WO2010064289A1

WO2010064289A1 - Solid content collection apparatus and solid content collection method

Info

Publication number: WO2010064289A1
Application number: PCT/JP2008/071789
Authority: WO
Inventors: 保寿田中; 一樹大森; 尚史桶谷; 匠金子; 寛之和田
Original assignee: 三菱化工機株式会社
Priority date: 2008-12-01
Filing date: 2008-12-01
Publication date: 2010-06-10
Also published as: JPWO2010064289A1; JP5346955B2

Abstract

A solid content collection apparatus which reliably prevents leakage of gas from a pressure filtration apparatus to a lower pressure side when collecting solid contents separated by the pressure filtration apparatus and reduces power expense. A discharger (22) used for the solid content collection apparatus (20) is provided with a two-shaft screw feeder (23) which carries wet cakes (C), a motor (24) which synchronously drives the two-shaft screw feeder (23), a solid content storage part (25) which stores the wet cakes (C) from the two-shaft screw feeder (23) as a consolidated layer to prevent the leakage of pressurized gas, a pressure opening/closing apparatus (26) which applies a predetermined pressure to an opening/closing body (26A) controlling the opening degree of the exit of the solid content storage part (25), to keep the consolidated layer within the solid content storage part (25), and an opening/closing control device (28) which controls the opening/closing operation of the opening/closing body (26A) of the pressure opening/closing apparatus (26).

Description

Solid content recovery device and solid content recovery method

The present invention relates to a solid content recovery device 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 a crystal is applied from a pressure and filtration environment. The present invention relates to a solid content recovery apparatus and a solid content recovery method that can be smoothly taken out under an atmospheric pressure environment.

As this type of conventional technology, for example, the technology 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.

For example, as shown in FIG. 3, the conventional crystal recovery device 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 from the machine to the atmospheric pressure downstream, and a dryer (not shown) for drying the wet cake under the atmospheric pressure downstream of the rotary valve 2 are provided. Further, instead of the rotary valve 2, there is a method in which, for example, two ball valves are provided as shutters, and the wet cake is taken out by a pressure difference and its own weight.

For example, as shown in FIG. 3, the pressurizing filter 1 is a slurry storage portion 1B connected to a slurry supply pipe 1A, and a rotation partly immersed in the slurry storage portion 1B and having a filter medium on the entire peripheral 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. Moreover, although not shown in figure, the pressurization type filter 1 is provided with the piping which collect | recovers the filtrate in the rotating drum 1C, and the washing | cleaning means which wash | cleans the wet cake on the surface of the rotating drum 1C.

As described above, the rotary valve 2 is disposed between the pressurizing filter 1 and the dryer under atmospheric pressure, and the pressurizing filter 1 while maintaining the airtightness in the housing 1D of the pressurizing filter 1. The wet cake is taken out to the atmospheric pressure side.

However, in the case of the crystal recovery apparatus shown in FIG. 3, when the plant is enlarged, the rotary valve 2 is also enlarged, the space blocking function of the rotary valve 2 is lowered, and the housing is removed when the wet cake is taken out from the pressure filter 1. There is a problem that gas in 1D leaks. As a technique for improving this problem, for example, a technique described in Patent Document 2 is known. The technique of Patent Document 2 relates to a method and apparatus for recovering crystals from a slurry, and this apparatus is generally configured as shown in FIG.

The crystal recovery apparatus shown in FIG. 4 includes a pressurizing filter 11 that pressurizes and filters the slurry S to obtain a wet cake, first

rotary valves

12 and 12 that take out the wet cake from the pressurizing filter 11, and these

Buffer tanks

13 and 13 for temporarily 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 And second

rotary valves

15 and 15 for taking out the wet cake from the

buffer tanks

13 and 13 adjusted to the atmospheric pressure by the

boosters

14 and 14. In addition, since the pressurization type filter 11 is comprised according to what is shown in FIG. 3, the number of the 10th series is attached | subjected to a corresponding part, and each description is abbreviate | omitted. Reference numeral 16 denotes a first screw conveyor, 17 denotes a second screw conveyor, and 18 denotes a pipe connecting the housing 11D and the booster 14.

