JP2005118754A - System and method for recovering solid component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that when a plant is large-sized, a rotary valve 2 is also large-sized, and the space cutout function of the rotary valve 2 lowers, and a gas in a housing 1C leaks when a wet cake is taken out of a pressurized filter 1. <P>SOLUTION: The recovery system is equipped with a pressure filter 11 for yielding the wet cake by pressurizing and filtering a slurry S, first rotary valves 12 and 12 for taking out the wet cake from the pressure filter 11, buffer tanks 13 and 13 for temporally storing the wet cake taken out by the first rotary valves 12 and 12, boosters 14 and 14 for adjusting the pressure in the buffer tanks 13 and 13 to atmospheric pressure, and second rotary valves 15 and 15 for taking out the wet cake from the buffer tanks 13 and 13 adjusted to atmospheric pressure by the boosters 14 and 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solid content recovery system and a solid content recovery method. More specifically, for example, a solid content obtained by pressurizing and filtering a slurry containing a solid content such as crystals is removed from a pressurized and filtered environment. The present invention relates to a solid content recovery system and a solid content recovery method that can be smoothly taken out under an atmospheric pressure environment.

  As a conventional technique of this type, for example, a technique described in Patent Document 1 is known. The technique described in Patent Document 1 relates to a method and apparatus for recovering crystals from a slurry, and the main part thereof is generally configured as shown in FIG.

  As shown in FIG. 2, the conventional crystal recovery apparatus includes a pressure filter 1 that pressurizes and filters the slurry S to obtain a wet cake (not shown) containing crystals (solid content), and a pressure filter. A rotary valve 2 for taking out the wet cake to the atmospheric pressure downstream, and a drier (not shown) for drying the wet cake under the atmospheric pressure downstream of the rotary valve 2. Further, instead of the rotary valve, for example, there is a method in which two ball valves are provided as shutters and the wet cake is taken out by the pressure difference and the dead weight.

  As shown in the figure, the pressurizing filter 1 has a slurry reservoir 1B connected to a slurry supply pipe 1A, and a rotation partly immersed in the slurry reservoir 1B and having a filter medium on the entire circumferential surface. A housing 1D that surrounds the drum 1C and the rotating drum 1C and forms a pressurized space with the slurry reservoir 1B, and is connected to the housing 1D and supplies pressurized gas (inert gas such as nitrogen) into the housing 1D. Gas supply pipe 1E and a peeling means (not shown) for pressurizing and filtering the slurry S in the slurry reservoir 1B with the pressurized gas from the gas supply pipe 1E and peeling the wet cake formed on the surface of the rotating drum 1C The wet cake is discharged from the cake discharge path 1F connected to the housing 1D to the rotary valve 2 as indicated by the white arrow. Although not shown, the pressure filter includes a pipe for collecting the filtrate in the rotating drum 1C and a cleaning means for cleaning the wet cake on the surface of the rotating drum 1C.

  Thus, as described above, the rotary valve 2 is disposed between the pressurizing filter 1 and the dryer under atmospheric pressure, and maintains the airtightness in the housing 1C of the pressurizing filter 1 while being pressurized. The wet cake is taken out from the filter 1 to the atmospheric pressure side.

Japanese Patent Laid-Open No. 11-179115

  However, in the case of the crystal recovery method and the crystal recovery apparatus described in Patent Document 1, the rotary valve 2 can efficiently take out the wet cake while maintaining the airtightness of the pressure filter 1 in a small plant. When the plant is enlarged, the rotary valve 2 is also enlarged, the space blocking function of the rotary valve 2 is reduced, and when the wet cake is taken out from the pressurized filter 1, the pressurized gas in the housing 1C leaks, and the leaked gas is downstream. It has been found to adversely affect various equipment such as a side dryer. Moreover, since gas leaks from the pressurizing filter 1, there is a problem that the loss of pressurizing gas is increased. Also in the method of providing two ball valves as a shutter, it was not possible to prevent gas leakage from the pressure filter as in the case described above.

