JP2012173122A - Slurry transfer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable improvement in continuity of stable operation by reducing measurement errors in a flow rate of slurry and enhancing reliability of an instruction from an electromagnetic flowmeter.SOLUTION: A slurry transfer apparatus comprises: a waste liquid storage tank 1 for storing a waste liquid; a head tank 2 for transferring a waste liquid to the waste liquid storage tank 1 using hydraulic head pressure; a waste liquid transfer pump 4 for transferring the waste liquid from the waste liquid storage tank 1 to the head tank 2; a water level adjustment valve 5 for adjusting a water level in the head tank 2 by adjusting a flow rate of a waste liquid transferred from the head tank 2 to the waste liquid storage tank 1; a drying machine 8 for housing and drying slurry; a slurry transfer pipe 6 for transferring slurry from the head tank 2 to the drying machine 8; an electromagnetic flowmeter 11 for measuring a transfer amount of slurry using electromagnetic force; a water level control device 12 for controlling a water level of slurry; and pulsation applying means 18 for applying pulsations to the flow rate of slurry transferred from the head tank 2 to the drying machine 8 using hydraulic head pressure.

Description

  The present invention relates to a slurry processing apparatus for processing a slurry contained in a waste liquid generated in a nuclear facility or the like, and more particularly to a slurry transfer apparatus that transfers a settling slurry to a dryer or the like by water head pressure.

  Conventionally, it is known to apply a cement solidification method as a treatment method of boric acid-containing waste liquid in a nuclear facility. In this cement solidification method, the sedimentary slurry generated by solidifying the waste liquid by chemical treatment or the like is transferred to a dryer and dried, and the powder and cement produced by this drying treatment are kneaded to obtain a cement solidified body. It is a method of forming.

  Among the cement solidification methods, a method is known in which, in the slurry drying step, the sedimentary slurry is transferred to the dryer according to the capacity of the dryer.

  FIG. 9 is a system configuration diagram showing the configuration and operation of a slurry transfer apparatus according to a conventional example for carrying out the above method.

  As shown in FIG. 9, when transferring a small amount of sedimentary slurry contained in waste liquid 100 generated in a nuclear facility to a dryer 108 by a slurry transfer device, a waste liquid storage tank 101 and a head tank disposed above the waste liquid storage tank 101 The slurry is circulated between the head tank 102 via the circulation pipes 103a and 103b, and the slurry is dried from the head tank 102 via the slurry transfer pipe 106 by the water head pressure according to the water level of the waste liquid 100 in the head tank 102. It is carried out and dried.

  Conventionally, as a technique for transferring a large amount of slurry, a system that pulsates the slurry flow rate by installing a centrifugal pump 104 on a transfer pipe for transferring a slurry connected from a transfer source to a transfer destination is a known technique. Are known.

JP 11-315999 A

  In the above-described waste liquid drying step, for the step of transferring the slurry obtained by chemically treating the waste liquid 100 to the dryer 108, the flow rate of the slurry transferred from the head tank 102 to the dryer 108 is measured by the water head pressure with the electromagnetic flow meter 111. The measured flow rate is fed back to the water level adjustment valve 105 installed in the return pipe (circulation pipe 103b) from the head tank 102 to the waste liquid storage tank 101 for storing the slurry, using an electric signal.

  By this feedback control, the water level of the head tank 102, that is, the slurry transfer flow rate based on the water head pressure is controlled.

  However, when the slurry settles on the measuring unit composed of the electromagnetic flow meter 111, the pipe diameter for measuring the flow rate becomes small, so that it is detected as a value smaller than the actual flow rate, and an error may occur in the flow rate instruction.

  When the above error occurs, the opening of the water level adjustment valve 105 is reduced by the feedback control of the flow rate, the water level of the waste liquid in the head tank 102 rises, and the system operation becomes unstable. Further, as the slurry settles, the slurry transfer pipe 106 may be blocked.