As described above, the second

rotary valves

15 and 15 are configured to discharge the wet cake to the atmosphere side while maintaining airtightness from the buffer tank 13 adjusted to a substantially atmospheric pressure by the

boosters

14 and 14. For this reason, the gas in the pressurizing filter 11 does not leak to the downstream side of the second

rotary valves

15, 15, and there is no possibility of adversely affecting equipment such as a dryer installed on the downstream side. Moreover, since the leaked gas is reused, the amount of inert gas used for pressurization can be saved.

JP-A-11-179115 JP 2005-118754 A

However, in the case of the crystal recovery method and the crystal recovery apparatus shown in FIG. 4, the first

rotary valves

12 and 12 and the second

rotary valves

15 and 15 are both pressure-resistant structures in order to maintain the airtightness of the pressure filter 11. Furthermore, if the plant is enlarged, the first

rotary valves

12 and 12 are also enlarged, and the space interruption of the first

rotary valves

12 and 12 is reduced. For this reason, when the wet cake is taken out by the first

rotary valves

12, 12, the amount of pressurized gas leaked from the first

rotary valves

12, 12 to the

buffer tanks

13, 13 increases. There is a problem that the power cost of the

boosters

14 and 14 for adjusting the pressure of the gas to the atmospheric pressure increases accordingly.

The present invention has been made to solve the above-described problems, and reliably collects gas from the pressure filter to the low pressure side when recovering solids separated by the pressure filter. It is an object of the present invention to provide a solid content recovery apparatus and a solid content recovery method capable of saving power costs.

The solid content recovery apparatus according to claim 1 of the present invention is connected to a pressure filter for separating the solid content and the liquid content by filtering the slurry with a pressurized gas, and a discharge path of the pressure filter. And a solid content recovery device comprising a discharge device for discharging the solid content, wherein the discharge device includes a screw feeder that conveys the solid content, a rotation drive mechanism that drives the screw feeder, and the screw. Applying a predetermined pressure to the solid content reservoir that stores the solid content from the feeder as a consolidated layer to prevent leakage of the pressurized gas, and the opening / closing body that controls the opening degree of the outlet of the solid content reservoir. And an opening / closing device for holding the opening / closing body of the opening / closing device, and an opening / closing control device for controlling opening / closing of the opening / closing body of the opening / closing device.

The solid content recovery device according to claim 2 of the present invention is characterized in that, in the invention according to claim 1, the opening / closing device has a cylinder mechanism for driving the opening / closing body. .

According to a third aspect of the present invention, there is provided the solid content recovery device according to the first or second aspect, wherein the open / close control device includes a detector that detects a load amount of the rotary drive mechanism. And a controller for controlling an opening / closing body of the opening / closing device based on a detection value of the detector.

According to a fourth aspect of the present invention, there is provided the solid content recovery apparatus according to any one of the first to third aspects, wherein the pressure filter is a rotary single chamber filter. It is characterized by being.

The solid content recovery device according to claim 5 of the present invention is the solid-state recovery device according to any one of claims 1 to 3, wherein the pressure filter is a rotary multi-chamber filter. It is characterized by being.

Further, the solid content recovery method according to claim 6 of the present invention is a method of recovering solid content from a slurry using the solid content recovery device according to claims 1 to 5, wherein a pressure filter is used. A step of conveying the solid content discharged from the screw feeder by a screw feeder, a step of temporarily storing the solid content conveyed by the screw feeder in a solid content storage unit to form a consolidated layer, and the solid content storage unit And a step of controlling the opening degree of the opening / closing body that opens and closes the outlet of the screw based on the load amount of the rotary drive mechanism that drives the screw feeder.

According to the present invention, when recovering solids separated by a pressure filter, gas leakage from the pressure filter to the low pressure side can be surely prevented and power cost can be saved. It is possible to provide a solid content recovery device and a solid content recovery method capable of producing a solid content.

