Ash extrusion device

Abstract

To enhance cost-effectiveness related to water supply by appropriately controlling the water supply to storage water in an ash extrusion device.SOLUTION: An ash extrusion device includes a cooling tank 2 provided with an introduction port 6 and an exhaust port 7 of incineration ash, a driving device 5 for making a scraper 4 installed in a drive chamber 2a perform reciprocation operation toward the exhaust port 7, a supply pipe 11 installed in the drive chamber 2a to supply water to the cooling tank 2, a solenoid valve 15 installed in the supply pipe 11, a water level gauge 10 for measuring a water level of storage water, and a control device 14 for sequentially and repeatedly executing three operations of extrusion operation, pulling-in pull-in operation and prescribed time stop operation of the scraper 4 by controlling the driving device 5. The control device 14 opens the solenoid valve 15 until the water level reaches a reference water level to execute first water supply to supply water from the supply pipe 11 if the water level is lower than the reference water level on the basis of information on the water level received from the water level gauge 10 during the prescribed time stop operation, and does not execute the first water supply during the extrusion operation or the pull-in operation.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ash extrusion device that cools and discharges incineration ash.

Background Art

[0002] Conventionally, an incinerator plant is known as a plant for incinerating incinerable materials such as garbage. In an incinerator (for example, a stoker furnace) in this plant, ash (incineration ash) generated by burning the incinerable material is dropped from an ash chute through an inlet into an ash extrusion device, cooled by the stored water in the cooling tank of the ash extrusion device, and then discharged from the ash extrusion device to a conveying device. The ash extrusion device is provided with a scraper (also called a "pusher") that pushes the incineration ash cooled by the stored water to an outlet. The scraper reciprocates in a forward direction toward the outlet side and a backward direction opposite to this by a driving device to push the incineration ash in the stored water to the outlet.

[0003] When the incineration ash is pushed out and discharged, the incineration ash is discharged in a state containing moisture. Therefore, for example, in Patent Document 1, during the operation of the scraper, the water level of the stored water is constantly measured by a water level gauge, and when the water level drops below the reference water level, water supply control is automatically performed to supply water up to the reference water level.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Generally, since the scraper operates slowly, usually, even if there is a reciprocating motion of the scraper, the water level of the stored water is substantially maintained constant. However, depending on the amount and properties of the stored incineration ash, when the scraper pushes out the incineration ash toward the discharge port side, due to the pushing operation of the scraper, the water level of the stored water in the drive chamber where the drive device is installed may temporarily drop significantly below the reference water level.

[0006] However, even in such a case, after the pushing operation, when the scraper is retracted toward the drive chamber side, the water level of the stored water in the drive chamber substantially returns to the reference water level. Nevertheless, when the water level of the stored water in the drive chamber drops significantly in this way, if water supply control is carried out based on the dropped water level, when the scraper is retracted toward the drive chamber side, the water level will rise toward the reference water level, and ultimately, there will be excessive water supply, and the stored water will overflow the drain pipe and be drained. The drained water is purified by wastewater treatment inside the plant and then discharged outside the plant.

[0007] In other words, in the conventional water supply control, every time the scraper makes a round trip, water supply and drainage may be repeated. Therefore, from the viewpoints of the cost related to the excessive water supply and the cost of the wastewater treatment for purifying the wastewater with an increased water volume due to the excessive supply using chemicals or the like, there was room for improvement to enhance the cost-effectiveness. Therefore, an object of the present invention is to provide an ash extrusion device capable of appropriately controlling the water supply to the stored water in the ash extrusion device and enhancing the cost-effectiveness related to water supply and drainage.

