JPH04134426U - Pressurized disc filter device - Google Patents

Abstract

(57) [Summary] [Purpose] In a disc filter device used for clarifying white liquor in the causticizing process of kraft pulp,
It not only ensures higher clarification function for a longer period of time, but also enables adaptation to other application fields. [Structure] A microporous plate 104 is used as the surface of the disk filter 42 instead of a conventional filter cloth. The attached solid matter can be removed from the inside of the disk filter 42 through the through hole 108.
This is done by applying counter pressure through the In addition, clogging can also be eliminated by supplying backwash liquid from inside the disc filtration 42. Microporous plate 10
4 is selected from ceramic, metal, synthetic resin, etc. depending on the characteristics of the liquid to be treated, and the size of the intergranular (pore) is selected depending on the size of solid matter in the liquid to be treated.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is useful for recovering solids from slurry or for recovering solids. Therefore, when clarifying the slurry or, conversely, enriching it with solids and concentrating it, The present invention relates to a pressurized disk filter device suitable for use in.

0002

[Conventional technology]

Traditionally, for example, green liquor (smelt) was used in the causticizing process at kraft pulp mills. From white milk (white liquor + lime mud) obtained by adding calcined lime to aqueous solution) A so-called white liquor clarification process is performed to remove the lime mud.

0003 Conventionally, this white liquor clarification was done by pouring white milk into a large tank, and over time. This was done by removing the lime mud that precipitated in the water.

0004 However, this method occupies a large amount of space and processing time, so In 2007, in patent application No. 102944/1986, a disc filter was used to reduce the Separation and collection of white liquor and lime mud can be performed in a short time and in a small space. A device that can do this has been proposed.

[0005] This device has a schematic configuration (perspective view) shown in Fig. 10 and a cross section shown in Fig. 11. , a tank in which a plurality of disc filters 2A to 2D are placed upright and some of them are under pressure. With the hollow shaft 8 positioned so that it is immersed in the white milk 6 in the tank 4, Rotate in your heart, Adhesion of lime mud due to passage of white milk 6 in the lower part of tank 4, Dehydration of adhering lime mud by passing through the gas phase part 10 in the upper part of the tank 4, and , The lye remaining after dehydration just before entering the white milk 6 at the bottom of the tank 4 again Scraping with Mumad's scraper 12, It is configured to be executed continuously.

[0006] The moisture content of lime mud attached to the disc filter is within White Milk 6 ( After exiting the filtration zone), it decreases rapidly, and from the first 1/3 of the gas phase 10 (dehydration zone) Since this dehydration can be completed in about 1/2, the dehydration remains on the disk. The solid matter (lime mud mixture) is scraped off with the scraper 12 and discharged. This makes it possible to separate and recover white liquor and lime mud extremely efficiently. That is, white liquor is , disk filters 2A to 2D, and the hollow part 8A of the hollow shaft 8 in a clarified state. It will be collected.

[0007] Traditionally, filter cloth has been used as the filter element of this disc filter. there was.

[0008]

[Problem that the idea aims to solve]

However, in structures that use filter cloth for the filter element, for example, When used for white liquor clarification as described above, the filter cloth alone does not have the required clarity. It is difficult to obtain (the request is about 20 mg/l or less, but in reality it is about 100 mg/l) sludge in the liquid to be treated). There was a problem with the need for records. Also, in this case, changing the pre-coating When fresh, there was a problem in that the clarity level inevitably deteriorated temporarily.

[0009] Additionally, sludge newly captured on the precoat surface is removed by the scraper 12. However, the filter cloth and scraper 12 must be placed close together (the scraper 12). due to the contact between this scraper 12 and the filter cloth. In order to prevent damage to the filter cloth, high manufacturing/processing precision is required, or the disc during operation is There was a problem in that swing management and the like were required.

0010 Furthermore, if counter pressure is applied to renew the precoat and the filter cloth is expanded from the inside, In some cases, there is also the problem that the strength of the filter cloth decreases or it is likely to be damaged.

[0011] On the other hand, the above-mentioned disc filter device is used for processing green liquor, for example. If so, the solid content in the green liquor is fine (1 μm or less) and has penetrated between the filter cloth fibers. Direct filtration with a filter cloth is not possible because of clogging. As a result, filtration using a pre-coat with lime mud in the latter stage has been attempted, but the mechanism , the driving operation is complicated. The lime mud used for pre-coat is causticized by the lime generated throughout the process. This amounted to 4 to 5% of the mud, which caused problems such as excessive loss.

0012 In addition, such a disc filter device can be used for purposes other than the kraft pulp process. For example, if you plan to use it in a corrosive slurry such as a strong acid or alkali, Then, there was also a problem that the durability easily deteriorated.