It is a mimetic diagram showing one embodiment of a solid content recovery device of the present invention. It is a graph which shows the relationship between the torque of the motor of the screw feeder shown in FIG. 1, and the pressurized air pressure of the pressurization apparatus of an opening-closing body. It is a schematic diagram which shows the principal part of the conventional solid content collection | recovery apparatus. It is a schematic diagram which shows the principal part of the other conventional solid content collection | recovery apparatus.

Explanation of symbols

20 Solid content recovery device 21 Pressure filter 21F Discharge path 22 Discharge device 23 Twin screw feeder (screw feeder)
24 motor (rotary drive mechanism)
25 Solid Content Storage Unit 26 Opening / Closing Device 26A Opening / Closing Body 26B Cylinder Mechanism 28 Opening / Closing Control Device

Hereinafter, the present invention will be described based on the embodiment shown in FIG. 1 and FIG. 1 is a schematic view showing an embodiment of the solid content recovery device of the present invention, and FIG. 2 is a relationship between the torque of the screw feeder motor shown in FIG. 1 and the pressurized air pressure of the pressurizing device of the opening / closing body. It is a graph which shows.

For example, as shown in FIG. 1, the solid content recovery device 20 of the present embodiment filters the slurry S under pressure to separate the solid content from the filtrate as a wet cake C, and the pressure type filter 21. A discharge device 22 that discharges the wet cake C separated in the filter 21.

The wet cake C discharge device 22 is connected to a discharge path 21F of the pressure filter 21 and is a screw feeder (for example, a biaxial screw feeder) 23 that conveys the wet cake C supplied from the pressure filter 21; The motor 24 that rotationally drives the biaxial screw feeder 23, the solid content reservoir 25 that stores the wet cake C conveyed by the biaxial screw feeder 23 as a compacted layer, and the opening degree of the outlet of the solid content reservoir 25 A pressure-type opening / closing device 26 having an opening / closing body 26 A to be adjusted and applying a predetermined pressure to the opening / closing body 26 A to hold the compacted layer of the solid content reservoir 25, and an outlet of the solid content reservoir 25. A container 27 for drivingly opening and closing the opening / closing body 26A of the pressurizing switch 26 and forming a discharge path for the wet cake C, and the pressurizing switch 26 An opening / closing control device 28 for controlling the pressure applied to the opening / closing body 26A and controlling the opening degree of the outlet of the solid content storage unit 25 by the opening / closing body 26A. It is configured to discharge to the side (not shown).

As shown in FIG. 1, the pressure filter 21 includes a slurry supply pipe 21A, a slurry reservoir 21B, a rotary drum 21C, a housing 21D, a gas supply pipe 21E, and a cake discharge path 21F. It is configured as a rotary single chamber filter that discharges the wet cake C to the twin screw feeder 23. In FIG. 1, 21G is a pipe through which the slurry overflows from the slurry reservoir 21B.

The biaxial screw feeder 23 is a motor that is a rotational drive mechanism that synchronously drives the two

screw shafts

23A and 23A formed with screw blades and arranged in parallel to each other, and the two screw shafts 23A and 23A. 24, and is connected to the cake discharge passage 21F of the pressure filter 21. In the biaxial screw feeder 23, the two screw shafts 23 A and 23 A are driven in synchronization via the motor 24, and convey the wet cake C from the pressure filter 21 into the solid content storage unit 25.

Thus, as shown in FIG. 1, the inlet of the solid content reservoir 25 formed in a cylindrical shape is connected to the carry-out port of the biaxial screw feeder 23. The solid content storage unit 25 temporarily stores the wet cake C transported from the twin screw feeder 23 to form a consolidated layer, and seals the pressurized gas from the pressurizing filter 21 by the consolidated layer. It has a function. As described above, the solid content reservoir 25 is a compacted layer and prevents the pressurized gas from leaking from the pressurized filter 21, whereby the amount of pressurized gas used in the pressurized filter 21 can be saved.