Means for Solving the Problem

[0008] The ash extrusion device of the present invention includes a cooling tank having an inlet through which incineration ash is introduced and an outlet through which the incineration ash cooled by stored water is discharged, a drive chamber disposed on the side opposite to the outlet with respect to the inlet in the cooling tank, a drive device installed in the drive chamber for reciprocatingly operating a scraper for extruding the incineration ash toward the outlet, a supply pipe installed in the drive chamber for supplying water to the cooling tank, a solenoid valve installed in the supply pipe, a water level gauge disposed in the vicinity of the supply pipe for measuring the water level of the stored water, and a control device for controlling the drive device to sequentially repeat three operations: an extrusion operation of causing the scraper to extrude the incineration ash toward the outlet, a retraction operation of retracting the scraper toward the drive chamber, and a predetermined time stop operation of stopping the retracted scraper for a first predetermined time. And, the control device in the ash extrusion device of the present invention, during the predetermined time stop operation, based on the information regarding the water level received from the water level gauge, when the water level is lower than the reference water level, performs a first water supply of opening the solenoid valve to supply water from the supply pipe until the water level reaches the reference water level, and does not perform the first water supply during the extrusion operation or the retraction operation.

Advantages of the Invention

[0009] According to the ash extrusion device of the present invention, only during the predetermined time stop operation of stopping the scraper for a first predetermined time, based on the information regarding the water level received from the water level gauge, when the water level is lower than the reference water level, a first water supply of opening the solenoid valve to supply water from the supply pipe until the water level reaches the reference water level is performed. On the other hand, during the extrusion operation of extruding the incineration ash toward the outlet by the scraper or during the retraction operation of retracting the scraper toward the drive chamber, the first water supply is not performed. In this way, since the first water supply can be performed only during the predetermined time stop operation in which the water level of the stored water is stable, the water supply to the stored water in the ash extrusion device is appropriately controlled without becoming excessive, and there is no increase in the amount of water drained from the ash extrusion device due to the excessive supply. As a result, the cost-effectiveness regarding water supply and drainage can be enhanced.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0011] Hereinafter, the ash extrusion device which is an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, for the sake of simplicity of explanation, a rectangular coordinate system using the X-axis and the Y-axis will be used for explanation as appropriate. The embodiment is merely an example, and there is no intention to exclude various modifications and applications of technologies that are not explicitly stated. Except for the essential configurations of the present invention, each configuration of the embodiment can be selectively adopted or variously modified as necessary and implemented.

[0012] The overall configuration of the ash extrusion device 1 of the embodiment will be described with reference to FIG. 1. The ash extrusion device 1 includes a cooling tank 2 in which stored water for cooling incineration ash is stored at a reference water level (dashed line in FIG. 1), a scraper 4 disposed in the cooling tank 2, and a drive device 5 disposed in a drive chamber 2a in the cooling tank 2. The cooling tank 2 is provided with an inlet 6 through which incineration ash is introduced and an outlet 7 through which the cooled incineration ash is discharged. The drive chamber 2a is a portion of the cooling tank 2 where the drive device 5 is disposed and is located on the side opposite to the outlet 7 with respect to the inlet 6. Note that the stored water and the liquid used for injection in the supply pipe 11 described later may have water as the main component, and may be tap water, industrial water, or recycled water (water treated after being used in the plant), or may be mixed water in which hydrochloric acid or the like is mixed and neutralized. Hereinafter, these liquids used for the stored water will be simply described as "water".

[0013] The inlet 6 of the cooling tank 2 is formed by a cylindrical (for example, rectangular cylindrical) wall surface 8. This cylindrical wall surface 8 is directly connected to an ash chute (not shown). Note that the upper end of the ash chute is connected to an incinerator (for example, the post-combustion stage of a stoker furnace) (not shown). In order to form a so-called "water seal", the lower end of the wall surface 8 is located below the reference water level of the stored water in the cooling tank 2. The reference water level is a position (reference line of the water level) preset as the water level at which the amount of stored water in the cooling tank 2 becomes a predetermined amount.

