Separation method and apparatus for immiscible fluids

Abstract

A wash separator ( 1 ) comprises a vessel ( 2 ) containing a first fluid ( 3 ) and a second fluid ( 4 ) whereby the second fluid ( 4 ) has a differentdensity from the first fluid ( 3 ). The first fluid ( 3 ) is immiscible with the second fluid ( 4 ) and the first and second fluids are separated from each other by an interface ( 5 ), wherein a feed stream ( 15, 24, 31, 61 ) is provided, the feed stream ( 15, 24, 31, 61 ) comprising a dispersion of the first and second fluid ( 3,4 ), such that the second fluid ( 4 ) is forming a dispersephase in the form of droplets which is distributed within the first fluid ( 3 ) forming a continuous phase. A distribution element ( 6 ) is provided in the vessel ( 2 ) to distribute the feed stream ( 15, 24, 31, 61 ) into the second fluid ( 4 ), wherein the feed stream ( 15, 24, 31, 61 ) after having discharged from said distribution element ( 6 ) has a retention time of at most 15 minutes in the feed second fluid in the vessel.

1 .- 16 . (canceled) 
     
     
         17 . A wash separator comprising
 a vessel having a first section for receiving a feed steam containing a first fluid and a second fluid wherein the second fluid has a different density from the first fluid and the first fluid is immiscible with the second fluid and wherein said feed stream separates into a first fluid above an interface therebetween and a second fluid below said interface; and   a distribution element within said vessel for distributing a feed stream comprising a dispersion of the first and second fluid into said second fluid below said interface wherein said second fluid forms a disperse phase in the form of droplets which is distributed within the first fluid forming a continuous phase.   
     
     
         18 . A wash separator as set forth in  claim 17  further comprising a supply element for adding a make up stream of the second fluid to said feed stream upstream of said distribution element relative to said vessel. 
     
     
         19 . A wash separator as set forth in  claim 18  further comprising a mixing element upstream of said distribution element for mixing said make up stream and said feed stream. 
     
     
         20 . A wash separator as set forth in  claim 17  further comprising a line connected to said first section of said vessel for recycling the second fluid into said feed stream upstream of said distribution element. 
     
     
         21 . A wash separator as set forth in  claim 17  wherein said vessel has a bottom and said distribution element has at least one outlet opening spaced from said interface a distance of at most 10 meters. 
     
     
         22 . A wash separator as set forth in  claim 17  wherein said distribution element has at least one outlet opening directed upwardly towards said interface and further comprising a solid retention element below said distribution element for separating a solid phase from said feed stream. 
     
     
         23 . A wash separator as set forth in  claim 17  further comprising an element for promoting coalescence is arranged above said distribution element. 
     
     
         24 . A wash separator as set forth in  claim 17  wherein said vessel has a second section adjacent said first section and a weir separating said first section from said second section whereby said first fluid is allowed to flow from said first section over said weir into said second section. 
     
     
         25 . A method for the separation of fluids comprising the steps of
 feeding a feed stream comprising a dispersion of a first fluid and a second fluid into a vessel of a wash separator, wherein the second fluid has a different density from the first fluid and the first fluid is immiscible with the second fluid;   allowing said feed stream to separate within the vessel into a first fluid above an interface therebetween and a second fluid below said interface;   thereafter distributing an additional feed stream into the second fluid within the vessel; and   thereafter removing the first fluid from above said interface.   
     
     
         26 . A method as set forth in  claim 25  further comprising the step of recycling at least a portion of said second fluid from the vessel below said interface into said additional feed stream prior to distribution within the vessel. 
     
     
         27 . A method as set forth in  claim 26  wherein said portion of said second fluid forming the dispersed phase in said additional feed stream is up to 90 volume %. 
     
     
         28 . A method as set forth in  claim 26  wherein said portion of said second fluid forming the dispersed phase in said additional feed stream is up to 45 volume %. 
     
     
         29 . A method as set forth in  claim 28  further comprising the step of adding additional first fluid as make-up fluid to said feed stream. 
     
     
         30 . A method as set forth in  claim 25  wherein the wash separator is operated under a pressure of less than the pressure at the critical point. 
     
     
         31 . A method as set forth in  claim 25  wherein the wash separator is operated at ambient pressure. 
     
     
         32 . A method as set forth in  claim 25  further comprising the step of feeding the feed stream through a distribution element within said vessel into said second fluid for a retention time of the feed stream in said second fluid of at most 15 minutes. 
     
     
         33 . A method as set forth in  claim 25  wherein said first fluid is an oil and said second fluid is water. 
     
     
         34 . A method as set forth in  claim 25  wherein said first fluid removed from above said interface is oil of at most of at most 10 volume % BSW preferably of at most 5 volume %.