JPH01151959A - Centrifugal separator - Google Patents

Abstract

PURPOSE:To raise a filtration rate of raw liquid and shorten the time required for discharging liquids as well, by providing a skimming pipe to discharge liquids which has been filtered through a filter holes of a diaphragm and stored in a liquid chamber. CONSTITUTION:Raw liquids L present within the inner periphery of a layer of solid substances S are filtered through the layer S and filter holes 17 of a circular wall 18 for filtration, while said liquids are filtered through filter holes 28, 29 of diaphragm 23, 24 respectively. The liquids which have been discharged through those partition walls into a liquid chambers 25, 26 are discharged through skimming pipes 45, 46. For washing the layer of solid substances, these pipes 45, 46 are moved backward and then washing liquid is supplied into a basket 16. At this time, the washing liquid which has passed through the filter holes of the diaphragm is collected in the liquid chambers. As a result, liquid levels of the washing liquid in the basket can be kept constant, causing sufficient quantity of washing liquid to be supplied for washing the layer of solid substances. In this manner, used washing liquid is discharged through skimming pipes from the liquid chambers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a centrifugal separator that supplies a stock solution into a rotationally driven basket and separates the stock solution into liquid and solid matter.

[Prior Art] In a basket-type centrifuge, a stock solution (slurry) is supplied into a rotating basket, and the stock solution is separated into liquids by discharging the liquid through permeation holes provided in the peripheral wall of the basket. and solid matter (cake).

In this type of centrifugal separator, the liquid supply rate is generally higher than the filtration rate, so the stock solution accumulates in the basket as the liquid is supplied. The stock solution collected in the basket takes on a cylindrical shape within the basket, and solids with a higher specific gravity than the liquid settle due to the centrifugal force generated by the rotation of the basket, forming a solid layer on the inner surface of the peripheral wall (filtering surface) of the basket. do. When a solid layer is formed in this way, the liquid on the inner periphery of the solid layer will be filtered through the solid layer, but in this case, the filtration will be done depending on the size and particle size of the crystal particles of the solid. The speed may be significantly slower.

Therefore, a centrifugal separator has been proposed in which permeation holes are formed in the end walls of the basket so that liquid is filtered through both the permeation holes in the peripheral wall of the basket and the permeation holes in the end walls. Third
The figure shows this conventional centrifuge, in which 1 is a casing, 2 is a basket attached to a rotating shaft 4 supported at the bottom of the casing 1 via a bearing device 3, and 5 is a basket. A driving device that rotates, 6 a liquid supply vibrator that supplies the raw solution into the basket, 7 a scraping blade that scrapes off solids formed on the inner periphery of the basket, and 8 a solid object that discharges the solids inside the basket. It is a discharge pipe. The peripheral wall 2a, the end wall 2b on the opening side, and the end wall 2c on the bottom side of the basket 2 are each provided with a large number of permeable holes 2al,
2 bl and 2 CI are formed, and the peripheral wall 2 of the basket
A filter 9 made of filter cloth, net, etc. is attached along the inner surfaces of the end walls 2b and 2c.

In this centrifugal separator, when the stock solution is supplied into the basket 2 from the liquid supply vibro while rotating the basket 2 at medium or high speed, the stock solution accumulates in the basket.

In the stock solution collected in the basket, solids with a high specific gravity settle due to centrifugal force, so a solid layer S is formed on the inner surface of the peripheral wall of the basket, and a liquid layer is formed on the inner peripheral side of the solid layer. Ru. A part of the liquid in this liquid layer passes through the solid layer S and the filter 9 and is discharged from the permeation hole 2a1 of the peripheral wall 2a of the basket 2, and the other part passes through the filter 9 and the end wall 2.
It is discharged through the transmission holes 2b1 and 2C1 of b and 2C.

According to this centrifugal separator, permeation holes are provided in the peripheral wall and end wall of the basket, and filtration is performed through these permeation holes, so that the filtration speed can be increased and the time required for deliquification processing can be shortened. .

[Problems to be Solved by the Invention] In the conventional centrifugal separator shown in FIG. In this case, a part of the cleaning liquid does not pass through the solid layer and passes through the permeation holes 2b of the end walls 2b and 2C.
There was a problem in that the cleaning effect was reduced because it passed through 1.2c1.

