FR2662373A3 - Improved decanter (sedimentation) centrifuge - Google Patents

Abstract

A drum (2) and a feed screw (3) are arranged inside a casing (1). Openings (7, 8) serve to remove the decanted liquid and the solid matter. In order to reduce the residual water content of the solid matter with a highly dispersed solid phase, a collector (15) is arranged beneath the drum (2) for the influx of hot gas. A nozzle (16) is provided on the upper part of the casing for the removal of the gas. Openings (17, 18) and directing blades (19, 20) serving to inject and eject the hot gas. These blades are, on the lower front face of the inner body (11), inclined in the direction of rotation of the drum (2) and, on the upper front face of the outer body (12), inclined in the opposite way to the direction of rotation of the drum (2).

Description

The present invention relates to a settling centrifuge

  to separate heterogeneous liquid mixtures using central forces

  trifuges A decanting centrifuge according to the invention can be used in the metallurgical, chemical, pharmaceutical or similar industries.

  A known decanting centrifuge of this type has a characteristic

  ter, a cylindrical and conical drum, a worm consisting of a cylindrical and conical drum of worm and a spiral fixed on the latter, a set of discs arranged inside

  the cylindrical part of the endless screw drum, windows

  intended to evacuate the decanted liquid and the solid matter, a disc

  pressure, supply hose and additional conical bodies

  or additional conical elements in the form of

  drums, which are arranged concentrically around the co-

  Drum screw The outer body is rigidly assembled to the drum.

  bour and the inner body is assembled to the endless screw drum, and some spiral bands or evacuation spirals are fixed on the

  outer faces of the drum and the body, for the transport of

solid.

  The object of the present invention is to lower the water content

  residual solids discharged.

  According to the invention, this object is, for a decanter centrifuge -

  tion of the aforementioned known type, achieved by the fact that a collector is arranged below the lower end of the drum for the supply

  hot gas, the casing is provided in its upper part with a tube

  lure for the evacuation of hot gas, the lower front face of the

  internal conical body of the worm and the upper front face

  upper of the outer body of the drum having openings and guide blades located on the periphery and used to bring in

  and take out the hot gas, the guide blades on the front face

  of the inner body being inclined in the direction of rotation of the drum, and the guide blades on the upper front face of the outer body being inclined opposite the direction of rotation of the drum

3 5 drum.

  The following discussion describes in more detail an example of an implementation

  tion of a decanting centrifuge according to the invention using the appended drawings, in which: FIG. 1 is a view in longitudinal section of a decanting centrifuge,

  FIG. 2 is a view in projection of part of the centrifuge

  settling tank according to FIG. 1, in the direction of arrow A, FIG. 3 is a view in projection in the direction of arrow B in FIG. 2, FIG. 4 is a view in projection in the direction of arrow C of Figure 2, Figure 5 is a longitudinal sectional view of a variant and

  Figure 6 is a sectional view of another variant.

  In Figure 1, the movement of a suspension is represented by black and white arrows, the flow of a decanted liquid

  by white arrows, and the flow of a gas by arrows on-

  dulantes. The decantation centrifuge has a casing 1, a drum

  cylindrical and conical 2, an endless screw 3 consisting of the cy-

  cylindrical and conical endless screw 4 and a spiral 5 fixed on the latter, a set of discs 6 arranged inside the cylindrical part of the endless screw drum 4, openings 7, 8 for the evacuation decanted liquid and solids, a pressure disc 9, a supply pipe 10, and additional bodies or additional conical elements in the form of drums 11, 12, which are arranged concentrically around the conical part of the drum 2 The outer body 12 is rigidly assembled to the drum

  2, and the inner body 11 is assembled to the worm drum 4.

  Spiral bands are fixed to the evacuation endless screw horn 13, 14 on the external faces of the drum 2 and of the body 11, to

  solid matter removal.

  A manifold 15 is disposed below the lower end

  drum 2 for the supply of hot gas; a pipe 16 is provided in the upper part of the casing 1 for the evacuation of the hot gas. The lower front face of the internal body 11 of the worm 3 and the upper front face of the external conical body.

  12 of the drum 2 have openings 17, 18 and direct blades

  19.20, located on the periphery and used to bring in and

  take out the hot gas The guide blades 19 on the front face

  of the inner conical body 11 are inclined in the direction of rotation of the drum 2, in order to guarantee that the pressure of the hot gas in the drum 2 is maintained, and the guide blades 20 on the upper front face of the outer conical body 12 are inclined at

  opposite the direction of rotation of the drum 2, in order to create a depression

sion in the openings 18.

  Openings 21 are configured in the upper part of the

  body 11 for the evacuation of partially de-solids

  hydrated, and openings 22 are configured in the outer body

  laughter 12 for the liquid expressed in solid matter A pocket 23 is configured in the casing 1, which surrounds the external body 12 in order to collect the liquid expressed in solid matter in the bodies 11, 12 The gap present between the pocket 23 and the body 23 is made small, so that the heat transfer fluid, by

  hot gas, for example, can hardly escape through this gap.

