Patent GB-344464-A (GB)
Title: Improvements in centrifugal separators and methods of operating same
IPC: B04B1/12
Filed: 1929-09-09
Abstract: 344,464. Centrifugal machines. FAWCETT, H. W., 3, Kent Road, Harrogate. Sept. 9, 1929, Nos. 27419/29, 31487/29, and 20282/30. [Class 23.] Density separators, discharging. -Suspended solids are separated from liquids, and their discharge through peripheral apertures in the drum of a centrifugal separator is assisted by an auxiliary liquid, which is supplied in the vicinity of the discharge apertures at such a rate that the interface or junction between the auxiliary liquid and the useful liquid undergoing treatment, is substantially s t a - tionary. The interface is formed in small apertures in a partition between the liquids. The bowl b has a number of bays,'the apices of which are fitted with plugs c having apertures c<1> for the discharge of solids. A liner m with plates l is secured inside the bowl, and the auxiliary liquid which is supplied through the pipe g to the chamber f passes through the passage e formed between the bowl and the liner, to the discharge apertures. The liquid for treatment passes through peripheral openings in the pipe h to the chamber a<1>, then through the channel a to the liner plates l which have the usual apertures l<1>. Plugs n<1> are screwed into the liner, each plug having an aperture n<2> substantially larger than the discharge aperture c<1>, and an annular passage between the liner and the bowl communicates between the various apertures c<1>, n<2> to equalize the discharge pressures. The interface between the auxiliary liquid and the useful liquid is preferably located in the apertures n<2>, and the centrifugal pressures are regulated to obtain this. An externally threaded pipe o can be screwed into or out from the chamber f to which the auxiliary liquid is supplied, to vary the head under which the wall of liquid is formed in the drum. The excess of auxiliary liquid passes through the return passage e<1> and is discharged over an annular disc q which may be replaced by others of different diameters. Similar arrangements are used to regulate the pressure of the useful liquid, a tube o being inserted for a variable distance into the chamber a<1>. A minimum clearance is left between the liner plates k and the casing b, and apertures k<1> are provided near the outer edges of the plates. A heavy liquid is introduced to form a wall u below the discharge apertures ; a heavy component of the liquid undergoing treatment will be deposited on this wall u and will float over the weir v. Two sets of bays may be superimposed in the same machine and additional liquid supply pipes may be provided. Means may be associated with the separator to regulate the pressure, or rate of supply of either or both liquids, and the quantity of liquid discharged through the apertures c<1> may be automatically controlled. The chambers or pipes through which the auxiliary liquid flows in the separator may be heat-insulated, so that the temperature of this liquid may be substantially different from that of the useful liquid. A second auxiliary liquid, of greater specific gravity than that of the useful liquid may be introduced into the separator. A third auxiliary liquid may also be used ; it is not miscible with the useful liquid or the seeond auxiliary liquid and has a specific gravity between the specific gravities of these liquids. Specification 330,958, [Class 23, Centrifugal machines &c.], is referred to.