tar through the wash box for some time. Had a test been made for a trace of napthalene at the outlet of the wash box at the time this sample was taken we would have found the wash box to have been doing no work whatever. Test No. 6 shows a condition just the reverse of that in test No. 2. The sample in this case was taken just after the supply tank had been filled. In this test the temperature was what was considered to be about the proper temperature at which to operate the piece of apparatus. However, the drop in B. T. U's was 19.7 B. T. U's. On July 27th, 1912, the overflow pot on the napthalene wash box as described above was put into commission. Test No. 9 shows a drop of 9.0 B. T. U's. The sample for this test was taken only a short time after the supply tank had been filled. Test No. II shows a drop of 0.4 B. T. U's. The sample for this test was taken only a short time before the supply tank had been filled. The varation in these results exemplifies the attention that this piece of apparatus requires. We have installed between the supply tank and the overflow pot in the fresh water gas tar line, a regulating device which now works very nicely and keeps the conditions referred to above under control. The drop across the napthalene wash box at temperatures from 80°F to 85°F was 7.5 B. T. U's as shown in Plate V. On account of the amount of coal tar fog entering the napthalene wash box it was thought the drop in B. T. U's at these temperatures could be partly accounted for. Tests were therefore made. at the outlet of the secondary washer-cooler with the P. & A. and napthalene wash box bypassed. Two samples were taken in each test. One sample was passed through a train of bottles in which the gas was bubbled through water gas tar. The water gas tar used was taken from the overflow pot of the napthalene wash box. The temperature of the gas in the main at the outlet of the secondary washer-cooler was the same as the atmosphere, so that no jacketing of the sampling tubes and wash bottles was necessary. Plate No. VI shows the results of these tests. An average drop of 13.0 B. T. U's was conclusive evidence that at temperatures around 80°F the scrubbing of coal gas with water gas tar is prohibitive. Simultaneous tests were made across the primary washer cooler and the P. & A. to determine the percentage of napthalene removed in these pieces of apparatus. The wide variation in the results are due to varying conditions in the Retort House caused by sudden changes in the weather and heavy rains together with varying quality in the coals used, thus affecting the heats in the benches. The results, while apparently not consistent, show approximately the amount of napthalene removed before the gas enters the napthalene wash box. Numerous tests have been made at the outlet of the napthalene wash box under almost every conceivable conditon for a trace of napthalene. The results of these tests have been very gratifying, for, with few exceptions, the amount of napthalene has been so small that we have felt no ill effects whatever. In conclusion:-The primary washer-cooler as a condenser shows great efficiency with no loss in B. T. U's. The P. & A. could be bypassed to great advantage if it were not for the present type and location of the napthalene wash box. The napthalene wash box is well worth the loss in B. T. U's and the necessary attention it requires. The general information received through our experiments indicates to us that we might be able to utilize our secondary washer-cooler to a much greater advantage. Instead of using all of the eight sections as a secondary condenser we might be able to use, say the first one or two sections to remove coal tar fog with no drop in temperature. The third and fourth sections could be used to remove napthalene by circulating water gas tar in the same manner as liquor is used in the washer-cooler. The fifth and sixth sections could be used as a secondary condenser and the seventh and eighth sections could be used to remove the last traces of tar fog, thus affording greater efficiency in the Ammonia Scrubber and less pressure in the Purifying Boxes. The feasibility of this arrangement we expect to determine with further experiments, using a miniature washer-cooler under different conditions at the inlet and outlet of each section of the secondary washer cooler. Circulating P. & A. Inlet Napthalene Secondary Ammonia Scrubber Inlet Inlet Outlet 96° Temp. Pres. Temp. Pres. Temp. Pres. Temp. Pres. Temp. Pres. 113° 25" 112° 22" 111° 17" 78° 15" 84° 13" Inlet Circulating Liquor Inlet Outlet Temp. P. & A. Inlet Napthalene Secondary Time Exposure Temp. Pres. Temp. Temp. C. W. Temp. Pres. Temp. Pres. Temp. Pres. Temp. Pres. Temp. Pres. 141. 21" 93° 121° 73° Bypassed Bypassed 104° 19" 79° 17" 83° 15" Date 7/30/12 5:50 p.m. 10 Sec. PLATE No. III. TESTS ACROSS PRIMARY WASHER COOLER. Circulating Liquor 91° 614.0 610.7 -3.3 2 7/17/12 8:40 a.m 144° 25" 109° 24" 108° 598.0 603.5 +5.5 3 7/17/12 2:25 p.m. 145° 25" 107° 25" 108° 580.5 582.5 +2.0 120° 88 70° 624.5 630.0 +5.5 29" 92° 118° 84 70° 595.3 593.0 -5.3 6 7/22/12 9:15 p.m. 141° 28" 97° 28" 92° 118° 80 70° 610.3 602.5 -7.8 7 7/23/12 10:50 a.m. 142° 29" 101° 28" 98° 115° 86 70° 593.0 598.0 +5.0 8 7/25/12 5:05p.m. 144° 26" 102° 26" 102° 130° 62 72° 589.2 594.7 +5.5 9 7/25/12 8:20 p.m. 137° 26" 115° 26" 106° 127° 58 72° 606.0 603.3 -5.7 10 7/26/12 10:10 a.m. 142° 26" 26" 118° 94° 132° 54 71° 628.3 625.3 -3.0 |