JPH05285697A - Device for separation of solid from liquid - Google Patents

Abstract

PURPOSE:To efficiently separate solid from liquid and to prevent the clogging of a filter surface by compressively transferring a material mixture composed of solid and liquid by rotation of a screw and scraping off the material sticking to the filter surface by a scraper according to the rotation of the screw. CONSTITUTION:The material mixture composed of solid and liquid is compressively transferred by receiving the compressive force generated by a volumetric change at which the volume of the screw grooves is decreased by the screw flights of the equal diameter screw part 7a according to the rotation of the screw 7a in a filter structural body 2A. The separated filtrate is discharged from a filtrate discharge port 6. The compressed material mixture composed of solid and liquid is further compressed in a circular conical part 2b and is squeezed by receiving high compression by the screw threads of the tapered screw part 7b, by which the material is made onto filter cake of only the solid material. This filter cake is taken out of a waste cake discharge port 12 to the outside. The back flow of the components to be filtered is prevented and the solid material sticking to the smooth inner peripheral surface of the filter element is scraped off by the scraper mechanism 13 during the rotation of the screw 7A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation device, and more particularly to efficient mechanical separation of a solid substance and a liquid substance from a highly viscous solid-liquid mixed substance such as tofu milk powder, crushed seeds and brewed food. The present invention relates to a solid-liquid separation device that is often used.

[0002]

2. Description of the Related Art Conventionally, this kind of solid-liquid separation is generally carried out by pressure filtration of a liquid substance by a batch method or by combined use of pressure filtration and compression filtration with a screw. Further, Japanese Patent Application Laid-Open No. 2-129205 discloses a closed multi-purpose filtration device having a diaphragm mechanism. An example of this conventional example will be described with reference to the side sectional view of the essential parts of the filtering device shown in FIG.

In FIG. 3, reference numeral 1 denotes an outer cylinder of a vertically arranged filter device main body, 2 denotes an inner cylinder provided inside the outer cylinder 1 through a filtrate flow path 1a, and holding an inner peripheral surface of a cylindrical filter medium F. Tube, 3
Is a conical throttle chamber which is connected to the inner cylinder 2 and whose inner diameter gradually decreases toward the tip. Below this throttle chamber 3, a filter residue discharge valve 4 is provided. Further, a supply port 5 for the solid-liquid mixed substance is provided in the upper part of the outer cylinder 1, and a filtrate discharge port 6 is provided in the lower part.

Reference numeral 7 denotes a taper screw (hereinafter referred to as a screw), which has a taper-shaped screw thread for compressing and transferring the substance to be filtered whose solid content is increased downward in accordance with the gradient of the throttle chamber 3. It is rotatably supported by the rotating shaft 8 inside the inner cylinder 2 in a non-contact manner with the peripheral surface 3a. Reference numeral 9 denotes a flooding liquid discharge valve which is operated when backfilling removes clogging substances deposited on the inner peripheral surface of the filter medium F.
Reference numeral 10 denotes a filter residue discharge pipe that takes out filter residue discharged by opening the filter residue discharge valve 4.

In the above structure, when a solid-liquid mixed substance (hereinafter referred to as a mixed substance) is supplied from the supply port 5 into the outer cylinder 1, the mixed substance is fed from the upper part of the outer cylinder 1 into the inner cylinder 2. .. At this time, the liquid substance in the mixed substance passes through the filter holes formed in the filter medium F by flowing downward on the inner peripheral surface of the filter medium F held on the inner periphery of the inner cylinder 2 at a predetermined pressure. Then, it is separated from the solid substance, flows downward in the filtrate channel 1a, and is taken out to the outside from the filtrate discharge port 6 in the lower portion. As the mixed substance flows downward, the liquid substance is separated and removed by the filter medium F to increase the solid content. When the mixed substance reaches the squeezing chamber 3, the screw 7 is compressed and transferred downward by the rotation of the rotary shaft 8. The filter residue reaching the filter residue discharge valve 4 arranged at the lower end of the throttle chamber 3 is compressed by the screw 7, and a part of the liquid substance separated from the mixed substance by this compression is inside the throttle chamber 3. Only the material that has flowed back upward from the gap between the surface 3a and the screw 7 and reached the filter medium F
It is taken out from the filtrate discharge port 6 through the. The filter residue compressed downward by the screw 7 is automatically opened by the filter residue discharge valve 4 and discharged from the filter residue discharge pipe 10 to the outside when a certain reduction ratio is reached.