At the outlet of the solid content reservoir 25, there is provided a pressure switch 26 for temporarily storing the wet cake C as a consolidated layer in the solid content reservoir 25. The pressurization type opening / closing device 26 is housed in a container 27 and opens / closes an outlet of the solid content reservoir 25 and a cylinder mechanism that reciprocates the opening / closing body 26A to open / close the outlet of the solid content reservoir 25. (For example, an air cylinder) 26B and an air source 26C that supplies pressurized air (for example, 0.7 MPa in terms of gauge pressure) to the cylinder mechanism 26B. The opening / closing body 26A adjusts the discharge amount of the wet cake C by adjusting the opening degree of the outlet of the solid content reservoir 25 via the cylinder mechanism 26B, and prevents pressurized gas from leaking from the compacted layer of the wet cake C. I am trying to control it.

The cylinder mechanism 26B of the pressure type opening / closing device 26 operates the opening / closing body 26A under the control of the opening / closing control device 28. The opening / closing control device 28 includes a detector 28A that detects the torque of the motor 24 based on a load amount (for example, current value) of the motor 24, and a pressurized air from the air source 26C based on the torque from the detector 28A. And a pressure controller 28B for setting the pressure to be applied to the cylinder mechanism 26B by controlling the pressure. A switching valve 28C is interposed between the pressure controller 28B and the cylinder mechanism 26B, and the cylinder mechanism 26B controls the opening degree of the opening / closing body 26A via the switching valve 28C. In this way, the opening degree of the outlet of the solid content reservoir 25 is controlled by the opening / closing body 26A, and the discharge amount of the wet cake C is controlled while keeping the bulk density of the consolidated layer to prevent the leakage of the pressurized gas constant. .

Thus, when the wet cake C from the pressurizing filter 21 starts to be transported and the wet cake C in the twin screw feeder 23 is small, the torque of the motor 24 is small. Is closed with a pressure higher than that of the pressurized gas in the biaxial screw feeder 23 to prevent leakage of the pressurized gas and to form a consolidated layer in the solid content reservoir 25. At this time, the torque of the motor 24 for driving the biaxial screw feeder 23 may be small. When a compacted layer is formed in the solid content storage unit 25 by transporting the wet cake C from the biaxial screw feeder 23, the amount of the wet cake C in the biaxial screw feeder 23 increases and the torque of the motor 24 gradually increases. As the pressure increases, the pressurized gas is sealed by the compaction layer to lower the back pressure at the outlet of the solid content reservoir 25. Therefore, the pressure applied to the compacted layer from the opening / closing body 26A is lowered and the outlet of the solid content reservoir 25 is opened. Increase the degree and discharge the wet cake C to the downstream dryer side.

When the pressurizing filter 21 is operated using a pressurized gas of 0.05 MPa (gauge pressure), the pressure applied from the opening / closing body 26A of the pressurizing switchgear 26 to the outlet of the solid content reservoir 25 is that of the motor 24. Control can be based on torque. At this time, it is preferable to control the pressure applied from the opening / closing body 26 A to the consolidation layer as shown in the control diagram of FIG. That is, as shown in FIG. 2, the motor 24 can be operated with energy efficiency when operated at a torque of 10 to 30% of the rated value. Therefore, when the pressure of the pressurized air of the cylinder mechanism 26B of the opening / closing body 26A is automatically controlled in the range of 0.05 to 0.3 MPa so that the torque of the motor 24 is controlled in the range of 10 to 30%, The leakage of the pressurized gas from the pressurized filter 21 can be prevented and the solid content recovery device 20 can be operated with high energy efficiency. In addition, when the pressurizing filter 21 is temporarily stopped and restarted, even if the biaxial screw feeder 23 is in an idle operation, the solidified layer remains in the solid content storage unit 25. It is possible to operate while maintaining the state where the gas is sealed and maintaining the pressure of the pressurized gas in the pressurized filter 21.

Next, a solid content recovery method using the solid content recovery apparatus 20 of the present embodiment will be described with reference to FIG. The solid content recovery device 20 is operated, and an inert gas such as nitrogen gas is supplied from the gas supply pipe 21E into the housing 21D to pressurize the inside of the housing 21D. When the slurry S is supplied from the slurry supply pipe 21A in this state, a part of the rotating drum 21C is immersed in the liquid level of the slurry S in the slurry storage portion 21B.

