JP6588291B2 - Solid-liquid separator - Google Patents

Description

  The present invention relates to a solid-liquid separation device for separating a solid from a suspension containing the solid.

  A liquid cyclone has been used as a solid-liquid separation device for separating a solid from a suspension (see, for example, Patent Document 1). The suspension supplied to the hydrocyclone is separated into a separated liquid with a high solid concentration and a drained liquid with a low solid concentration by centrifugation. The drained liquid having a low solid concentration is discharged from the upper portion of the liquid cyclone, and the separating liquid having a high solid concentration is discharged from the lower portion of the liquid cyclone. Usually, the separation liquid discharged from the lower part of the liquid cyclone is collected in a container provided at the lower part of the liquid cyclone. For example, the solid-liquid separation device described in Patent Document 1 includes a sedimentation section in which suspended particles flow into the lower part of a liquid cyclone.

JP 2011-79965 A

  However, in the conventional solid-liquid separation apparatus as described above, since the separated liquid in which the suspended particles and water are mixed is collected in the container below the liquid cyclone, the suspended particles are collected in a solid state. Needed to remove water from the separation. For this reason, in order to exclude water from the separated liquid collected in the container, a separate dedicated dehydrator is required.

  The present invention solves the conventional problems as described above, and provides a solid-liquid separation device that can easily recover solids from a separation liquid recovered from a liquid cyclone without adding a dedicated dehydration device. The purpose is to do.

  In order to achieve the above object, a solid-liquid separation device of the present invention is a solid-liquid separation device that separates solid matter from a suspension containing solid matter, and the concentration of solid matter is separated from the suspension by centrifugation. A liquid cyclone that separates into a high separation liquid and a drainage liquid with a low solids concentration, a pump that supplies the suspension to the liquid cyclone, and a recovery container to which the separation liquid discharged from the liquid cyclone is supplied And a compressed air supply means for supplying compressed air to the recovery container, and a water-permeable member provided at the lower part of the recovery container, and the compressed air is recovered in the state where the separation liquid is recovered in the recovery container. By supplying the water, water is forcibly removed from the separated liquid through the water-permeable member, and the solid matter in the separated liquid is recovered as a dehydrated cake. According to this configuration, water is forcibly removed from the separation liquid with a high concentration of solid matter discharged from the hydrocyclone, and the solid matter is recovered as a dehydrated cake from the collection container. Without separation, the solid matter can be separated and recovered from the suspension.

  The solid-liquid separation device of the present invention further includes a liquid storage container for storing the suspension and the drainage liquid, and the pump stores the liquid in the liquid storage container between the liquid storage container and the liquid cyclone. It is preferable to provide a circulation path. According to this configuration, since the liquid in the liquid storage container can be circulated while being repeatedly supplied to the liquid cyclone, the solids recovery rate can be increased.

  According to the present invention, water is forcibly removed from the separated liquid with a high solid concentration discharged from the hydrocyclone, and the solid is recovered as a dehydrated cake from the collection container. Without separation, the solid matter can be separated and recovered from the suspension.

1 is a schematic configuration diagram of a solid-liquid separation device according to an embodiment of the present invention. The figure which shows immediately after the driving | operation start of the solid-liquid separator which concerns on one Embodiment of this invention. The figure which shows the state which passed for several seconds since the driving | operation start of the solid-liquid separator which concerns on one Embodiment of this invention. The figure which shows the state with which the separation liquid was filled in the whole collection | recovery container of the solid-liquid separation apparatus which concerns on one Embodiment of this invention. The figure which shows the state which the solid-liquid separator which concerns on one Embodiment of this invention transfers to the dehydration process. The figure which shows the state which predetermined time passed since the solid-liquid separator which concerns on one Embodiment of this invention started dehydration. The figure which shows the collection | recovery process of the dewatering cake of the solid-liquid separator which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration diagram of a solid-liquid separation device 1 according to an embodiment of the present invention. First, the configuration of the solid-liquid separation device 1 will be described with reference to this drawing. The solid-liquid separation device 1 is a device that separates solids from a suspension containing solids using a liquid cyclone 2. Examples of the suspension include wastewater generated in the washing process of the diatomaceous earth filter device, and this wastewater is obtained by suspending solid diatomaceous earth and water. The liquid cyclone 2 is a device that separates a suspension into a separated liquid having a high solid concentration and a drained liquid having a low solid concentration by centrifugation.

