Patent GB-848817-A (GB)
Title: Method for removing solid contaminant and/or emulsified water from organic solvents and oils and apparatus for practising said method
IPC: B01D46/24
Filed: 1957-09-02
Abstract: Liquid to be purified, e.g. an oil (such as lubricating oil, high detergent oil, crankcase oil, vegetable oil or animal oil) or a solvent (such as Stoddart solvents used in dry-cleaning, or toluene, toluol or acetone), and containing solids, water, acids and air or other gases, is introduced at 141, Fig. 1, and drawn by vacuum, maintained in a chamber 17, through a heater 139 and a diaphragm control valve 153 to the inlet chamber 15 of a tank 11. It then passes through ports 152 (Fig. 1) or inlets 35, (Fig. 3) in a deck plate 13 to the inside of separating units 37, where contaminant is retained and water is separated out from the liquid in the form of droplets.  When the liquid with water droplets reaches the surface of the units the water vaporizes, carrying with it acids and air and other gases.  The tank 11 is cooled by water passing through a jacket 21 so that the vapour condenses on touching the tank wall, the condensate flowing down to the bottom 19.  Purified liquid falls into an opentopped collector 30 within the tank 11 and is discharged by a pump 137 through a regulator valve 99 (see also Fig. 6) at 157.  When there is sufficient liquid in the collector <PICT:0848817/III/1> <PICT:0848817/III/2> <PICT:0848817/III/3> 30 to raise a float valve (consisting of a float 89 supported on a pointed stem) off an orifice in a conduit, the pressure in a conduit 161, fed with purified liquid through an orifice 159, is relieved, whereupon a spring 165 acting through a diaphragm 163 (in valve 153) is enabled to bring a valve member 167 down on to its seating and stop the inflow of untreated liquid.  The temperature of the liquid is related to its water-content.  Thus, the valve member 110, Fig. 6, of regulator valve 99 is brought wholly or nearly into contact with its seating by bi-metallic strips 109 when liquid at too low a temperature enters chamber 108 from line 154, (see also Fig. 1), so that egress at 157 is wholly or partly prevented, and the liquid is forced along a by-pass line 173, Fig. 1, upstream of the valve 99, for re-circulation.  To produce the required vacuum in chamber 17, Fig. 1, a Venturi 125 is provided in the inlet line 119 supplying water to the waterjacket 21; the water is turned on before the purifying operation and is continuously discharged at 121 together with condensate, from the bottom 19, withdrawn by the Venturi 125. Each separating unit 37, Fig. 3, consists of a stack of fibre-glass discs 57, 59, (having different sized bores) alternately arranged, bonded with a thermosetting resin and compressed during curing of the resin. The stack is arranged between end caps 63, 65 each having slots (not shown) for securing in place by wire a stocking 71 of knitted cotton having a ribbed construction which is placed over the stack and end caps.  The assembly thus produced is retained between an end plate 51, fastened to an inlet tube 39, and an end plate 49 removably secured to a plug 43.  In Fig. 2, (not shown), the Venturi 125 is dispensed with and the condensate from bottom 19 is withdrawn by a vacuum pump.  This modification is appropriate where the liquid to be treated is heavily-contaminated solvent, the solvent being recovered as the condensate and the heavier distillation residue being recovered in the collector 30.