JPS6094109A - Dehydrating method by filter press - Google Patents

Abstract

PURPOSE:To increase the concn. of a solid component in a cake by supplying compressed air into a dehydrated cake from an air supply port of a filter plate, and discharging the clearance water and air to the outside of the filtration chamber from a liquid discharge port of an adjacent filter plate on the opposite side. CONSTITUTION:A slurry is continuously supplied into a filter cloth 16 by opening valves 19 and 28 and closing valves 20, 22, 30, 33, and filtered. After the filtration is finished, one of the adjacent valves 28 is opened and the other closed, and each corresponding valve 30 is reversed to the valve 28, and compressed air is supplied into a filtration chamber 15 from the opened valve 30. The compressed air from an air supply port 26 passes through a clearance having small flow resistance in a groove 27a, the filter cloth 16, and a cake, blows away the clearance water from the clearance, and is discharged through a groove 27b and a liquid discharge port 25. The opening and closing of the valves 28 and 30 are reversed in the operation at the succeeding stage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a filter press for dewatering a slurry in which solid particles and water are mixed, such as a coal-water slurry, and further improving the solid content of a cake formed thereby. Concerning the dehydration method by
Then, the excess water in the slurry is poured into one chamber of the filter press by the bitten cloth at the initial stage of e-filtration, and then onto the P cloth surface as d''' progresses. The formed cake layer is used to filter, separate, and discharge the cake.Finally, the cake fills the f chamber, and this cake is consolidated under a pressure commensurate with the slurry supply pressure, increasing the filtration resistance. The supply of slurry becomes impossible, and therefore the discharge of surplus water CPt&) is stopped, and the filtration and dewatering operations are completed.

The basic structure of the dehydrated cake formed by such an operation is shown in the first diagram. In the dehydrated cake, a skeleton structure is formed by the solid particles 1, and the gaps between the solid particles 1 are The water is saturated and is in a state of "t", and even if it takes more time to pump the slurry and pressurize it, it is not possible to reduce the moisture content of the cake.

In other words, since both the 1-type particles and water exhibit incompressibility, for example, if the 1-type particles are clayey with no water permeability, the slurry will be If the supply Vt+ becomes impossible and the solid particles are sandy with good water resistance, it may be a cake that has filled the inside of the basin. Only one plate thickened without being consolidated or dehydrated beyond a certain ratio, and as a result, the supply pressure of the slurry became in+, and the supply hole in the Karutani P chamber was clogged with cake, which eventually caused the filter press to become too thick. A leak is formed in the slurry supply pipe to the pipe, and slurry supply becomes impossible due to the pipe blockage or excessive resistance of J·N.

As mentioned above, in the case of the conventionally known dehydration method using a filter press, it is possible to remove the interstitial water between the particles of one type in the five cakes by light beam, and for this reason, the porosity of the cake is large (
In the case of a slurry in which the solid particles are coarse or the particle size distribution is uniform within a narrow range even if the solid particles are fine, there is a lot of pore water in the cake. Overall, residual moisture increases, resulting in a decrease in dehydration rate. For this reason, when selecting a conventional juice filtration machine, a filter press was considered to be an unsuitable model for the above-mentioned coarse slurry or slurry of uniform particle size.

The inventor of the present invention was able to obtain the following knowledge by considering the physical properties of a dehydrated cake consisting of a framework structure of solid particles and interstitial water.

1. All of the stress due to external forces applied from the outside is borne by the framework structure of solid particles, and the pore water does not share the stress with respect to this external force.

2. Since pore water is only attached to solid particles due to physical adhesion, heat can be easily separated by selectively applying force to this pore water if it has good water permeability. .

3 The gaps between particles are evenly distributed throughout the formed cake, and the cake itself is a porous aggregate of solid particles, and these gaps are not closed individually but mutually. Being in communication. For this purpose, if compressed air or the like is supplied locally into the cake from one side, it will pass through this passage with low passage resistance, which is now filled with interstitial water, to atmospheric pressure. It dissipates into the atmosphere through the other surface below.