[0014] The scraper 4 is a device that pushes the cooled incineration ash toward the discharge port 7 side. The scraper 4 includes an upper plate 4a facing upward, a pushing plate 4b facing the discharge port 7 side, and both side plates connected to the upper plate 4a and the pushing plate 4b (in FIG. 1, one of the side plates 4c is illustrated). Since the lower surface corresponding to the upper plate 4a is not arranged, the scraper 4 has a box shape that is open toward the bottom plate 9 of the cooling tank 2. The scraper 4 is connected to an arm 5b described later, and the lower end of the pushing plate 4b (that is, the tip 4d of the scraper 4) moves forward and backward along the bottom plate 9 while being in contact with the entire width of the bottom plate 9 of the cooling tank 2. Here, the "forward movement" of the scraper 4 means that the scraper 4 moves in the direction of pushing the incineration ash toward the discharge port 7 side (the +X-axis direction in FIG. 1, the forward movement direction Df). Also, the "backward movement" of the scraper 4 means that the scraper 4 moves in the opposite direction of "forward movement" (the -X-axis direction in FIG. 1, the backward movement direction Dr). Furthermore, the "entire width" of the bottom plate 9 of the cooling tank 2 means the dimension in the width direction (the direction perpendicular to the plane of FIG. 1) inside the cooling tank 2. Note that the incineration ash discharged from the discharge port 7 is conveyed to a predetermined storage site by a conveying device 3 such as a conveyor.

[0015] The driving device 5 is a device that drives the scraper 4 and is arranged on the side opposite to the discharge port 7 with respect to the inlet 6. The driving device 5 is located above a second inclined surface 9b described later and at a position not immersed in the stored water (above the "reference water level"). And the driving device 5 includes a drive shaft 5a that can rotate in two directions and an arm 5b that connects the scraper 4 and the drive shaft 5a. The driving device 5 drives the arm 5b by rotating the drive shaft 5a, and as a result, causes the scraper 4 connected to the arm 5b to perform a reciprocating operation of forward and backward movement.

[0016] The bottom plate 9 of the cooling tank 2 includes a first inclined surface 9a that slopes upward from directly below the inlet 6 toward the outlet 7 (specifically, the vertical and lower end of the outlet 7), and a second inclined surface 9b that slopes upward from directly below the inlet 6 toward the opposite side of the first inclined surface 9a. That is, the first inclined surface 9a is formed to gradually increase in height as it goes toward the forward direction Df. Also, the second inclined surface 9b is formed to gradually increase in height as it goes toward the backward direction Dr. In the cooling tank 2, the bottom plate portion directly below the inlet 6 (hereinafter referred to as the "lowest surface 9c") is the lowest, and the bottom plate 9 has a downwardly convex curved surface shape. The cross-sectional shape of the cooling tank 2 is uniform in the width direction, and the width dimensions (dimensions in the direction perpendicular to the paper surface of FIG. 1) of the first inclined surface 9a, the lowest surface 9c, and the second inclined surface 9b are all the same.

[0017] The ash extrusion device 1 includes a water level gauge 10 that detects the water level of the stored water in the cooling tank 2, and a supply pipe (water injection pipe) 11 that supplies water into the cooling tank 2 based on the water level detected by the water level gauge 10. The supply pipe 11 is installed in the drive chamber 2a, and the water level gauge 10 is arranged in the vicinity of the supply pipe 11. Specifically, the water level gauge 10 and the supply pipe 11 penetrate through the drive chamber ceiling plate 12 arranged above the second inclined surface 9b and above the drive device 5 in the drive chamber 2a and are fixed to the drive chamber ceiling plate 12.

[0018] Also, in the cooling tank 2, a drain pipe 13 for draining the stored water when the water level of the stored water exceeds the reference water level is provided. The position of the opening at the upper end of the drain pipe 13 (overflow level) is arranged above and in the vicinity of the reference water level (for example, about 10 cm above the reference water level). Thereby, excess stored water automatically overflows and is discharged from the drain pipe 13 without valve control.

[0019] The water level gauge 10 measures the water level of the water stored in the cooling tank 2 and transmits the measurement data to the control device 14. The supply pipe 11 is connected to a water source (not shown), such as a water storage tank, and has a nozzle 11a at its tip, and supplies water (water supply) to the cooling tank 2. An electromagnetic valve 15 is provided between the water source (not shown) and the nozzle 11a in the supply pipe 11, and the water supply and water supply stop from the supply pipe 11 are controlled by the opening and closing of the electromagnetic valve 15. Note that the nozzle 11a is arranged near the water level gauge 10 so that the water level gauge 10 can be automatically cleaned by all or at least a part of the water sprayed from the nozzle 11a of the supply pipe 11.