  As described above, in the conventional cement solidification method, slurry accumulates on the flow meter measuring unit that measures the flow rate of the slurry-like boric acid-containing waste liquid, and there is a possibility that an error occurs in the flow rate instruction.

  Further, there is a possibility that the water level adjusting valve (throttle valve) 105 on the slurry transfer pipe 106 of the slurry-like boric acid-containing waste liquid is clogged.

  The present invention has been made based on such circumstances, and contributes to improving the continuity of stable operation by reducing the measurement error of the sedimentary slurry flow rate and improving the reliability of the instructions of the flow meter. It is an object of the present invention to provide a slurry transfer device that enables the above.

  In the present invention, a waste liquid storage tank for storing waste liquid, a head tank for transferring waste liquid by hydraulic head pressure, a waste liquid transfer pump for transferring waste liquid from the waste liquid storage tank to the head tank, and a waste liquid storage tank from the head tank The water level adjustment valve for adjusting the water level of the head tank by adjusting the flow rate of the waste liquid, the dryer, the slurry transfer pipe for transferring the slurry from the head tank to the dryer, and the slurry transfer amount are measured. In a slurry transfer device comprising a flow meter and a water level control device for controlling the valve opening degree of the water level adjusting valve, pulsation imparting means for pulsating the slurry flow rate transferred from the head tank to the dryer by water head pressure A slurry transfer device is provided.

  According to the present invention, it is possible to improve the reliability of the instruction of the flow meter by reducing the measurement error of the slurry flow rate. Moreover, it becomes possible to contribute to the continuation of stable operation by reducing the possibility that the slurry transfer pipe is blocked.

The block diagram which shows the whole system | strain of the slurry transfer apparatus by 1st Embodiment of this invention. The perspective sectional view which expands and shows the inside of transfer piping of the slurry transfer apparatus shown in FIG. The enlarged view which shows the transfer piping rotation part shown in FIG. 2 as a partial cross section. The graph for demonstrating the effect | action of 1st Embodiment of this invention along a time-axis. The block diagram which shows the whole system | strain of the slurry transfer apparatus by 2nd Embodiment of this invention. The graph for demonstrating the effect | action of 2nd Embodiment of this invention along a time-axis. The block diagram which shows the whole system | strain of the slurry transfer apparatus by 3rd Embodiment of this invention. The graph for demonstrating the effect | action of 3rd Embodiment of this invention along a time-axis. The system block diagram which shows the structure and effect | action of the slurry transfer apparatus by a prior art example.

  Hereinafter, embodiments of a slurry transfer apparatus according to the present invention will be described with reference to the drawings.

First Embodiment (FIGS. 1 to 4)
FIG. 1 is an overall configuration diagram of a slurry transfer apparatus A1 according to a first embodiment of the present invention.

  As shown in FIG. 1, the slurry transfer apparatus A1 of the present embodiment includes a waste liquid storage tank 1 that stores waste liquid L1 generated in a nuclear facility and the like, and a waste liquid that is disposed above the waste liquid storage tank 1 due to water head pressure. A vertically long head tank 2 for transferring L1 to the waste liquid storage tank 1 is provided.

  On the upper wall portion of the waste liquid storage tank 1, there is provided a reflux pipe 3 a connected from the waste liquid storage tank 1 to the bottom side of the head tank 2 for returning the waste liquid L 1 into the head tank 2. Is provided with a delivery pipe 3b for delivering the waste liquid L1 to the waste liquid storage tank 1 from the side wall portion.

  The reflux pipe 3a is provided with a circulation pump 4 as a waste liquid transfer pump. The circulation pump 4 transfers the waste liquid L1 from the waste liquid storage tank 1 side to the head tank 2 side.

  A slurry transfer pipe 6 is connected between the lower side surface of the head tank 2 and the dryer 8, and the slurry is transferred from the head tank 2 to the dryer 8 by the head pressure of the head tank 2 to perform drying.

