Patent GB-514749-A (GB)
Title: Improvements in high vacuum condensation or diffusion pumps
IPC: F04F9/00
Filed: 1938-05-14
Abstract: 514,749. Injectors. EASTMAN KODAK CO. May 14, 1938, No. 14431. Convention date, May 18, 1937. [Class 71] In a fractionating, high vacuum or condensation pump using mixed organic pumping fluids, the vapour condensing immediately returns directly to the boiler compartment. A plurality of boiler compartments are connected for a limited liquid transference but not for transference of vapour. The vapour passes through jets towards the end of the pump connected to a source of suction. As shown a pump has a cylindrical casing 3 secured to flanges 4, 5 at the low-pressure and high-pressure ends respectively. The conduits 6, 7 lead to a backing-pump and the receptacle to be evacuated respectively. Half-moon shaped plates 16 in conduit 6 fractionate and segregate the most volatile components which are withdrawn at 17. A part-cylindrical, inner casing 8 is supported by ribs forming sides of the border. A constriction 11 of the casing 8 at the high-vacuum end has an umbrella jet 12. Partitions 13-15 form compartments A-D with staggered notched baffles which delay the flow of,fluid, A partition 20 secured to plate 5 by an extension 21 closes the low-vacuum end of casing 8. Segmental conical flanges 26-28 form approximately annular jets 22-24. The casing 8 has a series of openings 29-31 of decreasing diameter towards the high-pressure end. The level of the liquid in the various compartments is adjusted by a screw 40. The liquid in the various compartments is heated by individually-controlled means 41. A casing 43 provides a cooling- jacket for chamber 3. A modification is described with a flattened base which is raised at the high-vacuum end to form a dam for the liquid 32 in the reservoir. The jet casing is tapered towards the high-vacuum end to form jets of progressively-increasing area. A preferred form of pump is shown in Fig. 5. The main segmental casing 60 is tapered towards the low-vacuum end and extended to form a reservoir 62 with walls 63-65, Fig. 7. The partitions 13, 15 extend to the reservoir base and have communication openings 33, 35. The partition 14 has no opening and may be integral with the base. The casing 8 is supported by extensions 66 spaced from the walls 63, 64 by wedge-shaped spacers 68. The extensions 66 have communication nicks. Partition 14 prevents liquid from passing from boiler B to boiler C. The partitions 14, 15 are restricted and connected by a plate to form a passage way 80 between compartments B, D. The casing 8 is constructed at 73 to form an opening of small diameter which is capped to form a jet 72. Baffles and an outlet are shown at 74, 75, 76. A packed and oil-sealed adjustment screw 81 permits the adjustment of the jet clearances. In a further modification, the compartment C consists of a concentric chamber dipping into the reservoir and connected by a flared end to the chamber 8. The vapour from the chamber C passes to the end jet through a conduit warmed by the vapours in the end compartment which prevents initial condensation. In a further modification, the boiler and pump are divided by partitions into separate compartments which supply separate jets. The low-vacuum end .has a chamber with turbulence-preventing partitions and fractionating trays. Light or high-vapour constituents condense in the trays, low-vapour constituents return to the boiler. Unrefined liquid may be used. In a further modification, the main casing of a pump of the above type is connected to the intake alembic of a conventional condensation pump consisting of a jet, condenser, and boiler. The condenser has re-entrant or fractionating trays in the backing-pump circuit. The intake alembic and conventional boiler are connected to a pumping- liquid reservoir to which the C or outer compartment is connected by a conduit with a drop counter. Specification 473,978 is referred to.