JP2014228509A - Slurry supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately acquire flow rate of slurry using a flow meter of a type that is not appropriate for flow measurement of the slurry.SOLUTION: A slurry pressure feed unit 5 (slurry supply device) supplies iron powder slurry accumulated in a slurry accumulation unit 21 while adjusting the flow rate. The slurry pressure feed unit 5 includes: a thickening liquid accumulation unit 22 (comparison liquid accumulation unit) for accumulating thickening liquid (comparison liquid for measurement) whose property affecting the pump delivery is aligned to the iron powder slurry; a two-liquid interlock type pump 23 for delivering the iron powder slurry accumulated in the slurry accumulation unit 21 and the thickening liquid accumulated in the thickening liquid accumulation unit 22 under the same condition with separate systems; and a thickening liquid flow meter 42 for measuring the delivery flow rate of the thickening liquid.

Description

  The present invention relates to a slurry supply apparatus.

  In civil engineering, slurries such as iron powder slurry, cement milk, grout, and mortar are widely used. For example, iron powder slurry is supplied to the ground in order to purify the ground contaminated with VOC, and cement milk and mortar are supplied to the ground to strengthen the soft ground. Patent Document 1 describes a method in which fine bubbles are included in an iron powder slurry containing a thickener, and the iron powder slurry containing the fine bubbles is pumped.

  In general, the supply of slurry is managed based on the flow rate flowing through the supply path. For this reason, a flow meter for measuring the flow rate of the slurry is provided in the slurry supply path. There are various types of flow meters. For example, differential pressure type flow meters, electromagnetic flow meters, ultrasonic flow meters, vortex flow meters, Coriolis flow meters, positive displacement flow meters, area flow meters, thermal flow meters, and turbine flow meters are known.

JP 2004-332230 A

  When the above flow meter is used for measuring the flow rate of slurry, the following problems may occur.

  For example, an ultrasonic flowmeter can measure the flow rate of slurry in a non-contact manner and has the advantage that it is not affected by density and viscosity, but contains bubbles because ultrasonic waves are blocked in the presence of bubbles. It can be said that it is not suitable for measuring the flow rate of slurry.

  Although Coriolis flow meters and turbine flow meters can measure the flow rate of slurry, it is necessary to place pipes and turbines in the flow path. Maintenance is required. Furthermore, when measuring the flow rate of the iron powder slurry containing the iron powder, the error increases due to the precipitation of the iron powder.

  The electromagnetic flow meter has an advantage that the flow rate of the slurry can be measured without coming into contact with the fluid, but a measurement error becomes large for a slurry containing a magnetic material (iron powder) such as an iron powder slurry.

  This invention is made | formed in view of such a situation, The objective is to acquire the flow volume of the said slurry accurately using the kind of flowmeter which is not suitable for the flow volume measurement of a slurry.

  In order to achieve the above-mentioned object, the present invention is a slurry supply device that supplies the slurry stored in the slurry storage section with the flow rate adjusted, and the properties that affect pumping are aligned with the slurry. The comparison liquid storage part for storing the comparison liquid for use, the slurry stored in the slurry storage part, and the measurement reference liquid stored in the comparison liquid storage part are sent out in different systems under the same conditions. And a comparison liquid flow meter for measuring the flow rate of the measurement reference liquid.

  According to the present invention, the measurement comparative liquid whose properties affecting the delivery by the interlocking pump are aligned with the slurry to be supplied is used, and the interlocking pump uses the slurry and the measurement comparative liquid under the same conditions. To send. For this reason, the flow rate of the measurement reference liquid sent from the interlocking pump is the same as the flow rate of the slurry. Therefore, by selecting a measurement liquid that can be measured with a comparative liquid flow meter, the flow rate of the slurry can be obtained even if the type of the comparative liquid flowmeter is not suitable for measuring the flow rate of the slurry.

  In the above-described slurry supply device, it is preferable that the slurry supply apparatus includes a circulation flow path forming member that forms a circulation flow path for circulating the measurement reference liquid sent from the interlock pump to the comparison liquid storage unit. In this configuration, since the circulating flow path is formed by the circulating flow path forming member, the measurement comparison liquid sent from the interlocking pump is circulated to the comparative liquid storage section along the circulating flow path. Thereby, the measurement comparison liquid is circulated and used, and the flow rate of the slurry can be continuously measured with a limited amount of the measurement comparison liquid.

