JP2009000605A - Sludge kneading and conveying facility and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sludge kneading and conveying facility which enable conveying and kneading by a pressure pump device. <P>SOLUTION: The pressure pump device 6 having a first piston pump 61 and a second piston pump 62 which can move alternately to a first position communicating with a discharge passage 7 from a sludge storage tank 5 and a feed passage 9 to a next process respectively and a second position communicating with the discharge passage 7 and a return passage 8 to the sludge storage tank 5 respectively is installed to three passages, the discharge passage 7, the return passage 8, and the feed passage 9. Suction of sludge from the discharge passage 7 and discharge of the sludge to the feed passage 9 are carried out by the second piston pump 62 and the first piston pump 61 respectively at the first position. Subsequently, suction of the sludge from the discharge passage 7 and discharge of the sludge to the return passage 8 are carried out by the first piston pump 61 and the second piston pump 62 respectively at the second position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sludge treatment facility mainly used in a waste treatment plant or a water purification plant, and more particularly to a facility for conveying and kneading sludge.

  In waste treatment plants and water treatment plants, there is a process of transporting waste sludge. When the sludge is solid, conveyance by a belt conveyor is suitable, but after storing in the sludge storage tank, pumping by a pump is preferable in terms of conveyance efficiency. If you try to suck in solid sludge with a pump, the pump sucks in air and cannot suck it, so it needs to be hydrated. However, in order to inhale and pump sludge together with water while continuously adding water, a large amount of water is required, and the maintenance cost of the equipment becomes expensive. Therefore, a configuration is conceivable in which a relatively small amount of water is added to knead sludge to form slurry-like sludge and then pumped with a pump. In this case, since water tends to accumulate in the lower part of the sludge storage tank, a slurry pump is required to circulate and knead the water together with the sludge by sucking water and sludge from the lower part and returning it upward. In addition to this, a slurry pump for conveyance to the next process is also required (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-226294 (FIG. 1)

However, in the conventional sludge treatment equipment as described above, it is necessary to provide two pumps for kneading and for conveying, and there is a problem that the manufacturing cost increases.
In view of the above-described conventional problems, an object of the present invention is to provide a sludge kneading / conveying facility and a sludge kneading / conveying method that can be conveyed and kneaded by a single pumping pump device.

The sludge kneading and transporting facility of the present invention is configured to send a sludge storage tank for storing sludge, a pressure pump device for sucking and discharging sludge in the sludge storage tank, and feeding the sludge in the sludge storage tank to the pressure pump device. A discharge path, a feed path for sending sludge from the pressure feed pump device to the next process, and a return path for returning the sludge from the pressure feed pump device to the sludge storage tank.
In the sludge kneading and transporting equipment configured as described above, the sludge can be transported to the next process by sending the sludge sucked into the pressure feed pump device to the feed path. It is also possible to return the sludge sucked into the pressure pump device to the sludge storage tank via the return path, and the returned sludge is kneaded together with other sludge (including solids) in the sludge storage tank. Therefore, both conveyance and kneading can be performed with a single pumping pump device.

Further, in the sludge kneading and conveying equipment, the pressure feed pump device includes a first pressure feed operation for sucking sludge from the discharge path while discharging sludge to the feed path, and a sludge to the return path while sucking sludge from the discharge path. And the second position for communicating with the discharge path and the return path, and the second position for communicating with the discharge path and the return path, respectively. A pair of movable piston pumps and a first pumping operation by causing one piston pump to suck sludge from the discharge path and the other piston pump to discharge sludge to the feed path at the first position. A driving device for performing a second pumping operation by causing one piston pump to suck sludge from the discharge path and discharging the sludge to the return path to the other piston pump at the second position. It may be one was painting.
In this case, if the suction and discharge are alternately performed while moving the positions of the pair of piston pumps, two discharge ports can be secured to correspond to the two of the feed path and the return path. Moreover, since the existing product can be used as it is for the piston pump, the design of the pumping pump device becomes easy and inexpensive.

The sludge kneading and conveying equipment is composed of a feed path, a return path, and a plurality of open / close valves provided between them, and by selecting the open / close state of each open / close valve, the feed path is closed in the middle and returned. Any one of a kneading priority mode for communicating with the path, a conveyance priority mode for closing the return path in the middle and communicating with the feeding path, and a kneading and conveying mode with the feeding path and the return path as separate flow paths. It may be provided with a selectable switching device.
In this case, the sludge that is pumped alternately to the feed path and the return path by the pumping pump device is changed on the way by the switching device, and the sludge is pumped to only the feed path, only the return path, or both. can do.