4. When an external force (high feed pressure or squeezing force) is further applied to this J + Q 'M, there are sufficient gaps between the particles, and the solid particles are suspended in the pore water).
, -3" 7:C, that is, for a cake formed softly, its volume is gradually consolidated and solidified depending on the strength of this external force, and its condensation '1164i; The excess pore water of the he-she body 4γ is separated and discharged, and the water resistance is accelerated.However, its collection #i4iii is significantly reduced when the pressure exceeds 10 KP/cd, and the pore water is Do not limit the significant improvement in dehydration rate as it will remain in the cake.

5. When the volume of the cake decreases or changes, in materials that are not permeable, such as clay, pore water cannot immediately follow this change in volume, and therefore works to prevent the change in volume and temporarily Pore water pressure is generated, and it takes a considerable amount of time to resolve by separating, extracting, and draining this pore water at tide.

For this reason, in the case of a method in which the water content is reduced only by compacting the cake, which does not have water permeability, the filtration time will be considerably longer.

6. No matter how strong an external force is applied, the gaps between the particles will not become zero. When the ideal particle size structure is such that the particle size distribution of solid particles causes fine particles to fit into the gaps between coarse particles, and even fine particles to fit into the gaps between fine particles, in a well-balanced form in terms of quantity and size. Only by simple pressurization is it possible to obtain a cake with minimal moisture content.

This invention was made based on the above findings, and an object of the present invention is to provide a method that can increase the dewatering rate by separating and removing interstitial water in a dehydrated cake.

That is, this dehydration method of Qiangming has a plurality of 14 boards overlapping each other, a J Tamuro is formed between each board, and a F cloth is attached to the wall of the Nazawa room. Using a filter press in which through-holes are formed that pass through the fabrics , Ia & 1 and slow-acting to each υ chamber, solids are poured into each chamber through the negative passage holes with the MfJ mark plate under pressure. A slurry in which the particles and water are emulsified is supplied to form an IBz water cake, and then to this dehydrated cake circle, the pressure is supplied from a pressurizer to mix between the solid particles: ij! The interstitial water remaining between the particles is discharged outside the room, and compressed air is then supplied to the shell through hole from the fresh air supply tube to form a slurry without dewatering in the through hole. 'The special feature is to take it outside.

We will examine the embodiments of this invention shown in the drawings from FIG. 2 onwards.

FIG. 2 shows a slurry processing system incorporated as one step in the method of the present invention, in which the slurry settled and riveted by the Shirafuna 3 is sent to a tank 5 by a pump 4 and stirred, and further by a supply pump 6. It is sent to a filter press 7, where it is dehydrated.

As shown in FIGS. 3 to 5, the filter press 7 has a plurality of filter plates 11 suspended from a trapazor 10 fixed to a pair of pedestals 8 and 9, and the f-filter plate 11 is connected to the filter plates 11. Similarly, it is held between the movable plate 12 and the pedestal 8 which are suspended from the traverser IO.

By the operation of the cylinder 14 in which the piston 13 is attached to the 'oJ movement 12, the cylinders move between a position where they are overlapped and pressurized and a position where they are separated from each other. Recesses are provided on both sides of the first filter plate 11 (on one side for those located at both ends), and an f chamber 15 is formed by the cooperation of these recesses between the filter plates 11 that are based on each other. . A bag-shaped cloth 16 is attached to each r chamber 15, and this
The j pass plate 11 has a through hole 17 that passes through them and communicates the valley '1j''w (only that of the f pass plate 11 is shown in FIG. 4).
is provided. One end of the through hole 17 communicates with a supply port 8 provided in the pedestal 8, and this supply port 18 is connected to a valve 19.2.
It is connected to the supply Ponzoro via a pipe 21 with 0.