[0006]

Since the solid-liquid separation is conventionally performed as described above, the pressure filtration of the liquid substance by the batch method can increase the solid-liquid separation efficiency by increasing the pressure. It is possible, but it takes a very long time to filter, not only the installation space of the device is large, but also it takes a lot of time to remove the filter residue, and the filter medium is easily damaged because a high pressure is applied to the filter medium. There are drawbacks.

Further, in the latter screw compression system, the solid-liquid mixed substance flows backward from the gap between the screw 7 and the inner peripheral surface 3a of the throttle chamber, and compression cannot be performed sufficiently. Therefore, solid-liquid separation by the filter medium F cannot be performed sufficiently. .. Further, the liquid substance squeezed out by the screw 7 can only be taken out of the amount of the backward flow from the gap that has reached the filter medium F, and the filtration separation efficiency becomes low. Furthermore, there is no other way to remove the solids adhering to and depositing on the filter material F, except by backwashing by stopping the device.
There have been various problems such as lowering the operating rate and requiring periodical replacement of the filter media.

The present invention has been made in order to solve the above-mentioned problems of the conventional example, and can perform solid-liquid separation extremely efficiently even with a high-viscosity solid-liquid mixed substance having a large solid content. Moreover, it is an object of the present invention to provide a solid-liquid separation device capable of preventing a solid substance from clogging the filtration surface and maintaining a high operation rate for a long time.

[0009]

Therefore, the solid-liquid separation device according to the present invention is capable of solid-liquid separation comprising a cylindrical portion and a conical portion which is continuous with the cylindrical portion and whose diameter gradually decreases toward the tip. And an outer cylinder body capable of taking out the filtrate at a distance outside the outer circumference of the inner cylinder filtration structure and discharging the filtrate to the outside, along the inner peripheral surface of the inner cylinder filtration structure. The screw which is rotatably supported in the axial direction and provided with a scraper mechanism on the outer peripheral end face forcibly delivers the solid-liquid mixed substance from the supply port side to the filter residue discharge side, and at the same time, the tip of the inner tubular filtration structure. The filter dust discharging means is provided in the portion, the filter dust discharging means is provided with an opening / closing valve, and the inner cylindrical filter structure is helically engraved on the inner peripheral surface at a predetermined interval dimension. The top end portion of a wire having an isosceles triangular cross section is engaged with the groove and wound and fixed, By continuously forming a spiral slit having a desired width dimension, it is intended to achieve the above object.

[0010]

In the solid-liquid separation device according to the present invention having the above-described structure, when the solid-liquid mixed substance is supplied into the cylindrical portion of the inner tube filtration structure, the screw is compressed and transferred at a predetermined compression rate. Then, the liquid substance is efficiently separated and taken out from the inner cylinder filtration structure on the inner peripheral surface of the cylindrical portion. When the solid-liquid mixed substance with increased solid content reaches the conical portion of the inner tube filtration structure, the taper screw part further increases the compression rate and squeezes it. Only the filter residue separated from the inner peripheral surface of the conical portion of the structure and having the liquid substance sufficiently separated and removed is taken out to the outside by the discharging means.

The throttle pressure acting on the solid-liquid mixed substance is set and maintained under optimum conditions by the on-off valve provided in the discharge means, and the solid substance attached to the filtration surface of the inner cylinder filtration structure always depends on the rotation of the screw. Since it is effectively scraped off by the scraper mechanism, high filtration separation efficiency can be maintained and the device can be continuously operated for a long time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

(Structure) FIG. 1 is a sectional side view of a main part of a solid-liquid separator showing an embodiment of the present invention, and FIG. 2 is an enlarged side sectional view of a main part of the embodiment. The same or corresponding parts as those of the conventional example are designated by the same reference numerals.

