Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B31/00—Compressor arrangements
  • F25B31/002—Lubrication
  • F25B31/004—Lubrication oil recirculating arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
  • F25B43/006—Accumulators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/07—Details of compressors or related parts
  • F25B2400/075—Details of compressors or related parts with parallel compressors

Definitions

• This invention relates to a device for returning oil to at least one compressor in a cooling or refrigerating system in which the compressor sucks oil from at least one oil col ⁇ lecting container through at least one suction conduit connec- ted to the collecting container and having one or more gas or oil intakes situated above the oil level in the collec ⁇ ting container.
• GB patent specification 699,568 describes and shows an oil returning device which does not, however, permit retur ⁇ ning the oil together with the refrigerant.
• a definite oil level must be maintained in the collecting pipe, which is difficult to realize in practice.
• the object of the present invention is to provide a de- vice which permits returning . oil together with refrigerant and which ensures a continuous oil supply to the compressor when in operation irrespectively of -whether there are small or large amounts of oil in the collecting pipe.
• This is achi- ved according to the invention substantially with the use of the characteristic features defined in the appendant claim 1» Applying the features indicated in claim 1, it is rea- lized that, after the foaming of the oil at the start of the compressor has produced an oil coating on the inside of the collecting pipe up to the gas and oil intake, the oil can be caused to creep continuously upward on the walls of the col ⁇ lecting container and continuously sucked into the suction pipe and via the latter continuously into the compressor.
• figure 1 diagrammatically illustrates a freezing plant comprising a device according to the invention
• figure 2 is a section on line II-II in figure 1, that is through a collecting container and a suction pipe of the freezing plant.
• the freezing plant illustrated comprises three compres ⁇ sors 1 which are adapted to pump out hot gas through a hot gas conduit 2.
• large amounts of oil accompany the gas out of the compressors 1 and the major portion of this oil is separated from the hot gas in an oil separator 3 from which the oil is refluxed to the compressors 1 via a reflux pipe 4 which is provided with one oil level control 5 for each compressor 1.
• a reflux pipe 4 which is provided with one oil level control 5 for each compressor 1.
• no complete oil separa ⁇ tion can be attained in the oil separator 3 some oil will accompany the hot gas through the conduit 6 to a condensor 7 and via the condensate therefrom through a conduit 8 to a refrigerant container 9.
• the oil then accompanies the refrige- rant from the refrigerant container 9 through a conduit 10 to an evaporator 11 and the refrigerant vapour from said eva ⁇ porator to a collecting container 13.
• the intention then is for the oil 16 collected in the collecting container 13 to be supplied to the compressors 1 continuously and as uniform- ly distributed as possible between said compressors through suction conduits 14 which are adapted to supply gas in the form of refrigerant vapour from the collecting container 13 to the compressors 1.
• each suction conduit 14 is pro ⁇ vided with at least one gas and oil intake 15 which is loca ⁇ ted above the oil level 16a of the collecting container 13, connects onto the inside 17 of the collecting container 13 and has a substantially smaller throughflow area than the collecting container 13 to bring about such a gas velocity in the gas and oil intake 15 that the gas in capable of carrying along the collected oil 16 in an upward direction on the inside 17 of the collecting container 13 to the gas and oil intake 15 after the inside 17 has been coated with an oil film generated by the foaming of the oil at the start of the compressors.
• the oil 16 contained at the bottom of the collecting con ⁇ tainer 13 will foam up, said foaming being so vigorous that the inside 17 of the collecting container 13 is coated with an oil film 19 all the way up to the gas and oil intake 15.
• the gas will successively suck the oil film 19 into the gas and oil intake 15 and the film-like oil flow 19 will successively be replenished from below with oil 16 from the lower portions of the collecting container 13.