On the other hand, the sludge kneading and conveying method of the present invention includes a kneading step of kneading sludge by repeatedly sucking sludge stored in a sludge storage tank with a pumping pump device and returning it to the sludge storage tank, and the sludge storage The sludge stored in the tank is sucked and discharged by the pumping pump device, sent to the next process, and part of the sludge is returned to the sludge storage tank, so that the sludge is kneaded and conveyed to the next process. A kneading and conveying step.
In such a sludge kneading and conveying method, first, only the kneading step is performed to make sludge into a slurry, and then the sludge can be conveyed to the next step while kneading.

According to the sludge kneading and conveying equipment of the present invention, it is possible to carry out sludge transportation to the next process and sludge kneading together. Can be provided. When only one pumping pump device is required, the sludge kneading and conveying equipment can be manufactured at low cost.
In addition, according to the sludge kneading and conveying method of the present invention, only the kneading step is performed first to sludge the slurry, and then the sludge can be conveyed to the next step while kneading. While being able to carry and knead | mix, even sludge with a low moisture content can be reliably conveyed. Such reliable conveyance improves work efficiency.

  FIG. 1 is a diagram showing an outline of a sludge treatment facility in a waste treatment plant including a sludge kneading and conveying facility according to an embodiment of the present invention. In the figure, a truck 1 loaded with sludge that has been subjected to a temporary dehydration process puts solid sludge into a sludge storage hopper 2 by a dumping operation. The sludge thrown into the sludge storage hopper 2 is placed on the sludge supply conveyor 4 by the quantitative supply device 3. The sludge transported horizontally by the sludge supply conveyor 4 is temporarily stored in the sludge storage tank 5. The sludge in the initial state is solid and suitable for conveyor transport, but is difficult to suck with a pump. Therefore, the sludge is subjected to hydration and kneading in the sludge storage tank 5 to form a slurry.

  The sludge storage tank 5 is in communication with the pressure feed pump device 6 through the discharge path 7 and the return path 8. This pressure feed pump device 6 kneads the sludge in the sludge storage tank 5 via the discharge path 7 and the return path 8 and conveys the sludge from the feed path 9 to the next step (not shown). A water addition nozzle 10 is provided in the upper part of the sludge storage tank 5. By opening the hydrating nozzle 10, it is hydrated into solid sludge and is easily sucked by the pumping pump device 6. Between the return path 8 and the feed path 9 and between them, there is provided a switching device 11 with four on-off valves 111-114.

  Next, the function and operation of the pressure pump device 6 will be described with reference to FIGS. In these figures, the switching device 11 is not shown. In FIG. 2, the pressure-feed pump device 6 can open and close the stationary first piston pump 61 and the second piston pump 62, a piston drive device 63 that reversely operates these pistons, and the end of the return path 8. The shutter 64, the shutter 65 which can open and close the edge part of the feed path 9, and the raising / lowering drive apparatus 66 which raises / lowers each piston pump 61,62 whole and each shutter 64,65 are provided. The first piston pump 61 is connected to the feed path 9 and the second piston pump 62 is connected to the discharge path 7 (first position).

  First, assuming the state shown in FIG. 2, the first piston pump 61 is in a suction completion / discharge standby state in which the piston rod 61a is pulled to the right end. On the other hand, the second piston pump 62 is in a discharge completion / inhalation standby state in which the piston rod 62a is pushed to the left end. The return path 8 is blocked by the shutter 64. When the piston pumps 61 and 62 are driven by the piston driving device 63 from this state, the first piston pump 61 performs a discharge operation and the second piston pump 62 performs a suction operation (first pressure feeding operation). Therefore, as shown in FIG. 3, the sludge in the first piston pump 61 is sent to the next process through the feed path 9. Sludge is sucked into the second piston pump 62.

  Next, the piston pumps 61 and 62 and the shutters 64 and 65 are integrally lowered by the raising / lowering driving device 66 to be in the state of FIG. In FIG. 4, the first piston pump 61 is connected to the discharge path 7 and the second piston pump 62 is connected to the return path 8 (second position). In this position, the first piston pump 61 is almost empty, while the second piston pump 62 sucks sludge to the maximum extent. When the piston pumps 61 and 62 are driven by the piston driving device 63 from this state, the first piston pump 61 performs a suction operation and the second piston pump 62 performs a discharge operation (second pumping operation). Accordingly, as shown in FIG. 5, sludge is newly sucked into the first piston pump 61. Further, the sludge in the second piston pump 62 is returned to the sludge storage tank 5.

  When the piston pumps 61 and 62 and the shutters 64 and 65 are integrally raised from the state shown in FIG. 5 by the elevating drive device 66, the state becomes the state shown in FIG. 2 again, and the same steps are repeated thereafter. In this manner, sludge suction and sludge feed, sludge suction and sludge return are alternately repeated in the cycle of FIGS. 2 to 5 (see FIG. 6). Accordingly, it is possible to provide a sludge kneading and conveying facility that can be conveyed and kneaded by a single pumping pump device 6. Moreover, since it is 1 unit | set, it can be manufactured cheaply as a simple structure, and it contributes also to space saving.

