Abstract: A method of coalescing a disperse phase within a continuous phase of a fluid mixture comprising the steps of:(a) supplying said fluid mixture to a primary inlet of a coalescing device;(b) passing said fluid mixture from said primary inlet to a substantially cylindrical chamber of said coalescing device, said primary inlet being arranged substantially radially of said chamber;(c) introducing a fluid to said chamber via a secondary inlet of said coalescing device, said secondary inlet being arranged substantially tangentially to said chamber, thereby setting said fluid mixture into rotating motion within said chamber; and(d) allowing said fluid and said fluid mixture to exit said chamber via an outlet of said coalescing device having a longitudinal axis arranged coaxially with said chamber, such that said exiting fluid and fluid mixture are caused to spin about said longitudinal axis to cause coalescing of said disperse phase.

Abstract: A method of regulating the overflow from a cyclone, hydrocyclone or similar device (1) comprises the steps of passing the overflow (1C) to the main inlet (3C) of a fluidic valve (3) and passing at least a proportion of the underflow (1B) from the device (1) to the control inlet (3B) of the said fluidic valve (3). The flowrate of the overflow (1C) leaving the device (1) is maintained despite variations in feed flowrate or feed flow pressure (1A). Preferably, the underflow (1B) or proportion thereof is passed through a restriction (2) before being passed to the control inlet (3B) of the fluidic valve (3).