In addition to the through hole 18, the Dif6 is connected to an air compressor 24 via a pipe 23 equipped with a valve 22.

The inside of the JJ chamber 15 and the outside of the F chamber 15 are connected to the filtration &11 on both sides, and there are drain holes 25 and 11Jf for discharging the P liquid.
An air supply hole 26 is provided to supply air into i4-15. 111 holes 25 and 26 are branched into branch holes 25' inside the il'J pass plate 11.

25', 26', and 26', and these branch holes 2
5', 25' and 26', 26' are itJ room 150
A large number of vertical and horizontal ridges 27a, 2 for communication provided on both side walls.
It is open at 7b. The exhaust hole 25 is connected to a pipe 29 equipped with a valve 28, and the exhaust hole 25 is connected to a pipe 29 provided with a valve 28.
An exhaust hole for the air supplied into the chamber 15 is installed. The air supply hole 26 is connected to an air chamber 32 via a pipe 31 with a valve 3o, and this air chamber 32 is connected to a branch pipe 34 with a valve 33 from the pipe 23 connected to the air conditioner ``!II'' 24. has been done. 35 in FIG. 5 is a draining net.

Next, the device E7. Explain how to dehydrate using.

The cylinder 14 is actuated to pressurize the l-'I overplate 11, and the valve 19.28 is opened, the other valves 20.22,
30 and 33 are in a closed state, and in this state, slurry at a predetermined pressure is continuously supplied into the cloth 16 of the sump chamber 15P through the piping 21, the supply port 18, and the through hole 17 by the supply pump. The slurry fills the clothing 16, and at the beginning of t1, the P cloth 16 performs the Sawa cloth J2 filtration, which has relatively low filtration resistance, and after that, a layer of cake 36 is formed on the surface of the cloth within a short period of time. , the p overresistance generally increases and the
As the liquid decreases, the f overpressure increases.

P passes through 360 layers of cake and 1 fabric 6 to F fabric 1
6 After going outside, pass through the draining net 35 and enter 27 a.
, 27 b and branch hole 25'.

25', the liquid reaches the drain hole 25, passes through the drain hole 25, and is discharged four times to the outside of the 1A chamber 15. In this way l
As the filtration process continues, the amount of PM discharge gradually decreases until it reaches a drip-like level, and when the filtration pressure reaches a predetermined value, the operation of the supply pump is stopped and the first filtration process is completed. '1-.At this point, the cake formed in the r chamber 15 has been appropriately consolidated, but pore water remains in the gaps between the particles, and there is water in the through holes 17. The slurry remains without being dehydrated. Conventionally, this undehydrated slurry was removed after the A4 pass process, but in the present invention, interstitial water between particles is removed before that.

First, the valves 2B are set so that adjacent valves 2B are in the open and closed states, respectively, and the filter plate 1
1, the corresponding valve 30 is placed in the opposite state to the state of the valve 28, that is, if the square 28 is in the open state, the valve 30 is in the closed state,
If the valve 28 is closed, the valve 30 is opened. Further, the valve 33 is opened, and the other valves 19, 20, and 22 are closed.

The near compressor 24 is operated and the pressure m is passed through the piping 34.
Nitrogen is once sent to the air chamber 32, and from this air chamber 32, compressed air at a required pressure (same or higher than the slurry supply pressure from the supply pump 6) is passed through the pipe 31 with the valve 30 open. It is supplied to one chamber 15 on both sides of the overboard 11. In this case, the valve 30 of the pipe 31 is now marked with an arrow.
is open, compressed air is once supplied to the groove 27a on one side of the f chamber 15 via the air supply hole 26 and its branch holes 26', 26', and the compressed air flows along this groove 27a to l. 'F+i: Equally distributed to 27 a.

