JP2584946B2 - Pressurized disk filter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressurized disc filter device.

[0002]

2. Description of the Related Art Conventionally, for example, in a causticizing step of kraft pulp treatment, a causticizing reaction is performed by adding calcined lime to a green liquor (aqueous smelt solution), and the causticizing reaction causes Milk is generated. Since the white milk is composed of a mixture of white liquor (an alkaline liquid mainly composed of caustic soda used for digesting chips) and lime mud (calcium carbonate particles) which is an impurity, lime mud is separated from the white milk. In order to remove the white milk, a white liquor clarification treatment is applied to the white milk.

[0003] In the white liquor clarification treatment, white milk is put into a large tank, and lime mud that has settled (separated) with time and separated is removed. However, in the white liquor clarification process, not only the amount of impurities remaining in the white liquor is large, but also the processing time becomes longer. Although a vacuum drum filter or a stationary tube filter can be used, the amount of white liquor contained in the separated lime mud is large, and the processing efficiency is reduced.

Therefore, a pressurized disc filter device using a filter disc has been provided (Japanese Patent Laid-Open No. Sho 62-62).
-33897). FIG. 2 is a conceptual diagram of a conventional pressurized disk filter device, FIG. 3 is a conceptual diagram of a filter disk in the conventional pressurized disk filter device, and FIG.
FIG. 5 is a cross-sectional view of a conventional pressurized disk filter device, FIG. 5 is a diagram showing a seal structure in the conventional pressurized disk filter device, and FIG. 6 is an assembled state diagram of the conventional pressurized disk filter device. FIG. 4A is a longitudinal sectional view of the pressurized disc filter device, and FIG. 4B is a transverse sectional view of the pressurized disc filter device.

In FIG. 1, reference numeral 11 denotes a tank, in which a plurality of filter discs 13 are supported rotatably about a rotary hollow shaft 14. The rotary hollow shaft 14 includes a shaft main body 14 a rotatably supported by the tank 11, and a sleeve 14 b surrounding the shaft main body 14 a and forming a cylindrical space 16. The filter disk 13 is disposed so as to extend radially outward from the sleeve 14b at a predetermined distance in the axial direction.

A liquid phase is formed by containing white milk 15 in the lower part of the tank 11, and a gas phase is formed in the upper part of the tank 11. In addition, a lower part of each of the filter disks 13 is immersed in the white milk 15. The filter disk 13 is rotated in the tank 11 and passed through the liquid phase, that is, the white milk 15. At this time, the white milk 15 is filtered by the precoat filtration, and the white liquor as a filtrate passes through the filter disk 13 and is collected in the filter disk 13, while the lime mud 21 as a solid material is on the surface of the filter disk 13. Adheres to

In this case, the inside of the tank 11 is pressurized by the compressor 22, and the white milk 15 is pressed against the filter disc 13. Therefore, solid-liquid separation is performed on the surface of the filter disk 13 by this pressing force. The cylindrical space 16 is connected to a filtrate tank 17 outside the tank 11, and the white liquor collected in the filter disk 13 is sent to the filtrate tank 17 through the cylindrical space 16.

Next, when the filter disc 13 moves to the gas phase, the lime mud 21 attached to the surface in the liquid phase moves to the gas phase with the rotation of the filter disc 13. Then, as described above, the tank 11
Since the inside is pressurized by the compressor 22, the gas in the gas phase passes through the filter disk 13, and at this time, the lime mud 21 is dehydrated by ventilation.

[0009] Further, a rinsing water is sprayed on the filter disc 13 by a spray device (not shown) disposed at a predetermined position in the gas phase, and the lime mud 21 is washed. As a result of this washing, the white liquor that has adhered to the filter disc 13 together with the lime mud 21 is allowed to permeate into the filter disc 13 together with the washing water by ventilation, and is sent to the filtrate tank 17 through the cylindrical space 16. Can be

As described above, the filtrate tank 17 contains the white liquor collected in the filter disk 13, the gas that has passed through the filter disk 13 during dehydration, the white liquor that has passed through the filter disk 13 during washing, and the washing water. And gas are sent. At this time, since the tank 11 and the filtrate tank 17 are separately manufactured, the white liquor, the washing water and the gas are once (once) received by the filtrate valve 23 disposed at one end of the rotary hollow shaft 14. Then, it is sent to the filtrate tank 17.

