US3166503A

US3166503A - Apparatus for centrifugal separation

Info

Publication number: US3166503A
Application number: US176203A
Authority: US
Inventors: Thylefors Henric Wilhelm
Original assignee: Separator AB
Current assignee: Alfa Laval Holdings Amsterdam AB
Priority date: 1960-12-29
Filing date: 1962-02-28
Publication date: 1965-01-19
Anticipated expiration: 1982-01-19

Description

Jan. 19, 1965 H. W. THYLEFORS APPARATUS FOR CENTRIFUGAL. SEPARATION Filed Feb. 28, 1962 IN VEN TOR. Henric Wflhelm Tfylefors 3,166,503 APPARATUS FOR CENTRIFUGAL SEPARATEQN Henric Wilhelm Thylefors, Stockholm, Sweden, assignor. to -Aktiebolaget Separator, Stockholm, Sweden, a cor-' poration of Sweden Filed Feb. 28,1962, Ser. No. 176,203

2 Claims. (Cl. 233-4) This invention relates to an apparatus for the centrifi ugal separation of a mixture of liquids, particularly a.

mixture of liquids having limited solubility in each other (such as water and oil), wherein a separated first liquid is discharged into an evacuated receiving chamber. One of the constituents of the liquid mixture may be either a fatty or a mineral oil which is to be recovered in as dry a condition as possible. The other constituent of the liquid mixture may be water or the combination of a liquid of organic nature and anor-ganic extraction agent which is to be entirely removed from the liquid.

A known method and apparatus for performing this objective is described in Swedish Patent No. 133,520. However, that system has a serious drawback in that the separated water is discharged in an atomized state into a reception chamber where, due to the large contact area between the water droplets and the atmosphere within the chamber, the atmosphere becomes saturated with moisture vapor. In this known system the water receiving chamber communicates in turn with the receiving chamber for the separated oil, so that the latter chamber also has an atmosphere which is moist. As a result, water in solution in the oil evaporates poorly despite the fact that the oil is finely atomized when it reaches its receiving chamber and that the latter chamber is manitained under vacuum.

According to the present invention, the above-mentioned drawback is eliminated in that the reception chamber for the separated first liquid is maintained in vacuumconveying communication with a chamber in the centrifuge rotor from which a mixture of air and a separated second liquid is exhausted. This modification prevents the atmosphere in the receiving chamber for the separated first liquid from being saturated with vapors of the second liquid, because the latter liquid is removed after the separation without having had an opportunity for intense evaporation through atomization.

The exhaustion of the mixture of air and separated sec ond liquid from the centrifuge rotor may be effected by various types of pumping means; but for this purpose a paring member, preferably a paring disc, may be used to particular advantage.

A preferred form of the new apparatus for effecting the above-mentioned method of centrifugal separation will be hereinafter described in detail with reference to accompanying drawing, in which the single illustration is a vertical sectional view of the improved separator.

In the drawing, an outer stationary housing 1 hermetically encloses a centrifuge rotor 2 which is disposed for rotation on vertical rotor shaft 4 and forms a locus of centrifugal force. Hermetic sealing is maintained between the rotor shaft4 and housnig 1 by means of a slide bearing 3 disposed between the members. Water-bearing oils, destined for separation, is fed into the centrifuge through a stationary tube 5. It flows, via a distributor 6 and distribution holes 7, into a set of conical separator discs 8 in a separating zone of the centrifugal locus. From the inner edges of the disc set 8, separated oil is conveyed, via the inside of a top disc 9, into a chamber 10 disposed at the top of the rotor. Separated oil is discharged from chamber 10 through radial channels 11 dis- 3,166,503 Patented Jan. 19, 1965 "ice tributed about the periphery thereof, into stationary receiving chamber 12. The separated oil is discharged from chamber 12 thorugh pipe 13 by pump 14.