  The present invention has been made to solve the above-described problems, and prevents gas leakage from the pressure filter to the low pressure side, and has an adverse effect on various devices arranged on the downstream side of the pressure filter. An object of the present invention is to provide a solid content recovery system and a solid content recovery method that can be prevented.

  A solid content recovery system according to claim 1 of the present invention includes a pressure filter for separating a solid content and a liquid content by filtering a slurry under pressure, and a solid content separated in the pressure filter. A first rotary valve for taking out the liquid, a container for temporarily storing the solid content taken out by the first rotary valve, a pressure adjusting means for adjusting the pressure in the container to a reduced pressure, and a pressure adjusted by the pressure adjusting means And a second rotary valve for taking out the solid content from the container.

  Moreover, the solid content recovery system according to claim 2 of the present invention is the invention according to claim 1, wherein the solid content recovery system is provided with means for conveying the solid content from the pressure filter to the first rotary valve, Means for conveying the solid content downstream from the second rotary valve is provided.

  Moreover, the solid content recovery system according to claim 3 of the present invention is characterized in that, in the invention according to claim 1 or claim 2, a screw conveyor is provided as means for transporting the solid content. Is.

  The solid content recovery method according to claim 4 of the present invention includes a step of filtering the slurry under pressure using a pressure filter to separate the solid content and the liquid content, and a first rotary valve. A step of taking out the solid content separated in the pressure type filter, a step of temporarily storing the solid content taken out from the first rotary valve in the container, and a step of adjusting the pressure in the container to a reduced pressure. And a step of taking out the solid content in the container using the second rotary valve.

  A solid content recovery method according to claim 5 of the present invention is the method according to claim 4, wherein the solid content is transferred from the pressure filter to the first rotary valve, And a step of conveying the solid content from the rotary valve to the downstream side.

  Moreover, according to invention of Claim 1-Claim 5 of this invention, the leakage of the gas from a pressurized filter to the atmospheric pressure side is prevented, and the various arrange | positioned in the downstream of a pressurized filter It is possible to provide a solid content recovery system and a solid content recovery method capable of preventing an adverse effect on an apparatus.

  Hereinafter, the present invention will be described based on the embodiment shown in FIGS. 1 and 2. FIG. 1 is a view showing an embodiment of the solid content recovery apparatus of the present invention, (a) is a schematic view showing its side, (b) is a schematic view showing its front, and FIG. 2 is a view showing the present invention. It is a figure which shows other embodiment of the solid content collection | recovery apparatus of this, (a) is a schematic diagram which shows the side surface, (b) is a schematic diagram which shows the front.

  As shown in FIGS. 1A and 1B, the solid content recovery system 10 of the present embodiment is a pressure filter that filters the slurry S under pressure to separate the solid content from the filtrate as a wet cake. 11, a first rotary valve 12 for taking out the wet cake from the pressure filter 11, and a buffer tank 13 for temporarily storing the wet cake taken out to the low pressure side (atmospheric pressure side) through the first rotary valve 12 And a pressure adjusting means (booster) 14 for adjusting the pressure in the buffer tank 13 to atmospheric pressure, and a dryer installed under the atmospheric pressure downstream from the buffer tank 13 adjusted to atmospheric pressure by the booster 14. And a second rotary valve 15 for taking out the wet cake to a device such as (not shown).

  As shown in FIGS. 1A and 1B, the pressure filter 11 includes a slurry supply pipe 11A, a slurry reservoir 11B, a rotating drum 11C, a housing 11D, a gas supply pipe 11E, and a cake discharge path 11F. The wet cake is discharged from the cake discharge path 11F to the atmosphere side in the direction indicated by the white arrow. In FIG. 1A, 11G is a pipe through which the slurry overflows from the slurry reservoir 11B.

  Further, as shown in FIGS. 1A and 1B, a first screw conveyor 16 is disposed between the pressure filter 11 and the first rotary valve 12, and the first screw conveyor 16 is added via the screw conveyor 16. The wet cake discharged from the pressure filter 11 is conveyed to the first rotary valve 12. The first screw conveyor 16 has left and right screws 16A, 16B formed in spiral shapes opposite to each other, and the wet cake discharged from the cake discharge path 11F is discharged from the center of the cake discharge path 11F to the left and right outlets 16C, It is arranged to 16D.