At the beginning of the supply, compressed air passes through the P cloth 16 to the cake 3.
After that, solid particles clogging the P/ft] 16 are removed and the 1 cloth 16 is backwashed, passing through the P cloth 16 and entering the interior thereof. cake 36
The skeleton structure of the solid particles that form the solid particles is already consolidated, so it generates stress due to compression, but the pore water is only physically attached to the solid particles, so it is Separated. To compress air, select a continuous gap with low passage resistance in the cake and apply it there.
It blows away the interstitial water and exits into the groove 27b on the other side of the lJ presentation 15.

Compressed air is supplied from this hole 27b to branch holes 25', 25', 4
7+ pores; Piping 29 via the shredded exhaust 71iJLzs
It may also be discharged.

By supplying compressed air to the groove 27a on one side as described above, this compressed air is supplied into the dehydrated cake 36 for an appropriate time, but in the next step, the valve 28.
0 to make the opening/opening state opposite to the above.

As a result, compressed air is supplied to the groove 27b on the other side of the Ij tray 15, and following almost the same process as described above, the compressed air is supplied to the groove 27b on the other side of the Ij tray 15.
Exit to +727 a, go through 1jl, nx hole 25 and place 29
The score is 1-1. After that, this process is repeated as appropriate for each step, that is, pressurized air is alternately supplied to the grooves 27g and 27b on both sides of l'R1150, and the grooves 27b and 27b on the opposite side are respectively supplied with compressed air.
By exiting through 27a υ), the compressed air remains in the f chamber 15 for a sufficient time to remove interstitial water and is discharged without short-circuiting. Note that this repetition may be performed in units of several steps.

Next, valve 20.22 is opened, and other valves 19, 28°30.
33 is closed, compressed air is sent from the compressor 24 to the through hole 18 via the pipe 23, and the undehydrated slurry in the through hole 18 is discharged from the valve 20.

Thereafter, the pressure on the filter plate 11 is released and the cake 36 is taken out. An example in which a slurry whose solid particles are pulverized coal is dehydrated and filtered by the above method is as follows.

(Remaining days below) From the above results, the water content of the dehydrated cake was significantly reduced.
It can also be seen that the pushing pressure of the supply pump may be small and the dewatering time may also be short.

This release E! The following 5 effects can be obtained by JJ.

1. The lowest moisture content that can be achieved by mechanical methods.

2. The field of application of the filter press as a dehydrator can be expanded.

3 Like the conventional compression type filter press (not a method of applying force IJ through a diaphragm such as a rubber plate), it is inexpensive with a single line of 494717 without making major changes to the simple pressurization type machine +n in the United States. .

4. Instead of adding lime or other auxiliary agents, it is possible to use a slurry with a single substance to be filtered.

5. Because the pore water in the cake is replaced by air, the physical properties of the cake change, and unlike conventional compacted cakes, which are solid, they become fluffy, making them easier to crush and processing similar to the primary T. It becomes easier.

6 Air ventilation has the same effect as when the P fabric is blown back by air, so it prevents clogging of the d1 fabric, reduces the frequency of washing the P fabric, and makes it easier to wash the P fabric, reducing the amount of washing water. Finish.

7. Since the method does not reduce residual moisture only by compacting the cake, there is no need to apply excessive compaction to the cake, so the slurry supply pump should also be at low pressure.
Also, the filtration time per cycle should be shortened. Furthermore, since the required vibration mechanical strength is reduced, both equipment costs and running costs are reduced, making it economical.

