Patent GB-830380-A (GB)
Title: Apparatus for the removal of water, wax, gum and dirt from hydrocarbon liquids
IPC: C10G33/06
Filed: 1956-01-30
Abstract: <PICT:0830380/III/1> <PICT:0830380/III/2> <PICT:0830380/III/3> <PICT:0830380/III/4> <PICT:0830380/III/5> An apparatus for removing water, wax, dirt and other impurities from hydrocarbon liquids such as petrol comprises a container having the following zones through which the hydrocarbon liquid is passed in sequence:-(i) a scrubbing zone comprising a body of tower packing into which the hydrocarbon liquid is dispersed and washed with water; (ii) a water-contacting zone comprising a restricted opening through which the hydrocarbon liquid must pass and which is surrounded by a settling zone; (iii) a filtering zone in which solid impurities are filtered and smaller globules of water are coalesced, and which has setting zones before and after the filter; all three settling zones having contaminant discharge conduits, and means being provided for maintaining the water level constant at above the height of the contaminant discharge orifice in the settling zone surrounding the water-contacting zone (ii). The main container comprises four separable portions of which B contains the scrubbing zone (i) and water-contacting zone (ii), E contains the filtering zone (iii), J contains a dessicator for removing last traces of moisture, and K is a chamber which absorbs pressure shocks which might occur on start-up or shut-down. Portions B and E are shown in cross-section in Fig. 3.  To start up, drain valve 4a is closed and water introduced through distributer 8 (shown in plan in Fig. 4) until it reaches level L. Thereafter float switch 26 automatically maintains the level by opening or closing drain valve 4a.  The water supply is then disconnected and the hydrocarbon liquid passed in at 8.  It rises through perforated plate 12 and tower packing 13, which causes fine water droplets present in the hydrocarbon to coalesce and blend into the water of the water bath, and coarser solid impurities to settle.  The hydrocarbon then passes up through the conical restriction 16, which results in an increase in velocity and this, together with the sudden change of direction as the hydrocarbon passes under annular flange 18 causes more suspended water droplets to coalesce and separate out, with further solid impurities, which all drain down conduits 23, 24 and are continuously removed through drain 4.  The hydrocarbon passes up and over baffle 44, through a bank of leaf filters on frame 38 into settling chamber F, having a sump 48a for water and sediment. Fig. 8 shows the leaf filter assembly together with settling chamber F withdrawn from the main casing.  Each leaf filter comprises a frame 38 (Fig. 9) with perforated sides 38a carrying several layers of glass fibre 40, 40a, cotton linters 41, burlap or sisal sheeting 41a and an outer laminated filtering stocking 39.  Each frame is suspended cantilever fashion from plate 37 by nuts and bolts in slots 48.  Liquid passes through the filters into the hollow frames 38, through slots 48 into settling chamber 46 having vertical dividers 51 which have clearance at the bottom for the passage of water and sediment.  During operation the filter leaves are subject to external pressure, but when pressure is released on shut-down, the filter coverings expand slightly and shed adhering dirt.  Filtered hydrocarbon liquid passes up through perforated plate 47 and a second scrubber comprising packing 53, where further drops of water may separate out, settle in chamber H and drain down inclined floor 56 and conduit 59 to sump 48a.  The hydrocarbon then passes through dessicating material 62, such as rock salt or alumina, and out at 64.