GB1001622A - Electrically driven rotary mixing pump - Google Patents

Abstract

1,001,622. Centrifugal pumps. SIGMUND PUMPS Ltd. March 15, 1963 [Feb. 28, 1962 (2); Oct. 2, 1962], Nos. 7862/62, 7863/62 and 37396/62. Heading F1C. [Also in Divisions F4 and H2] An electrically driven rotary mixing pump comprises an impeller located in an impeller chamber, an inlet to the impeller chamber, a first passage for fluid providing an outlet from the impeller chamber and leading to an outlet from the pump, a second passage for fluid having its own inlet and outlet, a connection for flow of fluid from the first passage to the second passage, and an obturator arranged for controlling flow of fluid through the second passage or through the connection between the passages or through the outlet from the first passage and the pump. In the electrically-driven pump shown in Figs. 3 and 6, cool water from the radiators 53 of a space-heating system enters the pump at an inlet 33 and is discharged along a volute passage 34 to an outlet 35 and thence through a pipe 47 to a boiler 48. Hot water from the boiler passes via a pipe 49 and a further inlet 37 to a passage 36. A mixture of hot water from the passage 36 and cold water from the passage 34 passes through a further outlet 38 to a pipe 52 leading to the radiators 53. The temperature of the mixture can be adjusted manually by pivoting an obturator 42 to adjust the proportions of hot and cool water in the mixture. In one extreme position of the obturator 42, it closes the passage 36, and in the other extreme position it closes a port leading from the passage 34. In a modification, the obturator is located between the port 39 and a port connecting the passage 34 to the outlet 35 so as to control the flow of cool water to each outlet 35, 38. Although there is in this case no direct control of the flow of hot water through the passage 36, there is an indirect control of it provided by the control of the supply of cool water through the outlet 35 to the boiler. In further modifications, the obturator controls the flow solely through the passage 36 or the port 39 on the outlet 35. Figs. 7 and 8 show a pump in which the motor rotor 66 is combined with the pump impeller 76 and journalled on a stationary spindle 67 carried by a cylindrical body 61 of plastics material which also carries the motor stator 60. A casing 62 in two parts is'secured to the body 61 by a metal ring 63. Cool water from the radiators enters the pump at an inlet 78 and is impelled through channels 79 and a port 82 to an outlet 83 leading to the boiler. Some of the cool water can flow through a nozzle 90 to a mixing chamber 84, where it mixes with hot water from the boiler which enters the mixing chamber via an inlet- 86 and a nozzle 88. Flow through the nozzles 88, 90 is controlled by an obturator 93 carrying obturator plates 97, 98 and pivoted on a spindle 95. The obturator 93 is controlled automatically in accordance with the temperature in the mixing chamber 84 by means of a bimetallic coil 99, one end of which is secured to the spindle 95 and the other end is secured to a block 102 carried by a spindle 103 which can be rotated manually to set the temperature. The mixture flows to the radiators through an outlet 85 having a manually controlled obturator 104 by means of which the capacity of the pump can be varied. In a modification, the obturator 93 is controlled manually instead of automatically. In a further modification, Fig. 13, all inlets and outlets are at the same end of the pump casing, the motor facing in the opposite direction to that shown in Fig. 7 so that the impeller adjoins an internal wall 131. Cool water from the radiators passes via an inlet 132 and a port 134 to the impeller and is discharged through an arcuate port 144 to a chamber 143, whence it may flow through an outlet 145 leading to the boiler. Hot water from the boiler enters through an inlet 150 and passes through a port 148 to a mixing chamber 129 where it mixes with cool water entering from the chamber 143 through a port 146, the proportions of hot and cool water being controlled by a manually adjustable obturator 153. The mixture passes through an outlet 147 to the radiators. The capacity of the pump is controllable by means of a by-pass port 135 controlled by a manually adjustable obturator 136.