Separated water flows through a passage 9a between the top disc 9 and rotor cover 15, over a regulating disc 16, through channel 17 in the wall of chamber 10, and into a paring chamber 18 of the rotor. A stationary paring disc 19, disposed within the chamber, orcollecting region 13, has such a high exhaust capacity that, in addition to its capability of exhausting all the separated water,

it is also able to exhaust air to such an extent that a substantial vacuum will be maintained in the portion of paring chamber 18 which is free of liquid. The paring disc 19 exhausts the air-water mixture through a discharge pipe 20 connected to this disc and hermetically sealed into the top wall of housing 1. Thus, vacuum will be maintained not only within the rotor 2 but also within the oil reception chamber 12 (via annular opening 21 between the rotor 2 and the discharge pipe 20) as well as within the space between the housing 1 and the rotor 2 (via opening 22).

Water collected in the paring chamber 18 presents a very small contact area to the atmosphere therein, this contact being limited to a cylindrical area determined by the outer edge of the paring disc, thus minimizing the problem of water vaporization Within the chamber. Further, the paring disc 19 continuously exhaust-s air not only from the chamber 1% but also, via opening 21, from chamber 12. As the flow of air will now be from chamber 12 to chamber 18, water in paring chamber 18 cannot moisten the atmosphere in the oil receiving chamber 12. Thus, moisture present in the oil in chamber 12 may freely evaporate, in proportion to the degree of vacuum maintained and pass toward chamber 18 for removal from the system.

I claim:

1. A centrifugal separator comprising a hollow rotor forming a zone for centrifugally separating a mixture of liquids into first and second separated liquids, the rotor having an inlet for feeding the mixture to said zone, means forming an air-tight first chamber outside the'rotor for receiving the first separated liquid from said zone, the rotor having a second chamber for collecting the second separated liquid from said zone and which is in vacuumconveying communication with said first chamber, a first discharge pipe leading from said first chamber, a second discharge pipe leading from said second chamber, pump .means in said second chamber operable to discharge through said second pipe a mixture of air from said first chamber and second separated liquid from said second chamber, and a pump connected to said first discharge pipe and operable to withdraw said first liquid from said first chamber, whereby said first chamber is maintained under vacuum by said pump means and vapors from said first chamber are exhausted by way of the second chamber.

2. A centrifugal separator according to claim 1, in which said pump means is a paring member located in the second chamber and connected to the discharge pipe.

References Cited in the file of this patent UNITED STATES PATENTS 2,144,229 Ruda Jan. 17, 1939 2,302,512 Wilsmann Nov. 17, 1942 2,790,598 Besk-ow Apr. 30, 1957 FOREIGN PATENTS 133,520 Sweden Nov. 6, 1951

Claims

1. A CENTRIFUGAL SEPARATOR COMPRISING A HOLLOW ROTOR FORMING A ZONE FOR CENTRIFUGALLY SEPARATING A MIXTURE OF LIQUIDS INTO FIRST AND SECOND SEPARATED LIQUIDS, THE ROTOR HAVING AN INLET FOR FEEDING THE MIXTURE TO SAID ZONE, MEANS FORMING AN AIR-TIGHT FIRST CHAMBER OUTSIDE THE ROTOR FOR RECEIVING THE FIRST SEPARATED LIQUID FROM SAID ZONE, THE ROTOR HAVING A SECOND CHAMBER FOR COLLECTING THE SECOND SEPARATED LIQUID FROM SAID ZONE AND WHICH IS IN VACUUMCONVEYING COMMUNICATION WITH SAID FIRST CHAMBER, A FIRST DISCHARGE PIPE LEADING FROM SAID FIRST CHAMBER, A SECOND DISCHARGE PIPE LEADING FROM SAID SECOND CHAMBER, PUMP MEANS IN SAID SECOND CHAMBER OPERABLE TO DISCHARGE THROUGH SAID SECOND PIPE A MIXTURE OF AIR FROM SAID FIRST CHAMBER AND SECOND SEPARATED LIQUID FROM SAID SECOND CHAMBER, AND A PUMP CONNECTED TO SAID FIRST DISCHARGE PIPE AND OPERABLE TO WITHDRAW SAID FIRST LIQUID FROM SAID FIRST CHAMBER, WHEREBY SAID FIRST CHAMBER IS MAINTAINED UNDER VACUUM BY SAID PUMP MEANS AND VAPORS FROM SAID FIRST CHAMBER ARE EXHAUSTED BY WAY OF THE SECOND CHAMBER.