  On the inner peripheral surface of the slurry transfer pipe 6, there is provided a transfer pipe rotating portion 7 in which a spiral groove is formed along the axis of the slurry transfer pipe 6. The slurry transfer pipe 6 and the transfer pipe rotate. The pipe 7 is coaxially connected to the section 7 so that the transfer pipe rotating section 7 is integrally rotated by a driven gear 14a and a drive gear 14b.

  The transfer pipe rotating unit 7 has a rotation drive unit (shaft) 9 composed of a gear mechanism, and has a function of variable speed control of the rotation speed of the transfer pipe rotating unit 7 and a timer function for periodically shifting. A control device 13a is provided.

  A flow meter such as an electromagnetic flow meter 11 is installed in the slurry transfer pipe 6, and the flow rate of the slurry flowing through the slurry transfer pipe 6 can be measured. Further, in order to control the water level of the head tank in accordance with the flow rate of the slurry flowing through the slurry transfer pipe 6, a water level control device 12 that controls the valve opening degree of the water level adjusting valve 5 that operates is provided.

  FIG. 2 is a perspective cross-sectional view showing, in detail, the inner peripheral surface portion of the inside of the transfer pipe rotating portion 7 of the slurry transfer device A1 shown in FIG.

  As shown in FIG. 2, a spiral groove 7a centering on the axial center of the transfer pipe rotating part 7 is formed inside the transfer pipe rotating part 7 of the slurry transfer pipe 6. The groove 7a As a result, a spiral feeding action is applied to the slurry S flowing in the transfer pipe rotating portion 7 and the slurry S is forcibly sent.

  In this way, the spiral groove 7a is formed inside the transfer pipe rotating portion 7 of the slurry transfer pipe 6, and the transfer pipe rotating portion 7 is rotated around its axis at a variable period, so that the slurry transfer pipe 6 An axial streamline bundle (spiral feed) can be given to the slurry S flowing inside by the spiral groove 6a (that is, the flow rate can be changed). Instead of forming the spiral groove 7a inside the transfer pipe rotating unit 7, a spiral blade (not shown) may be provided inside.

  Therefore, the rotational drive unit 9 and the speed control device 13a can apply a rotational speed to the transfer pipe rotating unit 7 at a required period, pulsate the flow rate of the slurry flowing inside the slurry transfer pipe 6, and forcibly send it. .

  FIG. 3 is an enlarged view showing a part of the transfer pipe rotating unit 7 shown in FIG. 2 as a cross section.

  As shown in FIG. 3, a driven gear 14 a is installed in the vicinity of the axial end of the transfer pipe rotating unit 7, and the gear 14 a meshes with a drive gear 14 b for driving connected to the shaft of the motor 15. Then rotate.

  The motor 15 is configured to rotate at a variable speed by an electrical signal from the speed control device 13a. By driving the motor 15, the transfer pipe rotating unit 7 can be rotated at a variable speed.

  The speed control device 13a includes a speed control unit 16a and a timer 17a, and the speed control unit 16a has a plurality of rotational speed set points.

  The timer 17a is configured to periodically change the rotational speed of the motor 15 by providing a function of periodically switching the set point.

  FIG. 4 is a graph for explaining the action performed based on the above configuration along the time axis.

  As shown in FIG. 4, when the rotational speed (N) of the transfer pipe rotating unit 7 is increased by the speed control device 13a, a pulsation is generated in the slurry flow rate (W) following this, and the pulsation imparting means 18 is configured. is doing. The head tank water level (H) rises and falls in correspondence with the pulsation applying means 18.

  The pulsation applying means 18 can change the water head pressure in the head tank 2 by generating pulsation in the slurry flow rate (W). As a result, the pulsation imparting means 18 can pulsate the slurry flow rate to be transferred from the head tank 2 to the dryer 8 even by a change in the water head pressure in the head tank 2.

