GB390702A - Improvements in or relating to apparatus for regulating water tube steam generators - Google Patents

Abstract

390,702. Fluid-actuated valves. SULZER FR’RES SOC. ANON., Winterthur, Switzerland. Aug. 8, 1932, No. 22192. Convention date, Aug. 26, 1931. [Class 135.] Valves controlled by pilot or relay valves.- Valves controlling the water or fuel supply to a steam boiler, or the pressure or any other working valve of the boiler are actuated by servomotor devices operated not only in accordance with the temperature or pressure in the boiler, but also in accordance with the rate of change of the temperature or pressure. The expansion and contraction of a bent pipe 32 forming part of the boiler are communicated to a piston 12 in a cylinder 11 supplied with pressure fluid and having its ends connected together through a throttling device 14. The pressure in the pipe 16 leading from the cylinder is a measure of the rate of movement of the piston and of the rate of change of the temperature in the boiler. The expansion and contraction of another bent pipe 33 forming part of the boiler are communicated through a spring 36 to the piston 37 of a servomotor. The pressure of the fluid in the pipe 42 leading from the servomotor varies directly with the temperature in the boiler, and may operate the feed or fuel valve, and it may also act in conjunction with the pressure in the pipe 16 on the piston 46 of a servomotor through which pressure fluid is supplied to the device operating the feed or fuel valve. The bent pipe 32 may be connected to the piston 12 through a floating lever servomotor. A single bent pipe 65, Fig. 4, may be used to produce both the pressure impulse varying directly with the temperature &c. and the impulse varying with the rate of change of temperature &c. The pressure fluid from the servomotor 37 actuates the sliding valve 18 of a further servomotor in which a piston 24 actuating the feed &c. valve is acted upon on its under side by a second pressure fluid. The upper side of the piston 24 is supplied with a third pressure fluid, which enters and escapes from the cylinder 23 through a throttling device 71. The pressure in the pipe 68 leading from the throttling device, which pressure varies with the rate of change of the temperature in the boiler, is communicated through a servomotor to a rod 78 actuating the feed &c. valve. A rod 25 on the piston 24 and the rod 78 may be joined by a lever 90 to which is connected a rod operating the valve in accordance with the combined pressure impulses.