[0013] The present invention was devised in view of such conventional problems, and is We stopped using filter cloth as the filter element for filter equipment, and changed it to suit the purpose. By using a microporous plate material, slurry processing at high temperatures is possible. It is possible to treat corrosive slurries such as strong acids and strong alkalis, and it does not require pre-coating. Highly clear liquid can be obtained in the microfiltration area. The strength and life of the router element itself can be improved, and manufacturing/processing errors and vibration control can be strictly controlled. It is possible to reduce the size of the system, and also has advantages such as large capacity processing, compactness, and space saving. Furthermore, these advantages make it suitable for use only in kraft pulping processes. For example, it can be used for various clarification and separation and recovery of solid materials in the food and pharmaceutical fields. We provide a disc filter device that can expand the field of application and solve the above problems. This is what we are trying to solve.

[0014]

[Means to solve the problem]

In this invention, multiple disc filters are placed upright and placed around a hollow shaft. Rotate the slurry and remove solid matter from the slurry. Continuous operations can clarify, concentrate, or recover solids from a slurry. In the disk filter device configured to perform The above problem was solved by forming the surface with a microporous plate. It is.

[0015] In addition, the present invention provides a countermeasure against the attached solid matter from the inside of the disc filter. A means for applying pressure is provided, and the solid matter is removed by applying this reverse pressure. This solves the above problems.

[0016] Additionally, the present invention provides backwashing to remove adhering solid matter from the inside of the disc filter. This backwashing prevents the disk filter from being clogged with the solids. The above problem has been solved by solving the problem.

[0017]

[Effect]

In this invention, the surface of the disc filter is formed by a microporous plate. It is formed.

[0018] This microporous plate can be used depending on the characteristics of the liquid being treated (temperature, corrosivity) Selected from lamic, metal, synthetic resin, etc.

[0019] In addition, the size of the intergranular (pores) of the microporous plate is determined by the size of the solids to be captured in the liquid to be treated. Select by size. In addition, it is possible to select from submicron to micron order. be.

[0020] The element material of the disc filter can be changed from the conventional filter cloth to the porous plastic mentioned above. By using a high rate, high-temperature processing is possible, and the heat resistance of the filter medium is improved. It becomes possible to process a hot liquid without subjecting it to temperature lowering treatment in advance. As a result, Energy loss can be significantly reduced.

[0021] In addition, it is possible to treat corrosive liquids, reducing the durability of corrosive liquids such as acids and alkalis. You can now process it as is without having to do anything.

[0022] Furthermore, pre-coating is basically unnecessary, and highly clear liquid can be obtained without pre-coating. This eliminates the need for pre-coating materials and treatment equipment.

[0023] Furthermore, mechanical strength is improved, eliminating problems such as tears and holes. , can significantly extend the lifespan.

[0024] Taking advantage of these properties, this type of disk filter has traditionally been It has been used in fields other than the causticizing process of kraft pulp mills. This type of disk filter can be widely used even if .

[0025] For example, it is used in vacuum drum pre-coated filters for sterilization and purification in food and pharmaceutical processes. Conventionally, the filter element was a filter cloth, and the pre-coat material was coated with diatomaceous earth, etc. In addition, there is a problem that it is not economical because it requires the same processing equipment. Ta. Also, since it is a vacuum filter, it cannot process high temperature liquids, resulting in large energy loss. There was also the problem. Furthermore, there is a limit to the filtration differential pressure due to the vacuum filter, and the filtration Another problem was that the processing capacity per area was low. In addition, the drum type reduces the filtration area. On the other hand, there was also the problem that the size of the equipment was large.

[0026] However, even in the field of sterilization and purification for food and pharmaceutical processes, this invention can be applied, and the above-mentioned problems can be solved at once.

[0027] Similarly, in the field of sterilization and purification for food and pharmaceutical processes, conventional fixed batch systems Ramic filters were sometimes used, but this method The problem is that the filtration capacity decreases over time due to the accumulation of particles (and clogging of the filter media). There was also the problem that continuous processing was not possible and it was not efficient.

[0028] However, the present invention is capable of continuous processing in this respect as well, and has the following features. Since it can also provide such effects, it is possible to make full use of it.

[0029] That is, in the present invention, when removing attached solid matter, continuous dispersion is performed. Apply reverse pressure to the solids from inside the filter, or Solids are removed by backwashing them with a cleaning solution from inside the filter. This is done to remove or prevent clogging.

[0030] Furthermore, by adopting this removal method, it is possible to remove the The strictness of manufacturing/processing errors, vibration management, etc. can be relaxed compared to what was previously unavoidable. It also becomes like that.