The filtrate tank 17 has a white liquid collecting pipe 18 at the lower end and a gas circulation pipe 19 at the upper end. Then, the white liquor and washing water separated in the filtrate tank 17 are discharged through the white liquor recovery pipe 18 and sent to the next step such as a digestion step. On the other hand, the gas separated in the filtrate tank 17 passes through the gas circulation pipe 19 and is returned to the tank 11. During this time, the gas is compressed by the compressor 22.

On the other hand, the lime mud 21 adhered to the surface of the dewatered filter disk 13 increases in thickness by repeating the cycle, and when the lime mud reaches a predetermined thickness, the lime mud 21 is scraped by the scraper 25 immediately before entering the white milk 15. (Ka) It is scraped. In this way, the lime mud 21 separated from the white liquor is dropped into the mixing tank 27 through the introduction pipe 26, and the mixing tank 27
Is mixed with warm water to form a slurry, and sent to the next step, that is, a step of recovering residual alkali, a step of refiring, and the like. Reference numeral 23 denotes supply pipes 23a, 23
b, a wear valve comprising a rotating side plate 24a and a fixed side plate 24b, 27a
Is a propeller-type agitator for stirring (stirring) the lime mud 21 and warm water. Reference numeral 29 denotes a bridge groove.

As described above, in the pressurized disc filter device, the white milk 1 is filtered by the precoat filtration.
Since 5 is filtered, the amount of impurities remaining in the white liquor can be reduced. In addition, since the lime mud 21 is dehydrated and washed at the same time as the filtration, the processing efficiency is high, the processing time can be shortened, and the amount of white liquor contained in the separated lime mud 21 is reduced. Efficiency can be improved.

Further, the above processing is performed in the tank 11 in a pressurized state and in a sealed state. Therefore,
The temperature of the white liquor does not decrease, the consumption of the heating steam can be reduced in the cooking step, and the clogging of the pipe due to scaling can be prevented.

[0015]

However, in the above-mentioned conventional pressurized disk filter device, the structure is complicated and large, and the manufacturing cost and the maintenance / management cost are increased. That is, the pressurized disc filter device includes a filtration zone formed by the liquid phase portion and the gas phase portion in the tank 11, a filtrate zone formed by the filtrate tank 17, and the introduction pipe 26 and the mixing tank 27.
Having a slurry mixing zone formed by Therefore, when manufacturing the pressurized disc filter device, the tank 11, the filtrate tank 17 and the mixing tank 27 are manufactured in advance as dedicated pressurized containers for each zone, and the tank 11 is installed at the installation location of the pressurized disc filter device. The filtrate tank 17 and the mixing tank 27 are connected to each other and assembled.

The tank 11 has a rotating hollow shaft 14.
In addition, since the filter disc 13 is rotatably supported, the filter disc 13 and the mixing tank 27 need to be accurately connected. Therefore, the structure is complicated and large, and the manufacturing cost and the maintenance / management cost increase. In addition, when the tank 11, the filtrate tank 17, and the mixing tank 27 are connected to each other and assembled at the installation location, a self-standing structure cannot be provided. Therefore, as shown in FIG.
Is disposed on the frame 29, the tank 11, the filtrate tank 1
7 and the mixing tank 27 are sequentially attached to complete the pressurized disc filter device. Therefore, not only does the installation cost for manufacturing the frame 29 increase, but also the construction period required for installation increases.

Further, in order to form a pressure difference in each of the tank 11 and the filtrate tank 17 which are communicated via the filtrate valve 23, each slide of the rotary hollow shaft 14 and the filtrate valve 23 is performed. Wear plate 2 between faces
4 are provided. The wear plate 24 includes a rotating side plate 24a attached to the rotating hollow shaft 14 and a fixed side plate 24b attached to the filtrate valve 23, as shown in FIG. Is complicated, and it is necessary to attach it with high accuracy, which increases the manufacturing cost. Reference numeral 23a denotes a supply pipe mainly supplying gas to the filtrate tank 17, and reference numeral 23b denotes a supply pipe mainly supplying white liquor to the filtrate tank 17.