  For this reason, the pulsation imparting means 18 is pulsated to the flow of the slurry based on the rotation speed (N) of the transfer pipe rotator 7, and pulsation is generated at the head tank water level (H) according to the slurry flow rate (W). .

  Due to the pulsation of the head tank water level, the sedimentation of the slurry is suppressed, and the possibility of causing an error in the opening degree (V) of the water level adjustment valve 5 at the time of measuring the slurry flow rate can be reduced, and the stable operation can be continued. It becomes possible.

  According to this embodiment, the reliability of the instruction | indication of the electromagnetic flowmeter 11 can be improved by reducing the measurement error of the slurry flow volume of a small flow volume. Moreover, it becomes possible to contribute to the continuation of stable operation by reducing the possibility that the slurry transfer pipe 6 is blocked.

Second Embodiment (FIGS. 5 and 6)
FIG. 5 is a block diagram showing the entire system of the slurry transfer apparatus A2 according to the second embodiment, and FIG. 6 is a graph for explaining the action according to the second embodiment along the time axis.

  The difference of the second embodiment from the first embodiment is that the slurry transfer device A2 applied in the first embodiment is replaced with a transfer pipe rotating portion 7, a rotation driving portion 9, a pipe joint 10, and a speed control device 13a. Thus, the circulation pump 4 is provided with a speed control device 13b that performs control to periodically change the rotation speed.

  That is, in the second embodiment, the circulation pump 4 is configured to perform variable speed control by a signal from the speed control device 13b. Similar to the configuration of the speed control device 13a shown in the first embodiment, the speed control device 13b includes a speed control unit 16b and a timer 17b.

  For this reason, the water level of the head tank 2 is periodically raised or raised by periodically changing the rotational speed of the circulation pump 4. As the water level in the head tank 2 rises (or falls), the flow rate of the slurry flowing through the slurry transfer pipe 6 increases (or decreases) due to the water head pressure.

  Then, the flow rate detected by the electromagnetic flow meter 11 is fed back to the water level control device 12, and the water level adjustment valve 5 is operated by an electric signal from the water level control device 12 to control the head tank water level to return to the state before the rise. Is done. Thereby, pulsation can be given to the water level in the head tank 2, and as a result, as shown in FIG. 6, pulsation can be given to the flow rate of the slurry flowing through the slurry transfer pipe 6, and the pulsation imparting means 18b is configured. ing. The pulsation imparting means 18b is a means for imparting pulsation to the water level of the head tank 2, and is configured by periodically changing the rotational speed of the circulation pump 4 by a speed control device 13b having a timer 17b.

  Also according to the present embodiment, the reliability of the instruction of the flow meter can be improved by reducing the measurement error of the slurry flow rate with a small flow rate. Moreover, it becomes possible to contribute to the continuation of stable operation by reducing the possibility that the slurry transfer pipe 6 is blocked.

[Third Embodiment] (FIGS. 7 and 8)
FIG. 7 is a system configuration diagram showing the entire slurry transfer apparatus A3 according to the third embodiment, and FIG. 8 shows an operation performed based on the configuration shown in FIG. In addition, in FIG. 8, the fluctuation | variation effect | action of the water level adjustment valve opening degree V0, the head tank water level H, and the slurry flow rate W is shown as a graph for demonstrating along a time-axis.

  As shown in FIG. 7, in the slurry transfer device A3 of the present embodiment, the water level control device 12 includes a timer 17c instead of the speed control device 13a connected to the circulation pump 4 applied in the first embodiment. Has been applied.

  The timer 17c gives the water level control device 12 a function of periodically oscillating an electric signal. That is, when the water level control device 12 transmits an electrical signal that decreases the valve opening degree of the water level adjusting valve 5, the amount of slurry flowing from the head tank 2 to the waste liquid storage tank 1 becomes small. To rise.

  Due to the rise in the water level of the head tank 2, in this embodiment, as in the second embodiment, pulsation is given to the flow rate of the slurry S flowing through the slurry transfer pipe 6 to constitute the pulsation imparting means 18c.