[Brief explanation of drawings]

Figure 1 is a diagram schematically showing the basic structure of a dehydrated cake, Figure 2
Figure 3 is a schematic overall view showing an example of a filter press, Figure 4 is a vertical cross-sectional view of the filter press, Figure 5 is along the line ■-■ in Figure 4. An enlarged cross-sectional view taken along. 7...filterless 11...1 over plate 14.
...Shilling 15...-day Room 16...1 Cloth
17...Through hole 19.20, 22.2++, 30
．． 33... Valve 24... Near compressor 25...
・Drainage hole 26...Air supply hole 27a, 27b...Pain 36...Cake Atsushi 1 Figure Death 4 Figure Death 5 Figure 2゜Continued from page 1 0 Inventor Tadashi Ito Sumi Tanashi City Yato-cho None Inventor Kaoru Aoki Tanashi-shi Yato-cho None Inventor Yube Ito 1 company, Chuo-ku, Tokyo 0 Inventor Teruo Jokawa 2-1, 1 company, Chuo-ku, Tokyo No. 1 Sumitomo Heavy Industries Co., Ltd. Ta 2-1-1 Sumitomo Heavy Industries Co., Ltd. Ta 1 Honbashi Kayabacho 2-9
No. 4 Rasa Shoji Stock 1 2-9-4, Kayabacho, Honbashi Rasa Shoji Stock Proceedings Amendment Statement March 27, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of Case 1988 Patent Application No. 199763 Relationship to Case No. 1 Patent Applicant: Electric Power Development Co., Ltd., 1-8-2 Marunouchi, Chiyoda-ku, Tokyo (2 others) President: 1) Masaru 34, Agent 5, Subject of amendment (1) of the description Each column of "% Claims" and "Detailed Description of the Invention" (11 Claims will be amended as shown in the attached sheet. 1st
"As shown in the figure" is corrected. (3) "1 filter plate" on page 7, line 10 is corrected to "furnace chamber." (4) "Compressed air" in line 13 of the same page is corrected to "compressed air via the air supply hole provided in the filter plate." (5) In line 15 of the same page, "interstitial water" is amended to "interstitial water and air are passed through drainage holes provided in the filter plate adjacent to and on the opposite side of the filter plate." do. (6) "Through hole 18J" on page 9, line 6, "Through hole 17"
and correct it. (7) Correct "ν passing plate 11J" in line 7 of page 10 to "inside P chamber 15." +8J Correct "compressed air" in line 6 of page 13 to "compressed air and pore water." (Correct "mu." in line 6 of page 17 of 91 as follows. Interstitial water and air are discharged to the outside of the furnace chamber through drainage holes provided in the filter plate adjacent to and on the opposite side, so the compressed air can be used to remove interstitial water inside the furnace chamber without short-circuiting. "7" in line 7 of the same page should be amended to "8". 7. Inventory of attached documents Paper 1 General rule Paper patent claims 1. A furnace chamber is formed between each filter plate, an F cloth is attached to the wall of each P chamber, and a through hole passes through the filter plate and the filter cloth to communicate each furnace chamber. Using a filter press in which the inside of the furnace chamber is pressurized, a slurry containing a mixture of solid particles and water is supplied to each furnace chamber through the through holes to form a dehydrated cake. Compressed air is supplied into the dehydrated cake from an air supply source through the air supply holes provided in the filter plate, and is passed between the solid particles, so that the interstitial water and air remaining between the particles are separated from the filter plate. The liquid is discharged to the outside of the furnace chamber through a drain hole provided in an adjacent and opposite filter plate, and then compressed air is supplied from the air supply source to the through hole to drain the undehydrated slurry in the through hole. A dewatering method using a filter press, which is characterized by discharging water outside the furnace room.

Claims (1)

[Claims] 1. It has a plurality of passing plates that bend to each other, one room is formed between each P grade, and one cloth is opened on the wall of each F room, 14
IJ
While the recording plate is pressurized, a slurry in which solid particles and water are combined is supplied to each chamber e through the through holes to form a dehydrated cake, and then an air supply source is supplied into the dehydrated cake. Compressed air is supplied to pass between the solid particles to remove the interstitial water that accumulates between the particles outside the room, and then compressed air is supplied from the air supply source to the through hole. 1. A dewatering method using a filter press characterized in that the undehydrated slurry in the through hole is discharged to the outside of the chamber.