JP3988112B2 - Raw material pumping method for garbage, etc. - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a raw material pumping method for garbage such as raw garbage and sewage sludge and the like, in which an object (pumped raw material) having low moisture content and poor fluidity is pumped without excessive compaction.
[0002]
[Prior art]
In the waste fertilizer plant, for the purpose of reusing resources, for example, fertilizer is made by adding wood chips to raw garbage and fermenting.
[0003]
In this case, it is necessary to feed the raw garbage to the fermenter as the required compaction properties, but it is difficult to stably feed the raw garbage because of its low moisture content and poor fluidity.
[0004]
As a pumping device for pumping an object having such a low moisture content and poor fluidity, for example, a pumping device described in JP-A-10-205435 has been proposed. This pressure feeding device is intended for dewatered sludge, and includes a screw conveyor that pushes the dewatered sludge into the sludge container, and a pump that sucks the dewatered sludge in the sludge container and pumps it to the transportation pipe. Operation is performed with a bypass pipe for returning the dewatered sludge to the screw feeder, and the amount of dewatered sludge pushed by the screw feeder is always set larger than the amount of dewatered sludge pumped by the pressure pump.
[0005]
[Problems to be solved by the invention]
However, in the case of the proposed pumping device, the screw conveyor continues to drive even when the pumping pump is stopped, and the dewatered sludge pushed excessively into the sludge container is passed through the bypass pipe to the screw conveyor. Since it is structured to return, waste of energy is large, and pushing pressure acts on the dewatered sludge even during standby, so if it is used for pumping garbage for fertilizer, it will compress the garbage However, when it is pumped to the fermenter, for example, there is a problem that fermentation is difficult.Furthermore, immediately after the operation of stopping the pumping pump and screw conveyor is stopped, it is placed in the sludge container. Since there is a residual pressure due to the indentation pressure, sludge may be scattered when the bottom cover of the sludge container is opened for cleaning or the like.
[0006]
Therefore, the present invention allows a pressure-feed material such as garbage to be fed to a pressure-feed pump without applying excessive pressure so that the pressure-feed material can be pumped without being excessively compressed (compressed). It is intended to be able to eliminate the problem of residual pressure at the end of pumping.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention first pushes the raw material into the hopper by the screw feeder when the raw material such as garbage pushed from the screw feeder into the hopper of the pressure pump is pumped by the pump. The pumping pump starts to operate after the pressing pressure reaches a value within a predetermined target range. After the pumping pump starts operating, the material pressing pressure into the hopper is within the target range. The feed feeder is operated while controlling the number of rotations of the screw feeder so that the raw material is pumped, and when the feed of the raw material is finished, the screw feeder is stopped first, and the raw material into the hopper raw your pushing pressure from reduced than the lower limit of the target range, to so that is removed residual pressure stops the feed pressure to stop the operation of the feed pump As a raw material feeding method and the like.
[0008]
The raw material intrusion pressure into the hopper by the screw feeder is maintained within the target range from the start of operation to the steady operation, so that excessive compression of the raw material is prevented. Since the driving is stopped in the order of the pumps, the residual pressure is removed.
[0009]
Also, instead of stopping the operation in the order of the screw feeder and the pump, when the feed of the raw material is finished, after the operation of the screw feeder and the pump is stopped at the same time, the indentation pressure of the raw material is the target. by range reversing the screw feeder only until less than the lower limit of to so that is removed residual pressure, the pumping quantity, it can be adjusted precisely to the target delivery amount.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
1 to 4 show an example of an apparatus used for carrying out the pressure feeding method of the present invention. A screw feeder 2 for conveying raw material 1 such as garbage to the downstream while mixing and compressing, and discharging from the screw feeder 2. The feed pump 6 configured to alternately suck and discharge the raw material 1 sent into the hopper 3 by the two pumping cylinders 4 and 5 and the supply pressure of the raw material 1 fed into the hopper 3 are based on the above. And a control device 7 for controlling the drive of the screw feeder 2.