• the oil will "creep" from the lower portions of the collecting container 13 on the inside 17 to the gas and oil intake 15 in a continuous oil flow 19.
• the gas and oil intake 15 is so arranged that the oil flow 19 is not interrupted when it passes from the in ⁇ side 17 into the suction conduit 14.
• Such an uninterrupted flow can be brought about because the upper edge 20 of the ga and oil intake 15 lies in the prolongation of the inside 17, i.e. the upper edge 20 connects exactly onto the inside 17 to form a prolonged part thereof. It is not, however, absolutel necessary for the upper edge 20 to be placed absolutely exactly in the prolongation of the inside 17 but said upper edge 20 can be placed at a slightly higher level without causing any decisive negative interruption of the flow.
• the oil flow can also be kept fairly undisturbed if the upper edge 20 for some reason should end up slightly below the prolongation of the inside 17.
• a threshold bu provided this threshold is not too high and the gas velocity is sufficient, the gas will nevertheless be able to "suck” the oil « into the suction conduit 14.
• Such a “threshold” should, however, be avoidedas a rule because it will interrupt the oil flow 19 if it extends too far downward below the prolongation of the inside 17 and/or if the gas velocity is insufficient.
• the parts 21 of the suction conduit 14 which are situated inside the gas and oil intake 15 present substantially the same throughflow area as the gas and oil intake 15. As a result, the velocity of the gas flowing into the suction conduit 14 is maintained, which in turn implies an effective oil transport also in ⁇ side the gas and oil intake 15.
• the said parts 21 of the suction conduit 14 may be provided with a filling 23.
• a structurally simple embodiment is obtained by provi ⁇ ding the suction conduit 14 with an end portion 22 which is lowered radially into the collecting container 13 and which in its side wall has two gas and oil intakes 15 opposite one another, as shown in figure 2.
• the suction conduit 14 may preferably be vertically directed and inserted in the upper part of the collecting container 13 such that the gas and oil intakes 15 will con ⁇ nect onto the uppermost portions of the inside 17.
• the collecting container 13 may be a pipe of circular cross section and the suction conduit 14 may be radially directed in relation to said pipe.
• the suction conduit 14 has a shoulder 24 which is spaced from the gas and oil intake 15 a distance corresponding to the wall thickness of the collec ⁇ ting container 13.
• the shoulder 24 is preferably formed by a transitional portion at which the suction conduit 14 outsid the collecting container 13 merges into an end portion 22 of smaller diameter.
• Said shoulder 24 permits disposing the gas and oil intake 15 of the suction conduit 14 in exactly correct relation to the inside 17 of the collecting container 13 simply by inserting the suction couduit 14 in a hole made for that purpose in the collecting container 13 until the shoulder 24 abuts against the outer side 25 of the collecting container 13.
• the device can also be uti ⁇ lised in refrigerating systems, and the constituent parts may vary in shape, disposition and number and still function in the manner contemplated.
• the device is usable for one and preferably for several compressors. In the latter case, it can be utilised to advantage for a uniform oil distribu ⁇ tion between the compressors.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Power Engineering (AREA)
• Compressor (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Devices That Are Associated With Refrigeration Equipment (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20357026

Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (6)

Citations (4)

Family Cites Families (5)

• 1984
  • 1984-09-17 SE SE8404641A patent/SE8404641L/sv not_active IP Right Cessation
• 1985
  • 1985-09-16 JP JP60504163A patent/JPS62500259A/ja active Pending
  • 1985-09-16 EP EP85904695A patent/EP0196314B1/en not_active Expired
  • 1985-09-16 DE DE8585904695T patent/DE3567266D1/de not_active Expired
  • 1985-09-16 WO PCT/SE1985/000350 patent/WO1986001882A1/en active IP Right Grant
  • 1985-09-16 US US06/865,194 patent/US4702089A/en not_active Expired - Fee Related
  • 1985-09-16 AT AT85904695T patent/ATE39752T1/de not_active IP Right Cessation
• 1986
  • 1986-05-13 NO NO86861891A patent/NO164126C/no unknown
  • 1986-05-14 DK DK222586A patent/DK154245C/da not_active IP Right Cessation

Patent Citations (4)

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