[0031]

【Example】

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0032] In FIGS. 3 and 4, reference numeral 40 indicates the rotation of the disk filter 42 around its axis. When white milk is supplied to the electric motor 44 through piping (not shown), Both tanks can be pressurized, 46 is a white liquor recovery tank, and 48 is a lime mud recovery tank. It's a tank.

[0033] The electric motor 40 is connected to a hollow tube 50 having a double hollow structure. this A plurality of disc filters 42 stand upright in the hollow tube 50 at equal intervals in the axial direction. It is assembled like this. The specific configuration of the disk filter 42 will be explained later. Explain in detail. From the position where this disc filter 42 is installed, the disc filter 42 is The white liquid of white milk flows into the first hollow part 52 of the hollow tube 50 through the filter 42. (arrow A).

[0034] Lime mud attached to each disc filter 42 is removed by a method described later. The removed lime mud is transferred to the lime mud receiver via the drop tube 54. lime mud collection tank 48 by screw 58. It is designed to be collected in

[0035] The disk filter 42 is specifically configured as shown in FIG.

[0036] (B) is an exploded perspective view of the filter element 42A of the shaded part in (A). is equivalent to Note that the arrow X direction in the figure corresponds to the circumferential direction.

[0037] This filter element 42A is arranged in a series with the element holder 100 as the center. A bolt material 102 and a microporous plate 104 are arranged, and these 106.

[0038] The element holder 100 was dehydrated through the opening 109 and the through hole 108. The white liquid can flow into the first hollow part 52, and the white liquid can flow into the first hollow part 52. to allow fluid to pass through when removing lime mud by applying back pressure. , and allows the backwashing liquid to pass through here when performing backwashing. The sea urchin is turning. This configuration is specifically shown in FIG.

[0039] In FIG. 2, 110 is a fixed sliding plate, which is clarified (lime mapped). A through hole 112 for passage of white liquor (dehydrated from solids), and a through hole 112 for passing fluid for applying reverse pressure. A through-hole 114 for passing through, and a through-hole for backwashing liquid to pass through for backwashing. 116 are provided.

[0040] On the other hand, the first hollow part 52 of the hollow tube 50 has several independent parts along the axial direction. It has shaft spaces 50A to 50M, and filtration and During dehydration, clarified white liquor and fluid for applying counter pressure pass through or Alternatively, backwashing liquid for backwashing may pass through. The regulations and controls on the circumference are as described above. This is done by a fixed sliding plate 110. In the example in the figure, the axis space 50C is 50E corresponds to the shaft space through which the fluid for applying back pressure passes, and the shaft space through which the backwash liquid passes. Ru. FIG. 5 shows this control mode.

[0041] Note that FIG. 5 is viewed from the direction of arrow V in FIG.

[0042] Now, the part of the disc filter 42 corresponding to the filter element 42A is To explain the operation pattern focusing on movement in the circumferential direction, the filter element 42 When A is in the filtration zone, the pressure in the tank 44 causes the white milk to Lime mud adheres to the surface of the disc, and along with it, white liquor also flows through the disc filter. The liquid enters the disk in a form that is filtered through 42 microporous plates. Eventually , when the filter element 42A enters the dehydration zone, it is blown away by the pressurized air in the tank. The dehydrated liquid is taken into the disc filter 42, where dehydration (recovery of white liquor) is performed. be exposed. Next, when the filter element 42A reaches the reverse pressure application zone, it is fixed. The through hole 114 of the constant sliding plate 110 and the shaft corresponding to this through hole 114 at this time Liquid for applying reverse pressure is ejected from the inside of the disc filter 42 through the space 50C. The dehydrated lime mud is separated from the disk filter 42. And this The separated lime mud is collected into a receiving box 56 via a falling tube 54. will be done. The filter element 42A then reaches the backwash zone; Corresponding to the through hole 116 of the fixed sliding plate 110 here and this through hole 116 at this time. The microporous plastic is backwashed by the backwashing liquid supplied through the shaft space 50E. Any remaining lime mud in the individual holes of the plate is flushed clean and then re-washed. to avoid reducing the filtration capacity in white milk when it enters the filtration zone. It is something that

[0043] In other words, with conventional filters that are pre-coated on filter cloth, the surface part is coated with a scraper. In this example, this zone The lime mud is removed by applying back pressure (from air, water, steam, etc.) in the tank. It is something that separates and removes. This operation is performed all the time (each filter of the disk filter 42 This can be done each time the disk element is in this zone) or several times. It is also possible to perform the rotation once (for one rotation) each time the rotation is made.