When a part of the rotating drum 21C is immersed in the liquid surface of the slurry S, the slurry S is filtered in the rotating drum 21C under pressure by a pressurized gas while the rotating drum 21C rotates in the direction of the arrow, and the surface of the rotating drum 21C is solid. The portion is collected as wet cake C. While the rotary drum 21C rotates, the wet cake C is washed in the washing region, and then the wet cake C is peeled off from the rotary drum 21C by the peeling means. The rotary drum 21C from which the wet cake C has been peeled reaches the liquid level of the slurry S, and repeats the steps from pressure filtration to peeling. On the other hand, the filtrate in the rotating drum 21 C is discharged out of the rotating drum 21.

The wet cake C peeled off from the rotating drum 21C is discharged into the twin screw feeder 23 from the cake discharge path 21F. In the biaxial screw feeder 23, the two screw shafts 23 A and 23 A are synchronously driven via the motor 24, and the wet cake C is conveyed to the solid content storage unit 25 by the two screw shafts 23 A and 23 A. At this time, since the outlet of the solid content reservoir 25 is blocked by the opening / closing body 26B, the wet cake C is stored in the solid content reservoir 25 and the pressurized gas is sealed by the opening / closing body 26A.

When the wet cake C is conveyed and a wet layer of the wet cake C is formed in the solid content reservoir 25 and the pressurized gas can be sealed, the torque of the motor 24 begins to exceed 10% of the rating. Since the torque of the motor 24 is constantly monitored by the detector 28A of the pressure control device 28, the pressure of the pressurized air of the cylinder mechanism 26B applied to the opening / closing body 26A based on the detection value of the detector 28A as shown in FIG. Begin to control. If the wet cake C in the biaxial screw feeder 23 continues to increase, the torque of the motor 24 increases. Therefore, the pressure of the pressurized air of the cylinder mechanism 26B that the pressure controller 28B applies to the opening / closing body 26A based on the torque at that time. It lowers and the opening degree of the exit of the solid content storage part 25 is adjusted, and the wet cake C is discharged | emitted from the container 27 to the dryer side. At this stage, since the compaction layer is formed in the solid content storage unit 25, the pressurized gas of the pressurizing filter 21 is sealed by the compaction layer, and the leakage of the pressurized gas to the container 27 can be prevented. it can.

Thereafter, when the amount of the wet cake C in the twin screw feeder 23 gradually increases and the torque of the motor 24 exceeds 30% of the rated value, the pressure of the pressurized air of the cylinder mechanism 26B applied to the opening / closing body 26A thereafter. Is limited to a constant value (for example, 0.05 MPa as a gauge pressure), and the motor 24 is driven in an energy efficient manner. By making the pressure applied to the compacted layer from the opening / closing body 26A constant, leakage of the pressurized gas can be prevented by the compacted layer, the energy consumption efficiency of the motor 24 can be increased, and the energy saving operation can be performed, thereby reducing the operating cost. be able to.

In addition, even if the pressure type filter 21 is temporarily stopped and then restarted to filter and collect the same wet cake C, even if the biaxial screw feeder 23 is idled, the solid content storage unit Since the compaction layer is already formed in 25, the pressurized gas can be sealed by the compaction layer to prevent the pressurized gas from leaking. Further, when the compacted layer in the solid content reservoir 25 cannot seal the pressurized gas, the outlet of the solid content reservoir 25 is closed with 0.3 MPa (gauge pressure) with the opening / closing body 26A as in the intended operation. Thus, leakage of pressurized gas can be prevented.