In FIGS. 1 and 2, 1A is an outer cylinder of a solid-liquid separation apparatus, 1a is a filtrate channel (hereinafter referred to as a channel) provided on the inner circumference of the outer cylinder 1A, and 2A is a channel 1a. It is an inner cylinder filtration structure (hereinafter referred to as a filtration structure) held inside the outer cylinder body 1A via the. This filtering structure 2A comprises a cylindrical portion 2a having a desired length and a conical portion 2b which is continuous with the cylindrical portion 2a and which is formed with a desired gradient in which the diameter gradually decreases toward the tip, and the peripheral surface thereof. Each of them has a large number of liquid circulation holes 2c.

A locking groove 2d having a V-shaped cross section is engraved in a spiral shape on the inner peripheral surface of the filtering structure 2A with a predetermined spacing dimension p. The locking groove 2d is engaged with its top end portion, A wire rod 14 having an isosceles triangular cross section is wound and locked, and a slit s having a desired width dimension is continuously formed in a spiral shape in the middle of the wire rods 14. Then, the cylindrical filter element F _{A is} formed by the cylindrical portion 2a and the conical portion 2b around which the wire 14 is wound.
And a conical filter element F _B. The inner peripheral surface R of the filter elements F _A and F _B is a smooth peripheral surface in which the wire 14 has a triangular bottom surface 14 a.

Reference numeral 7A is a screw that is rotatably supported in the filtering structure 2A by rotating shafts 8 and 8a. This screw 7A follows the inner peripheral surface R of the filter elements F _A and F _B to form a small gap. It is composed of an equal-diameter screw portion 7a having the same outer diameter and a conical taper screw portion 7b which rotate without contacting the inner peripheral surface R. A plurality of divided scraper mechanisms 13, which are pressed against the inner peripheral surface R by a spring member and slidably contact each other, are provided on the outer peripheries of the threads of the equal-diameter screw portion 7a and the taper screw portion 7b. Has been done.

In the screw 7A, the shape of the thread of the equal-diameter screw portion 7a is formed with a variable pitch in which the pitch dimension of the thread gradually decreases, and the volume of the thread groove becomes smaller toward the tip, so that the desired compression rate is achieved. Compress the material to be filtered,
The threads of the taper screw portion 7b are formed in a conical shape, and the volume of the thread groove is further gradually reduced, that is, the compression rate is high. The compression rate may be adjusted by a so-called variable depth method in which the depth of the thread groove is made shallow, and in any case, the compression rate is set to a desired value.

Reference numeral 11 is a filtrate outlet provided in the lower portion of the outer cylindrical body 1A, and discharges the filtrate filtered by the filter element F _B to the outside.

Reference numeral 12 is a filter residue discharge port for discharging the solid substance filtered out and separated, that is, filter residue to the outside. The filter residue discharge port 12 adjusts the compressive force applied to the filter residue to the outside. Ejection means A for ejecting to. The drainage means A narrows down the discharge cross-sectional area of the filter residue, and the screw 7A
Is configured to generate a desired back pressure by the rotation of, and in this embodiment, an on-off valve (hereinafter referred to as a valve) 4A.

(Operation) An operation will be described based on the above configuration.

First, the solid-liquid mixed substance to be filtered is supplied to the supply port 5.
When the solid-liquid mixed substance is fed into the filtration structure 2A from
According to the rotation of the screw 7A, the thread of the equal-diameter screw portion 7a is compressed and transferred toward the tip end while receiving the compressive force generated by the volume change in which the volume of the screw groove gradually decreases. At this time, the filtrate separated by passing through the slits s on the inner peripheral surface R of the filter element F _A flows down in the flow path 1 a and is discharged from the filtrate discharge port 6 to the outside. The solid-liquid mixed substance gradually compressed to increase the solid content is further conical portion 2b.
And is compressed by the thread of the taper screw portion 7b due to a further large volume change and is squeezed, and the liquid substance is sufficiently filtered and separated by the filter element F _B to form a solid residue-only filter residue. From outlet 12 to valve 4
After passing through A, it is taken out from the filter residue discharge pipe 10.

The compressive force applied to this filter residue is the screw 7
It is arbitrarily adjusted by adjusting the rotation speed of A and the opening degree of the valve 4A. Therefore, by adjusting the throttling pressure by operating the valve 4A according to the property of the solid-liquid mixed substance to be filtered, it is possible to efficiently perform various kinds of solidification. Solid-liquid separation of liquid-mixed substances can be performed.