  Two first rotary valves 12 and 12 are connected to the left and right outlets 16C and 16D of the first screw conveyor 16, respectively. The rotary cakes 12 and 12 allow the wet cake to be discharged from the pressurized first screw valve 16. The wet cake is taken out and supplied to the buffer tanks 13 and 13 on the atmospheric pressure side connected to the rotary valves 12 and 12, respectively. As described above, when the first rotary valve 12 becomes large in size, the airtightness is not always perfect, and when the wet cake is taken out from the first screw conveyor 16, the pressurized gas in the first screw conveyor 16 is buffered by the buffer tanks 13, 13. Leak into.

  The buffer tank 13 is a sealed container that temporarily stores the leaked gas from the first screw conveyor 16 together with the wet cake, and the sealed container is pressurized by the leaked gas. Therefore, a booster 14 is provided in the buffer tank 13, and the booster 14 is connected to the housing 11 </ b> D of the pressure filter 11 through a pipe 17. The booster 14 increases the gas in the buffer tank 13 (however, the pressure is lower than that of the first screw conveyor 16) to a predetermined pressure (for example, the pressure in the pressurizing filter 11), and pressurizes It returns to the inside of the filter 11, and the inside of the buffer tank 13 is adjusted to the pressure substantially equal to atmospheric pressure. In addition, the booster 14 and the piping 17 are abbreviate | omitted in (b) of FIG.

  The buffer tank 13 is provided with a pressure sensor (not shown). The pressure sensor detects the pressure in the buffer tank 13 and drives the booster 14 when the detected value exceeds a predetermined value. . The gas in the buffer tank 13 may be supplied to a place other than the housing 11D. The pipe 17 may be connected to the gas supply pipe 11E.

  Further, a second screw conveyor 18 is connected to each buffer tank 13, 13 via a second rotary valve 15, 15, and the wet cake taken out by the second rotary valve 15, 15 is transferred to the second screw conveyor 18. Supply. The second rotary valve 15 is driven when the pressure sensor of the buffer tank 13 detects a pressure substantially equal to the atmospheric pressure. In this way, the second rotary valve 15 is configured to take out the wet cake from the buffer tank 13 adjusted to approximately atmospheric pressure to the second screw conveyor 18 side on the atmosphere side. Gas does not leak to the second screw conveyor 18.

  The second screw conveyor 18 includes a screw 18A for conveying the wet cake in one direction (from left to right in FIG. 1B), left and right inlets 18B and 18C for receiving the wet cake, and an outlet 18D for the wet cake. The wet cake delivered by the second rotary valves 15 and 15 is supplied from the outlet 18D to a device such as a dryer under atmospheric pressure.

  Next, a solid content recovery method using the solid content recovery system 10 of the present embodiment will be described with reference to FIGS. The solid content recovery system 10 is driven, and an inert gas such as nitrogen gas is supplied from the gas supply pipe 11E into the housing 11D to pressurize the inside of the housing 11E. When the slurry S is supplied from the slurry supply pipe 11A in this state, a part of the rotating drum 11C is immersed in the liquid level of the slurry S in the slurry reservoir 1B.

  When a part of the rotating drum 11C is immersed in the liquid surface of the slurry S, the slurry S is filtered in the rotating drum 11C by the pressurized gas while the rotating drum 11C rotates in the direction of the arrow, and the solid content is wet on the surface of the rotating drum 11C. Collect as a cake. The wet cake is washed in the washing region while the rotating drum 11C rotates, then reaches the peeling region, and the wet cake is peeled from the rotating drum 11C by the peeling means. The rotating drum 11C from which the wet cake has been peeled reaches the liquid level of the slurry S, and repeats the pressure filtration and washing described above. On the other hand, the filtrate in the rotating drum 11C is discharged out of the rotating drum 11.