  The pulsation imparting means 18 c is a means for imparting pulsation to the water level in the head tank 2. The pulsation imparting means 18 c includes a water level control valve 5 that controls the water level in the head tank 2, and a water level adjustment valve 5 according to the slurry flow rate transferred from the head tank 2 to the dryer 8 measured by the electromagnetic flow meter 11. And a timer 17c that gives the water level control device 12 a function of generating an electric signal for periodically changing the valve opening of the water level control valve 5.

  The pulsation imparting means 18 c can impart pulsation to the slurry flow flowing through the slurry transfer pipe 6 by pulsating the water level in the head tank 2.

  And the graph which shows the state which gives the pulsation to the slurry flow volume which flows through the slurry transfer piping 6 in FIG. 8 is shown. As shown in this graph, the water level adjusting valve opening V0 gradually closes smaller at the initial stage of operation, and then gradually increases. Thereafter, the substantially horizontal state is maintained, and after one action cycle, the same action as described above is performed.

  Due to the above action, a pulsation is given to the slurry having a small flow rate, the measurement error of the slurry flow rate can be reduced, and the reliability of the instruction of the flow meter can be improved. Moreover, it becomes possible to contribute to the continuation of stable operation by reducing the possibility that the slurry transfer pipe 6 is blocked.

1 Waste liquid storage tank 2 Head tank 3a Reflux pipe 3b Delivery pipe 4 Circulation pump (waste liquid transfer pump)
5 Water Level Control Valve 6 Slurry Transfer Pipe 7 Transfer Pipe Rotating Unit 8 Dryer 9 Rotation Drive Unit 10 Pipe Joint 11 Flow Meter (Electromagnetic Flow Meter)
12 water level controller 13a speed controller 13b speed controller 14a driven gear 14b tribe gear 15 motor 16a speed controller 16b speed controller 17a timer 17b timer 17c timer 18, 18b, 18c pulsation applying means (pulsation applying means)
A1, A2, A3 Slurry transfer device

Claims (5)

A waste liquid storage tank for storing waste liquid, a head tank for transferring waste liquid by water head pressure, a waste liquid transfer pump for transferring waste liquid from the waste liquid storage tank to the head tank, and a waste liquid returning from the head tank to the waste liquid storage tank A water level adjusting valve for adjusting the water level of the head tank by adjusting the flow rate, a dryer, a slurry transfer pipe for transferring slurry from the head tank to the dryer, and a flow meter for measuring a slurry transfer amount; In a slurry transfer device configured with a water level control device for controlling the valve opening degree of the water level adjustment valve, pulsation imparting means for pulsating the slurry flow rate transferred from the head tank to the dryer by water head pressure is provided. A slurry transfer device. The pulsation imparting means includes a pipe having a spiral groove or a spiral blade formed on the inner surface, a driving device connected to the pipe via a pipe joint and rotating the pipe around an axis, and rotation of the driving device. The slurry transfer device according to claim 1, wherein the slurry is a control device that periodically controls a variable speed. The slurry transfer device according to claim 1, wherein the pulsation imparting means is means for imparting pulsation to a water level of the head tank. The pulsation imparting means includes a speed control device having a function of variable speed control of the rotation speed of the pump and a timer function of periodically performing the variable speed control, and a pump for transferring the waste liquid from the waste liquid storage tank to the head tank. The slurry transfer apparatus according to claim 3. The pulsation imparting means controls a water level control valve for controlling the water level of the head tank and a valve opening degree of the water level adjusting valve according to the flow rate of the slurry transferred from the head tank to the dryer as measured by an electromagnetic flow meter. The slurry transfer apparatus according to claim 3, further comprising: a water level control device that performs the operation, and a timer that gives the water level control device a function of generating an electrical signal that periodically changes the valve opening degree of the water level control valve.

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