  In the above-described slurry supply apparatus, it is preferable to have a slurry flow meter that measures the delivery flow rate of the slurry delivered from the interlocking pump. In this configuration, it is possible to determine the deterioration of the measurement comparison liquid based on the correlation between the flow rate of the slurry measured by the slurry flowmeter and the flow rate of the measurement reference liquid measured by the comparison liquid flowmeter.

  In the above-described slurry supply apparatus, the slurry is an iron powder slurry in which a thickener is added to water and iron powder is dispersed, and the comparative liquid for measurement has a viscosity by adding a thickener to water. Is a thickening liquid arranged in the iron powder slurry, and the comparative liquid flowmeter is preferably an electromagnetic flowmeter. In this configuration, the flow rate of the iron powder slurry can be measured using an electromagnetic flow meter.

  ADVANTAGE OF THE INVENTION According to this invention, the flow volume of the said slurry can be acquired accurately using the kind of flowmeter which is not suitable for the flow volume measurement of a slurry.

It is a figure explaining the in-situ purification system which has a pumping apparatus. It is a block diagram explaining a slurry pumping part. It is a figure explaining a slurry storage part and a thickening liquid storage part. It is a figure explaining a 2 liquid interlocking type pump. It is a figure explaining an electromagnetic flowmeter. It is a figure explaining the detection part which an electromagnetic flowmeter has.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, an in-situ purification system that purifies the contaminated ground in the original position by supplying iron powder slurry to the contaminated ground contaminated with VOC is taken as an example.

  An in-situ purification system 1 shown in FIG. 1 has a pressure feeding device 2 and a purification construction machine 3. And these pumping apparatus 2 and the purification construction machine 3 are connected so that communication with the sequencer board which is not illustrated is possible, and operate | moves according to the control signal from a sequencer board.

  The pressure feeding device 2 is a device that manufactures, stores, and pressure feeds iron powder slurry and bubbles, and adjusts the discharge amount of the iron powder slurry and bubbles according to the control information transmitted from the sequencer panel. The pumping device 2 includes a bubble pumping unit 4 and a slurry pumping unit 5. The bubble pumping unit 4 is a part that foams a foaming material to produce bubbles, and pumps the produced bubbles. Moreover, the slurry pumping part 5 is a part which pumps an iron powder slurry and a thickening liquid by another system | strain, and is equivalent to the slurry supply apparatus which concerns on this invention. The slurry pumping unit 5 will be described in detail later.

  The purification construction machine 3 is an apparatus that excavates the contaminated ground G to be purified and mixes the iron powder slurry and bubbles sent from the pressure feeding device 2 with the contaminated ground G. The illustrated purification construction machine 3 includes a main body 11, a leader 12, a stirring auger 13, a stirring rod 14, a stirring blade 15, a merging pipe 16, and a line mixer 17.

  The main body 11 is provided with a driver's seat where an operator is seated, a caterpillar for movement, and the like. The leader 12 is a member that supports the stirring rod 14 movably along the vertical direction. The leader 12 is attached to the front of the main body 11 by a stay 12a or the like. The stirring auger 13 is a part that generates power for rotating the stirring rod 14. The stirring auger 13 moves in the vertical direction along the leader 12 as the stirring rod 14 moves.

  The stirring rod 14 is constituted by a cylindrical steel pipe. And the stirring blade 15 is attached to the lower end part of the stirring rod 14, and the swivel joint 14a is attached to the upper end part. The swivel joint 14a is supplied with a mixture of bubbles and iron powder slurry from the line mixer 17 (hereinafter referred to as bubble slurry). Then, the bubble slurry supplied to the swivel joint 14a flows down inside the stirring rod 14 and is discharged from the lower end portion to the contaminated ground G. The stirring blade 15 is rotated together with the stirring rod 14.

  The merge pipe 16 is a part that joins the bubbles sent from the pressure feeding device 2 through the bubble supply pipe 18 and the iron powder slurry sent from the pressure feeding device 2 through the slurry supply pipe 19, for example, a Y-shaped tube or a T-shape. Composed by a tube. The joining pipe 16 is provided immediately before the swivel joint 14 a together with the line mixer 17, and bubbles and iron powder slurry are joined before the stirring rod 14. The line mixer 17 is disposed between the merging pipe 16 and the swivel joint 14a, and is a part that mixes the bubbles after the merging and the iron powder slurry to form a bubble slurry.

