor signal saturation on the first output.

The following trends indicate the particulate emission monitor signals captured during

Measurement No. 7 on the 15th of June 2016 with 619 MW boiler loading. The trends show the

saturated signal on Output No. 1 and the normal trend from Output No. 2.





from 37.9 to 126.3 mg/Nm3 Dry @ 10% O2. The maximum measured emission of 126.3

mg/Nm3 Dry @ 10% O2 was above the negotiated cap value of 100 mg/Nm

3 Dry @ 10% O2.


from 13.7 to 18.7 mA. The resulting co-ordinates produced the following correlation with a



A correlation derived for Output No. 2 based on the monitor settings of 0 to 2.0 extinction is presented in the following Figure. This correlation also complies with the requirements of the

ISO 10155, and includes the cap limit of 100 mg/Nm3 Dry @ 10% O2.









period.




following profile.


34.8 & 31.8 m/s respectively. The minimum and maximum deviation from the Average



5.7. Unit No. 4 Particulate Matter Size Distribution In addition to the correlations for the particulate emissions and the gas flows, a set of extended

measurements were conducted on Unit No. 4 during the 23rd

and 24th

of March of 2016. The

purpose of these extended measurements was to provide sufficient particulate matter, from the stack gas, for a particle size analysis. The collated particulates from all the measurements

conducted on the 23rd

and 24th of March were combined into one sample. The following figure

and tables, take from the lab report, presents the particle size distribution determined from this

sample.


The results show that approximately 20% of the particles fall below 1 µm, 63% fall below 2.5

µm and 95% fall below 10µm. The remaining 5% of particles fall between 10 and 100 µm.

The full lab sheet has been presented in Appendix No. 8.


The correlation on Unit No 5 was completed form the 12th

to the 17th of December 2015. A

total of fifteen measurements were conducted of which only three measurements were included

in the final particulate emission monitor correlation for Output No. 1. All fifteen measurements were however included in the correlation for Output No. 2. Only data from Measurements No.

7, 12 & 15 could be included in the correlation for Output No. 1 as these were the only three

measurements where the monitor signal did not saturate the first output.


Measurement No. 1 on the 12th of December 2015 with 602 MW boiler loading. The trends

show the saturated signal on Output No. 1 and the normal trend from Output No. 2.


The outputs settings have been set to 0 to 0.03 extinction on Output No. 1 and 0 to 2.0 extinction on Output No. 2.





3 Dry @ 10% O2.






presented in the following Figure. This correlation also complies with the requirements of the

ISO 10155, and includes the cap limit of 100 mg/Nm3 Dry @ 10% O2.









period.



The corresponding stack gas velocity data captured during Measurement No. 5 produced the following profile.

The minimum, maximum and average gas velocity for this measurement was recorded as 22.3, 28.6 & 25.6 m/s respectively. The minimum and maximum deviation from the Average




The correlation on Unit No 6 was completed form the 12th

to the 17th of December 2015. A

total of fifteen measurements were conducted of which eight measurements were included in

the final particulate emission monitor correlation for Output No. 1. All fifteen measurements were however included in the correlation for Output No. 2. Measurements No. 1 to 6 & 13

were excluded from the correlation for Output No. 1 as a result of monitor signal saturation on

the first output.


Measurement No. 2 on the 12th of December 2015 with 602 MW boiler loading. The trends

show the saturated signal on Output No. 1 and the normal trend from Output No. 2.



The measured particulate emission concentrations on Unit No.6, included in the correlation for




3 Dry @ 10% O2.







3 Dry @ 10% O2.









period.




following profile.


37.7 & 33.8 m/s respectively. The minimum and maximum deviation from the Average



5.12. Unit No. 4 Start Up or Light Up Measurements

On the 16th of March 2016 a set of three measurements were conducted on Unit No. 4 during a

Unit Light Up/Start Up. The first two measurements were conducted prior to synchronisation

and the third during the load ramping from 130 to 350 MW. The following trends and tables show the Boiler Load, Ait flow & Mill PF flow variation during the measurement period.