[0044] Since a scraper is not required, the tolerance for the flatness of the disk filter 42 is also reduced. This also eliminates the risk of damage caused by contact between the two. Note that this removal operation Spray air, water, steam, etc. onto the disc filter 42 for the purpose of assisting. It is possible to install a nozzle or directly contact the surface of the disc filter 42. It is also possible to install a highly flexible scraper.

[0045] Regarding backwashing, the filter element located in the backwash zone during continuous filtration The disc may be backwashed constantly, or once every few revolutions of the disc. It is also possible to carry out the process for several minutes. In addition, if necessary, stop the operation and use backwashing chemicals. This zone may be used to backwash the entire disc filter several times. .

[0046] In any case, by having this back pressure application zone and back cleaning zone, Stable continuous operation is possible over a long period of time without impairing the filtration capacity of the disc filter 42. becomes.

[0047] Depending on the application, dehydration of solid materials may not be necessary, or gas-liquid contact may be preferable. If this is not the case, completely submerge the disc filter 142 in the liquid, as shown in FIG. The liquid is solidified by the concentrate discharge device 143, which is placed close to the disk in the counter pressure application zone. It is also possible to remove the concentrated liquid containing the solids from the system. In this case, the filtrate or The cleaning solution flows back through the counter pressure application zone to peel and remove solids and obtain a concentrated solution. .

[0048] Next, FIG. 7 shows another embodiment of the present invention.

[0049] In this disc filter, the filter element 242A itself is microporous. It is formed by integrally molding the plate 204. Its cross section is shown in Figure 8. may be a hollow part 280, or a fine porous plate 304 as shown in FIG. The structure may be filled with coarse-grained porous plates 380 that are coarser than the .

[0050] By adopting such a structure, assembly is simplified, and component parts can be easily assembled. As the number of parts is drastically reduced, maintenance becomes easier and the probability of malfunctions is reduced. The rate also decreases accordingly.

[0051]

【Effect of the invention】

As explained above, according to the present invention, slurry processing at high temperatures is possible, and It is now possible to treat corrosive slurries such as strong acids or strong alkalis, and no pre-coating is required. It is possible to obtain highly clarified liquid with less water, improving the strength and life of the filter element itself. This makes it possible to reduce manufacturing/processing errors and vibration control, and also allows for large-capacity processing and compaction. The excellent effect of being able to obtain advantages such as compaction and space saving. can get.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view and a partially exploded perspective view showing the configuration of a disk filter of a disk filter device according to an embodiment of the present invention.

FIG. 2 is an exploded schematic diagram showing the general configuration of the vicinity of the hollow tube of the disc filter device.

FIG. 3 is a sectional view showing the entire apparatus of the embodiment.

FIG. 4 is a sectional view taken along line VI-VI in FIG. 3;

FIG. 5 is a schematic diagram for explaining the operation of the disk filter device.

FIG. 6 is a front sectional view and a partial side sectional view of a disk filter showing another embodiment of the present invention.

FIG. 7 is a partial perspective view of a disk filter showing another embodiment of the present invention.

FIG. 8 is a partial cross-sectional view of the disc filter shown in FIG. 7.

9 is a partial sectional view showing another example of the cross section of the disc filter shown in FIG. 7. FIG.

FIG. 10 is a perspective view schematically showing a conventional disc filter device.

FIG. 11 is a sectional view of the conventional device.

[Explanation of symbols]

42, 142...disc filter, 44...tank, 46...white liquid recovery tank, 48...Lime mud recovery tank, 50...Hollow tube, 52...first hollow part, 54...Falling tube, 50A~50M...Axis space, 100...element holder, 102...Sealing material, 104, 204, 304...microporous plate, 106...Bolt, 110... fixed sliding plate, 112...Through hole corresponding to filtration/dehydration zone, 114...Through hole corresponding to the reverse pressure application zone, 116...Through hole corresponding to backwash zone, 280...Hollow part, 380...Coarse grain porous plate.

Claims (3)

[Scope of utility model registration request] Claim 1: A plurality of disc filters are placed upright in a pressurized container and rotated around a hollow shaft, and
In the pressurized disk filter device, the slurry is clarified, concentrated, or solids are recovered from the slurry by successively attaching solids in the slurry and removing the attached solids. A pressure disc filter device characterized in that the surface of the disc filter is formed by a microporous plate. 2. The pressure disc filter device according to claim 1, further comprising means for applying a reverse pressure to the adhered solids from inside the disc filter, and removing the solids by applying the reverse pressure. 3. The filter according to claim 1, further comprising means for backwashing adhered solid matter from the inside of the disc filter, and this backwashing eliminates clogging of the disc filter due to the solid matter. Perform pressurized disc filter device.