  Next, the slurry pumping unit 5 will be described in detail. As shown in FIG. 2, the slurry pumping unit 5 includes a slurry storage unit 21, a thickened liquid storage unit 22, a two-liquid interlocking pump 23, and a flow rate measurement unit 24.

  The slurry storage unit 21 is a part that stores the iron powder slurry, and also has a function of manufacturing the iron powder slurry in the present embodiment. The slurry storage part 21 shown to Fig.3 (a) has the storage container 21a, the mixer 21b, etc. FIG. One end of a slurry suction tube 25 is inserted into the storage container 21a. The slurry suction pipe 25 is a tubular member for forming a suction flow path for the iron powder slurry from the slurry reservoir 21 to the two-liquid interlocking pump 23, and the other end is a suction port of the two-liquid interlocking pump 23 ( It is connected to a first suction port 33a) to be described later. Moreover, the exit end of the water pipe 21c is arrange | positioned in the position which faces the upper end opening of the storage container 21a.

  An iron powder slurry is manufactured by storing water in the storage container 21a, adding a thickener, and dispersing the iron powder while stirring the mixer 21b. The iron powder slurry to be produced is one whose iron powder concentration is adjusted according to the construction conditions such as pollutants and concentration, and has a high concentration in terms of reducing the amount of mud during supply to the contaminated ground G ( It is desirable to use an iron powder concentrated slurry). In addition, regarding the slurry storage part 21, you may not have a manufacturing function of an iron powder slurry. That is, the iron powder slurry manufactured separately may be stored.

  The thickening liquid reservoir 22 is a part for storing a nonmagnetic and conductive thickening liquid. As shown in FIG. 3B, the thickening liquid storage unit 22 has a storage container 22 a, a mixer 22 b, and the like, similar to the slurry storage unit 21. One end of the thickening liquid suction pipe 26 and one end of the thickening liquid reflux pipe 27 are inserted into the storage container 22a. The thickening liquid suction tube 26 is a tubular member for forming a suction flow path for the thickening liquid from the thickening liquid reservoir 22 to the two liquid interlocking pump 23, and the other end is a suction port of the two liquid interlocking pump 23 ( It is connected to a second suction port 33c) to be described later. The thickening liquid recirculation tube 27 is a tubular member for forming a recirculation flow path for the thickening liquid from the flow rate measuring unit 24 (thickening liquid flow meter 42) to the thickening liquid storage unit 22, and the other end to the flow measuring unit 24. It is connected. In addition, also in the thickening liquid storage part 22, the exit end of the water pipe 22c is arrange | positioned in the position which faces the upper end opening of the storage container 22a.

  The thickening liquid is a liquid in which the viscosity, which is one of the properties affecting pump delivery, is equal to the viscosity of the iron powder slurry, and corresponds to the measurement comparison liquid. The reason why the thickening liquid is non-magnetic and conductive is that an electromagnetic flowmeter is employed as the thickening liquid flowmeter 42 (see FIG. 2) of the flow measurement unit 24. Such a thickening liquid is manufactured by adding the thickener used at the time of manufacture of an iron powder slurry to the water stored by the storage container 22a, for example. Note that the thickened liquid reservoir 22 may not have a manufacturing function. That is, the thickening liquid manufactured separately may be stored.

  The two-liquid interlocking pump 23 shown in FIG. 2 individually flows the iron powder slurry stored in the slurry storage unit 21 and the thickening liquid (measurement comparison liquid) stored in the thickening liquid storage unit 22 at the same flow rate. It is a device that feeds pressure to the measurement unit 24.

  As shown in FIG. 4, the two-liquid interlocking pump 23 has a motor unit 32 and a pump unit 33 mounted on a plate frame 31. The motor unit 32 is a part that generates power in the two-liquid interlocking pump 23. The pump unit 33 is a part that obtains power from the motor unit 32 and pumps the target liquid (iron powder slurry, thickening liquid). Therefore, the pump unit 33 includes a first suction port 33a for sucking the iron powder slurry, a first discharge port 33b for discharging the iron powder slurry, a second suction port 33c for sucking the thickening solution, and a first suction port for discharging the thickening solution. 2 discharge ports 33d.

