GB435668A - Improvements in cooling means for furnaces provided with underfeed stokers - Google Patents

Abstract

435,668. Grates; ashpits. AMERICAN ENGINEERING CO., Aramingo Avenue, Philadelphia, U.S.A. Dec. 24, 1934, No. 36971. Convention date, Oct. 23. [Class 51 (i)] In an underfeed stoker furnace provided with alternately disposed retorts and rows of tuyÞre blocks, cooling tubes are arranged above the tuyÞre blocks to form a screen for chilling any molten ash flowing from the fuel bed above the tuyÞres. As shown in Fig. 1, cooling tubes 25 extend downwardly from a header 26 and over the tuyÞre blocks 4 and are connected to a lower header 28 both headers being in communication with the water circulating system of the boiler. In the modification shown in Fig. 2, the cooling tubes pass downwardly over fixed extension grates, arranged between movable extension grates 9, and are connected to a header 35 from which extend tubes 38 forming a shelf for ashes &c., connected to a lower header 39. In a further modification the tubes 25 are continued downwardly to the lower header 39 while intermediate tubes are disposed between the header 35 and the lower header 39. In the modification shown in Fig. 5, the tubes 25 are carried downwardly at 54 to form a wall of the ashpit 53 and are connected to a header 55. Intermediate tubes 56 are arranged between the extensions 54 and connected to headers 55 and 57. A pump 101 may be employed to assist circulation. The tubes 25 may terminate in vertical extensions with top and bottom headers or a bottom header only to form cooling means for any molten ash entering the ashpit. The tuyÞre blocks 4 may be provided with recesses 67, Fig. 12, to receive the cooling tubes and with cooling ribs 68. Fig. 11 shows a modification in which the cooling tubes 25 are spaced from the tuyÞre blocks 4.