JP2000102705A - Filtration method and filter for applying its filtration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the treating efficiency in a filter contg. a cylindrical filter medium and used and to eliminate the generation of bridges due to nonuniform caking in filtration. SOLUTION: This filter 1 consists of a filter main body 2 contg. a cylindrical filter element 8 and filtering a liq. sample and a feed pump 3 connected to the main body 2 and supplying the liq. sample. In this case, a first circulating pipe 4 with one end connected to the main body 2 and the other end connected to the feed pipe 3 is provided. Besides, at least a part of the liq. supplied to the main body 2 from the feed pipe 3 is passed through the first circulating pipe 4 before filtration to recirculate the liq. between the feed pipe 3 and main body 2, hence the concn. distribution in an insoluble matter in the main body 2 is uniformized, and a cake is uniformly formed on the element 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration method and a filtration device used therefor, and more particularly to a filtration method and a filtration device suitable for filtering a liquid sample containing a substance which has a large amount of insoluble components to be filtered and is difficult to filter.

[0002]

2. Description of the Related Art For example, in the production of beer and low-malt beer (hereinafter referred to as "beer and the like"), beer and the like discharged from a liquor storage tank after liquor storage initially contains a large amount of yeast and insoluble proteins. It is difficult to filter and the amount supplied to the filtration device is small, so that a large amount of filtration time is required. FIG. 1 shows an example of a typical filtration device, in which a plurality of cylindrical filtration elements 102 (ceramic, sintered metal or wire-wound elements) are provided.
The beer or the like supplied to the primary side 105 of the tank 103 is suspended through the partition 104 on the primary side 105 (the side into which beer to be filtered or the like is injected) through the element 102, This is a known type of filtration device in which filtered beer or the like is collected on the upper secondary side 106 in the tank 103 and discharged from the filtration device main body 101 through a pipe 107.

[0003]

When beer or the like whose storage has been finished is filtered using this filter device, the element 10
2, a cake layer is formed intensively, and adjacent elements come into contact with each other via the cake, and in extreme cases, there is a risk that the element 102 may be deformed or damaged.

According to the research results of the present inventor, since the filtration flow rate is small, insoluble matter contained in beer or the like in the primary side 105 gradually precipitates below the primary side, and the element 102
It has been found that the concentration of insoluble matter such as beer located beneath is increased, and the cake layer is necessarily thickened. Further, in the filtering device, the state where the cake is uniformly formed on the entire filtering surface of the element is the most efficient, and therefore, an appropriate filtering operation is not performed.

[0005] In addition to the above-mentioned type of filtration device, a filtration element in which the filtration surface is extended in the depth direction of the tank in the filtration tank of the filtration device body to form a primary filtration side is provided. The device had to avoid the above problem in some way. The present invention has been made to solve the above-described problems, and has as its object to provide a filtration device capable of increasing filtration efficiency and preventing bending or breakage of a filtration element.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventor has significantly increased the filtration flow rate in a filtration device,
An insoluble substance in the liquid to be filtered was diffused so that a uniform cake layer was formed on the entire filtering surface. That is, the flow rate of the liquid to be filtered supplied to the primary side of the filtration device is increased, and a part of the liquid is discharged from the primary side to the outside of the filtration device without being filtered. Therefore, although the filtration flow rate is not substantially different, the flow rate on the primary side is large, so that the liquid to be filtered is not stirred and the insoluble substance does not precipitate.

According to a first aspect of the present invention, a filtration element is installed in a filtration tank constituting a filtration device so that a filtration surface thereof is extended in a depth direction of the tank to constitute a primary filtration part. In a filtration method in which a liquid to be filtered is introduced into a primary side to obtain a filtrate through the element, a part of the liquid to be filtered introduced into the primary side should be filtered during a filtering operation. A filtering method characterized by returning a liquid to an input side for introducing a liquid into a filtering device.

According to a second aspect of the present invention, there is provided a filtration tank, a filtration element installed in the filtration tank such that a filtration surface is extended in a depth direction of the tank, and a liquid to be filtered including the filtration element. In a filtration device having at least a filtration primary side formed in the filtration tank into which the filtration tank is introduced, the introduction path for introducing the liquid to be filtered into the filtration device and the filtration primary side are connected to each other. A filtration device provided with a circulation path for returning a part of the liquid to be filtered introduced into the primary side to the introduction path.

