Patent GB-642376-A (GB)
Title: Improvements in hydraulic apparatus for supplying fluid under pressure
IPC: F23J1/00
Filed: 1946-12-10
Abstract: 642,376. Water-waste preventing. BABCOCK & WILCOX, Ltd., and SILK, P. B. Dec. 10, 1946, No. 36418. [Class 26] [Also in Group XXIX] Means for providing a periodic discharge of liquid under pressure comprises an air-tight vessel for confining a charge of gaseous fluid and having an inlet for liquid under pressure and an inlet for gaseous fluid, a discharge valve for controlling the flow of liquid from the vessel, a float adapted when the liquid has compressed the charge of gaseous fluid by rising to an upper level to effect opening of the discharge valve and when the liquid in the vessel has fallen to a lower level to effect closure of the discharge valve and means adapted by automatically effecting replenishment of gaseous fluid of the charge to ensure the maintenance within the vessel during variation of liquid level between the said limits of a fluid pressure above a minimum value. The pressure-tight vessel 1. Fig. 1 has a water inlet valve 4 discharge valve 11 and air supply valve 30. The valve 11 is carried on a vertica hollow spindle 14 carrying a ring 19, with sloping faces 20, 21, which engages spring catches 22, when the spindle is forced upwardly by engagement of the upper face of a float 25 sliding on the spindle with a collar 27 fixed to the spindle: when the water level falls, the bottom of the float 25 engages the valve 11 to close it. The valve 30, which may be a non-return or reducing valve, is to introduce additional air under pressure as necessary. Fig. 2 shows the application of two such devices to a furnace installation comprising travelling or chain grates 50 discharging ash into hoppers 51, 52. 53 and thence into extractor vessels 54, 55, and extractor tanks 521 all of which are periodically sluiced through the pipes 56. In a modification, Fig. 3, the outlet valve 81 is carried by an auxiliary float 93 secured to a spindle 83 on which the main float 88 rides. Water is admitted to the main chamber 72 at 74 and air at 116 through a reducing valve 117 from a smaller chamber 73 which may be formed integrally with or separately from the main chamber. The smaller chamber 73 is also connected to the water supply through a non-return valve 101 and comprises a discharge valve 103, leading to waste, carried on a spindle 120 on which rides a float 110 that contacts a collar 112 in its raised position. The upper end of the spindle 120 is provided with a collar 105 engaged by the forked end of a pivoted lever counterweighted at 109 to exert an upthrust on the spindle. Air enters through a non-return valve 115. A single chamber 73 may be used with two or more main chambers of the 'kind shown in Figs. 1 or 3. In a still further modification, Figs. 5 and 8. the discharge valve 140 is secured to a vertical spindle comprising a cylindrical hollow closed lower part 145 and a cylindrical hollow open upper part 146, the latter extending through a central passage in the float 148 which contacts a flange 150 on the spindle in its upper position and a catch comprising pivoted arms 152 in the lower position, Pivoted to the arms 152 are catch fingers 154 normally extending externally of the spindle: extensions 155 of the arms 152 normally engage a hollow catch control member 156 having a collar 157 that engages a guide 158 when the control member moves upwardly. An air valve 162 comprises a spring-loaded valve member 163 operated by a control rod 164 carying a collar 166 and passing freely through the float 148. A pressure responsive device 167 compising a spring- loaded flexible diaphragm 168 is secured to a regulator rod 169 passing through the float and carrying a collar 171 at its lower end: the upper end of the rod 169 comprises an eye through which passes a lever 172 linked to another lever, 174, slotted to receive a pivot and having a pivoted contact finger 175 co-acting with a collar 160 on the catch control member 156. Downward movement of the regulator rod 169 causes the finger 175 to engage the collar 160 and raise the control member 156 up to a point at which the finger slips from the collar. In ordinary operation the float moves between the flange 150 and the arms 152 opening and closing the valve 140, but if the air pressure drops too low, engagement of the finger 175 and collar 160 causes relative movement of the catch control member 156 and a spindle member releasing the arms 154, at the same time preventing closing of the valve 140 by engagement of the members 157, 158. As the water falls, the float first engages the collar 166 to open the air valve 162 and then the collar 171, causing disengagement of the finger 175 and collar 160 to close the discharge valve 140. In all forms the float 25 is preferably filled with air or gas at a pressure between atmospheric and that within the vessel when the water is at its highest level.