FR2475936A1 - FULL AND VISIBLE BOW CENTRIFUGE - Google Patents

Abstract

THE INVENTION CONCERNS A CENTRIFUGE INCLUDING A BOWL WITH FULL WALLS AND A CONVEYOR SCREW, FOR THE CONTINUOUS SEPARATION OF SOLID-LIQUID MIXTURES AS WELL AS MIXTURES OF LIQUIDS OF DIFFERENT DENSITY OR PHASES OF DENSITY. THE DRUM BOWL 1 AND THE CONVEYOR SCREW 2 ARE CYLINDRICAL, AND THE DRUM BOWL 1 IS EQUIPPED WITH OPENINGS 3, ESPECIALLY NOZZLES 8, IN THE SOLID MATERIAL DISCHARGE AREA OR DENSE PHASE.

Description

The invention relates to a centrifuge

  with a full-walled bowl and a transpor-

  for the continuous separation of solid-

  liquid as well as mixtures of liquids of different densities, that is to say phases of different densities. The solid bowl and screw auger centrifuges known until now consist, for the bowl, of a cylindrical part and of a conical part and, for the auger, also of a cylindrical part and from one part

  conical, placed respectively in the corresponding parts

  of the bowl. In these known centrifuges the solids or the densest phases are moved upwards in the conical zone of the drum bowl by means of the screw conveyor and are thus extracted from the liquid and explused. In this area, it is impossible to avoid mixing the liquid with the solids or the densest phase from which it has already been separated. This phenomenon may, in many cases, have an adverse effect on the effectiveness of the separation. In addition, the installation of wear plates on the propeller

  of the conical shape of the conveyor screw is an ope-

  rationing not only painful but still very

expensive in matter and money.

  The technical problem that arose was the following given a solid bowl centrifuge, greatly simplifying the construction and, at the same time, improving the separation efficiency, this

  while avoiding the disadvantages described above.

  This technical problem is solved in the

  centrifuge according to the invention, which is

  characterized in that the drum bowl and the auger

  are cylindrical, and the drum bowl is equipped with

  in particular, in the area where the solid material or the denser phase are discharged. Since the drum bowl and the auger, in accordance with the present invention, have only a cylindrical shape and no longer have conical parts, in comparison with the known solid bowl centrifuges, not only simplification with regard to construction but still a much appreciated economy of material and money. Furthermore, because openings, in particular nozzles, are formed in the drum bowl in the zone through which the solid material or the heaviest phase emerges, it is definitely avoided that the phases already separated from one of the other mix again and one improves

  so much the separation efficiency.

  According to another preferred embodiment

  In the present invention, the apertures, in particular the nozzles, are of varying sizes. This is a very advantageous way to affect the quantity of solids or the heaviest phases that one

wants to get out.

  According to another embodiment of the invention,

  the openings, in particular the nozzles, are

  connected in cooperation with an action-control

  mechanically so that the openings in the drum bowl or the nozzles are

  alternatively covered or free during the movement

  the conveyor screw in relation to the drum bowl.

  Thanks to these measurements it is very advantageous to vary, in quantity, automatically, the evacuation of the solids or the densest phases by modifying the difference between the speed of rotation of the screw conveyor and that of the drum bowl and, so,

the optimiser.-

  Other details, features and advantages of the invention will appear on reading the following description which describes a bowl centrifuge.

  full and screw conveyor, shown schematically

  longitudinally in the accompanying drawing.

  As seen in this drawing, the drum bowl 1 and the conveyor screw 2 are cylindrical in the centrifuge according to the invention. In the zone o where the discharge of the solid matter or the

  heavier phase the drum bowl 1 is equipped with

  tures 3 which are evenly distributed around the drum bowl. The conveyor screw 2 is mounted on a hollow shaft 4 which constitutes the body of the screw and through which is introduced into the drum of the centrifuge, in the direction indicated by the arrow 5, the mixture of materials to be separated from each other, that is to say the mixture of a solid material and a liquid or the

  mixture of liquids of different densities.

  When running this centri-

  With a full bowl and a screw feeder, the centrifugal drum 1 and the conveyor screw 2 are rotated at different speeds, so that the conveyor screw 2 rotates at a slightly higher or even slightly lower speed than the centrifugal drum 1. Under the action of centrifugal force the solids separate from the liquid or the denser phase separates from the lighter phase, the solids or the denser phase being deposited in the region of the bottom of the drum bowl and the liquid or

  the lightest phase forming an upper layer.

  The solid matter, or the densest phase, is then

  grabbed by the conveyor screw 2 which leads to the openings

  tures in the drum bowl in the area of the

  cuation, openings through which it leaves in the direction of the arrow 6. The liquid, or the lightest phase, out in the direction of arrow 7 by an opening (not shown in detail in the drawing) formed in the front wall of the drum bowl 1, on the right side of the solid bowl centrifuge and

conveyor screw.

  Because, according to the invention, the drum bowl 1 and the conveyor screw 2 are cylindrical and the evacuation of the solid material or the densest phase is through the openings in the drum bowl 1, we can be sure that the phases already separated from each other do not mix in the evacuation zone - unlike what happens in the known full-screw and solid-screw centrifuges - so that the efficiency separation is much improved. In addition, the bowl centrifuge

  full and screw transforteuse which is the subject of the in-

  vention is particularly noteworthy for its simple and economical construction. Instead of the openings 3 or also in addition to the openings 3 it is however possible, and even very advantageous, that the drum bowl carries - as this is represented by a dashed line in the drawing - the nozzles 8 which are linked with cooperation to a control device - also represented by a dashed line in the drawing having the shape of an annular disk 9 and fixed on the hollow shaft 4 of the screw, so that the openings 3 and / or the nozzles 8 are alternately coated

  and released during the relocation of the conveyance

  2 relative to the drum bowl 1. To achieve

  this goal it is good to provide the annular disc 9 with

terruptions.

  This control device actuated mechanically

  In accordance with the present invention, a device which cooperates with the openings 3 and / or the nozzles 8 constitutes a very advantageous means for varying the discharge rate of the solids or of the densest phase and thus for improve the separation efficiency. It is also possible to modify or vary very advantageously the quantities of solids or the heaviest phases leaving

  centrifugal drums if the openings 3, more

  particularly the openings of the nozzles 8, are provided so as to vary in size. For this we can be content with simple more or less elastic fittings whose opening width can be changed in relatively wide intervals by screwing

  more or less deep in openings 3 or nozzles 8.

Claims (4)

  1.- Centrifuge with a solid bowl and with the continuous separation of solid-liquid mixtures as well as mixtures of liquids having different densities, or phases with different densities, centrifuge characterized in that the drum bowl (1) and the auger (2) are cylindrical, and in that the drum bowl (1) is provided with openings (3), in particular nozzles (8), in the evacuation zone   solid matter or the densest phase.   2. Centrifuge according to claim 1,   characterized in that the openings (3), more particularly   the openings of the nozzles (8), are designed   so that their width can be changed.   3. Centrifuge according to one of the   1 and 2, characterized in that the openings (3), more especially the openings of the nozzles (8), are cooperatively connected to a control device   mechanically actuated, so that the openings   (3) and / or the drum bowl nozzles (8) are   alternatively covered or released during the movement   relative position of the auger (2) relative to in the drum bowl (1).   4. Centrifuge according to any one   Claims 1 to 3, characterized in that the   control device consists of an annular disk   wire (9) mounted on the shaft (4) of the screw.