Measurement No. 1

The following table presents the conditions as captured during Measurement No. 1.

Boiler Load

Stack Oxygen

Monitor Output

(0 to 2 Ext) Output No.2

2015

Correlation Measured Dust Mass

Test No. MW % mA mg/Nm3 (dry) @

Stack O2

1 0.0 12.2 >20.0 638.0

LoadMill A PF

flow

Mill B PF

flow

Mill C PF

flow

Mill D PF

flow

Mill E PF

flow

Mill F PF

flow

Total air

flow

Total air

flow

MW

US-

04NM10U

603-C153

US-

04NM20U

603-C157

US-

04NM30U

603-C161

US-

04NM40U

603-C165

US-

04NM50U

603-C169

US-

04NM60U

603-C173

US-

04NG00F6

00-C90

US-

04NG00F6

00-C90

Average 0.0 4.6 1.0 -0.4 3.4 -2.6 -0.2 272.9 272.9

Max 0.0 5.5 10.4 3.8 3.6 11.9 3.4 537.1 537.1

Min 0.0 3.2 -11.2 -34.3 1.2 -34.3 -30.8 118.8 118.8

11:45:00 0.0 4.8 -0.6 -34.3 1.2 -0.1 -30.8 340.8 340.8

11:50:00 0.0 3.3 3.8 -34.3 3.5 -5.0 -30.4 366.8 366.8

11:55:00 0.0 3.2 3.8 3.6 3.6 3.2 3.4 537.1 537.1

12:00:00 0.0 3.2 3.8 3.6 3.5 3.2 3.4 209.8 209.8

12:05:00 0.0 3.2 3.8 3.8 3.6 3.2 3.4 280.3 280.3

12:10:00 0.0 3.2 3.8 3.6 3.6 3.2 3.4 227.9 227.9

12:15:00 0.0 3.2 3.8 3.6 3.5 3.2 3.4 226.2 226.2

12:20:00 0.0 3.2 3.8 3.6 3.6 3.2 3.4 118.8 118.8

12:25:00 0.0 5.5 -10.6 3.6 3.6 -34.3 3.4 167.2 167.2

12:30:00 0.0 5.5 -11.2 3.6 3.5 -34.3 3.4 174.8 174.8

12:35:00 0.0 5.4 -7.2 3.6 3.5 -14.2 3.4 245.5 245.5

12:40:00 0.0 5.4 10.4 3.6 3.6 11.9 3.4 303.9 303.9

12:45:00 0.0 5.3 3.9 3.6 3.6 3.9 3.4 288.3 288.3

12:50:00 0.0 5.4 -7.0 3.6 3.6 -7.3 3.4 272.3 272.3

12:55:00 0.0 5.3 5.3 3.6 3.5 1.3 3.4 289.3 289.3

13:00:00 0.0 5.3 5.2 3.6 3.5 9.8 3.4 295.5 295.5

13:05:00 0.0 5.4 -2.8 3.6 3.5 -1.5 3.4 275.8 275.8

13:10:00 0.0 5.5 -0.3 3.6 3.5 -1.9 3.4 274.8 274.8

13:15:00 0.0 5.4 8.0 3.6 3.5 3.3 3.4 290.8 290.8


Measurement No. 2


Boiler

Load

Stack

Oxygen

Monitor Output

(0 to 2 Ext)

