DESIGN OF OPEN-HEARTH FURNACES
TABLE 18
267
Gas Checker
Air Checker
A checkerwork height has been assumed, in order to illustrate the effect of a high checkerwork. On this basis: The number of passes required will be determined by dividing the lineal amount of pass required by the height of checkerwork: n for gas =4763 -f-7 . 00 = ..................
681
n for air =8361 -=-7. 00= ...................
1195
Any desired length or width of chamber that will contain the number of passes may be selected. When a square pass is used, it is necessary that the chamber dimensions should be multiples of the pass dimension, plus one wall. The length of both chambers will be alike. Let n = number of passes in length of chamber, then Z = 190n+63. Assume n =40, then the length of the chamber will be: 190X40+63= .....
7 m 663
25 14 ft
For the width of the chambers, n may be assumed as some number which will give a number of passes slightly in excess of that computed above. For the case in hand, let n = 18 for gas and 30 for air. The corrected number of passes will be, therefore: 40X 18 for gas = ..........
720
40X 30 for air == ...................
1200
The width of the chambers required will be : For gas- 190X18+63 =
3 m 483
For air: 190X30+63 = ....................
5m 763
The area occupied by the checkerwork will be: For gas: 7.663X3.483= .................
11.425ft 26 m2 69
18.90ft
For air: 7.663X5.763= ...................
44 m2 16
The corrected checkerwork volume will be: For gas: 26.69X7 00= ...............
287. 4 sq ft 186 m3 83
475. 4 sq ft
For air: 44.16X7.00= .................
309 m3 12
6602 cu ft
10,916 cu ft