[0012]
As shown in FIGS. 1 to 3, the screw feeder 2 is provided with a casing 9 extending in the lateral direction on a base 8 installed so as to straddle the pressure feed pump 6 and arranged in parallel in the casing 9. The two screws 10 and 11 are accommodated, and both shaft end portions of the two screws 10 and 11 are rotatably supported by bearings 12 installed outside the casing 9, and one of the screws 10 and 11 is supported. The sprockets 13 and 14 are provided at the shaft end of the casing 9, and a motor 15 as a driving device is installed beside the longitudinal end of the casing 9, and the drive sprocket 16 attached to the output shaft of the motor 15 and the above-mentioned An endless chain 17 is hung between the sprockets 13 and 14 via a guide sprocket 18, and the chain 17 and sprocket 13 are driven by the motor 15. 14, the screws 10 and 11 are rotated in opposite directions as indicated by an arrow X (FIG. 3), and a charging port 19 is provided on one end of the casing 9 in the longitudinal direction. A discharge port 20 is provided on the lower surface side of the other end portion of the casing 9 in the longitudinal direction, and the discharge port 20 is communicated with the hopper 3 of the pressure pump 6 via a guide chute 21.
[0013]
The pressure pump 6 is of a reciprocating piston type, and as shown in FIGS. 1 and 4, two suction / discharge ports 22 are provided side by side at the lower part of the front surface of the hopper 3. Two pressure-feeding cylinders 4 and 5 respectively communicating with the suction / discharge port 22 are installed in parallel, and the pressure-feeding pistons 23 housed in the pressure-feeding cylinders 4 and 5 are washed in the pressure-feeding cylinders 4 and 5. The main hydraulic pistons 27 of the main hydraulic cylinders 25 and 26 connected through the chamber 24 are integrally connected to each other through one rod 28, and the main hydraulic cylinders 25 and 26 are alternately advanced and retracted for pressure feeding. The pistons 27 are alternately moved forward and backward, and an oscillating tube 29 bent in an S-shape is positioned in the hopper 3, and a seal ring 30 is attached to one end of the oscillating tube 29. The two inhalations The connecting shaft 32 is configured so that it can be alternately matched with the outlet 22, the other end of the swing pipe 29 is connected to the pressure feed pipe 31 through the back surface of the hopper 3, and is fixed in the middle of the swing pipe 29. Are connected to two oscillating cylinders 33, 34 installed outside the hopper 3 via an operation lever 41, and the oscillating tube 29 is tilted to the left and right to thereby move the oscillating tube 29 in the left-right direction around the connecting shaft 32. Can be swung.
[0014]
As shown in FIG. 1, the control device 7 includes an earth pressure gauge 35 as a pressure detector installed on the inner wall surface of the guide chute 21 on the inlet side of the hopper 3, and the pushing of the raw material 1 detected by the earth pressure gauge 35. A calculation controller 37 for comparing and calculating the pressure detection signal a and the target range of the indentation pressure and sending the control command signal b to the drive control panel 36 for the screw feeder 2, and driving based on the control command signal b By controlling the rotation (frequency) of the motor 15 of the screw feeder 2 by the command signal c and controlling the rotation of the screws 10 and 11, the raw material 1 can be supplied into the hopper 3 with an appropriate pressure.
[0015]
In the figure, reference numeral 38 denotes a pressure feed pump installation base, 39 denotes an inspection window for the guide chute 21, and 40 denotes an inspection window for the casing 9 of the screw feeder 2.
[0016]
In the above configuration, when the operation switch is turned ON, the screw feeder 2 is driven by the motor 15 and the drive is transmitted to the sprockets 13 and 14 via the chain 17 so that the two screws 10 and 11 are mutually connected. When the raw material 1 such as garbage is introduced into the casing 9 through the input port 19, the raw material 1 is mixed and compressed by the rotation of the screws 10 and 11, and the discharge port. It is conveyed to the 20 side and discharged so as to be sequentially pushed out from the discharge port 20.