The present invention solves the problems of the above-mentioned pressurized disc filter device, and has a simple structure and a small size, and can reduce the manufacturing cost and the maintenance and management cost. The purpose is to provide.

[0019]

To this end, a pressurized disc filter device according to the present invention is provided with a first tank closed at both ends by end plates and at one end of the first tank surrounding the end plate. A second tank forming a filtrate zone. A semi-cylindrical intermediate vat is disposed at a lower portion in the first tank, and forms a filtration zone above and a slurry mixing zone below. Above the intermediate bat, a filter disk is rotatably supported with respect to the first tank.

The apparatus further comprises means for supplying the filtrate and gas which have passed through the filter disk to the filtrate zone, and means for supplying solids adhering to the surface of the filter disk to the slurry mixing zone. In another pressurized disc filter device of the present invention, the means for supplying the filtrate and the gas having passed through the filter disc to the filtrate zone is a rotary hollow shaft penetrating the end plate at one end of the first tank. The space between the rotary hollow shaft and the end plate is sealed by a seal ring.

In still another pressurized disc filter device of the present invention, a slurry circulation path is provided in the slurry mixing zone, the slurry is sucked from the slurry mixing zone, and the slurry is jetted from the nozzle to the slurry mixing zone. .

[0022]

According to the present invention, as described above, the pressurized disc filter device is provided with the first tank closed at both ends by the end plates, and the one end of the first tank surrounding the end plate. A second tank forming a liquid zone.
A semi-cylindrical intermediate vat is disposed at a lower portion in the first tank, and forms a filtration zone above and a slurry mixing zone below. Above the intermediate bat, a filter disk is rotatably supported with respect to the first tank.

The apparatus further includes means for supplying the filtrate and gas which have passed through the filter disk to the filtrate zone, and means for supplying solids adhered to the surface of the filter disk to the slurry mixing zone. When, for example, white milk is supplied to the filtration zone, filtrate and gas pass through the filter disk and are supplied to the filtrate zone. In addition, solids adhere to the surface of the filter disk and are supplied to the slurry mixing zone.

In another pressurized disk filter device of the present invention, the means for supplying the filtrate and gas permeated through the filter disk to the filtrate zone is provided at one end of the first tank through a rotating hollow penetrating the end plate. A shaft, and the space between the rotary hollow shaft and the end plate is sealed by a seal ring. Therefore, the filtration zone can be maintained in a pressurized state.

In still another pressurized disk filter device of the present invention, a slurry circulation path is provided in the slurry mixing zone, the slurry is sucked from the slurry mixing zone, and the slurry is jetted from the nozzle to the slurry mixing zone. . Therefore, the solid and the hot water can be stirred without disposing the agitator in the slurry mixing zone.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of a pressurized disc filter device showing a first embodiment of the present invention, FIG. 7 is a cross sectional view of a pressurized disc filter device showing a first embodiment of the present invention, and FIG. FIG. 2 is a view showing a state of attachment of a seal ring in the first embodiment of the present invention.

In the figure, reference numeral 31 denotes a drum-shaped first forming a filtration zone Z ₁ and a slurry mixing zone Z ₂ .
It is a tank and both ends are closed by end plates 31a and 31b. The second tank 33 is disposed, the second tank 33 is the filtrate zone Z ₃ is formed so as to surround the end plate 31a at one end of the first tank 31. The end plate 31a forms a pressure partition.

Further, the bottom of the first tank 31 intermediate vat 35 of semi-cylindrical shape is disposed, slurry mixing zone Z ₂ below together with the filtration zone Z ₁ above the intermediate batt 35 is formed It is formed. In this case, the filtration zone Z ₁ and slurry mixing zone Z ₂ is the pressure is uniform. Therefore, the intermediate butt 3
5 can be a thin plate structure in which the both are opened.

