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THE UNIVERSITY OF MICHIGAN LIBRARIES

3.2 Electrical equipment for energizing the installation, as follows: Twelve Silicon, 70 KVp, 1000 ma rectifier sets arranged in cabinets. Control units are located adjacent to the precipitator roof elevation.

4. RATING

The normal rated gas capacity for this installation is 960,000 cfm per precipitator at an inlet gas temperature of 250° F, and an inlet gas pressure not to exceed +5.0" positive pressure.

5. GUARANTEE

Research-Cottrell, Inc. guaranteed that when this installation was adjusted and operating within its rated capacity and under the normal operating conditions specified by Research-Cottrell, the suspended matter present in the exit gases from the installation would not exceed 2.5 percent of the suspended matter present in the gases entering the installation for treatment.

Research-Cottrell guarantees, when the equipment covered by this agreement is adjusted and operated at the normal operating conditions specified herein, that 97% of the suspended matter present in the gases at the inlet of the equipment shall be removed, provided the gas does not require cleaning below an outlet concentration of .05 grains per cubic foot at 32° F and 29.92'' Hg.

6. OPERATING DATA

This installation was placed in operation on August 27, 1964. Prior to tests, plant personnel were instructed in the operation of the installation. Performance tests were run from August 20 to August 24, 1965. The test procedures followed are in general agreement with the ASME Power Test Code and Research-Cottrell test bulletin entitled "Test Method for the Determination of Gas Velocity, Moisture, Dust, Acid, and Tar Contents."

The boilers were operating at steaming rates varying between 2.13 to 2.18 x 10 lbs/hr.

Test samples were drawn from the sampling stations located in the downcomer breeching before the precipitator and in the breeching immediately before the stack.

Remarks: No. 1 precipitator was tested in an "as found" condition. Two inlet sections were grounded so total rectifier outputs were applied to the remaining two sections.

No. 2 precipitator was tested following a second outage in which hoppers were cleaned and new discharged electrodes were installed replacing those which were found broken.

7.1 No. 1 Precipitator

7. DISCUSSION OF TEST RESULTS

Three tests were made to prove the performance of the installation.

7.1.1 Test No. 2 was at 132 percent of rated volume, or 1,262,000 cfm, corresponding to a steam flow of 2,180,000 lbs/hr. The inlet concentration was 2.74 gr per cu ft; the outlet, 0.0265 gr per cu ft, giving an efficiency of 98.5 percent.

7.1.2 Test No. 3 was at 130 percent of rated volume, or 1,249,000 cfm, corresponding to a steam flow of 2,150,000 lbs/hr. The inlet concentration was 2.88 gr per cu ft; the outlet, 0.286 gr per cu ft, giving an efficiency of 90.2 percent. The resultant low efficiency of this test was due to sampling technique.

7.1.3 Test No. 4 was at 130 percent of rated volume, or 1,249,000 cfm, corresponding to a steam flow of 2,150,000 lbs/hr. The inlet concentration was 3.01 gr per cu ft; the outlet, 0.642 gr per cu ft, giving an efficiency of 98.0 percent.

7.2 No. 2 Precipitator

Three tests were made to prove the performance of the installation.

7.2.1 Test No. 1 was at 138 percent of rated volume, or 1,326,350 cfm, corresponding to a steam flow of 2,400,000 lbs/hr. The inlet concentration was 2.69 gr per cu ft; the outlet, 0.066 gr per cu ft, giving an efficiency of 97.6 percent.

7.2.2 Test No. 2 was at 134 percent of rated volume, or 1,282,000 cfm, corresponding to a steam flow of 2,400,000 lbs/hr. The inlet concentration

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was 2.14 gr per cu ft; the outlet, 0.0865 gr per cu ft, giving an efficiency of 96.0 percent.

7.2.3 Test No. 3 was at 134 percent of rated volume, or 1,282,000 cfm, corresponding to a steam flow of 2,420,000 lbs/hr. The inlet concentration was 2.325 gr per cut ft; the outlet, 0.0553 gr per cu ft, giving an efficiency of 97.62 percent.

All test results and other pertinent operating data are shown on the attached summary sheets.

8. CONCLUSION

On the basis of the test results, it is concluded that this installation is meeting its guarantee.

Respectfully submitted,

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THE UNIVERSITY OF MICHIGAN LIBRARIES

2. Requests for data as to the tons per day of flue gas and fly ash discharged into the atmosphere from the stacks at each of Pepco's five generating stations. In response to these requests there is enclosed a copy of a tabulation entitled "Potomac Electric Power Company, Flue Gas and Ash Discharged in 1965 and 1966 from Pepco's Five Steam-Electric Generating Stations".1

Potomac Electric Power Co. flue gas and ash discharged in 1965 and 1966 from
Pepco's 5 steam-electric generating stations1

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Flue gas Ash Flue gas Ash Flue gas Ash Flue gas Ash Flue gas Ash

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1 Total plant discharge equals tons flue gas plus tons ash.

NOTE.-Tons of flue gas includes products of combustion for coal and oil.

1 As I indicated in my testimony, I do not believe that under average weather conditions either Chalk Point or Dickerson contributes measurably to the air pollution problems of Washington.

The daily averages for the year 1966, and for the months of highest and lowest fuel consumption, are as follows:

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In response to this request these data are furnished as to the average particle size of fly ash leaving the boiler and entering the fly ash collector:

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99.4

.58

Percent finer than 297 micron (50 mesh)

Percent coarser than 297 micron----

NOTE.-1 micron equals 1 inch divided by 25,400 equals 0.00004 inch.

The fly ash leaving the collector equipment and being discharged from the stacks into the atmosphere is much finer than that given above.

4. A question was raised as to Pepco's estimate of its proportionate contribution to air pollution in the District of Columbia area.

In response to this question we have made a diligent effort to appraise Pepco's effect and have deevloped the following pertinent information:

A. No. 6 fuel oil

This is the relatively high sulphur content fuel oil about which there is so much concern. Pepco burns this type of oil only at its Benning Station. This oil is furnished by the Steuart Petroleum Company of Washington, D.C., and has an average 2.75% sulphur content.

THE UNIVERSITY OF MICHIGAN LIBRARIE

According to the best data available to us, approximately 250,000,000 gallons of residual oil (mostly No. 6) were burned in the Washington Metropolitan Area during the year 1966. Of these 250 million gallons, 714,985 gallons or only a fraction of one percent (0.3%) were burned by Pepco.

Nevertheless, Pepco is committing itself to the policy of changing over to
lower sulphur content residual oil as rapidly as it becomes available in the
Washington area.
B. Products of combustion for year 1966

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5. Request for data as to comparative costs of No. 6 and No. 2 fuel oil. In response to this request there is enclosed a copy of a tabulation captioned "Potomac Electric Power Company, Washington, D.C., Fuel Oil Costs-19651966".

Potomac Electric Power Co., Washington, D.C., fuel oil costs, 1965-66

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