During the rotation of the screw 7A, the scraper mechanism 13 always prevents the backflow of the substance to be filtered,
Moreover, since the solid substances attached to the smooth inner peripheral surface R of the filter elements F _A and F _B are scraped off, clogging is prevented, and extremely high filtration separation efficiency is maintained for a long time. The operation of the device can be continued.

In this embodiment, the inner tubular filter structure is formed by winding a wire having an isosceles triangular cross section on the inner peripheral surface. However, the wound wire has a cross sectional shape of an isosceles triangle. Not limited to, circular, equilateral triangle, square, trapezoid, polygon, etc.
A wire rod having an appropriate shape may be used, or a filter material having a mesh structure may be used. Furthermore, the wire rod may be fixed to the inner tubular filtration structure by using an appropriate method such as an adhesive or spot welding.

Further, the discharging means is not limited to the open / close valve, and a throttle mechanism most suitable for the capacity of the apparatus and the property of the solid-liquid mixture may be used, such as a mechanism for adjusting the opening gap by using a throttle plate of an appropriate shape. ..

Further, although the case where the solid-liquid separation device is a vertical type has been described in this embodiment, it goes without saying that a tilted type or a horizontal type is also included in the present invention.

[0027]

As described above, according to the present invention, the inner tubular filtering structure is formed such that the cylindrical portion and the conical portion are continuous, and the inner tubular filtering structure is formed along the inner peripheral surface thereof. The screw supported rotatably in the axial direction is rotated to compress and transfer the solid-liquid mixed substance to continuously perform solid-liquid separation, and the scraper mechanism provided on the outer peripheral end face of the screw is slidably contacted with the filter peripheral face. It is possible to prevent the backflow of the solid-liquid mixed substance by moving it, to prevent the clogging from occurring at all times, and to adjust the squeezing compression force arbitrarily by the discharging means. To obtain a very high performance solid-liquid separation device that can operate solid-liquid separation filtration for a long time while maintaining extremely high separation efficiency even for solid-liquid mixed substances of all properties that are difficult to separate. be able to.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration of essential parts of a solid-liquid separator according to an embodiment of the present invention.

FIG. 2 is an enlarged side sectional view of a main part of the solid-liquid separation device of the above embodiment.

FIG. 3 is a side sectional view of a main part configuration of a conventional filtering device.

[Explanation of symbols]

 1A Outer cylinder 2A Inner cylinder filtration mechanism 2a Cylindrical part 2b Conical part 2c Liquid circulation hole 2d Locking groove 5 Supply port 6,11 Filtrate discharge port 7A Screw 12 Filter residue discharge port 13 Scraper mechanism 14 Wire rod A Discharge means p Interval dimension s slit Note that the same reference numerals in the drawings indicate the same or corresponding portions.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location B01D 29/37 29/64 29/48 7112-4D B30B 9/14 G

Claims (3)

[Claims] 1. A solid-liquid separable inner cylinder filtering structure comprising a cylindrical part and a conical part which is continuous with the cylindrical part and whose diameter gradually decreases toward the tip, and an outer periphery of the inner cylinder filtering structure. It is composed of an outer cylinder body that can take out the filtrate at a distance in one direction and discharge it to the outside. The outer cylinder body is supported rotatably in the axial direction along the inner peripheral surface of the inner cylinder filtration structure and the scraper mechanism is provided on the outer peripheral end surface. The solid-liquid mixed substance is forcibly delivered from the supply port side to the filter residue discharge port side by the screw, and the filter residue discharge means is provided at the tip of the inner cylinder filtration structure. Solid-liquid separation device. 2. The solid-liquid separation apparatus according to claim 1, wherein the means for discharging the filter residue comprises an opening / closing valve. 3. The inner cylinder filtration structure is wound by engaging a top end portion of a wire having an isosceles triangular cross section with a locking groove formed in a spiral shape on the inner peripheral surface at a predetermined interval dimension. The solid-liquid separation device according to claim 1 or 2, wherein the solid-liquid separation device is fixedly mounted and continuously formed with a spiral slit having a desired width dimension between the wires.