  4 to 5, when the sludge (solid sludge and water mixture) in the second piston pump 62 is returned to the sludge storage tank 5, the sludge returns at a high pressure. By returning through the path 8 and being kneaded in the sludge storage tank 5, it becomes a slurry. In the sludge storage tank 5, the slurry-like sludge and the unkneaded solid sludge are mixed. At this time, the sludge in the form of slurry promotes kneading instead of water, so that it becomes a state suitable for suction by the first and second piston pumps 61 and 62 without additional water addition. Further, the slurry is further sucked and returned to the slurry by sucking and returning the mixture of the slurry sludge and the solid sludge.

  Next, the structure and method of sludge kneading conveyance using the switching apparatus 11 are demonstrated. FIG. 7 is a diagram showing the connection of the sludge storage tank 5, the pressure pump device 6, and the switching device 11. As described above, the switching device 11 includes the four on-off valves 111 to 114. The on-off valves 111 and 112 are provided in the feed path 9 and the return path 8, respectively. A first bypass path 89 having an opening / closing valve 113 is connected from the upstream side of the opening / closing valve 112 to the downstream side of the opening / closing valve 111. A second bypass path 98 having an opening / closing valve 114 is connected from the upstream side of the opening / closing valve 111 to the downstream side of the opening / closing valve 112. In the figure, black open / close valves 113 and 114 are closed, and white open / close valves 111 and 112 are open. The reason why the bypass paths 89 and 98 are indicated by dotted lines is to indicate a state in which sludge does not flow when the on-off valves 113 and 114 are closed (the same applies hereinafter).

  When the sludge having a low water content is stored in the sludge storage tank 5, the water is added by the hydration nozzle 10 (FIG. 1) until the sludge is immersed in water. First, among the on-off valves 111 to 114 constituting the switching device 11, the on-off valves 112 and 114 are opened and the on-off valves 111 and 113 are closed (see FIG. 8A). Thereby, the sludge pushed out from the pressure pump device 6 to the return path 8 is returned to the sludge storage tank 5 through the opening / closing valve 112. On the other hand, the sludge once pushed out to the feed path 9 is joined to the return path 8 via the second bypass path 98 and the opening / closing valve 114. That is, all the sludge sent out from the pressure feed pump device 5 is returned to the sludge storage tank 5, and only kneading is performed by the pressure at the time of returning (kneading priority mode).

When the sludge starts to become a slurry by kneading, among the on-off valves 111 to 114, the on-off valves 111 and 112 are opened and the on-off valves 113 and 114 are closed (see FIG. 7). Thereby, conveyance of sludge to the next process and kneading by returning sludge are alternately repeated, and both pressure feeding and kneading are performed (kneading conveyance mode).
According to such a sludge kneading and conveying method, first, only the kneading step is performed to sludge the sludge, and then the sludge can be conveyed to the next step while kneading. Therefore, even sludge with a low moisture content can be reliably conveyed. Thereby, work efficiency can be improved.

  In addition, as long as the sludge in the vicinity of the discharge path 7 in the sludge storage tank 5 is in a slurry state, even if additional sludge having a different moisture content is added, it can be pumped while sufficiently kneaded. Since it can be pumped after being sufficiently kneaded, even if sludge having a relatively low water content is added, it can be made into a slurry without adding water. Of course, it is needless to say that water may be added if necessary.

On the other hand, when only the sludge with a high moisture content is desired or when it is desired to empty the sludge storage tank, the on-off valves 111 and 113 are opened and the on-off valves 112 and 114 are closed (see FIG. 8B). ). Thereby, the sludge pushed out to the feed path 9 from the pressure feed pump apparatus 6 is sent to the next process through the opening / closing valve 111. On the other hand, the sludge once pushed out to the return path 8 is joined to the feed path 9 via the first bypass path 89 and the opening / closing valve 113. That is, all the sludge sent out from the pressure feed pump device 5 is transported to the next process (transport priority mode).
As described above, kneading and / or conveyance suitable for sludge having various moisture contents can be performed.