  The liquid storage container 4 stores a suspension. This suspension is, for example, supplied with drainage from a diatomaceous earth filtration device (not shown). A liquid supply channel 6 is connected between the liquid storage container 4 and the liquid cyclone 2. A pump 5 is interposed in the liquid supply flow path 6, and the suspension of the liquid storage container 4 is supplied to the liquid cyclone 2 by the pump 5. The valve 10 is a valve for allowing the suspension stored in the liquid storage container 4 to flow out, and is open during the operation of the pump 5.

  As described above, the suspension supplied to the hydrocyclone 2 is separated into a separation liquid having a high solid concentration and a drainage liquid having a low solid concentration by centrifugation. The separation liquid is supplied to the collection container 3. A compressed air supply means 16 including a compressed air supply source 13, a valve 14, and a compressed air supply channel 15 is connected to the recovery container 3. In addition, a water-permeable member 17 is provided at the lower part of the collection container 3 so that water in the separation liquid can pass therethrough. As will be described later in detail, the solid matter in the separated liquid supplied to the recovery container 3 is recovered as a dehydrated cake.

  On the other hand, the drained liquid separated by the liquid cyclone 2 is returned to the liquid storage container 4 through the reflux channel 7, and the liquid storage container 4 stores the drained liquid together with the suspension. The liquid in the liquid storage container 4 is supplied to the liquid cyclone 2 through the liquid supply flow path 6, and again separated into the separation liquid and the drainage liquid by the liquid cyclone 2. Then, the separation liquid is supplied to the recovery container 3, and the drainage liquid is returned to the liquid storage container 4 through the reflux channel 7. That is, the liquid supply channel 6 and the reflux channel 7 constitute a circulation path 8 that circulates the liquid in the liquid storage container 4 between the liquid storage container 4 and the liquid cyclone 2.

  Hereinafter, the operation of the solid-liquid separator 1 will be described in the order of steps with reference to FIGS. The solid-liquid separation device 1 shown in FIGS. 2 to 7 has the same configuration as the solid-liquid separation device 1 shown in FIG. 1, and each flow path shown by a line for convenience is a portion where the fluid is flowing. A thick line indicates that the valves 10 to 12 and 14 are filled in when they are in a closed state. Moreover, although it demonstrates, giving an Example (numerical example) suitably, it is an example and is not limited to this.

  FIG. 2 is a view immediately after the start of operation of the solid-liquid separator 1. The valve 10 is open, and the suspension in the liquid storage container 4 is supplied to the liquid cyclone 2 by the pump 5. The liquid storage container 4 stores a suspension in which 8 kg of diatomaceous earth is mixed with 300 L of water. The maximum value of the discharge pressure of the pump 5 is 0.3 MPa.

  FIG. 3 shows a state in which several seconds have elapsed from the start of operation of the solid-liquid separator 1. In the state of this figure, the suspension is supplied into the liquid cyclone 2, and the suspension is separated into a separated liquid having a high solid concentration and a drained liquid having a low solid concentration by centrifugation. The valve 11 is open, and the separation liquid is supplied to the collection container 3 (capacity 38L) (arrow a). The drainage liquid is returned to the liquid storage container 4 through the reflux channel 7, and the liquid storage container 4 stores the drainage liquid together with the suspension.

In the recovery container 3, not only water in the separation liquid but also solids smaller than the mesh openings of the water permeable member 17 fall through the water permeable member 17 at the initial stage of operation, but after a predetermined time has elapsed. A solid layer is formed on the water-permeable member 17 so that only water falls. For this reason, the density | concentration of the solid substance in the separation liquid collected in the collection container 3 becomes high gradually. The liquid containing solids that passes through the water-permeable member 17 in the initial stage of operation may be returned to the liquid storage container 4. The water-permeable member 17 is a stainless steel mesh, the mesh area is 0.126 m ² , and the mesh opening is 89 μm.

  FIG. 4 shows a state in which the separation liquid 20 is filled in the entire collection container 3 of the solid-liquid separation device 1. This state is about 2 minutes after the start of operation. Thereafter, liquid supply to the hydrocyclone 2 is continued, and the pump 5 is stopped, the valve 11 is closed, and the valve 14 of the compressed air supply means 16 is opened based on the elapsed time (for example, 15 minutes) from the start of operation. . As a result, the solid-liquid separator 1 moves to the dehydration step.