[0017]
On the other hand, when the rocking tube 29 is swung by the operation of the rocking cylinders 33 and 34 and is positioned at the suction / discharge port 22 corresponding to the pressure feeding cylinder 4, the pressure feeding pump 6 The pressure feed piston 23 is advanced by the main hydraulic cylinder 25 and the raw material 1 sucked into the pressure feed cylinder 4 is discharged into the pressure feed pipe 31 through the swinging pipe 29 and simultaneously fed to another pressure feed. In the cylinder 5, the pressure-feeding piston 23 is retracted and the raw material 1 in the hopper 3 is sucked through the suction / discharge port 22, and then the swing pipe 29 swings and the suction / discharge port 22 corresponding to the pressure-feed cylinder 5. When positioned on the side, the raw material 1 sucked into the pressure feeding cylinder 5 is continuously discharged into the pressure feeding pipe 31 through the rocking pipe 29 and is pumped.
[0018]
As described above, the raw material 1 is discharged from the discharge port 20 of the screw feeder 2 and supplied into the hopper 3 of the pressure feed pump 6 in a series of operation processes in which the raw material 1 is charged into the screw feeder 2 and discharged by the pressure feed pump 6. The indentation pressure of the raw material 1 is detected by the earth pressure gauge 35 installed on the inner wall surface of the guide chute 21, and the indentation pressure detection signal a and the indentation pressure target range are compared and calculated by the arithmetic controller 37. Will be. In the arithmetic and control unit 37, when the indentation pressure detection signal a exceeds the upper limit value of the indentation pressure target range, that is, when the indentation pressure of the raw material 1 is too high, a control command for reducing the number of revolutions of the screws 10 and 11 When the signal b is output to the drive control panel 36 for the screw feeder 2 while the value of the indentation pressure detection signal a is below the lower limit value of the indentation pressure target range, that is, when the indentation pressure of the raw material 1 is too low Then, a control command signal b for increasing the rotational speed of the screws 10 and 11 is output to the drive control panel 36 for the screw feeder 2. Further, the drive control panel 36 sends a drive command signal c based on the control command signal b to the motor 15 to control the rotation (frequency) of the motor 15 to increase or decrease the rotational speed of the screws 10 and 11. To control.
[0019]
When the present invention is carried out using the apparatus shown in FIGS. 1 to 4, when the raw material 1 such as the garbage pushed into the hopper 3 of the pressure feed pump 6 from the screw feeder 2 is pumped by the pressure feed pump 6, The operation of the pumping pump 6 is started after the pressing pressure when the raw material 1 is pushed into the hopper 3 by the screw feeder 2 reaches a value within a predetermined target range, and the operation of the pumping pump 6 is started. Thereafter, the pressure feed pump 6 is operated to feed the raw material 1 while controlling the rotation speed of the screw feeder 2 so that the pushing pressure of the raw material 1 into the hopper 3 is maintained within the target range. When the pressure feed of the feed pump 6 is stopped, the screw feeder 2 is stopped first, and the pushing pressure of the raw material 1 into the hopper 3 falls below the lower limit of the target range. The stop so as to stop the pumping.
[0020]
A specific description will be given with reference to FIG. 5 showing the flow from the start of operation to the steady operation and FIG. 6 showing the relationship between the indentation pressure and the frequency over time.
[0021]
First, the corresponding frequency of the motor 15 as the number of rotations of the screws 10 and 11 of the screw feeder 2 is determined in advance according to the moisture content and properties of the raw material 1 to be pumped. In this state, the operation switch is turned on to drive the screw feeder 2, and when the screw feeder 2 starts up, the determined frequency is read by the volume and the target pushing pressure is set. In this case, for example, the indentation pressure has three stages of L (: 10 kPa), M (: 20 kPa), and H (: 30 kPa), and an allowance of 5 kPa above and below is allowed as an allowable range. FIG. 6 shows a case where the corresponding frequency is 50 Hz and the target pushing pressure is M. As a result, the raw material 1 is supplied into the hopper 3 of the pressure feed pump 6 and the indentation pressure at that time is detected by the earth pressure gauge 35. At this time, the initial driving of the screw feeder 2 is since the pressure in the hopper 3 is found to be low, for example, until the required time T ₁ is elapsed without performed pressure reading of the soil pressure gauge 35, and so as not to frequency control is also performed. After the time T ₁ elapses, the pressure reading of the earth pressure gauge 35 is started, and when the pushing pressure enters the target range A, the pump 6 is driven, and thereafter the steady operation is performed.