  The other end of the slurry suction tube 25 is connected to the first suction port 33a, and the other end of the thickening solution suction tube 26 is connected to the second suction port 33c. One end of the first connection pipe 28 is connected to the first discharge port 33b, and one end of the second connection pipe 29 is connected to the second discharge port 33d. Accordingly, the iron powder slurry is sucked into the first suction port 33 a through the slurry suction tube 25, and then discharged from the first discharge port 33 b and flows through the first connection tube 28. Similarly, the thickening liquid is sucked into the second suction port 33 c through the thickening liquid suction tube 26, and then discharged from the second discharge port 33 d and flows through the second connection tube 29. As shown in FIG. 2, the first connection pipe 28 and the second connection pipe 29 are disposed between the two-liquid interlocking pump 23 and the flow rate measuring unit 24, and the iron powder slurry and the thickening liquid are supplied. Guide to the flow rate measuring unit 24.

  Next, the flow rate measuring unit 24 will be described. As shown in FIG. 2, the flow rate measuring unit 24 includes a slurry flow meter 41 and a thickening liquid flow meter 42. The slurry flow meter 41 is a device that measures the flow rate of the iron powder slurry, and corresponds to the slurry flow meter according to the present invention. The thickening fluid flow meter 42 is a device that measures the flow rate of the thickening fluid, and corresponds to the comparative fluid flow meter according to the present invention. The other end of the first connection pipe 28 is connected to the inlet of the slurry flow meter 41, and the other end of the second connection pipe 29 is connected to the inlet of the thickening liquid flow meter 42. Thereby, the iron powder slurry is introduced into the slurry flow meter 41, and the thickening liquid is introduced into the thickening liquid flow meter 42.

  In the present embodiment, both the slurry flow meter 41 and the thickening liquid flow meter 42 are electromagnetic flow meters. As shown in FIG. 5, the electromagnetic flow meter 43 includes a measuring unit 44 that measures the flow rate of the fluid, and a recording unit 45 that records the measurement result of the measuring unit 44 on a sheet or the like. The measurement unit 44 includes a housing 44a, a nonmagnetic pipe 44b, and a flow rate detection unit 44c. The housing 44a is configured by a box-shaped body. And the nonmagnetic pipe 44b is arrange | positioned in the state which penetrates the front and back of the housing | casing 44a. The flow rate detection unit 44c is attached in a state of being close to the peripheral surface of the nonmagnetic pipe 44b.

  As shown in FIG. 6, the flow rate detector 44c includes an excitation coil 44d, an excitation power supply 44e, a capacitive electrode 44f, and an amplifier 44g. The exciting coil 44d is a part that generates magnetic lines of force, and is composed of a pair of coils that face each other with the nonmagnetic pipe 44b interposed therebetween. The excitation power supply 44e is a power supply for causing the excitation coil 44d to generate an electromagnetic field (lines of magnetic force), and is electrically connected to the excitation coil 44d via a conducting wire. The capacitive electrodes 44f are portions for taking out an electromotive force proportional to the flow velocity of the fluid, and a pair of capacitive electrodes 44f are provided at positions rotated 90 degrees around the axis of the nonmagnetic pipe 44b with respect to the pair of exciting coils 44d. Yes. The amplifier 44g is a part that amplifies the electromotive force extracted by the capacitive electrode 44f.

  In the flow rate detector 44c, when an excitation signal is output from the excitation power supply 44e to the excitation coil 44d, an electromagnetic field is generated by the excitation coil 44d in the cross-sectional direction of the nonmagnetic pipe 44b. When a conductive liquid (iron powder slurry or thickening liquid) flows in the electromagnetic field, an electromotive force proportional to the flow velocity is generated in a direction perpendicular to the flow. The electromotive force is taken out by the capacitive electrode 44f and amplified by the amplifier 44g to obtain a measurement signal corresponding to the flow velocity. The obtained measurement signal is input to the recording unit 45 and drawn as a waveform on the chart paper or stored in the memory as digital data.