In this way, the filtration zone Z ₁ , the slurry mixing zone Z ₂ and the filtrate zone Z ₃ are integrated. Wherein in the filtration zone Z ₁ has a plurality of filter disks 37 is rotatably supported with respect to the first tank 31 about the rotation hollow shaft 38, radially from the rotational hollow shaft 38 in the axial direction at predetermined distances It is arranged to extend outward. One end of the rotary hollow shaft 38 penetrates the end plate 31 a and enters the second tank 33, and a space 39 in the rotary hollow shaft 38 is connected to the second tank 33 through an outlet 41.
Communicating with the filtrate zone Z ₃ in the tank 33. The seal ring 42 is provided, the filtration zone Z ₁ filtrate zone Z ₃ is separated between the rotary hollow shaft 38 and the end plate 31a. The seal ring 42 can be formed of a metal ring, a soft fluorine resin ring, or the like, and does not require the use of an expensive mechanical seal and does not require high dimensional accuracy. When a ring made of fluororesin is used, maintainability can be improved by adopting a divided structure as shown in FIG.

On the other hand, the other end of the rotary hollow shaft 38 penetrates the other end plate 31b of the first tank 31 and the electric motor 40
Is linked to Then, the white milk 15 is supplied into the intermediate vat 35 through a supply port 44 formed in the end plate 31b, a liquid phase is formed in the intermediate vat 35, and a gas phase is formed above the liquid phase. Is formed. In addition, a part below each of the filter disks 37 is immersed in the white milk 15.

The filter disk 37 is provided in the filtration zone Z.
_It is rotated in ₁ and passed through the liquid phase, ie white milk 15. At this time, the white milk 15 is filtered by the precoat filtration, and the white liquor as a filtrate in the white milk 15 passes through the filter disk 37 and is collected in the filter disk 37. On the other hand, a lime mud (not shown) as a solid material Adhere to the surface of the filter disk 37.

In this case, the inside of the filtration zone Z ₁ is pressurized by the compressor 45, and the white milk 15 is pressed against the filter disk 37. Therefore, solid-liquid separation is performed on the surface of the filter disk 37 by this pressing force. The space 3 in the rotary hollow shaft 38
9 because it has communicated with the filtrate zone Z ₃ in said second tank 33 through the discharge port 41, the filter disc 3
White liquor recovered within 7 is sent to the filtrate zone Z ₃ through the space 39.

Next, when the filter disk 37 moves to the gas phase, the lime mud adhering to the surface in the liquid phase moves to the gas phase as the filter disk 37 rotates. Then, as described above, the filtration zone Z ₁
Since the inside is pressurized by the compressor 45, the gas in the gas phase passes through the filter disk 37, and at this time, the lime mud is dehydrated by ventilation.

The washing water is supplied to the filter disk 37 by a spray device 46 disposed at a predetermined position in the gas phase.
And the lime mud is washed. As a result of this washing, the white liquor that has adhered to the filter disc 37 together with the lime mud is allowed to permeate into the filter disc 37 together with the washing water by aeration, and the space 39
Through it sent to the filtrate zone Z _3.

[0035] Thus, the該Roeki zone Z _3, white liquor collected in the filter disc 37, the gas passing through the filter disc 37 at the time of dehydration, as well as white liquor passing through the filter disc 37 at the time of washing, washing Water and gas are sent. Meanwhile, the filtrate zone Z ₃ has the white liquor recovery pipe 47 at the lower end, a gas circulation tube 49 at the upper end. The white liquor and washing water separated in the filtrate zone Z ₃ is discharged through said white liquor recovery pipe 47, and sent to the next step, such as cooking processes. Meanwhile, the gas is a white liquid mist is separated by spontaneous sedimentation rises, it is returned to the filtration zone Z ₁ through the gas circulation tube 49. During this time, the gas is
Compressed by

[0036] Incidentally, the filtrate zone Z ₃ in as necessary to disposed the demister 50 can be separated white fluid mists from rising gas. Filter disk 3 after dehydration
The lime mud adhering to the surface of 7 increases in thickness by the repetition of the cycle, and when the lime mud reaches a predetermined thickness, is scraped off by a scraper 25 immediately before entering the white milk 15. In this case, the lime mud having a thickness corresponding to the clearance between the filter disk 37 and the scraper 25 remains as a precoat layer, and only the lime mud remaining and deposited thereafter is scraped off.

