Liquid coolant treating process and apparatus

Claim 1

IN A PROCESS FOR USE IN A MACHINE TOOL COOLANT SYSTEM CONTAINING A CIRCULATING BODY OF AQUEOUS COOLANT EMULSION CONTAINING AS IMPURITIES BACTERIA, PARTICULATE SOLID CONTAMINANTS AND TRAMP OIL, SAID TRAMP OIL BEING PRESENT AS A SEPARATE LIQUID PHASE ENTRAPPED IN SAID EMULSION AND WETTING SAID SOLID CONTAMINANTS, THE STEPS OF: A. CONTINUOUSLY WITHDRAWING FROM ABOUT 0.01% TO 1% PER MINUTE OF THE VOLUME OF SAID CIRCULATING EMULSION, B. CONTINUOUSLY PREHEATING THE WITHDRAWN EMULSION IN A HEAT EXCHANGE MEANS, C. HEATING SAID WITHDRAWN EMULSION TO A TEMPERATURE OF FROM ABOUT 160* TO ABOUT 200*F. WHILE RETAINING AT SAID TEMPERATURE AND SUBSTANTIALLY QUIESCENT IN A POOL IN A TANK FOR A PERIOD OF TIME ON THE ORDER OF FROM ABOUT 30 TO ABOUT 90 MINUTES TO, SUBSTANTIALLY SIMULTANEOUSLY, (1) KILL THE BACTERIA IN SAID PORTION, (2) RELEASE ENTRAPPED TRAMP OIL FROM SAID EMULSION, AND (3) RELEASE SOME OF SAID SOLID CONTAMINANTS FROM THE EMULSION OF SAID OIL, D. SKIMMING THE RELEASED TRAMP OIL FROM THE SURFACE OF SAID POOL AND REMOVING IT FROM SAID TANK,

Claim 3

An apparatus for use in a machine tool coolant system containing a circulating body of aqueous coolant emulsion containing as impurities bacteria, tramp oil and solid contaminants, the tramp oil being present as a separate liquid phase entrapped in said emulsion and wetting said solid contaminants, the improvements of: a. a tank, b. first conduit means connecting the tank to the coolant system and accommodating the flow of coolant from the system to the tank, c. second conduit means connecting the tank to the coolant system and accommodating the return flow of coolant from the tank to the system, d. flow control means in one of said conduit means, e. said first and second conduit means and said flow control means, being constructed and arranged bypass from about 0.01% -1% per minute of the volume of the circulating body through the tank, f. said tank being of a capacity and being constructed and arranged to retain therein the bypassed portion as a quiescent pool for at least one half hour, g. heating means located in said tank and in heat exchanger relation with the pool of coolant retained in the tank, h. control means for said heating means to maintain the coolant in said quiescent pool at a temperature of from about 160*F. to about 200*F., i. skimming means located at the surface of the pool for removing tramp oil from the pool and from the tank, j. solids removal means located at the bottom of the pool for removing solid contaminants from the pool and from the tank, k. a heat exchanger having first and second isolated fluid passages in thermally conductive proximity to one another, said passages being interposed, respectively, in said first and second conduit means to utilize the residual heat of coolant in the second consuit means to pre-heat coolant in first conduit means, l. and a pump interposed in said second conduit means between said tank and said heat exchanger (1) to flow return coolant emulsion from said tank through said heat exchanger and (2) to agitate the still hot coolant to improve the dispersion of the coolant at substantially the temperature of said pool in the aqueous emulsion.

Claim 4

An apparatus for use in a machine tool coolant system containing a circulating body of aqueous coolant emulsion containing as impurities bacteria, tramp oil and solid contaminants, the tramp oil being present as a separate liquid phase entrapped in said emulsion and wetting said solid contaminants, the improvements of: a. a tank, b. first conduit means connecting the tank to the coolant system and accommodating the flow of coolant from the system to the tank, c. second conduit means connecting the tank to the coolant system and accommodating the return flow of coolant from the tank to the system, d. flow control means in one of said conduit means, e. said first and second conduit means and said flow control means, being constructed and arranged bypass from about 0.01% -1% per minute of the volume of the circulating body through the tank, f. said tank being of a capacity and being constructed and arranged to retain therein the bypassed portion as a quiescent pool for at least one half hour, g. heating means located in said tank and in heat exchanger relation with the pool of coolant retained in the tank, h. control means for said heating means to maintain the coolant in said quiescent pool at a temperature of from about 160*F. to about 200*F., i. skimming means located at the surface of the pool for removing tramp oil from the pool and from the tank, j. solids removal means located at the bottom of the pool for removing solid contaminants from the pool and from the tank, k. a heat exchanger having first and second isolated fluid passages in thermally conductive proximity to one another, said passages being interposed, respectively, in said first and second conduit means to utilize the residual heat of coolant in the second consuit means to pre-heat coolant in first conduit means, l. and a pump interposed in said second conduit means between said tank and said heat exchanger (1) to flow return coolant emulsion from said tank through said heat exchanger and (2) to agitate the still hot coolant to improve the dispersion of the coolant at substantially the temperature of said pool in the aqueous emulsion.