THE PRELIMINARY PURIFICATION OF COAL GAS 529
liquor rather than a continuous flow, and in such cases the tumbler may be conveniently employed. Another means of providing for intermittent flow is by introducing the principis of Mann’s discs (Fig. 337). The upper disc revolves whilst the lower remains stationary,
so that when the holes in the discs coincide a flush of water or liquor is given.
THE CAPACITY OF WASHERS AND SCRUBBERS
The necessary capacity of the washing and scrubbing plant depends very largely on. the type of apparatus employed. Owing to the introduction. of more efficient plant the size of the vessels has undergone some considerable reduction of late years. For washers of the Livesey and similar types the following rule is reliable :—
Allow ) to | cubic foot of capacity per 1,000 cubic feet of gas passed per diem.
The standard sizes of Livesey washers for dealing with various quantities of gas may be taken as follows :—
Gas dealt with per 24 Hours. Length and Width of W ashei. Depth of Washer.
ft. in. ft. in. ft. in.
3J-4 million cubic feet 20 0 X 7 6 o 6
,, ,, ,, 15 0X7 6 3 6
H-2 „ „ „ ....... 10 0X7 6 3 6
H „ „ „ 5 0X76 3 6
500-750,000 „ „ ....... 6 0X40 3 0
300-500,000 „ „ 5 0X36 2 6
200-250,000 „ „ 3 0X40 2 6
75-100,000 „ „ 3 8X13 2 6
For mechanical washer-scrubbers an allowanoe of | to J cubic foot per 1,000 cubic feet of gas passed per diem may be made.
MM