In this manner, the line separated from the white liquor is obtained.
The mu mud passes through the inlet pipe 52 and the slurry mixing sol.
Z_TwoInto the slurry mixing zone.
N Z _TwoBy mixing with hot water at
And the next step, a step of recovering residual alkali,
It is sent to a re-firing process and the like. In this case, the inside of the introduction pipe 52
Space is formed through a square tubular opening formed in the intermediate bat 35.
And slurry mixing zone Z_TwoTo communicate with
And the structure is simplified.

It should be noted, 54 is a communication path for temporarily communicated filtration zone Z ₁ and slurry mixing zone Z _2, filtration zone Z ₁ or slurry mixing zone Z
It can be discharged and washing water in the filtration zone Z ₁ by opening the valve 55 when cleaning the _second internal. Reference numeral 56 denotes a hot water supply pipe, and 57 denotes a slurry discharge pipe.

Next, the slurry circulating passage for stirring the lime mud and hot water is described in the slurry mixing zone Z _2. FIG. 9 is a sectional view of a slurry mixing zone according to the first embodiment of the present invention, and FIG. 10 is a plan view of the slurry mixing zone according to the first embodiment of the present invention. FIG. 9A is a cross-sectional view of the slurry mixing zone, and FIG. 9B is a vertical cross-sectional view of the slurry mixing zone.

In the figure, 31 is a first tank, and 35 is an intermediate bat. Reference numeral 58 denotes a slurry circulation path for stirring the slurry, and the circulation pump 59 circulates the slurry. The slurry is sucked from the slurry mixing zone Z ₂ of the suction port 61 disposed in a predetermined position, the sent by the circulation pump 59, is injected from a plurality of nozzles 62 disposed in another predetermined position You. As shown in FIG. 10, the nozzle 62 is arranged with a direction, and injects the slurry at an angle set with respect to the axis of the first tank 31. Thus, while stirring the lime mud and hot water in the slurry mixing zone Z _2, to prevent the slurry ejected from the nozzles 62 from interfering with each other.

Further, the slurry mixing zone Z ₂
When the partition plate 63 is disposed along the axial direction, a swirling flow of the slurry is formed and the dead zone is eliminated. Therefore, it is possible to prevent the lime mud from settling and depositing on the bottom surface of the first tank 31. In this way, the first tank 31 and the second tank 33 are integrally formed, and the intermediate vat 35 is disposed in the first tank 31 so that the filtration zone Z ₁ (FIG. 1), the slurry mixing zone Z ₂ and the filtrate zone Z ₃ can be formed, so that the weight of the pressurized disc filter
[%] Can be reduced, and the structure can be simplified and downsized. In addition, manufacturing costs,
Management costs can be reduced.

Further, since the pressure type disk filter device has a self-standing structure, it can be placed directly on a foundation at an installation location. Therefore, it is not necessary to arrange a dedicated frame, and not only the installation cost can be reduced, but also the construction period required for the installation can be shortened. One end of the rotary hollow shaft 38 penetrates the end plate 31a and enters the second tank 33, and the rotary hollow shaft 38 and the end plate 3
Since the space between 1a is sealed by the seal ring 42, the sealing structure can be simplified, the mounting can be performed with high accuracy, and the manufacturing cost can be reduced.

Next, a second embodiment of the present invention will be described. FIG. 11 is a sectional view of a pressurized disc filter device showing a second embodiment of the present invention. In the figure, Z _1A ,
Z _1B is a first and second filtration zone, Z _2A and Z _2B are first and second slurry mixing zones, and Z _3A and Z _3B are first and second filtrate zones. The first and second filtration zones Z _1A ,
In _Z1B , different stock solutions can be filtered.

Reference numeral 37 denotes a filter disk, and 38 denotes a time.
Rolled hollow shaft, 40 is an electric motor, 44a, 44b is supply of undiluted solution
Tubes, 47a and 47b are filtrate collection tubes, and 57a and 57b are tubes.
Rally discharge pipe, 71 is the first tank, 72 is the second tank
, 73 is the third tank, 74 is the middle bat, 75 is the
Presser 76 is provided in the first and second filtration zones Z._1A, Z
_1BAnd the first and second slurry mixins
Gzone Z_2A, Z_2BThis is a partition plate for separating.