According to the first and second aspects of the present invention, at least a part of the liquid sample supplied from the supply pipe to the filter body passes through the first circulation pipe before filtration. It is possible to circulate between the supply pipe and the filter body. Therefore, by increasing the flow rate of the liquid sample supplied to the filter main body and circulating the liquid sample between the supply pipe and the filter main body, the insoluble content contained in the liquid sample in the filter main body is increased. The substance can be made to flow vigorously, and the particles of the insoluble substance are blown up, so that sedimentation can be suppressed.

Therefore, the concentration of the insoluble substance in the filter main body becomes uniform, and the filter medium provided in the filter main body at the time of the filtration treatment can form a uniform cake, thereby enabling high-efficiency and high-precision filtration.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a filtering device for filtering and removing insoluble substances in beer supplied from a storage tank using the filtering device body according to the embodiment of the present invention. As shown in FIG. 2, a filtration device 1 according to an embodiment of the present invention
Is a filter body 2 for filtering the liquid sample beer,
A supply pipe 3 connected to the filter body 2 and supplied with the liquid sample by a filtration pump 7 provided.

The filter body 2 has basically the same structure as the filter body shown in FIG. 1, and includes a cylindrical filter element 8 provided with a partition wall 8a provided at an upper portion in a tank 9.
, And is configured so that a filtrate can be obtained from a secondary-side chamber 9b above a partition wall 8a communicating with an upper end of the tubular filtration element 8. The filter device 1 according to the embodiment of the present invention is connected to the filter body 2 at one end and to the supply pipe 3 at the other end, and is provided with a valve 16 and a valve 19 provided in the middle. A first circulation pipe 4 that can be opened and closed is provided. Therefore, by passing through the first circulation pipe 4, at least a part of the liquid sample supplied from the supply pipe 3 to the filter main body 2 is separated from the supply pipe 3 and the partition wall in the tank 9 of the filter main body 2 before the filtration process. Circulation is possible with the chamber 9a on the primary side below 8a. At this time, the first circulation pipe 4 is provided with a conductivity meter 12 and a blow valve 13 in the middle thereof, and detection of beer and formation of a blow line are also enabled.

The supply pipe 3 is provided with a cushion tank 5 capable of holding the liquid sample in the middle thereof, and the liquid sample is supplied to the filter body 2 through the cushion tank 5. 4 is configured to be connected to the supply pipe 3 by being connected to the cushion tank 5 at the end on the supply pipe 3 side. Further, in the filtration device 1 according to the embodiment of the present invention, one end is connected to the upper chamber 9b on the secondary side of the tank 9 serving as the filtrate discharge portion of the filter body 2, and the other end is connected to the cushion tank 5. The second circulation pipe 6 which is connected and can be opened and closed by valves 17 and 18 provided on the way.
Is provided. The second circulation pipe 6 has a turbidity meter 11,
The liquid sample filtered by the filter body 2 can be circulated between the cushion tank 5 and the filter body 2 while evaluating turbidity. The first circulation pipe 4 is provided with a conductivity meter 14 and a blow valve 15 in the middle thereof, so that beer detection and formation of a blow line are also enabled.

The filter 1 can be supplied to a supply pipe 3 from a liquor storage tank (not shown) via a pipe 29 and a valve 30. Next, a filtration process performed using the filtration device 1 according to the embodiment of the present invention will be described with reference to FIG. Precoating process The cushion tank 5 is used as a precoat tank used for precoating the filtration element 8. Then, the first-stage filter aid previously suspended in water is added. In the description of the precoating step, the cushion tank is referred to as a precoat tank.

2. The filter aid-containing liquid is transferred to the filter body 2 using the filtration pump 7. At this time, a path from the first circulation pipe 4 to the precoat tank 5 and a path from the second circulation pipe 6 to the precoat tank 5 are formed, and the air in the filter body 2 is evacuated. Further, the pre-coat tank 5 is replenished with an amount of water that can be circulated between the pre-coat tank 5 and the filter body 2. By circulating for a predetermined time, the concentration of the first stage filter aid in the precoat tank 5 and the filter body 2 is made uniform.