Output No.2

2015

Correlation

Measured Dust Mass


Stack O2

2 0.0 11.7 >20.0 3242.9

LoadMill A PF

flow

Mill B PF

flow

Mill C PF

flow

Mill D PF

flow

Mill E PF

flow

Mill F PF

flow

Total air

flow

MW

US-

04NM10U

603-C153

US-

04NM20U

603-C157

US-

04NM30U

603-C161

US-

04NM40U

603-C165

US-

04NM50U

603-C169

US-

04NM60U

603-C173

US-

04NG00F6

00-C90

Average 0.0 5.5 8.9 3.6 3.5 10.6 3.4 311.7

Max 0.0 5.6 28.7 3.6 3.6 28.1 3.4 332.0

Min 0.0 5.4 -0.8 3.6 3.5 -1.3 3.4 296.1

14:00:00 0.0 5.4 8.8 3.6 3.6 11.6 3.4 315.6

14:05:00 0.0 5.4 10.8 3.6 3.6 7.0 3.4 313.3

14:10:00 0.0 5.5 2.9 3.6 3.5 0.5 3.4 300.4

14:15:00 0.0 5.5 3.3 3.6 3.5 -1.3 3.4 296.1

14:20:00 0.0 5.5 4.6 3.6 3.5 2.4 3.4 301.2

14:25:00 0.0 5.5 3.3 3.6 3.6 11.8 3.4 315.2

14:30:00 0.0 5.5 0.8 3.6 3.5 6.3 3.4 300.0

14:35:00 0.0 5.5 -0.8 3.6 3.6 5.2 3.4 302.1

14:40:00 0.0 5.5 -0.5 3.6 3.6 4.0 3.4 302.5

14:45:00 0.0 5.5 9.1 3.6 3.5 9.8 3.4 310.5

14:50:00 0.0 5.4 20.2 3.6 3.6 19.4 3.4 319.3

14:55:00 0.0 5.5 28.7 3.6 3.6 28.1 3.4 332.0

15:00:00 0.0 5.5 16.6 3.6 3.5 19.7 3.4 328.1

15:05:00 0.0 5.6 16.7 3.6 3.6 20.8 3.4 314.8

15:10:00 0.0 5.5 7.3 3.6 3.6 10.8 3.4 309.2

15:15:00 0.0 5.5 10.2 3.6 3.5 13.9 3.4 327.0


Measurement No. 3


.

Boiler

Load

Stack

Oxygen

Monitor Output

(0 to 2 Ext)

Output No.2

2015

Correlation

Measured Dust Mass


Stack O2

3 370.0 7.9 >20.0 2557.2

LoadMill A PF

flow

Mill B PF

flow

Mill C PF

flow

Mill D PF

flow

Mill E PF

flow

Mill F PF

flow

Total air

flow

MW

US-

04NM10U

603-C153

US-

04NM20U

603-C157

US-

04NM30U

603-C161

US-

04NM40U

603-C165

US-

04NM50U

603-C169

US-

04NM60U

603-C173

US-

04NG00F6

00-C90

Average 378.0 7.3 31.2 3.6 18.6 31.8 15.9 440.5

Max 610.1 25.4 38.2 3.6 38.8 37.9 37.4 604.9

Min 131.3 3.2 15.3 3.6 -34.3 14.7 -10.5 338.9

15:45:00 131.3 5.6 30.4 3.6 3.6 32.6 3.4 346.1

15:50:00 160.6 5.5 30.0 3.6 -34.3 32.9 3.4 338.9

15:55:00 201.7 5.5 31.6 3.6 -34.3 34.0 3.4 348.0

16:00:00 248.5 5.6 31.0 3.6 -10.5 34.3 3.4 367.6

16:05:00 294.6 5.6 15.3 3.6 5.8 14.7 3.4 367.0

16:10:00 337.0 5.5 32.6 3.6 28.3 32.8 3.4 418.0

16:15:00 348.6 5.5 33.7 3.6 33.0 33.4 3.4 410.4

16:20:00 357.5 5.8 34.6 3.6 25.6 34.9 3.4 414.6

16:25:00 356.5 5.6 33.2 3.6 34.4 33.5 -10.5 436.9

16:30:00 363.0 3.2 21.5 3.6 25.2 22.4 21.0 433.0

16:35:00 409.8 4.7 28.2 3.6 29.0 28.2 27.9 441.2

16:40:00 452.2 3.2 31.5 3.6 31.8 31.9 31.4 457.0

16:45:00 493.9 3.2 35.1 3.6 35.5 35.1 34.4 477.3

16:50:00 517.5 4.4 32.6 3.6 33.2 32.8 32.6 504.5

16:55:00 551.0 8.5 35.4 3.6 36.1 35.1 35.2 519.5

17:00:00 593.0 22.1 38.2 3.6 38.8 37.9 37.4 604.1

17:05:00 610.1 25.4 34.8 3.6 35.6 34.8 34.5 604.9


5.13. Unit No. 6 Shutdown Measurements

On the 27th

of June 2016 two measurements were conducted on Unit No. 6 during a Unit

Shutdown. The first measurement was conducted during the load reduction from 270 to 0 MW.

