GB694336A - Improvements in or relating to gas producers or shaft furnaces having means for indicating and/or controlling the level of the charge - Google Patents

Abstract

694,336. Automatic level control systems. GAZ DE FRANCE (G.D.F.) SERVICE - NATIONAL. Jan. 17, 1951 [Jan. 21, 1950 ; Dec. 30, 1950], No. 1321/51. Class 38 (iv). [Also in Group XII] In a system for detecting the level of the charge in a gas producer or shaft furnace, the pressure of a fluid reacting with the charge or resulting from reaction of the charge is measured at different levels below and above the surface of the charge which corresponds to a point of pressure discontinuity. In Fig. 2 a watercooled gas producer tank 1a is supplied with fuel through a distributer cone 15 and air and steam through a pipe 12a, the gas produced being led away through a conduit 8b and the slag removed by a grate 6a. Pipes 16, 17, 18, 19, 20 which communicate with the tank at different levels are associated with differential pressure devices T<SP>1</SP>, T<SP>2</SP>, T<SP>3</SP> which respectively operate contacts 50, 51, 52 when the compared pressures are equal. Normal fuel level is between pipe 17 and pipe 18 or 19 according to position of two-way valve 36. For the position of valve 36 shown, when the level is between pipes 17 and 19, contacts 50, 52 are closed and contact 51 open. Contacts . 50, 51, 52 are associated with a relay circuit, Fig. 3 (not shown), producing the following effects :- (a) When fuel level is normal as above, indicator lamps 45, 46 are on. (b) When fuel level falls from normal to between pipes 19 and 20, contact 51 closes, lamp 45 is extinguished and after about 50 seconds operation of a delayed relay causes the delivery of a measured quantity of'fuel to cone 15 to restore the level to normal. If the level is not restored within 3-5 minutes, operation of another delayed relay switches on visual and audible alarms 48, 42. (c) When fuel level rises from normal to between pipes 16 and 17 contact 50 opens, lamp 47 is switched on and subject to the same delay as at (b) above, the visual and audible alarms are operated. (d) Should fuel level fall under abnormal conditions to below pipe 20, all lamps 45, 46, 47 are switched off and the alarms operated. Electrical faults may also cause the alarms to operate. Measured quantities of fuel may be supplied to cone 15 by manual operation of a push button. Fuel level is recorded on a chart 49. There are references to automatic extraction of solid material from the tank upon rise in level, to control of kilns and blast furnaces and to a liquid passing through the solid material instead of a gas. Specification 670,464, [Group XII], is referred to.