An object of the present invention is to provide a centrifugal separator that feeds a stock solution into a rotationally driven basket and separates the stock solution into liquid and solid matter, in which the filtration rate can be increased without reducing the cleaning effect. This is what I did.

[Means for solving the problem] Therefore, in the present invention, the basket is provided with a peripheral wall for filtration having a large number of permeation holes, and one end adjacent to at least one end in the axial direction of the peripheral wall for filtration. a peripheral wall for forming a liquid reservoir chamber that does not have a permeation hole; an annular end wall that does not have a permeation hole that is provided so as to protrude radially inward from the other end of the peripheral wall for forming a liquid reservoir chamber; A filtration partition wall with a permeation hole provided to protrude radially inward from the boundary between the filtration peripheral wall part and the liquid reservoir forming peripheral wall part,
An annular reservoir is formed between the end wall and the filtering partition. A skimming pipe inserted into the liquid reservoir is provided, and the liquid in the liquid reservoir is discharged by the skimming vibe.

[Operation of the invention] With the above structure, the liquid on the inner peripheral side of the solid layer is filtered through the solid layer and the permeation holes in the filtration peripheral wall, and at the same time, it is also filtered through the permeation holes in the filtration partition wall. Therefore, the filtration rate can be increased and the time required for the deliquification process can be shortened. The liquid discharged into the liquid reservoir chamber through the filtration partition is discharged through the skimming pipe.

In the cleaning process, cleaning liquid is supplied into the basket while the skimming pipe is evacuated from the liquid storage chamber. At this time, the cleaning liquid drawn out through the permeation holes of the filtration partition wall accumulates in the liquid storage chamber, preventing the cleaning liquid from being lost from the filtration partition side and keeping the level of the cleaning liquid in the basket constant (inside the end wall). (in a circumferential position), and a sufficient amount of cleaning liquid can wash the solids to improve the cleaning effect. After cleaning is completed, the cleaning liquid in the liquid storage chamber can be discharged using a skimming vibrator.

[Example 1 The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of an embodiment of the present invention.
In the figure, 10 is a casing supported by a support device 11 equipped with a shock absorber. The casing 10 is formed into a cylindrical shape with a bottom, and its upper end opening is closed by a removable lid plate 12. A bearing device 13 is disposed at the center of the bottom of the casing 11.
3, the rotating shaft 1 extends vertically inside the recasing 10.
4 is supported. The lower end of the rotation shaft 14 is connected to a rotation drive device 15 whose drive source is a hydraulic motor or the like.

Reference numeral 16 denotes a basket housed in the casing 1, and the basket 16 has one end adjacent to a filtration peripheral wall part 18 having a large number of permeation holes 17, and one end and the other end in the axial direction of the filtration peripheral wall part 18, respectively. Permeable walls 19 and 20 for forming a liquid reservoir chamber and having no permeation holes, and permeable walls 19 and 20 for forming a liquid reservoir chamber and projecting inward in the radial direction from the other ends of the peripheral walls 19 and 20 for forming a liquid reservoir chamber, respectively. An annular end wall 21 and 22 having no holes, a filtration wall protruding radially inward from the boundary between the filtration peripheral wall 18 and the liquid reservoir forming peripheral wall 19 and 20. Annular liquid reservoir chambers 25 and 26 are formed between the end wall 21 and the filtration partition 23 and between the end wall 22 and the filtration partition 24, respectively. A filtration chamber 27 is formed between the application partitions 23,24. Filtration partition walls 23 and 2
4 are formed with transmission holes 28 and 29, respectively.

The inner diameter of the filtration partition wall 23 located on the opening side of the basket is set smaller than the inner diameters of the end walls 21 and 22.

In this example, the filtration partition wall 24 constitutes a portion of the bottom wall 30 of the basket near the outer periphery, and a boss portion 31 for mounting a rotating shaft provided at the center of the bottom wall 30 is fitted onto the rotating shaft 14. It is worn. A recess 3 for accommodating solids concentrically surrounding a boss 31 is provided in a central portion of the bottom wall 30 of the basket.
2 is formed.