Measurement No. 2 was conducted after with zero MW load and with just fans running. The following trends and tables show the Boiler Load, Mill PF flow variation during the

measurement period.


Measurement No. 1


LoadMill A PF

flow

Mill B PF

flow

Mill C PF

flow

Mill D PF

flow

Mill E PF

flow

Mill F PF

flow

MW

US-

06NM10U

603-C153

US-

06NM20U

603-C157

US-

06NM30U

603-C161

US-

06NM40U

603-C165

US-

06NM50U

603-C169

US-

06NM60U

603-C173

Average 55.5 5.1 4.4 3.8 8.6 7.2 7.5

Max 272.1 5.2 28.7 3.8 37.0 34.0 8.9

Min 0.0 5.0 2.9 3.8 -7.0 -12.0 3.5

20:40:00 272.1 5.2 28.7 3.8 4.1 0.4 8.8

20:45:00 263.9 5.2 6.1 3.8 37.0 34.0 8.8

20:50:00 243.4 5.2 2.9 3.8 14.5 -3.3 8.8

20:55:00 186.3 5.1 2.9 3.8 29.4 12.9 8.8

21:00:00 88.9 5.2 2.9 3.8 30.0 9.5 8.8

21:05:00 0.0 5.2 2.9 3.8 6.0 -8.8 8.8

21:10:00 0.0 5.2 2.9 3.8 -7.0 -12.0 8.9

21:15:00 0.0 5.2 2.9 3.8 1.2 -9.2 8.8

21:20:00 0.0 5.2 2.9 3.8 2.3 -6.5 8.9

21:25:00 0.0 5.2 2.9 3.8 3.9 29.1 8.9

21:30:00 0.0 5.2 2.9 3.8 5.4 32.0 8.9

21:35:00 0.0 5.2 2.9 3.8 6.6 33.1 8.9

21:40:00 0.0 5.2 2.9 3.8 6.3 3.8 8.9

21:45:00 0.0 5.2 2.9 3.8 5.8 3.8 8.1

21:50:00 0.0 5.1 2.9 3.8 3.6 3.8 6.4

21:55:00 0.0 5.0 2.9 3.8 3.6 3.8 3.5

22:00:00 0.0 5.0 2.9 3.8 3.6 3.8 3.5

22:05:00 0.0 5.0 2.9 3.8 3.6 3.8 3.5

22:10:00 0.0 5.0 2.9 3.8 3.6 3.8 3.5


Measurement No. 2

The following table presents the conditions as captured during Measurement No. 1 & 2 with the

particulate concentration in mg/Nm3 dry @ stack O2 conditions.

Boiler

Load

Stack

Oxygen

Monitor Output

(0 to 2 Ext)