  The wet cake peeled from the rotating drum 11C is supplied from the cake discharge path 11 into the first screw conveyor 16. The first screw conveyor 16 distributes the wet cake from the center to the left and right by the left and right screws 16A and 16B, and supplies the wet cake to the first rotary valves 12 and 12 from the left and right outlets 16C and 16D. The first rotary valves 12 and 12 gradually take out the wet cake from the outlets 16 </ b> C and 16 </ b> D of the first screw conveyor 16 into the buffer tanks 13 and 13. Although the buffer tanks 13 and 13 are spatially cut off from the first screw conveyor 16 via the first rotary valves 12 and 12, the airtightness of the first rotary valves 13 and 13 is not necessarily perfect. The pressurized gas in the conveyor 16 leaks into the buffer tanks 13 and 13 via the first rotary valves 12 and 12, and the buffer tanks 13 and 13 become pressurized due to the leaked gas.

  When the wet cake accumulates in the buffer tanks 13 and 13, the pressure in the buffer tanks 13 and 13 rises due to the leakage gas. At this time, when the pressure sensor detects the pressure in the buffer tank 13 and the detected value reaches a predetermined value after a predetermined time has elapsed, the booster 14 is automatically driven to increase the gas in the buffer tank 13 while increasing the pressure. While supplying to the pressure filter 11 via the piping 17, the pressure in the buffer tank 13 is returned to substantially atmospheric pressure. When the pressure in the buffer tanks 13 and 13 returns to approximately atmospheric pressure, the pressure sensor detects the atmospheric pressure and drives the second rotary valves 15 and 15. The second rotary valves 15 and 15 take out the wet cake in the buffer tanks 13 and 13 and supply it to the second screw conveyor 18. At this time, since the pressure in the buffer tanks 13 and 13 is atmospheric pressure like the second screw conveyor 18 on the downstream side, gas does not leak from the buffer tanks 13 and 13 to the second screw conveyor 18. .

  The second screw conveyor 18 conveys the wet cake taken out by the second rotary valves 15 and 15 to the outlet 18D at one place (right side in FIG. 1B) by the screw 15A, and the downstream side from the outlet 18D. Supply to equipment such as dryers. At this time, since the second screw conveyor 18 does not contain the leaked gas from the pressure filter 11, there is no possibility of adversely affecting downstream equipment such as a dryer.

  As described above, according to the present embodiment, the slurry S is filtered under pressure using the pressure filter 11 to separate the wet cake from the filtrate to the surface of the rotating drum 11C, and then the wet cake is removed from the rotating drum 11C. The wet cake was removed from the pressure filter 11 side using the first rotary valves 12 and 12 and temporarily stored in the buffer tanks 13 and 13. At this time, the wet cake was stored in the buffer tanks 13 and 13. After the leaked gas from the pressurizing filter 11 is returned into the pressurizing filter 11 by the action of the booster 14 and the pressure in the buffer tanks 13 and 13 is adjusted to approximately atmospheric pressure, the second rotary valves 15 and 15 are used. Since the wet cake in the buffer tanks 13 and 13 is taken out, the gas in the pressure filter 11 is discharged from the second rotary valves 15 and 15. Without leaking into the flow side, there is no adversely affect the equipment dryer or the like which is disposed downstream. Moreover, since the leaked gas is reused, the amount of inert gas used for pressurization can be saved.

  In addition, according to the present embodiment, the wet cake is conveyed from the pressure filter 11 to the first rotary valves 12 and 12 via the first screw conveyor 16, and the second rotary via the second screw conveyor 18. Since the wet cake is conveyed from the valves 15 and 15 to the downstream side, the wet cake collected in the pressure filter 11 can be smoothly conveyed and supplied to a device such as a dryer on the downstream side.

  FIG. 2 is a diagram showing a solid content recovery system according to another embodiment of the present invention. Therefore, the same reference numerals are given to the same or corresponding parts as in FIG. 1, and the features of the collection system of this embodiment will be described. As shown in FIG. 2, the recovery system 10 of the present embodiment includes a filtrate tank 19 disposed in the middle of a pipe 17 that connects the booster 14 and the housing 11 </ b> D of the pressure filter 11. The filtrate tank 19 is a tank that separates the filtrate from the pressurized filter 11 and the pressurized gas and temporarily stores the leaked gas from the buffer tank 13. In FIG. 2, 11H is a center pipe, 11I is a filtrate pipe, and the filtrate in the rotary drum 11C is supplied to the filtrate tank 11 via the center pipe 11H as will be described later. Reference numeral 11J denotes a valve shoe, and an inert gas such as nitrogen gas is ejected from the valve shoe 11J in the direction of the arrow to peel the wet cake from the rotating drum 11C.