An annular liquid guide member 33 having an angular cross section is welded to the lower inner surface of the peripheral wall of the casing 10, and a liquid drain port 34 is provided near the lower end of the peripheral wall of the casing 10. The liquid guide member 33 is inclined so as to be lowest near the liquid drain port 34, so that the liquid discharged from the basket 16 is guided to the liquid drain port 34 by the liquid guide member 33.

A liquid supply vibrator 35 is inserted into the basket through the lid plate 12 of the casing 10, and the stock solution to be treated is supplied into the filtration chamber 27 of the basket 16 from the spout hole 35a of this liquid supply vibrator. There is.

A scraping bag @3 is rotatably and slidably penetrated through the lid plate 12.
6 drive shafts 37 are provided, and a scraping blade 38 is attached to the lower end of the drive shaft 37 inserted into the basket. The drive shaft 37 is connected to a drive device (not shown), and the drive device causes the scraping blade 38 to enter the filtration peripheral wall 18 side of the basket 16 and to lower the scraping blade 38 to the bottom 30 side of the basket 16. It is designed to cause the user to perform the following actions.

In addition, a solid material discharge pipe 3 is inserted into the basket by penetrating the lid plate 12.
9 is inserted, and the lower end opening of the solid matter discharge pipe 39 is opposed to the bottom 32a of the recess 32. The solid matter discharge pipe 39 is connected to a suction pump (not shown), and the solid matter accumulated in the recess 32 is suctioned and discharged by the solid matter discharge pipe 39.

A filter 40 made of cloth, net, or the like is disposed inside the filtration chamber 27 of the basket 16.

This filter 40 consists of an endless cylindrical part 41 along the inner surface of the filtration peripheral wall part 18 of the basket, and annular parts 42.43 joined to both ends of the cylindrical part 41. They are arranged along the inner surfaces of the filtration partition walls 23 and 24, respectively.

Ring-shaped filter fixing members are attached to the inner peripheries of the annular portions 42 and 43, respectively, and these fixing members are bolted to the inner peripheries of the end walls 23 and 24 of the basket.

Skimming pipes 45 and 46 are provided to penetrate the lid plate and bottom wall of the casing 10, respectively, and to be inserted into the liquid reservoir chambers 25 and 26 of the basket, respectively.

These skimming pipes are L-shaped,
As shown in FIG. 2, the tips 45a and 46a are tilted toward the opposite side of the rotation direction with respect to the radial direction of the basket. The skimming position is inserted into the liquid in the liquid reservoir chambers 25 and 26, and the respective openings are inserted into the liquid in the liquid reservoir chambers 25 and 26.
It can be rotated between a retracted position where it does not touch the liquid inside.

Next, the operation of this embodiment will be explained. First, go to Basquera 116
is rotated at medium or high speed to supply the stock solution from the liquid supply vibrator 35 into the basket. At this time skimming pipe 4
The tips of 5 and 46 are attached to the peripheral wall portion 19 of the liquid reservoir chambers 25 and 26.
and 20 side. Since the liquid supply rate is higher than the filtration rate, a solid layer S is formed on the inner periphery of the filtration chamber 27, and a liquid layer is formed on the inner periphery side of the solid layer S. Part of the liquid in the liquid layer is solid layer S
and is discharged to the outside of the basket through the filter 40 and the permeation hole 17 of the filtration application peripheral wall part 18, and the other part is discharged into the liquid storage chambers 25 and 26 through the filter 40 and the permeation holes 28 and 29 of the filtration partition walls 23 and 24. enter. Since the liquid that has entered the liquid reservoir chambers 25 and 26 is pumped out by the skimming pipes 45 and 46, the liquid that has entered the liquid reservoir chambers 25 and 26
Almost no liquid accumulates therein, and filtration through the filtration partition walls 23 and 24 continues without any problem.

The deliquification step ends when the separation of liquid and solid matter is completed. Next, a cleaning liquid is supplied from the liquid supply vibrator 35 into the filtration chamber 27 to wash the solid matter.

At this time, the tips of the skimming vibrators 45 and 46 are retracted to the inner side of the liquid reservoir chambers 25 and 26 in the radial direction.