Output No.2

2015

Correlation

Measured Dust Mass


Stack O2

1 55.5 13.6 >20.0 7608.3

2 0.0 20.6 >20.0 6311.3

LoadMill A PF

flow

Mill B PF

flow

Mill C PF

flow

Mill D PF

flow

Mill E PF

flow

Mill F PF

flow

Total air

flow

MW

US-

04NM10U

603-C153

US-

04NM20U

603-C157

US-

04NM30U

603-C161

US-

04NM40U

603-C165

US-

04NM50U

603-C169

US-

04NM60U

603-C173

US-

04NG00F6

00-C90

Average 0.0 5.5 8.9 3.6 3.5 10.6 3.4 311.7

Max 0.0 5.6 28.7 3.6 3.6 28.1 3.4 332.0

Min 0.0 5.4 -0.8 3.6 3.5 -1.3 3.4 296.1

14:00:00 0.0 5.4 8.8 3.6 3.6 11.6 3.4 315.6

14:05:00 0.0 5.4 10.8 3.6 3.6 7.0 3.4 313.3

14:10:00 0.0 5.5 2.9 3.6 3.5 0.5 3.4 300.4

14:15:00 0.0 5.5 3.3 3.6 3.5 -1.3 3.4 296.1

14:20:00 0.0 5.5 4.6 3.6 3.5 2.4 3.4 301.2

14:25:00 0.0 5.5 3.3 3.6 3.6 11.8 3.4 315.2

14:30:00 0.0 5.5 0.8 3.6 3.5 6.3 3.4 300.0

14:35:00 0.0 5.5 -0.8 3.6 3.6 5.2 3.4 302.1

14:40:00 0.0 5.5 -0.5 3.6 3.6 4.0 3.4 302.5

14:45:00 0.0 5.5 9.1 3.6 3.5 9.8 3.4 310.5

14:50:00 0.0 5.4 20.2 3.6 3.6 19.4 3.4 319.3

14:55:00 0.0 5.5 28.7 3.6 3.6 28.1 3.4 332.0

15:00:00 0.0 5.5 16.6 3.6 3.5 19.7 3.4 328.1

15:05:00 0.0 5.6 16.7 3.6 3.6 20.8 3.4 314.8

15:10:00 0.0 5.5 7.3 3.6 3.6 10.8 3.4 309.2

15:15:00 0.0 5.5 10.2 3.6 3.5 13.9 3.4 327.0


6. Monitoring Deviations

6.1. The numbers of measurements included in some of the correlations are inconsistent with the requirements of the ESKOM Standard for Emission Monitoring and Reporting (420-

56242363).

7. Recommendations

It is recommended that:

7.1. The particulate emissions from Units No. 1, 2, 4, 5 & 6, reported to the authorities, are according to the correlation functions presented in Figures No. 1 to 10 of this report.

7.2. New compliant correlations are conducted on Units No. 1, 2, 4, 5 & 6 during the first quarter of 2018.

7.3. The first Output range on Unit No. 1 to 6 be selected to a higher extinction range in order to

include the cap limit of 100 mg/Nm3 dry @ 10% O2.

8. Acknowledgement

The author expresses sincere appreciation for the co-operation and assistance of the Lethabo

personnel during the correlation.

9. References

9.1. South African Air Quality Act No. 39 of 2004 9.2. ISO 9096 Stationary source emission – Manual Determination of mass concentration of

particulate matter.

9.3. ISO 12141 Stationary source emission – Determination of concentration of particulate matter (dust) at low concentrations – Manual gravimetric method.

9.4. ISO 10155 Stationary source emissions – Automated monitoring of mass concentrations of particles – Performance characteristics, test methods and specifications

9.5. 420-56242363 ESKOM Standard for Emission Monitoring and Reporting

10. Distribution 10.1. Yaseen Waja Eskom Lethabo Power Station 10.2. Ebrahim Patel Eskom Enterprises Park 10.3. R Rampiar Eskom Enterprises Park


Appendix No. 1

Detailed Measurement Results


Units No. 1

Table No. 1

Measurements No. 1 to 5

Date 9th

to 16th

March 2016

Dust Concentration [mg/Nm

3] is the measured dust concentration Normalised to gas conditions at 0°C and 101,325 kPa.

Customer Name Lethabo Lethabo Lethabo Lethabo Lethabo

Unit No. 1 1 1 1 1

Location Stack Stack Stack Stack Stack

Measurement No. 1 2 3 4 5

Date yyyy/mm/dd 2016/03/09 2016/03/09 2016/03/16 2016/03/16 2016/03/16

Start Time 00H00 11H16 15H06 12H07 13H53 15H35

End Time 00H00 13H38 16H20 13H25 15H07 16H47

Plant Load MW 610 610 610 610 610

Monitor

lethabo power station units no. 1 to 6 particulate ......no. 1 to 6 at lethabo power station during...

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