  In the kneading and conveying mode in the above embodiment, as shown in FIG. 6, the feeding operation is always performed by the first piston pump 61, and the returning operation is always performed by the second piston pump 62. Here, the feed path 9 has a longer pumping distance than the return path 8 due to the arrangement of the equipment. Therefore, the first piston pump 61 in charge of pressure feeding to the feed path 9 has a larger load than the second piston pump 62, and therefore the first piston pump 61 is more likely to be consumed in each part of the piston pump. In order to prevent such a bias in wear, the on-off valves 111 and 112 may be closed and the on-off valves 113 and 114 may be opened on a regular basis (for example, at each activation) as shown in FIG. . Accordingly, the feed / return from the pressure feed pump device 6 has a reverse relationship to that in FIG. 7, and the second piston pump 62 is responsible for pressure feed to the feed path 9. That is, in this way, each piston pump 61, 62 can be evenly consumed.

  In the above embodiment, a pair of piston pumps 61 and 62 is used. However, even with one piston pump (one discharge port), if the discharge destination is alternately moved to the feed path / return path, The same kneading conveyance is possible. Further, it is possible to switch the destination (feed path / return path) by providing an on-off valve or the like in the middle of the piping without moving the piston pump.

In addition, although the piston pump was used in the said embodiment, it is also possible to use a rotary pump. Moreover, if there are two discharge ports in the pump itself, sludge can be sent to two places simultaneously. In that case, since sludge is always pumped without staying in the feed path and the return path, the working time is shortened.
Moreover, the sludge kneading | conveying equipment by the said embodiment can be used not only in a waste treatment plant but in other sludge treatment facilities, such as a water purification plant.

It is a figure which shows the outline of the sludge treatment equipment containing the sludge kneading | mixing conveyance equipment by one Embodiment of this invention. It is a figure which shows the general | schematic structure of a pressure pump apparatus, and the connection with the exterior, and has shown the state immediately before the suction | inhalation of sludge and conveyance to a feed path. FIG. 3 shows a state where sludge is sucked and transported to the feed path from the state of FIG. 2. It is a figure which shows the state which the piston pump descend | falls from the state of FIG. 3, and connected with the discharge path and the return path. It is a figure which shows the state which performed the suction | inhalation and return (kneading | mixing) of sludge from the state of FIG. It is a figure which shows cycle operation | movement of a pair of piston pump. It is a figure which shows the connection of a sludge storage tank, a pumping pump apparatus, and a switching apparatus, and shows the state of the kneading | mixing conveyance mode in which conveyance and kneading | mixing are performed together. It is a figure which shows the connection of a sludge storage tank, a pumping pump apparatus, and a switching apparatus, (a) has shown the state of kneading | mixing priority mode, (b) has each shown the state of conveyance priority mode. It is a figure which shows the connection of a sludge storage tank, a pressure feed pump apparatus, and a switching apparatus, and shows the state from which the correspondence relationship of a piston pump and a feed path / return path is reverse with FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Sludge storage tank 6 Pressure pump apparatus 7 Discharge path 8 Return path 9 Feed path 11 Switching apparatus 61 1st piston pump 62 2nd piston pump 63 Piston drive apparatus 66 Lift drive apparatuses 111-114 Open / close valve

Claims (4)

A sludge storage tank for storing sludge;
A pressure-feed pump device that sucks and discharges the sludge in the sludge storage tank;
A discharge path for feeding the sludge in the sludge storage tank to the pressure pump device;
A feed path for sending sludge from the pumping pump device to the next process;
A sludge kneading and conveying facility, comprising: a return path for returning sludge from the pressure pump device to the sludge storage tank. The pumping pump device sucks sludge from the discharge passage while discharging sludge to the feed passage, and sucks sludge from the discharge passage while discharging sludge to the return passage. The two pumping operations are performed alternately,
A pair of piston pumps movable alternately to a first position communicating with the discharge path and the feed path and a second position respectively communicating with the discharge path and the return path;
The first pumping operation is performed by causing one piston pump to suck sludge from the discharge passage and the other piston pump to discharge sludge to the feed passage at the first position, respectively. And a driving device for causing the second pumping operation to be performed by causing one piston pump to suck sludge from the discharge passage at the position 2 and discharging the sludge to the return passage to the other piston pump. The sludge kneading and conveying equipment according to claim 1.   The kneading priority is constituted by the feed path, the return path, and a plurality of on-off valves provided between them, and by selecting the open / close state of each on-off valve, the feed path is closed halfway to communicate with the return path One of a mode, a transport priority mode in which the return path is closed in the middle and communicated with the feed path, and a kneading transport mode in which the feed path and the return path are separate from each other can be selected. The sludge kneading and conveying equipment according to claim 1, further comprising a switching device. A kneading step of kneading the sludge by repeatedly sucking the sludge stored in the sludge storage tank with a pumping pump device and returning it to the sludge storage tank;
The sludge stored in the sludge storage tank is sucked and discharged by the pumping pump device, sent to the next process, and a part of the sludge is returned to the sludge storage tank while kneading the sludge. And a kneading and conveying step for conveying to the process.

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