As described above, according to the present embodiment, the pressurized filter 1 that separates the wet cake C and the liquid component by filtering the slurry S with the pressurized gas, and the cake discharge path 21 F of the pressurized filter 1. And a discharge device 22 that discharges the wet cake C. The discharge device 22 includes a biaxial screw feeder 23 that conveys the wet cake C, a motor 24 that synchronously drives the biaxial screw feeder 23, and two The solid cake storage section 25 that stores the wet cake C from the shaft screw feeder 23 as a compacted layer to prevent the leakage of pressurized gas, and the opening / closing body 26A that controls the opening degree of the outlet of the solid content storage section 25 are predetermined. And a pressure switchgear 26 that holds the compacted layer in the solid content reservoir 25, and an open / closer that controls the opening / closing operation of the switchgear 26A of the pressure switchgear 26. When the wet cake C is recovered from the slurry S using the solid content recovery device provided with the control device 28, the wet cake C discharged from the pressure filter 21 is conveyed by the twin screw feeder 23, The wet cake C conveyed by the biaxial screw feeder 23 is temporarily stored in the solid content storage unit 25 to form a compacted layer, and the opening degree of the opening / closing body 26A that opens and closes the outlet of the solid content storage unit, Since the control is performed based on the torque of the motor 24, a solidified layer of the wet cake C is formed in the solid content storage unit 25 to prevent the leakage of the pressurized gas in the pressurized filter 21, and the solid content is recovered. The operation cost (power cost) can be reduced by operating the device 20 with energy efficiency.

According to the present embodiment, the opening / closing control device 28 includes a detector 28A that detects the torque of the motor 24, and a pressure controller 28B that controls the opening / closing body 26A of the opening / closing device 26 based on the detection value of the detector 28A. Therefore, the motor 24 can be driven stably with high energy efficiency. Moreover, since the opening / closing device 26 includes the cylinder mechanism 26B that drives the opening / closing body 26A, the opening degree of the outlet of the solid content reservoir 25 can be opened and closed with a simple configuration.

Needless to say, the present invention is not limited to the above embodiment. In the above embodiment, a biaxial screw feeder is used as the screw feeder, but the screw feeder may be a single screw feeder or a multiaxial screw feeder. In short, the solid content recovery device of the present invention is a screw feeder that discharges the solid content supplied from the pressure filter to the downstream side and conveys the solid content while kneading, and the screw feeder is driven to rotate. Rotation drive mechanism, solid content storage unit that stores solid content conveyed by screw feeder as a compacted layer and prevents leakage of pressurized gas, and opening / closing body that controls the opening degree of the outlet of the solid content storage unit And an opening / closing device that applies a predetermined pressure to the opening / closing body to hold the compacted layer of the solid content storage section, and an opening / closing control device that controls opening / closing of the opening / closing body of the opening / closing device. Any method may be used as long as it is a method for separating a solid content from a slurry.

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.

Claims

Solid having a pressure filter that separates solids and liquids by filtering the slurry with pressurized gas, and a discharge device that is connected to a discharge path of the pressure filter and discharges the solids. In the minute recovery device, the discharge device stores the solid content from the screw feeder that transports the solid content, a rotation drive mechanism that drives the screw feeder, and the solid content from the screw feeder as a compacted layer. A solid content storage unit that prevents gas leakage, an opening / closing device that applies a predetermined pressure to the open / close body that controls the opening degree of the outlet of the solid content storage unit to hold the compacted layer of the storage unit, and the opening / closing An open / close control device that controls open / close of the open / close body of the device.
2. The solid content recovery apparatus according to claim 1, wherein the switchgear includes a cylinder mechanism for driving the switchgear.
The open / close control device includes a detector that detects a load amount of the rotary drive mechanism, and a controller that controls an open / close body of the open / close device based on a detection value of the detector. The solid content recovery apparatus according to claim 1 or 2.
4. The solid content recovery apparatus according to claim 1, wherein the pressure filter is a rotary single-chamber filter.
4. The solid content recovery apparatus according to claim 1, wherein the pressure filter is a rotary multi-chamber filter.
6. A method for recovering solid content from a slurry using the solid content recovery device according to claim 1, wherein the solid content discharged from the pressure filter is conveyed by a screw feeder; and the screw feeder. The screw feeder is driven by the step of temporarily storing the solid content conveyed in the solid content storage section to form a compacted layer and the opening of the opening / closing body that opens and closes the outlet of the solid content storage section. And a step of controlling based on a load amount of the rotation drive mechanism.