  In order to avoid heat loss, the casing 1 of the centrifuge is

  fitted with thermal insulation 24, and the connection between the central

  runaway and a solids collector is made substantially airtight. We will now describe the operation of the settling centrifuge. The drum 2 provided with the conical body 12 and the worm screw 3 provided with the conical body 11 are put into an omega rotation movement by a corresponding drive, not shown The drive produces a slight delay or an advance of the worm 3 relative to the drum

  2, for example from 10 to 20 revolutions / minute.

  Before loading a suspension, hot gas is sent into

  the centrifuge by the collector 15 Due to its co-configuration

  nique, the body 12 transports the hot gas towards the larger diameter end The guide blades 19, disposed in front of the openings 17, push the hot gas into the chamber formed by the drum 2 and the body 11 The guide blades 20 , arranged in front

  the openings 18 produce a depression in the region of the openings

  This contributes to the fact that the gases and vapors of a volatilizing liquid, during the supply of a suspension in the

  centrifuge, are forcibly removed from the chamber

  driven by the drum 2 and the conical bodies 11, 12 Under the action of the heat transfer fluid, there is a heating of the additional conical bodies 11, 12 as well as of the conical part of the drum 2 and that of the endless discharge screws 13, 14 In order for the action of the heat transfer fluid on the external face of the body 12 to be more effective, the

  pocket 23 intended to receive the expressed liquid is configured near

  mite openings 22 This arrangement of the pocket 23 increases the contact surface of the outer face of the body 12 with the fluid

coolant.

  Following a prior heating of the bodies 11, 12, the above

  initial pension is, without supply of hot gas as heat transfer fluid

  carrier, introduced by the supply pipe 10 into the centri-

  runaway, and it enters the conical part of the drum 2 and forms

  inside the latter an annular layer, the radius of which

  laughter is determined by the position of the openings 7 During the pass-

  wise through the settling zone of the drum 2 and of the disc assembly 6, the liquid phase of the suspension is separated from the particles of solid matter, which are discharged from the drum 2 in the form of solid matter through the opening 7 , and which are removed from the centrifuge by the pressure disc 9 The particles deposited on the walls of the drum 2 form a layer of solid matter, which is transported by the worm 3 along the wall of the drum 2 to the end of smaller diameter, and transferred to the inner face of the body 11, along which, using the worm evacuation screw 13, it is transported towards the largest

  diameter, up to the openings 21 The solid particles are trans-

  carried out by these openings 21 on the inner face of the body 12, and transported by the evacuation endless screw 14 to the window 8,

  to be removed from the drum 2.

  During transport along the inner faces of the bodies 11, 12, additional dehydration of the solid materials takes place, as a result of drying or even a draining of water in

  the centrifugal force field The liquid removed from the solids

  The liquid flows out of the external body 12, through the openings 22, into the receiving pocket 23, and it is evacuated from the centrifuge. The hot gas penetrates further into the chamber formed by the wall of the drum 2 and the body 12. inside the drum 2, the gas only penetrates up to

  the annular layer formed by the liquid, leading to a hy-

  hydraulics. The vapors of the liquid phase formed during the transport and drying of the solid materials are, together with the gas flow, discharged from the drying zone through the openings 22, then

  of the centrifuge housing by pipes 16.

  The invention makes it possible to obtain dry solid matter which can be

  free, without the need for additional heat treatment

stop.

  The variant shown in FIG. 5 also presents a

  heating jacket H, which surrounds the casing 1.

  Figure 6 shows in section a variant for the separation of suspensions in which are contained crystals which are themselves lighter than the filtrate In this case, a filter cloth F is provided which retains the crystals The filtrate is evacuated by the by means of a separate chamber FK and a discharge pipe S. In order to improve the drying of the separated crystals, the separation chamber can be connected to a condenser or to a pump system with

empty.

Claims (4)

  1 Decanting centrifuge, comprising a casing (1), a cylindrical and conical drum (2), a worm device (3) consisting of a cylindrical and conical drum of worm (4) and a screw endless (5) fixed on the latter, a set of discs (6) arranged inside the cylindrical part of the screw drum   endless (4), openings (7, 8) for respectively discharging the li-   decanted and the solids, a pressure disc (9) and a supply pipe (10), characterized in that in order to decrease the residual water content of the solids with very dispersed phase, a collector (15) is arranged below the lower end of the drum (2) for the supply of hot gas, the casing (1) is provided in its upper part with a tube (16) for the evacuation of hot gas, the face lower front of the internal conical body (11) of the worm (3) and the upper front face of the external body (12) of the   drum (2) having openings (17, 18) and direct blades   trices (19, 20) located on the periphery and used to bring in and out the hot gas, the guide blades (19) on the front face   lower of the inner body (11) being inclined in the direction of ro-   tation of the drum (2), and the guide blades (20) on the front face   upper sheet of the outer body (12) being inclined opposite the direction of rotation of the drum (2).   2 Decanting centrifuge according to claim 1, charac-   terized in that a heating jacket (H) is fixed around the casing   (1) to improve the drying effect.   3 Decanting centrifuge according to claim 1, charac-   terized in that in order to separate suspensions in which the crystals are lighter than the filtrate, the crystals are retained by a filter cloth (F), and the filtrate is discharged via a separate chamber (FK) and a drain pipe (S).   4 Decanting centrifuge according to claim 1, charac-   In that in order to improve the drying of the separated crystals, the separation chamber of the settling centrifuge is connected to a   condenser / vacuum pump system.