[0020] Since the nozzle 11a is often installed with its injection port facing vertically downward (in the Y-axis direction), in order to automatically clean the water level gauge 10, it is desirable to use a nozzle whose spray pattern spreads widely over a wide range as it moves away from the injection port, such as a full cone nozzle, an air cone nozzle, a fan nozzle, etc. When the injection port of the nozzle 11a is directed toward the water level gauge 10 and the nozzle 11a is installed, not limited to these, a nozzle with a spray pattern that becomes a straight pattern can also be used according to the design. In this case, it is possible to automatically clean the water level gauge 10 using all of the water sprayed from the nozzle 11a.

[0021] The control device 14 receives measurement data (information) regarding the water level from the water level gauge 10 during the "predetermined time stop operation" described later. In other words, the control device 14 activates (powers on) the water level gauge 10 during the "predetermined time stop operation" to measure the water level with the water level gauge 10, and during the "extrusion operation" and "retraction operation" described later, the power consumption of the water level gauge 10 can be reduced by stopping (powering off) the water level gauge 10. The measurement data is information indicating, for example, the actual water level (water level X) of the stored water stored in the cooling tank 2. In addition, the control device 14 transmits an operation control signal to the drive device 5 to drive the drive device 5, and transmits an opening / closing control signal to the electromagnetic valve 15 to open or close the electromagnetic valve 15.

[0022] The control device 14 performs the operation control of the scraper 4 and the water supply control using the supply pipe 11. First, the operation control of the scraper 4 will be described. The operation control of the scraper 4 is to control the scraper 4 to reciprocate along the forward direction Df (+X-axis direction in FIG. 1) or the reverse direction Dr (-X-axis direction in FIG. 1), so as to push the incineration ash in the cooling tank 2 toward the discharge port 7. The control device 14 controls the drive device 5 to sequentially repeat the three operations of the "pushing operation", the "pulling operation", and the "stopping operation for a predetermined time" of the scraper 4. The pushing operation is an operation to cause the scraper 4 to push the incineration ash toward the discharge port 7. The pulling operation is an operation to pull the pushed-out scraper 4 toward the drive chamber 2a. The stopping operation for a predetermined time is an operation to stop the pulled-in scraper 4 in the drive chamber 2a for a first predetermined time. The first predetermined time is, for example, 3 minutes.

[0023] Among the reciprocating operations of the scraper 4, in the forward stroke toward the forward direction Df, the scraper 4 moves from the drive chamber 2a side to the discharge port 7 side and pushes the incineration ash in the cooling tank 2 toward the discharge port 7 (pushing operation). In the return stroke toward the reverse direction Dr, the scraper 4 that has moved to the discharge port 7 side is pulled into the drive chamber 2a (pulling operation). After the scraper 4 performs one reciprocating operation (once the pushing operation is performed and immediately after the pulling operation is performed), the control device 14 stops the rotation of the drive shaft 5a for a first predetermined time to temporarily stop the scraper 4 in the drive chamber 2a (stopping operation for a predetermined time). Then, after the stopping operation for a predetermined time, the pushing operation of the scraper 4 is performed again. The first predetermined time t (0 < t) is a timer (first timer) provided in the control device 14 and can be set appropriately by the operator. The first timer is reset when the stopping operation for a predetermined time is completed and the operation shifts to the pushing operation.

[0024] Next, the water supply control using the supply pipe 11 will be described. The water supply control of the supply pipe 11 is to open the solenoid valve 15 installed in the supply pipe 11 to supply water to the cooling tank 2, or to close the solenoid valve 15 to stop the supply of the water. For the water supply control of the supply pipe 11, there is water supply control for water level adjustment (first water supply) implemented to keep the water volume of the stored water in the cooling tank 2 at the reference water level, and water supply control for water level gauge cleaning (second water supply) implemented to clean the water level gauge 10. Note that even during the first water supply, the water level gauge 10 is cleaned.