  FIG. 5 shows a state where the solid-liquid separator 1 has shifted to the dehydration step. In the dehydration step, compressed air is supplied into the collection container 3 by the compressed air supply means 16. The air supply pressure is 0.1 MPa. At this time, since the valve 11 is closed, water is forcibly removed from the separation liquid 20 through the water-permeable member 17 by supplying compressed air. FIG. 6 shows a state in which a predetermined time (about 2 minutes) has passed since the start of dehydration. The separation liquid 20 in FIG. 5 is dehydrated to form a dehydrated cake 21 having a water content of about 60% in FIG.

  FIG. 7 shows a process for collecting the dehydrated cake 21. In the state of this figure, the valve 14 is closed and the supply of compressed air is stopped, and the valve 11 closed in the dehydration process is kept closed. In this recovery step, the valve 12 is opened and the inside of the recovery container 3 is depressurized. The water-permeable member 17 is provided at the lower part of the collection container 3 integrally with an annular frame fixed to the collection container 3 with bolts or the like. The water-permeable member 17 has a structure that can be opened and closed by a hinge or the like (not shown) provided on an annular frame, and is open in FIG. Thereby, the dehydrated cake 21 can be recovered from the recovery container 3. In the present embodiment, the inner peripheral surface of the recovery container 3 is tapered so that the lower side is widened. This makes the dehydrated cake 21 easy to slide downward along the inner peripheral surface of the recovery container 3, and the dehydrated cake. 21 is easily collected.

  In the above-mentioned examples that give numerical examples as appropriate, the solid content weight was calculated from the dehydrated cake 21 and compared with the diatomite weight charged, the recovery rate was 95%. Further, since the liquid in the liquid storage container 4 has a small amount of solid matter, it can be drained to the outside of the solid-liquid separator 1 as it is.

  As described above, by using the solid-liquid separation device 1, the suspension supplied to the liquid cyclone 2 is discharged from the liquid cyclone 2 as a separated liquid having a high solid concentration, and water is discharged from the separated liquid. The solid matter is forcibly removed and the solid matter is recovered from the recovery container 3 as a dehydrated cake 21. That is, it is possible to separate and recover the solid matter from the suspension without adding a separate dedicated dehydrator.

  In the embodiment, the liquid supply flow path 6 and the reflux flow path 7 constitute the circulation path 8 for circulating the liquid in the liquid storage container 4 between the liquid storage container 4 and the liquid cyclone 2. According to this configuration, since the liquid in the liquid storage container 4 can be circulated while being repeatedly supplied to the liquid cyclone 2, the solids recovery rate can be increased. On the other hand, a configuration in which the liquid is not circulated between the liquid storage container 4 and the liquid cyclone 2 may be employed. In the case of this configuration, the drainage from the reflux channel 7 is processed without being supplied again to the hydrocyclone 2. In this case, the recovery rate is 80%, and the value of this recovery rate is a low value compared to the method of circulating the liquid, but it is still a good recovery rate.

DESCRIPTION OF SYMBOLS 1 Solid-liquid separator 2 Liquid cyclone 3 Recovery container 4 Liquid storage container 6 Supply flow path 7 Reflux flow path 8 Circulation path 16 Compressed air supply means 17 Water-permeable member 20 Separation liquid 21 Dehydrated cake

Claims (2)

A solid-liquid separator for separating diatomaceous earth from a suspension containing diatomaceous earth ,
A liquid cyclone that is separated from the suspension into a separated solution having a high diatomaceous earth concentration and an effluent having a low diatomaceous earth concentration by centrifugation;
A pump for feeding the suspension to the hydrocyclone;
A recovery container to which the separation liquid discharged from the hydrocyclone is supplied;
Compressed air supply means for supplying compressed air to the collection container;
A valve for depressurizing the inside of the collection container;
A water-permeable member provided at the lower part of the recovery container and capable of opening and closing the recovery container ;
With the separation liquid recovered in the recovery container, by supplying the compressed air, water is forcibly removed from the separation liquid through the water-permeable member,
After depressurizing the inside of the recovery container by the valve, the water-permeable member is opened to recover the diatomaceous earth in the separated liquid as a dehydrated cake. The liquid storage container which stores the said suspension liquid and the said waste liquid is further provided, The path | route which circulates the liquid in the said liquid storage container between the said liquid storage container and the said liquid cyclone with the said pump is provided. The solid-liquid separator described in 1.

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