JPS6219266A - Screw decanter type continuous centrifugal separator - Google Patents

Abstract

PURPOSE:To improve the dehydratability of a solid content and the clearness of a separated liquid by lining a sloped part of a bowl including a dehydration zone with a filter medium which is lower in filtration resistance than a cake layer. CONSTITUTION:This invention relates to a screw decanter type continuous centrifugal separator for separating the solid content contained in liquid such as a PVC resin, etc. in which a screw conveyor 2 having spiral vanes is disposed to the inside of the bowl 1 and the sloped part 1' of the bowl including the dehydration zone D is lined with the filter medium 12 consisting of a filter cloth 12a and metallic net layer 12b in order to improve the dehydration efficiency. A cleaning water supply pipe 15' is provided to the inside of a feed pipe 15 for conducting an original liquid into the separator to wash the filter medium 12. Then the cake layer is dehydrated over the entire medium 12. Then the cake layer is dehydrated over the entire surface and the water is made easily removable even with the low centrifugal force; in addition, the cake is smoothly discharged and the clearness of the separated liquid is good.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a screw decanter type continuous centrifugal separator for separating solids contained in PVC resin and other various liquids from liquids.

[Conventional technology]

Conventionally, in this type of separator, sufficient dewatering performance could not be obtained at low speeds, and as shown in Figs. 2 and 3, the feed pipe (5
The dehydration mechanism in the dehydration zone D) above the liquid level of (7), where the solid content is supplied with the stock solution and sedimented and separated (hereinafter referred to as the conveyed cake), is that the adhering water flows through the cake layer into the dehydration channel (9). The liquid is allowed to flow and escape through the screw conveyor blade (2') tip clearance Ql). By increasing this tip clearance αυ, the passage area increases,
Although this improves dewatering, it actually worsens because the amount of force leakage increases and the thickness of the conveyed cake increases, making it easier to break particles.Therefore, in order to improve dewatering, requires an increase in residence time in the dewatering zone (CD) without increasing cake thickness. In response to these requirements, 9. One possible solution to the structure of the separator is to reduce the depth P of the pool liquid (6) remaining in the machine.
The goal is to increase the angle (θ) of the bowl (1). However, this will deteriorate the clarity of the separated liquid.
When the bowl angle (θ) is increased, the radius on the small diameter side becomes smaller and the centrifugal force decreases.

Therefore, in the conventional separator, the dewaterability of the discharge cake (8),
It is extremely difficult to simultaneously satisfy both of the following requirements:

[Problem that the invention seeks to solve]

As mentioned above, in separating and dewatering the solid content contained in PVC resin and other various liquids, the present invention simultaneously improves both the dewaterability of the solid content and the clarity of the separated liquid due to the structure of conventional methods. The aim is to solve the problem of not being able to provide satisfactory operating conditions.

[Means for solving problems]

For this reason, the present invention provides a bowl slope (
1') is lined with a door material az which has a lower bed resistance than the cake layer.

[Effect]

According to the present invention as described above, the solids settle in the bowl (1) which is rotating at high speed due to the action of centrifugal force, and are carried up the slope by the scree conveyor (2) and out of the pool.

Dehydration is carried out in the dehydration zone (D).

The filter medium ( ) 2 lined in the inclined bowl part (1') dewaters the entire surface of the cake layer, so water can be removed even with a low centrifugal force, and the bowl taper angle can also be made small, allowing smooth conveyance of the cake (7). ) can be discharged, and the clarity of the separated liquid is also improved.

Moreover, since the diameter of the small end of the bowl can be made large, a decrease in centrifugal force at the cake discharge port (4) can be suppressed to a minimum.

〔Example〕

The following two embodiments of the present invention will be explained based on FIG.
A scree conveyor (2) with spiral blades is disposed inside the bowl (1).

A cake outlet (4) is provided at the end of the bowl (1). In addition, a filter medium Q7J consisting of a furnace cloth (12a) and a wire mesh layer (12b) is attached to the bowl slope part (1') including the dewatering zone G)) in which dewatering is carried out in order to increase the dewatering efficiency. A wash water supply pipe (15') for backwashing the F material α2 is installed inside the feed pipe (15) which is lined with a bowl head (13) and leads the raw solution into the separator. Washing water can be supplied to the furnace cloth (12a) and the wire mesh layer (12b) through a passageway (13') provided in the furnace cloth (12a) and the wire mesh layer (12b).

In the screw decanter type continuous centrifugal separator configured as described above, the solids in the stock solution supplied through the feed pipe (15) are sedimented by the action of centrifugal force in the bowl (1) which rotates at high speed.

It is conveyed toward the small end side by the screw conveyor (2). Then go up the slope.

Dewatering takes place in the dewatering zone D) exiting the pool P). In this dehydration zone D), material F (12) consisting of a furnace cloth (12a) and a wire mesh layer (12b) is used as a lining for the inclined bowl part (1).

Since water is dehydrated over the entire surface of the cake (7b) layer, water drains well even with low centrifugal force, improving the dehydration properties of the cake (7b).Furthermore, the bowl taper angle can be made as small as 0 to 5°, making the cake (7b) smooth. is discharged.

In addition, when the furnace cloth (12a) is clogged with solid particles, the cleaning water is passed through the cleaning water supply pipe (15) to the passage (1).
By feeding the furnace cloth (12a) and the wire mesh layer (12b) through the separator 3'), the cloth F (12a) is backwashed and the separator can be used for a long period of time without disassembling it.

2. The present invention is not limited to the above-mentioned embodiments, and various modifications may be made without departing from the gist of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, the dehydration zone CD)
Furnace cloth (12a) and wire mesh layer (12b) to improve water flow.
) The door material (12) is lined with a bowl, so water is dehydrated over the entire surface of the cake layer, and water drains well even with low centrifugal force, resulting in good dehydration of the cake. Moreover, since the bowl taper angle can be as small as 0 to 5 degrees, the cake (7b) can be smoothly discharged, and the clarity of the separated liquid is also improved by adding filtering by the furnace cloth.

In addition, when the P cloth (12a) becomes clogged 9, it can be backwashed with washing water at regular intervals, so the separator can be used for a long period of time without disassembling it, and maintenance costs can be significantly reduced. Of course, the taper angle is within the conventional range. 5-1
It may be at 5°.

[Brief explanation of drawings]

Fig. 1 is an explanation of the main parts showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the main parts of a conventional screw decanter type continuous centrifuge, and Fig. 3 is an enlarged explanation of part A shown in Fig. 2. It is a diagram. (1) ... bowl, (one ... bowl slope part,
(2)...Screw conveyor, (2')...Screw conveyor blade. (4) Cake discharge port, (5) Feed pipe, (7) Transfer cake, (7b) Cake, (12) F material, (12a) Furnace cloth,
(12b)...wire mesh layer, (13)...bowl head. (13...Passage, (15)...Feed pipe, (15')...Washing water supply pipe $2s$3 Diagram

Claims (1)

[Claims] In a screw decanter type continuous centrifuge in which a screw and a conveyor having spiral wings are arranged in a bowl consisting of a cylindrical part and an inclined part connected to the cylindrical part and gradually narrowed, A screw decanter type continuous centrifuge characterized by having a sloping part lined with a filter medium.