Patent GB-182528-A (GB)
Title: Refrigerating apparatus
IPC: F25B3/00
Filed: 1921-03-24
Abstract: 182,528. Remer, J. G. de. March 24, 1921. Screw Sprengel pumps.-In compression refrigerating machines a compressor of the centrifugal entrainment type surrounded by a condenser coil 15, and an evaporator surrounded by a coil 22, are mounted at an inclination to and rotate with a motor-driven shaft 42, and have also a rotation about their own axis. The shaft 42 is provided with counterbalanced arms 45, 46 formed with bearings 43, 44 for the ends of the compressor and evaporator elements, one arm 46 being hollow and containing a shaft 52 fitted with a bevel wheel 53 gearing with a fixed wheel 51, whereby motion is communicated to a bevel wheel 55 on the end of the compressor element. The motions may be in the same sense or in opposite senses. The condenser coil may be cooled merely by exposure to the air, or water from a sprayer 62 may be distributed over it. The evaporator element is insulated from the compressor element by a partition 67, and may be located in a chamber in communication with a domestic refrigerator, or, as shown, may serve to cool brine, which is circulated by a pump 72 from the bottom of a tank 66 to a cooling-coil 71, and returned through a sprayer 73. The compressor element, shown in section in Fig. 4, comprises a casing 2 fitted with a hollow member 8 having a helical passage 5 around it, the passage being of gradually diminishing section from the low pressure chamber 6 to the high pressure chamber 7. Another helical passage 12 is provided between the inner wall of the member 8 and a tube 9. The compressor is partly filled with the propelling liquid, preferably mercury, and the evaporator contains a charge of refrigerant, for example sulphur dioxide. Upon starting, the refrigerant vapour passes from the evaporator through the hollow shaft or connecting-tube 18 into the chamber 6, and is entrained by the mercury through the helical passage 5 to the high-pressure chamber 7. The mercury collects in a cap 13 and seals the end of the extension 14 of the tube 9 against the flow of compressed refrigerant back through the tube, whereby the vapour is forced through the inner helix 12 to the inlet end 16 of the condenser coil. This coil consists of an outer helix pitched in the same sense as the helix 5, and an inner reversed helix leading to the evaporator by a pipe 17 passing through the hollow shaft 18. To prevent the flow of mercury to the evaporator, the shaft 18 is extended into the chamber 6 and a baffle 36 is fitted over its end. A guard 56 and deflector 57 are provided around the part 13 to prevent the entrance of matter into the bearing. The pipe 17 extends into a tube 24, Fig. 3, in the evaporator element, and is provided with an aperture 26 at a distance from its closed end. The tube 24 is filled with propelling liquid, acting also as a sealing liquid, and the condensed refrigerant escaping through the perforation 26 bubbles through this liquid and passes through apertures 27 into a chamber 32. The refrigerant passes through a coil 22 around this chamber and returns again through a pipe 33 into the tube 24. The vaporized refrigerant is withdrawn from the chamber 32 through apertures 35 in the hollow shaft 18. To ensure the return of excess propelling liquid from the sealing tube and evaporator element, a tube 37 is fitted within the sealing tube, with its open end beyond the aperture 26. It is connected to a coil 38 leading to a return tube 39 extending to the compressor side of the unit. Under the action of centrifugal force any liquid rising in the tube 24 above the point where the tube 37 branches into the coil is thus returned to the low-pressure chamber 6. A vent tube 41 is fitted to the coil 38 to prevent complete withdrawal of the liquid from the sealing tube by the creation of a vacuum. A baffle 40 is provided in the chamber 32 to prevent the bulk of the refrigerant liquid from being agitated by the coil 38 and returned to the compressor without evaporation. The helix 12 of the compressor element is designed to ensure the passage of some propelling liquid to the evaporator each time the machine is started, while the coil 22 around the evaporator ensures the movement back into the sealing tube of any propelling liquid collected in the chamber 32 during a stoppage. Several similar units may be mounted in succession on a single shaft.