  Here, the electromagnetic flow meter 43 measures the flow velocity based on the electromotive force proportional to the flow velocity of the fluid. For this reason, when the fluid is magnetized, an error occurs in the obtained flow velocity. Therefore, in this embodiment, the non-magnetic and conductive thickening liquid is sent out in a separate system under the same conditions as the iron powder slurry (conditions where the flow velocity is equal), and the thickening liquid obtained by the thickening liquid flowmeter 42 The flow rate is regarded as the flow rate of the iron powder slurry.

  As shown in FIG. 2, the iron powder slurry whose flow rate has been measured is pumped to the merging pipe 16 through the slurry supply pipe 19 connected to the outlet of the slurry flow meter 41. Further, the thickened liquid whose flow rate has been measured is circulated to the storage container 22 a of the thickened liquid storage section 22 through the thickened liquid circulation tube 27. For this reason, the other end of the thickening liquid reflux tube 27 is connected to the outlet of the thickening liquid flow meter 42. The thickened liquid whose flow rate has been measured is mixed with the thickened liquid in the recycle container 22a and used repeatedly. The thickening liquid circulation tube 27 forms a circulation flow path for circulating the thickening liquid to the storage container 22a, and thus corresponds to a circulation flow path forming member.

  In the pumping device 2 of the present embodiment configured as described above, the viscosity of the thickening liquid is aligned with the viscosity of the iron powder slurry, and the iron powder slurry and the thickening liquid are subjected to the same condition by the two-liquid interlocking pump 23. Sending out. Thereby, the flow rate of the thickening liquid sent from the two-liquid interlocking pump 23 becomes the same as the flow rate of the iron powder slurry. Since the thickening liquid is a non-magnetic and conductive liquid, the flow rate can be measured with high accuracy by the electromagnetic flow meter 43. Therefore, even if it is the electromagnetic flowmeter 43 which is not suitable for the measurement of an iron powder slurry by measuring the flow volume of a thickening liquid with the thickener liquid flowmeter 42 comprised with the electromagnetic flowmeter 43, the flow volume of an iron powder slurry is changed. It can be acquired with high accuracy.

  Further, in the pressure feeding device 2, the thickened liquid after the flow rate measurement is circulated to the thickened liquid storage unit 22 through the thickened liquid circulation tube 27. As a result, the thickener is circulated and used, and the flow rate of the iron powder slurry can be continuously measured with a limited amount of the thickener.

  Moreover, in this pumping device 2, since the delivery flow rate of the iron powder slurry is measured by the slurry flow meter 41, the delivery flow rate of the iron powder slurry and the delivery flow rate of the thickening liquid measured by the thickening fluid flow meter 42 are Correlation can be obtained. For example, the flow rate difference between the delivery flow rate of the iron powder slurry and the delivery flow rate of the thickening liquid can be acquired in time series. Thus, by acquiring the flow rate difference in time series, it is possible to determine the deterioration of the thickening liquid.

  For example, when the delivery flow rate of the thickening liquid is excessively increased even though the delivery flow rate of the iron powder slurry is within a predetermined error range, the viscosity of the thickening solution is increased due to temperature rise or deterioration. It is assumed that it has declined. On the other hand, when the delivery flow rate of the thickening liquid is excessively decreased, it is assumed that the viscosity of the thickening liquid is increased due to evaporation of moisture or the like. As described above, the deterioration determination of the thickening liquid can be performed based on the flow rate difference between the delivery flow rate of the iron powder slurry and the delivery flow rate of the thickening liquid.

  The above description of the embodiment is for facilitating the understanding of the present invention, and does not limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof. For example, you may comprise as follows.

  In the above-described embodiment, the thickening liquid is exemplified as the measurement comparison liquid, but the present invention is not limited to this. It is sufficient if the slurry to be supplied and the property affecting the pumping are the same liquid. In other words, any liquid having a property (for example, viscosity or density) that can obtain the same flow rate when the two-liquid interlocking pump 23 is fed under the same conditions as the slurry to be supplied.

  Further, the slurry to be supplied is not limited to the iron powder slurry. For example, cement milk, grout, and mortar may be used. The grout is not limited to a cement type and may be a glass type.