[0025] In order to prevent unnecessary water supply due to water level fluctuations caused by the reciprocating motion of the scraper 4, the control device 14, when the operation stops for a predetermined time, in other words, when the water level of the stored water in the cooling tank 2 is stable, based on the information regarding the water level received from the water level gauge 10, implements the first water supply when the water level of the stored water is lower than the reference water level. On the other hand, during the extrusion operation or the retraction operation, even if the water level of the stored water is lower than the reference water level, the control device 14 cannot implement the first water supply. On the other hand, regarding the second water supply, the control device 14 implements it regularly regardless of the operating status of the scraper 4 and the water level of the stored water.

[0026] Now, the first water supply for water level adjustment will be described. First, the reason for implementing the first water supply during the operation stop for a predetermined time will be explained. Although the scraper 4 operates slowly, during these extrusion operations or retraction operations, that is, while the scraper 4 is moving, the water level of the stored water in the cooling tank 2 is likely to fluctuate. In particular, depending on the amount and properties of the incineration ash, the water level of the stored water in the cooling tank 2 may fluctuate significantly due to the movement of the scraper 4. In contrast, during the predetermined time stop operation in which the scraper 4 is temporarily stopped, the water level of the stored water in the cooling tank 2 does not fluctuate and stabilizes. Therefore, during the predetermined time stop operation in which the water level is stable, the water level of the stored water in the cooling tank 2 can be accurately measured. Thus, the control device 14 implements the first water supply during the predetermined time stop operation in which the water level is stable.

[0027] Next, the details of the first water supply will be explained. Hereinafter, the reference water level will be denoted by the symbol S. When the control device 14 is in the stop operation for a predetermined time and the measurement data received from the water level gauge 10 (measurement data corresponding to the water level X of the stored water) is lower than the reference water level S, the control device 14 opens the solenoid valve 15 to inject water from the nozzle 11a of the supply pipe 11 into the cooling tank 2. The control device 14 keeps the solenoid valve 15 open and continues the water injection until the water level X reaches the reference water level S. Note that the water injection amount per unit time is set in advance so that the water level can increase with a margin up to the reference water level S during the stop operation for a predetermined time.

[0028] Whether the water level X of the stored water is lower than the reference water level S or not may be determined as follows: (1) Whether the water level X is lower than the reference water level S or not as stated. Alternatively, (2) Whether the water level X is lower than the reference water level S by a predetermined value T or more, that is, whether S - T ≧ X or not may be used for determination. The predetermined value T is a value used to set a threshold for determining the start of the first water supply to a water level lower than the reference water level S, and can be set to, for example, "10 cm" according to the design and specifications.

[0029] The control device 14 determines whether the water level X of the stored water indicated by the measurement data is lower than the reference water level S using either of the above determination conditions (1) or (2). Which of the determination conditions (1) or (2) to use is set in advance. Then, when the water level X of the stored water is equal to or higher than the reference water level S based on the measurement data, the control device 14 closes the solenoid valve 15 to stop the water injection into the cooling tank 2. Note that the excess stored water automatically overflows and is discharged from the drain pipe 13. That is, the water level X of the stored water in the cooling tank 2 is adjusted by the control device 14 and the drain pipe 13 so as to be maintained at the "reference water level S".

[0030] Figure 2 is a processing flow for explaining an example of the control of the first water supply implemented by the control device 14. The control device 14 repeatedly executes the processing flow of Figure 2. In step S1, the control device 14 determines whether the operation control (current operating state) of the scraper 4 has been stopped for a predetermined time. The control device 14 can determine whether the scraper 4 is in a stopped operation for a predetermined time from the status of the operation control of the scraper 4 that it itself is performing (that is, the operation control signal transmitted to the drive device 5).

[0031] If it is not in the stopped operation for a predetermined time, that is, if it is in the extrusion operation or the retraction operation (NO in step S1), the control device 14 ends the processing in this cycle (returns). If it is in the stopped operation for a predetermined time (YES in step S1), in step S2, the control device 14 activates (turns on the power) the water level gauge 10 and receives measurement data from the water level gauge 10.