3. The valve 16 of the first circulation pipe 4 is closed, and circulation is performed using only the second circulation pipe 6. 4. After a predetermined time, the control value of the filtrate of the filter aid-containing liquid determined in advance is confirmed by the turbidity meter 11. 5. Next, the second-stage filter aid previously suspended in water is charged into the precoat tank 5, and circulation using only the second circulation pipe 6 is continued. After a predetermined time, the control value of the filtrate is confirmed, and the precoating of the filter aid is completed. At this time, in order to minimize the amount of liquid in the precoat tank 5,
The blow valve 15 of the second circulation pipe 6 is opened to reduce the amount of liquid. The flow rate is also adjusted to a value suitable for the filtration process.

6. After reducing the amount of liquid, the valve 15 is closed and returned to the pre-coat tank circulation path again. Thus, on the cylindrical filtration element 8 arranged in the filter body 2,
A filter aid layer consisting of two layers, a first stage and a second stage, is formed. Introduction and filtration of beer Beer, which is a filtering material from a storage tank (not shown), is introduced into the cushion tank 5 through a pipe 29.
At this time, the blow valve 26 just before the cushion tank 5
Is opened, the valve 30 is closed, and the conductivity meter 27 waits for detection of beer. 2. Immediately after the conductivity meter 27 detects beer, the valve 26
Is closed, and the valve 30 is opened to switch the path from the blow to the cushion tank 5. Thereafter, the beer is introduced into the cushion tank 5 while monitoring the acceptable level of the cushion tank 5 until the payout from the storage tank is completed. 3. The filter 1 also opens the blow valves 13 and 15 in both the first circulation pipe 4 and the second circulation pipe 6 to form a blow line, and waits for detection of beer by the conductivity meters 12 and 14, respectively. 4. Immediately after the second circulation pipe 6 detects the beer, the blow valve 15 is closed to stop the formation of the blow line and return to the circulation path again. 5. 5. Close the valve 16 of the first circulation pipe 4 and perform circulation using only the second circulation pipe 6. Using the turbidimeter 11, it is confirmed that the predetermined control value for beer is satisfied, the second circulation pipe 6 is closed by the valve 17, and the filtrate is sent to the filtrate outlet. 7. In the filtration process, if a state in which the turbidity value applied to the filtrate does not satisfy the control value occurs before the filtration is completely completed, the valve 17 is opened at any time, the second circulation pipe is opened, and the circulation path is opened. Once formed, the filtration process is repeated until the turbidity value recovers and meets the control value. After the control value is satisfied, the second circulation pipe 6 is closed again by the valve 17, and the transfer of the filtrate to the filtrate outlet is restarted. 8. A predetermined time after beer is introduced into the filter body 2, the valve 16 is opened to form a circulation path between the filter body and the cushion tank 5 by the first circulation pipe 4. At the same time, the flow rate is increased, and particles of insoluble substances such as yeast and insoluble proteins settled at the bottom of the filter body 2 are blown up and raised. By this blowing, the concentration of the insoluble substance in the filter body 2 becomes uniform.

After a lapse of a predetermined time, the first circulation pipe 4 is closed by the valve 16, and the filtration flow rate is returned to the original flow rate before being raised to blow up the particles, and the filtration is continued. These operations are repeated at regular intervals, and the
The operation of the filter 1 is performed so that insoluble substances are not deposited on the bottom of the filter. The reason for changing the flow rate by forming the circulation path by the first circulation pipe 4 is that the flow rate at the time of filtration is not enough to blow up particles of the insoluble substance, and as a result, causes filtration stagnation, and This is because the flow rate for blowing up is too large to perform filtration.