[0022]
During the steady operation, the detected value of the earth pressure gauge 35 is compared with the target range A of the indentation pressure. At this time, even if the detected value of the earth pressure gauge 35 exceeds the upper limit value of the target range A, the screws 10 and 11 are immediately used. of not to reduce the rotational speed, to delay the required time T ₂ only control start. This is because, for example, a hard lump or the like in the garbage may hit the earth pressure gauge 35, and it is considered that the pressure temporarily rises even though the indentation pressure is within the target range.
[0023]
Therefore, when the detected value of the earth pressure gauge 35 exceeds the upper limit value of the target range even after the time T ₂ has elapsed, the screw 10 or 11 is reduced in frequency as shown in FIG. When the detected value of the earth pressure gauge 35 still exceeds the upper limit value of the target range A by this control, as shown in FIG. The frequency is further decreased to further reduce the rotational speed of the screws 10 and 11. On the contrary, when the detected value of the earth pressure gauge 35 falls below the lower limit value of the target range A, as shown in (c) and (d) of FIG. , 11 is increased.
[0024]
As described above, in the present invention, the screw feeder 2 is driven first, and the pumping pump 6 is driven after the pressing pressure of the raw material 1 into the hopper 3 reaches the target range A. Occasionally, there is no occurrence of a situation in which the suction and discharge pressure becomes insufficient, and the control is performed so that the pushing pressure is maintained within the target range A during the steady operation, so that excessive compression of the raw material 1 can be prevented. it can. Further, when the operation is stopped, after the screw feeder 2 is stopped, the pressure pump 6 is stopped after the detected value of the earth pressure gauge 35 falls below the lower limit value of the target range. Can be removed. Therefore, even when the operation is stopped and the operation is resumed after the lapse of the required time, the raw material 1 is not excessively compressed by the residual pressure, and the screw feeder 2 and the pressure feed are supplied during the standby. Since the driving of the pump 6 is stopped, waste of energy can be eliminated, and even when the operation is stopped and the bottom cover of the hopper 3 is opened and washed immediately after that, the raw material 1 Can be prevented from occurring due to the residual pressure.
[0025]
Next, as another embodiment of the present invention, when the feed of the raw material 1 is finished, the drive of the screw feeder 2 is stopped and then the drive of the pump 6 is stopped based on the detected value of the earth pressure gauge 35. Instead, when ending the pumping, the pumping pump 6 and the screw feeder 2 are stopped at the same time, and immediately after that, the screw feeder 2 is driven in the reverse direction, and based on the detected value of the earth pressure gauge 35, the raw material 1 When the pushing pressure of the screw feeder 2 falls below the lower limit value of the target range A, the reverse drive of the screw feeder 2 is stopped.
[0026]
In the above-described embodiment, the driving is stopped in the order of the screw feeder 2 and the pumping pump 6 at the end of the pumping, so that the raw material 1 is discharged from the pumping pump 6 even after the screw feeder 2 stops. Assuming that the operation stop switch needs to be pushed shortly before the pumping amount as the discharge amount reaches the target pumping amount as the target discharge amount, according to the present embodiment, the screw feeder 2 and the pumping pump 6 Are stopped at the same time, so it is advantageous to press the operation stop switch when the pumping amount reaches the target pumping amount. Further, the screw feeder 2 is reversed immediately after the screw feeder 2 and the pumping pump 6 are stopped. The problem of residual pressure does not occur.
