Refrigeration lubrication system and method

Claim 1

A METHOD OF PROVIDING LUBRICATION IN A REFRIGERATION MACHINE UTILIZING A REFRIGERANT AND A LUBRICANT MISCIBLE WITH THE REFRIGERANT, AND SAID MACHINE HAVING A LUBRICATION SYSTEM AT LEAST IN PART EXPOSED TO THE REFRIGERANT AND INCLUDING A FIRST ZONE AT A RELATIVELY LOW PRESSURE FOR CONTAINING A SUPPLY OF LUBRICANT AND A SECOND ZONE REQUIRING LUBRICATION AND NORMALLY AT A RELATIVELY HIGHER PRESSURE WHEN THE MACHINE IS SHUT DOWN, SAID METHOD COMPRISING THE STEPS OF CIRCULATING LUBRICANT BETWEEN SAID ZONES FOR LUBRICATING THE MACHINE, PROVIDING A RELATIVELY LOWER PRESSURE IN SAID ZONE DURING COOLING OPERATION OF THE MACHINE, THEREBY EFFECTIVELY PREVENTING THE LUBRICANT FROM ABSORBING SUBSTANTIAL QUANTITES OF REFRIGERANT, SHUTTING DOWN THE MACHINE AND SUBSTANTIALLY CONCURRENTLY PASSING SUBSTANTIALLY ALL OF THE LUBRICANT FROM SAID SECOND ZONE TO SAID FIRST ZONE, AND THEN EFFECTIVELY PREVENTING THE PASSAGE OF REFRIGERANT INTO SAID FIRST ZONE DURING SHUTDOWN, THEREBY EFFECTIVELY PREVENTNG THE LUBRICANT FROM ABSORBING THE REFRIGERANT DURING SHUT-DOWN, AND UPON STARTING THE MACHINE PASSING LUBRICANT FROM SAID FRIST ZONE TO SAID SECOND ZONE AND SUBSTANTIALLY CONCURRENTLY EFFECTIVELY EQUALIZING THE PRESSURE IN SAID ZONES AT A PRESSURE INTERMEDIATE THE ZONE PRESSURES DURING SHUT-DOWN, WHEREBY DURING START-UP THE PRESSURE OF THE LUBRICANT IS ABOVE THE PRESSURE IN SAID FIRST ZONE DURING SHUT-DOWN, THEREBY EFFECTIVELY PREVENTING FLASHING OF REFRIGERANT IN THE LUBRICANT AND FOAMING OF THE LUBRICANT IN SAID FIRST ZONE AT START-UP OF THE MACHINE.

Claim 2

A METHOD OF PROVIDING LUBRICATION IN A REFRIGERATION MACHINE UTILIZING A REFRIGERANT AND A LUBRICANT MISCIBLE WITH THE REFRIGERANT, AND SAID MACHINE HAVING A LUBRICATION SYSTEM AT LEAST IN PART EXPOSED TO THE REFRIGERANT AND INCLUDING A FIRST ZONE AT A RELATIVELY LOW PRESSURE FOR CONTAINING A SUPPLY OF LUBRICANT AND A SECOND ZONE REQUIRING LUBRICATION AND NORMALLY AT A RELATIVELY HIGHER PRESSURE WHEN THE MACHINE IS SHUT DOWN, SAID METHOD COMPRISING THE STEPS OF CIRCULATING LUBRICANT BETWEEN SAID ZONES FOR LUBRICATING THE MACHINE, PROVIDING A RELATIVELY LOWER PRESSURE IN SAID ZONE DURING COOLING OPERATION OF THE MACHINE, THEREBY EFFECTIVELY PREVENTING THE LUBRICANT FROM ABSORBING SUBSTANTIAL QUANTITES OF REFRIGERANT, SHUTTING DOWN THE MACHINE AND SUBSTANTIALLY CONCURRENTLY PASSING SUBSTANTIALLY ALL OF THE LUBRICANT FROM SAID SECOND ZONE TO SAID FIRST ZONE, AND THEN EFFECTIVELY PREVENTING THE PASSAGE OF REFRIGERANT INTO SAID FIRST ZONE DURING SHUTDOWN, THEREBY EFFECTIVELY PREVENTNG THE LUBRICANT FROM ABSORBING THE REFRIGERANT DURING SHUT-DOWN, AND UPON STARTING THE MACHINE PASSING LUBRICANT FROM SAID FRIST ZONE TO SAID SECOND ZONE AND SUBSTANTIALLY CONCURRENTLY EFFECTIVELY EQUALIZING THE PRESSURE IN SAID ZONES AT A PRESSURE INTERMEDIATE THE ZONE PRESSURES DURING SHUT-DOWN, WHEREBY DURING START-UP THE PRESSURE OF THE LUBRICANT IS ABOVE THE PRESSURE IN SAID FIRST ZONE DURING SHUT-DOWN, THEREBY EFFECTIVELY PREVENTING FLASHING OF REFRIGERANT IN THE LUBRICANT AND FOAMING OF THE LUBRICANT IN SAID FIRST ZONE AT START-UP OF THE MACHINE.