  Thus, as shown in FIG. 2, the filtrate tank 19 is connected to the center pipe 11H in the rotary drum 11C via the pipe 20, and receives the filtrate discharged from the pressure filter 11 from the pipe 20. The filtrate and the pressurized gas are separated. A liquid level sensor (not shown) is attached to the filtrate tank 19, and the filtrate is discharged when a predetermined amount of filtrate is accumulated by the liquid level sensor.

  The filtrate tank 19 receives the leaked gas boosted by the booster 14 and then discharges the leaked gas together with the pressurized gas. The gas discharged from the filtrate tank can be reused as pressurizing gas through the dehumidifying means and the pressure adjusting means.

  Also in this embodiment, the same effect as the said embodiment can be expected.

  Needless to say, the present invention is not limited to the above embodiment. For example, in this embodiment, two series of first and second rotary valves and buffer tanks are used, but it goes without saying that one series may be used. The reason why the wet cake take-out line is divided into two lines is that, if one line is used, the rotary valve becomes larger as the pressure filter becomes larger. In short, the pressure filter and the downstream dryer are important. The first and second rotary valves are interposed between the first and second rotary valves, and the buffer tank (container) is interposed between the first and second rotary valves. Any device that does not leak into a device such as a vessel is included in the present invention. Moreover, although the booster 14 was used as a means to adjust the pressure in the container, other equipment may be used.

  INDUSTRIAL APPLICABILITY The present invention can be used in fields such as general chemical industry, fertilizer industry, metal industry, food industry, etc. in which a slurry is filtered to recover a solid content.

It is a figure which shows one Embodiment of the solid content collection | recovery system of this invention, (a) is a schematic diagram which shows the cross-sectional structure of a side surface, (b) is a schematic diagram which shows the cross-sectional structure of the direction orthogonal to (a). . It is a figure which shows other embodiment of the solid content collection | recovery system of this invention, (a) is a schematic diagram which shows the cross-sectional structure of a side surface, (b) is a schematic diagram which shows the cross-sectional structure of the direction orthogonal to (a). is there. It is a schematic diagram which shows the principal part of the conventional solid content collection | recovery system.

Explanation of symbols

10 Solid content recovery system 11 Pressure filter 12 First rotary valve 13 Buffer tank (container)
14 Booster (pressure adjustment means)
15 2nd rotary valve 16 1st screw conveyor (means to convey)
18 Second screw conveyor (conveying means)

Claims (5)

  A pressure filter that separates solids and liquids by filtering the slurry under pressure, a first rotary valve that extracts the solids separated in the pressure filter, and a first rotary valve that takes out the solids. A container for temporarily storing the solid content, a pressure adjusting means for reducing the pressure in the container, and a second rotary valve for taking out the solid content from the container whose pressure is adjusted by the pressure adjusting means. A solid content recovery system characterized by comprising.   2. A means for conveying the solid content from the pressure filter to the first rotary valve and a means for conveying the solid content downstream from the second rotary valve are provided. The solid content recovery system described in 1.   The solid content recovery system according to claim 1 or 2, wherein a screw conveyor is provided as means for conveying the solid content.   Filtering the slurry under pressure using a pressure filter to separate the solids and liquids; removing the solids separated in the pressure filter using the first rotary valve; A step of temporarily storing the solid content taken out from the first rotary valve in the container; a step of adjusting the pressure in the container under reduced pressure; and a step of taking out the solid content in the container using the second rotary valve. And a solid content recovery method. 5. The method according to claim 4, further comprising: a step of conveying the solid content from the pressure filter to the first rotary valve; and a step of conveying the solid content from the second rotary valve to the downstream side. The solid content recovery method described.

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