If the filtration treatment is continued without making the concentration of the insoluble substance uniform, the cake is concentrated on the lower part of the filter element 8, and the diameter of the lower part becomes thicker. As a result, a bridge is formed by the cake at the lower part of the filter element 8, and as a result, the tubular filter element is bent and broken. Therefore,
By making the concentration of the insoluble substance in the filter body 2 uniform as described above, the cake formed on the filter element 8 can also have a uniform thickness. Of the cake and breakage of the filtration element can be prevented.

Water push 1. When the liquor storage tank detects an empty level, the path is changed to form a water pushing path, and the beer in the pipe 29 of the filtration facility 10 is washed away with water. When the conductivity meter 27 detects water, the water pressing is terminated. 2. The filter 1 side of the filtration equipment 10 is a cushion tank 5
At the time when the level of has decreased, water is introduced, and the cushion tank 5 and the filter body 2 are sequentially replaced with water from beer.

3. A conductivity meter (not shown) is also provided at the outlet of the filtrate, and when the conductivity meter detects water, the collection of the filtrate is terminated. Draining and washing When the filtration process is completed, the filtration pump 7 is stopped, drained, the cake is discharged, and the filtration device 1 is washed.

By performing the above-mentioned filtration steps, the pre-coating of the tubular filtration element disposed in the filter body can be performed easily and efficiently, and the filtration can be performed uniformly on the tubular filtration element. This makes it possible to prevent the formation of bridges, increase the speed of the processing solution flowing in the filter body, and increase the processing efficiency.

Therefore, it is possible to filter sake with high accuracy and high efficiency without fear of bending and breakage of the tubular filtration element in the filter body. Although the embodiment shown in FIG. 2 described above is an example in which the cushion tank 5 is also used as a precoat tank, as shown in FIG. 3, it is also possible to separately provide a precoat tank. In FIG. 3,
The same components as those in FIG. 3 are described with the same reference numerals for convenience of explanation. In this case, the secondary circulation pipe 6 is connected to a precoat tank (not shown) connected to the supply pipe 3 so as to form a circulation path.

FIG. 4 shows an example in which the present invention is applied to a filtration device that does not use a cushion tank. Also in this example, the same components as those in FIG. 3 are described with the same reference numerals. In this case, the supply pipe 3 is a storage tank (not shown)
The primary circulation path is formed by directly connecting the primary circulation pipe 4 to the supply pipe 3. In either of the embodiments of FIGS. 3 and 4 above, by circulating the process during filtration using the primary circulation path, FIG.
As in the embodiment, it is possible to prevent the filter element from being damaged and to increase the filtration efficiency.

[0025]

According to the first and second aspects of the present invention, the concentration of the insoluble substance in the filter main body becomes uniform, and a uniform cake can be formed with the filter medium provided in the filter main body during the filtration process. Thus, high-efficiency and high-precision filtration becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a filtration device using a cylindrical filtration element.

FIG. 2 is a diagram illustrating a filtration device according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a filtration device according to another embodiment of the present invention.

FIG. 4 is a view showing a filtration device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filtration apparatus 2 Filtration machine main body 3 Supply pipe 4 First circulation pipe 5 Cushion tank (precoat tank) 6 Second circulation pipe 7 Filtration pump 8 Filtration element 9 Tank 10 Filtration equipment 11 Turbidity meter 12, 14, 27 Conductivity meter 13,15,26 Blow valve 16,17 valve

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) B01D 35/02 N

Claims (2)

[Claims] A filtration element is installed in a filtration tank constituting a filtration device so that a filtration surface thereof is extended in a depth direction of the tank to form a filtration primary side, and a filtration is provided on the primary side. In a filtration method of introducing a liquid to be filtered and obtaining a filtrate through the element, during the filtering operation, a part of the liquid to be filtered introduced into the primary side portion, the liquid to be filtered is filtered into a filtration device. A filtering method characterized by returning to an input side for introduction. 2. A filtration tank, a filtration element installed in the filtration tank so that a filtration surface thereof extends in a depth direction of the tank, and the filtration element including the filtration element and into which a liquid to be filtered is introduced. In a filtration device having at least a filtration primary side formed in a filtration tank, an introduction path for introducing a liquid to be filtered into the filtration device and the filtration primary side are connected and introduced into the primary side. A filtration path for returning a part of the liquid to be filtered to the introduction path.