At this time, the cleaning liquid enters the liquid reservoir chambers 25 and 26 through the filtration partition walls 23 and 24, but the end walls 21 and 22 prevent the cleaning liquid from flowing out of the basket. The liquid accumulates and eventually overflows from the inner peripheral portions of the end walls 21 and 22. Therefore, the level of the cleaning liquid in the basket is maintained at the inner peripheral position of the end walls 21 and 22, and the cleaning liquid passes through the filter 40 and the permeation hole 17 of the filter application peripheral wall 18 while uniformly cleaning the solid layer S. It is discharged. After washing the solid matter, the ends of the skimming pipes 45 and 46 are inserted into the liquid storage chambers 25 and 26.
The cleaning liquid in both liquid storage chambers is pumped out, and the basket is rotated at high speed for a certain period of time to dehydrate the solids.

Thereafter, the basket is decelerated and a solid material scraping process is performed.

In this scraping step, the scraping blade 38 is moved into the solid matter layer and is displaced downward to scrape off the solid matter and cause it to fall into the recess 32 at the bottom of the basket. Then, the inside of the solid matter discharge pipe 31 is evacuated by a suction pump, and the solid matter in the recess 32 is discharged through the solid matter discharge pipe 31. After this scraping process is completed, the basket is stopped.

In the above embodiment, the liquid storage chamber and the filtration partition were provided on both the opening side and the bottom side of the basket, but the liquid storage chamber and the filtration partition were provided only on either the opening side or the bottom side of the basket. A partition wall may also be provided. In this case, of course, one of the skimming pipes is omitted.

In the above embodiment, the rotating shaft is provided on the bottom side of the casing, but the present invention can also be applied to a type of centrifugal separator in which the rotating shaft is supported on the cover plate side of the casing.

Further, in the above embodiment, four parts are provided at the bottom of the basket, and the solids dropped into the recesses are discharged through the solids discharge pipe 39, but the solids can be discharged in any manner. For example, an opening for discharging solids may be provided at the bottom of the basket and the solids may be discharged through the opening.

In the embodiments described above, the skimming pipes 45 and 46 may be operated manually or automatically by sequence control.

[Effects of the Invention] As described above, according to the present invention, the liquid on the inner peripheral side of the solid layer is filtered through the permeation holes of the filtration partition wall, and the liquid that has passed through the filtration partition wall is stored. Since the liquid in the liquid storage chamber is discharged through the skimming pipe, the filtration rate can be increased and the time required for the liquid removal process can be shortened.

In addition, in the cleaning process, by supplying the cleaning liquid into the basket with the skimming vibrator evacuated from the liquid storage chamber, the cleaning liquid discharged through the permeation hole of the filtration partition can be stored in the liquid storage chamber. This has the advantage of preventing the cleaning liquid from being lost from the filtration partition and keeping the level of the cleaning liquid in the basket constant, and increasing the cleaning effect by washing solids with a sufficient amount of cleaning liquid. be.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line n-[ of FIG. 1, and FIG. 3 is a vertical cross-sectional view showing a conventional centrifuge. 10...Casing, 16...Basket, 17.
...Transmission hole, 18...Peripheral wall for filtration, 19.20...
・Peripheral wall for forming liquid reservoir chamber, 21.22... End wall, 2
3゜24...Filtration partition wall, 25.26...Liquid reservoir chamber, 28゜29...Transmission hole, 40...Filter, S.
...solid layer, L...liquid layer. Figure 3

Claims (1)

[Claims] A centrifugal separator that feeds a stock solution into a rotationally driven basket and separates the stock solution into liquid and solid matter, the basket comprising a filtration peripheral wall portion having a large number of permeation holes; , a liquid reservoir forming peripheral wall having no transmission hole, the peripheral wall having one end adjacent to at least one end in the axial direction of the filtering peripheral wall, and a radial direction from the other end of the liquid reservoir forming peripheral wall. an annular end wall having no permeation holes, which is provided so as to protrude inwardly from the boundary portion between the peripheral wall portion for filtration and the peripheral wall portion for forming a liquid reservoir; a filtration partition wall with permeable holes, an annular liquid storage chamber is formed between the end wall and the filtration partition wall, and the liquid storage chamber is inserted into the liquid storage chamber to remove the liquid in the liquid storage chamber. A centrifugal separator characterized by being provided with a skimming pipe for discharging liquid.