[0027]
The earth pressure gauge 35 may be installed directly on the inner wall surface of the hopper 3 as indicated by a two-dot chain line in FIG. 4. In this case, the supply pressure can be detected at a position close to the suction position of the raw material 1. Therefore, in the embodiment, the case of using the oscillating valve type pressure feed pump 6 has been shown. However, a slip valve type may be adopted. Of course, the raw material 1 to be pumped is not limited to garbage, but may be sewage sludge or the like, and other various modifications may be made without departing from the scope of the present invention.
[0028]
【The invention's effect】
As described above, according to the raw material pressure feeding method of the garbage etc. of the present invention, when the raw material such as garbage pushed into the hopper of the pressure feeding pump from the screw feeder is pumped by the pressure feeding pump, first, by the screw feeder. The operation of the pumping pump is started after the pressing pressure when the raw material is pushed into the hopper reaches a value within a predetermined target range. After the operation of the pumping pump is started, the raw material into the hopper The feed pump is operated to control the rotation speed of the screw feeder so that the indentation pressure is maintained within the target range so that the feedstock is pumped.When the feed of the feed is finished, the screw feeder is stopped first. Te, removed from pushing pressure of the feed into the hopper is lowered than the lower limit of the target range, the residual pressure by stopping the feed pressure to stop the operation of the feed pump Because it so that not, without even as suction and discharge pressure by the pressure pump at the start of operation is insufficient, at the time of steady operation can be maintained stably and appropriately the suction and discharge pressure, and the standby energy In addition to eliminating waste, over-compression of the raw material can be prevented, and when the pumping by the pump is stopped, the residual pressure can be removed, so that the raw material may be excessively compressed by the residual pressure. In addition, it is possible to prevent the raw material from being scattered due to internal pressure even when the hopper bottom lid is opened and cleaning work is performed, and when the feed of the raw material is finished, the screw feeder Instead of stopping the operation in the order of the pressure pumps, after the simultaneous operation of the screw feeder and the pressure pump, By the so that by reversing the screw feeder is removed residual pressure only until less than the lower limit of a target range it can be removed residual pressure of the pressure pump, and adjust the pumping quantity accurately in the target delivery amount It exhibits excellent effects such as
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of an apparatus used for carrying out a raw material pressure feeding method for garbage such as garbage according to the present invention.
FIG. 2 is a plan view of a screw feeder used in the apparatus of FIG.
3 is a left side view of a screw feeder used in the apparatus of FIG. 1. FIG.
4 is a detailed view of a pressure pump used in the apparatus of FIG.
FIG. 5 is a flow from the start of operation to the steady operation of the raw material pressure feeding method of the present invention.
FIG. 6 is a diagram showing an example of the rotational speed (frequency) control by the pressing pressure over time.
[Explanation of symbols]
1 Raw Material 2 Screw Feeder 3 Hopper 6 Pressure Pump A Target Range

Claims (2)

When a raw material such as garbage that has been pushed from the screw feeder into the hopper of the pressure feed pump is fed by the pressure feed pump, first, the pushing range when the material is pushed into the hopper by the screw feeder is determined in advance. When the pressure feed pump starts operating, the rotation speed of the screw feeder is controlled so that the pressure of the raw material into the hopper is maintained within the target range. While driving the pressure feed pump to feed the raw material and ending the feed of the raw material, stop the screw feeder first, and the pressure of pushing the raw material into the hopper will fall below the lower limit of the target range. after the raw material pumped method of garbage, etc., characterized in that the so that to remove the residual pressure by stopping the feeding stopped pressure operation of the feed pump. Instead of stopping the operation in the order of the screw feeder and the pump, when stopping the pumping of the raw material, after stopping the operation of the screw feeder and the pumping pump at the same time, the pressing force of the raw material is within the target range. feedstock pumping method of garbage or the like according to claim 1, wherein only reversing the screw feeder to so that is removed residual pressure and until less than the lower limit.

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