[0032] In step S3, the control device 14 determines whether the water level X of the stored water is lower than the reference water level S based on the measurement data received from the water level gauge 10. Information indicating the reference water level S is stored in advance, for example, in the storage device of the control device 14. The control device 14 determines whether the water level X of the stored water is lower than the reference water level S using the above-mentioned determination conditions (1) or (2) set in advance. If the water level X of the stored water indicated by the measurement data is higher than or equal to the reference water level S (NO in step S3), the control device 14 ends the processing in this cycle (returns). If the water level X of the stored water indicated by the measurement data is lower than the reference water level S (YES in step S3), in step S4, the control device 14 opens the solenoid valve 15 and starts water injection from the supply pipe 11. During water injection, the control device 14 receives measurement data from the water level gauge 10 (step S5), and continues the water injection and the processing of step S5 until the water level X of the stored water indicated by the measurement data becomes higher than or equal to the reference water level S (NO in step S6). When the water level X of the stored water reaches a height higher than or equal to the reference water level S (YES in step S6), the control device 14 closes the solenoid valve 15 to stop the water injection of the supply pipe 11 and stops (turns off the power) the water level gauge 10 (step S7), and ends the processing in this cycle (returns). When the processing flow in FIG. 2 reaches the return, the control device 14 executes the processing flow again from the start in FIG. 2.

[0033] As described above, among the three operations of the extrusion operation, the retraction operation, and the predetermined time stop operation, the control device 14 can perform the first water supply only during the predetermined time stop operation. During the extrusion operation or the retraction operation, the control device 14 does not perform the first water supply. That is, the first water supply can be performed only during the predetermined time stop operation of the scraper 4 when the level of the stored water in the cooling tank 2 is stable. Therefore, unnecessary water supply due to the water level fluctuation caused by the reciprocating motion of the scraper 4 can be prevented. Thus, the water supply to the stored water can be appropriately controlled to enhance the cost effectiveness regarding the water supply in the ash extrusion device 1. In addition, when the first water supply is performed using the determination condition (2) when the water level X is lower than the reference water level S by a predetermined value T or more, the opportunity to perform the first water supply is likely to be suppressed, so that the cost effectiveness regarding the water supply can be further enhanced. Furthermore, in the first water supply, the water level gauge 10 is automatically cleaned with the water supplied from the supply pipe 11 in step S4. Since the supply pipe 11 in FIG. 1 is provided with a nozzle 11a at the tip, the cleaning of the water level gauge 10 can be performed more effectively.

[0034] By the way, even if the three operations of the extrusion operation, the retraction operation, and the predetermined time stop operation are repeated in a plurality of cycles, if the water level X of the stored water remains the same as or higher than the reference water level S (NO in step S3 of FIG. 2), the first water supply is not performed. In this case, there is a possibility that the water level gauge 10 may be contaminated and the water level cannot be accurately measured. Therefore, the control device 14 may periodically perform the second water supply regardless of the operation status of the scraper 4 and the water level of the stored water. In the second water supply, the control device 14 opens the solenoid valve 15 for a predetermined short period of time to supply water from the supply pipe 11 and clean the water level gauge 10. Then, immediately after the elapse of the predetermined short period of time, the solenoid valve 15 is closed to stop the water injection into the supply pipe 11. The predetermined short period of time is a time preset as the time required for the periodic cleaning of the water level gauge 10, and is set to, for example, "10 seconds". This time is usually shorter than the time required for the first water supply. The details of the second water supply will be described below.

[0035] The start condition of the second water supply is preset. The start condition is, for example, (Condition 1) the number of reciprocating operations of the scraper 4 reaches a predetermined number, or (Condition 2) a predetermined time (second predetermined time) is measured. The number of reciprocating operations of the scraper 4 is the number of times of performing three operations of an extrusion operation, a retraction operation, and a predetermined time stop operation in one cycle. For example, the predetermined number can be set to "10 times". The second predetermined time is a time appropriately set as the time when water cleaning is required due to dirt adhering to the water level gauge 10 or the like. For example, the second predetermined time can be set to "1 hour".