The present invention is not limited to the above embodiments, but can be variously modified based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0046]

As described above in detail, according to the present invention, the pressurized disc filter device comprises a first tank closed at both ends by end plates, and the end plate surrounding one end of the first tank. A second tank disposed to form a filtrate zone. A semi-cylindrical intermediate vat is disposed at a lower portion in the first tank, and forms a filtration zone above and a slurry mixing zone below. Above the intermediate bat, a filter disk is rotatably supported with respect to the first tank.

Further, there are provided means for supplying the filtrate and gas which have passed through the filter disk to the filtrate zone, and means for supplying solids adhered to the surface of the filter disk to the slurry mixing zone. Therefore, the structure is simplified, and the size of the pressurized disc filter device can be reduced. Further, manufacturing costs and maintenance / management costs can be reduced. Furthermore, since it has a self-standing structure, it can be placed directly on the foundation at the installation location. And there is no need to arrange a dedicated frame,
Not only can the installation cost be reduced, but also the time required for installation can be shortened.

In another pressurized disc filter device of the present invention, the means for supplying the filtrate and gas permeated through the filter disc to the filtrate zone is provided at one end of the first tank through a rotary hollow penetrating the end plate. A shaft, and the space between the rotary hollow shaft and the end plate is sealed by a seal ring. Therefore, the seal structure is simplified, the seal ring can be attached with high accuracy, and the manufacturing cost can be reduced.

In still another pressurized disc filter device of the present invention, a slurry circulation path is provided in the slurry mixing zone, the slurry is sucked from the slurry mixing zone, and the slurry is jetted from the nozzle to the slurry mixing zone. . Therefore, since it is not necessary to dispose an agitator in the slurry mixing zone, the size of the pressurized disc filter device can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a pressurized disc filter device showing a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a conventional pressurized disc filter device.

FIG. 3 is a conceptual diagram of a filter disk in a conventional pressurized disk filter device.

FIG. 4 is a sectional view of a conventional pressurized disc filter device.

FIG. 5 is a view showing a seal structure in a conventional pressurized disc filter device.

FIG. 6 is an assembled state diagram of a conventional pressurized disc filter device.

FIG. 7 is a cross-sectional view of the pressurized disc filter device according to the first embodiment of the present invention.

FIG. 8 is a mounting state diagram of the seal ring according to the first embodiment of the present invention.

FIG. 9 is a sectional view of a slurry mixing zone according to the first embodiment of the present invention.

FIG. 10 is a plan view of a slurry mixing zone in the first embodiment of the present invention.

FIG. 11 is a sectional view of a pressurized disc filter device showing a second embodiment of the present invention.

[Explanation of symbols]

31 and 71 the first tank 31a, 31b end plate 33,72 second tank 35,74 intermediate vat 37 filter disc 38 rotating hollow shaft 41 outlet 42 sealing ring 45 compressor 58 slurry circulating passage 62 nozzles Z ₁ filtration zone Z ₂ slurry mixing Zone Z ₃ filtrate zone

Claims (3)

(57) [Claims] (A) a first tank closed at both ends by end plates; and (b) a second tank disposed at one end of the first tank and surrounding the end plate to form a filtrate zone. ,
(C) a semi-cylindrical intermediate vat disposed at a lower portion in the first tank and forming a filtration zone above and forming a slurry mixing zone below; and (d) above the intermediate vat, A filter disk rotatably supported with respect to the first tank, (e) means for supplying filtrate and gas permeating the filter disk to the filtrate zone, and (f) adhering to the surface of the filter disk. And a means for supplying the solid matter to the slurry mixing zone. 2. A means for supplying a filtrate and a gas which have passed through a filter disk to said filtrate zone, wherein:
2. The pressurized disc filter device according to claim 1, further comprising: a rotary hollow shaft penetrating the end plate at one end of the tank, and (b) a space between the rotary hollow shaft and the end plate is sealed by a seal ring. 3. A slurry disposed in the slurry mixing zone, sucking slurry from the slurry mixing zone,
The pressurized disc filter device according to claim 1, further comprising a slurry circulation path for injecting the slurry from a nozzle to a slurry mixing zone.