  Moreover, although the electromagnetic flowmeter 43 was illustrated regarding the slurry flowmeter 41 and the thickening liquid flowmeter 42, other types of flowmeters may be used. For example, a Coriolis flow meter, a turbine flow meter, and an ultrasonic flow meter may be used. In this case, it is only necessary to select a measurement liquid that can accurately measure the flow rate with the flow meter used. For example, when a Coriolis flow meter is used, a measurement comparison liquid having the same density as the slurry to be supplied may be used. Moreover, when using an ultrasonic flowmeter, what is necessary is just to use the same kind of slurry as the slurry to be supplied, which has been degassed.

  Moreover, in the above-mentioned embodiment, although the structure provided with the slurry flow meter 41 and the thickening liquid flow meter 42 was illustrated, about the slurry flow meter 41, it is not necessary to provide. That is, it is sufficient that at least the comparative liquid flow meter according to the present invention is provided.

  Further, regarding the interlocking pump, the two-liquid interlocking pump 23 is exemplified, but other types of pumps can be used as long as the slurry to be supplied and the comparison liquid for measurement can be sent out in different systems under the same conditions. There may be.

  Moreover, regarding the slurry supply apparatus, the slurry pumping unit 5 provided in the purification construction machine 3 is illustrated, but other types of apparatuses may be used as long as the apparatus supplies the slurry.

DESCRIPTION OF SYMBOLS 1 ... In-situ purification system, 2 ... Pressure feeding apparatus, 3 ... Purification construction machine, 4 ... Bubble pressure feeding part, 5 ... Slurry pressure feeding part, 11 ... Main part of purification construction machine, 12 ... Leader, 12a ... Stay, 13 ... Stirring Auger, 14 ... stirring rod, 14a ... swivel joint, 15 ... stirring blade, 16 ... confluence pipe, 17 ... line mixer, 18 ... bubble supply pipe, 19 ... slurry supply pipe, 21 ... slurry reservoir, 21a ... slurry reservoir Storage container, 21b ... mixer for slurry storage part, 21c ... water pipe for slurry storage part, 22 ... thickener storage part, 22a ... storage container for thickener storage part, 22b ... mixer for thickener storage part, 22c ... increase Water pipe of the mucus reservoir, 23 ... 2 liquid interlocking pump, 24 ... Flow rate measuring part, 25 ... Slurry suction pipe, 26 ... Thickened liquid suction pipe, 27 ... Thickened liquid reflux pipe, 28 ... First connection pipe, 29 ... 2 connection pipes, 31 ... plate-like frame of a two-liquid interlocking pump, 32 ... motor unit, 33 ... pump unit, 33a ... first suction port, 33b ... first discharge port, 33c ... second suction port, 33d ... first 2 discharge ports, 41 ... slurry flow meter, 42 ... thickening liquid flow meter, 43 ... electromagnetic flow meter, 44 ... measuring unit of electromagnetic flow meter, 44a ... housing of measuring unit, 44b ... non-magnetic pipe, 44c ... flow rate detection 44d ... excitation coil, 44e ... excitation power supply, 44f ... capacitive electrode, 44g ... amplifier, 45 ... recording part of electromagnetic flow meter, G ... contaminated ground

Claims (4)

A slurry supply apparatus that adjusts the flow rate and supplies the slurry stored in the slurry storage unit,
A comparison liquid storage section for storing a measurement comparison liquid whose properties affecting pump delivery are aligned with the slurry;
An interlocking pump for sending the slurry stored in the slurry reservoir and the measurement reference liquid stored in the comparison fluid reservoir in a separate system under the same conditions;
A slurry supply apparatus comprising a comparison liquid flow meter for measuring the flow rate of the measurement reference liquid.   2. The slurry supply according to claim 1, further comprising a circulating flow path forming member that forms a circulating flow path for circulating the measurement reference liquid sent from the interlocking pump to the comparative liquid storage unit. apparatus.   The slurry supply apparatus according to claim 1, further comprising a slurry flow meter that measures a delivery flow rate of the slurry delivered from the interlocking pump. The slurry is an iron powder slurry obtained by adding a thickener to water and dispersing iron powder,
The measurement comparison liquid is a thickening liquid whose viscosity is aligned with the iron powder slurry by adding a thickening agent to water,
The slurry supply apparatus according to claim 1, wherein the comparison liquid flow meter is an electromagnetic flow meter.

Images