[0036] The control device 14 can count the number of reciprocations of the scraper 4 by a counter (not shown) provided in the control device 14, and can measure the second predetermined time by a timer (second timer, not shown) provided in the control device 14. The counting by the counter of the number of reciprocating operations in Condition 1 and the measurement by the second timer of the second predetermined time in Condition 2 start, for example, together with the start of the operation of the ash extrusion device 1, are reset every time the second water supply is performed once, and restart. That is, the first second water supply after the start of the operation of the ash extrusion device 1 is performed when Condition 1 or Condition 2 is achieved from the start time of the operation of the ash extrusion device 1. The second water supply and subsequent ones are performed when the number of reciprocating operations is counted in ascending order from 1 by the counter and reaches the predetermined number after the immediately previous second water supply has been performed, or when the second timer is started from 0 seconds and the second predetermined time is measured after the immediately previous second water supply has been performed. As for which of Condition 1 and Condition 2 is to be used as the start condition of the second water supply, it is preset.

[0037] As described above, regardless of whether the scraper 4 is in the extrusion operation, the retraction operation, or the operation status of stopping for a predetermined time, the control device 14 can periodically perform the second water supply. Therefore, even if the first water supply is not performed no matter how many times the three operations of the extrusion operation, the retraction operation, and the operation of stopping for a predetermined time are repeated, the water level gauge 10 can be appropriately cleaned by the second water supply periodically. Thus, it is possible to prevent measurement errors due to dirt adhesion or the like to the water level gauge 10 and ensure the accuracy of water level measurement.

Explanation of Signs

[0038] 1 Ash extrusion device 2 Cooling tank 2a Drive chamber 3 Conveyor 4 Scraper 4a Upper plate 4b Extrusion plate 4c Side plate 4d Tip 5 Drive device 5a Drive shaft 5b Arm 6 Inlet 7 Outlet 8 Wall surface 9 Bottom plate 9a First inclined surface 9b Second inclined surface 9c Lowest surface 10 Water level gauge 11 Supply pipe (water injection pipe) 11a Nozzle 12 Drive chamber ceiling plate 13 Drain pipe 14 Control device 15 Electromagnetic valve Df Forward direction Dr Reverse direction

Claims

1. A cooling tank having an inlet through which incineration ash is introduced and an outlet through which the incineration ash cooled by stored water is discharged, a driving device installed in a driving chamber disposed on the side opposite to the outlet with respect to the inlet in the cooling tank, the driving device reciprocating a scraper that pushes the incineration ash toward the outlet toward the outlet, a supply pipe installed in the driving chamber for supplying water to the cooling tank, a solenoid valve installed in the supply pipe, a water level gauge disposed in the vicinity of the supply pipe for measuring the water level of the stored water, a control device that controls the driving device to sequentially repeat three operations: an extrusion operation of pushing the incineration ash toward the outlet by the scraper, a retraction operation of pulling the scraper toward the driving chamber, and a predetermined time stop operation of stopping the pulled scraper for a first predetermined time, wherein the control device is an incineration ash extrusion device that, during the predetermined time stop operation, based on the information regarding the water level received from the water level gauge, when the water level is lower than a reference water level, performs first water supply by opening the solenoid valve to supply water from the supply pipe until the water level reaches the reference water level, and does not perform the first water supply during the extrusion operation or the retraction operation.

2. The incineration ash extrusion device according to claim 1, wherein the control device performs second water supply by periodically opening the solenoid valve to supply water from the supply pipe for cleaning the water level gauge while sequentially repeating the three operations.

3. The incineration ash extrusion device according to claim 2, wherein the control device performs the second water supply when the number of reciprocating operations is counted and the number reaches a predetermined number, or when a second predetermined time is measured.

4. The incineration ash extrusion device according to claim 3, wherein the control device performs the first water supply only when the water level is lower than a predetermined value or more than the reference water level based on the information regarding the water level received from the water level gauge during the predetermined time stop operation.

5. The incineration ash extrusion device according to any one of claims 2 to 4, wherein the supply pipe is provided with a nozzle at its tip, and water is sprayed from the nozzle to clean the water level gauge during the first water supply or the second water supply.

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