JPH0347550A - Concentration apparatus for regenerating washing residue of unhardened concrete - Google Patents

Abstract

PURPOSE:To continuously perform concn. by providing a shutoff valve to the pipeline for supplying sludge water connected to a feed pipe and providing a washing nozzle to a casing. CONSTITUTION:A washing pipeline 92a is connected to a washing nozzle 91 and a washing pipeline 92b is connected to a feed pipe 70 through pipeline 26 and pressurized washing water is supplied to the washing nozzle 91 or the feed pipe 70. The separated liquid B separated from a sludge component K contains the already hydrated component and component considered not to be hydrated of the cement with low specific gravity in sludge water as suspended substances to be discharged from an outlet 86 through the first discharge port 56 and sent to a separated liquid storage tank 37 through a pipeline 27. The sludge water KH is stored in a concn. control tank 30. By this method, regeneration efficiency can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technology for recycling the washing residue of ready-mixed concrete that is generated when a transport vehicle, a plant mixer, etc. is washed with a ready-mixed concrete brand. More specifically, the sludge water obtained by wet-classifying fresh concrete washing residue to remove gravel and sand is continuously separated by centrifugal force into high-concentration sludge water whose main component is unhydrated cement and a separated liquid. This invention relates to a concentration device for recycling fresh concrete washing residue.

[Prior Art] The present applicant has extracted unhydrated cement from the washing residue of ready-mixed concrete, which conventionally had little use and had no choice but to throw it away, without drying it, and mixed it with new cement. A patent application was filed for a method and device for recycling the washing residue of ready-mixed concrete, which can be combined to produce high-quality concrete (Japanese Patent Application No. 3171-1983).
22).

In this regeneration method, the washed concrete residue is first wet-classified using a classifier, gravel and sand are removed, and sludge water is extracted. Next, a concentrator using centrifugal force continuously separates this sludge water into high-concentration sludge water whose main component is unhydrated cement and a separated liquid, and the supernatant water of this separated liquid is used to create high-concentration sludge water. Dilute and adjust the sludge water to a specified concentration. Finally, this sludge water is vibrated and pulverized using a vibrating ball mill to obtain a slurry of fine sludge particles in which a portion of unhydrated cement appears on the surface.

[Problems to be Solved by the Invention] However, when the above-mentioned concentrator continuously concentrates sludge water, the solid content of the sludge water accumulates in the concentrator, and this tends to change over time and solidify. Conventional thickeners do not have special cleaning equipment, so the entire equipment for recycling fresh concrete washing residue must be periodically stopped for cleaning. As a result, there were problems in that the efficiency of regenerating the washing residue decreased and the number of cleaning steps for the concentrator increased.

The purpose of the present invention is to prevent the solid content of sludge water from accumulating and solidifying in the outer barrel bowl and inner barrel screw, and to prevent the solid content of sludge water from accumulating and solidifying in the outer barrel bowl and inner barrel screw, and to prevent the solid content of sludge water from accumulating and solidifying in the outer shell bowl and inner barrel screw, without having to stop the thickener and periodically clean the inside of the machine. An object of the present invention is to provide a concentration device for regenerating the washing residue of fresh concrete, which can be concentrated by washing.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the present invention will be explained based on FIG. 1 corresponding to an embodiment.

The concentration device for regenerating fresh concrete washing residue of the present invention includes:
A feed pipe 70 for introducing sludge water H obtained by wet-classifying fresh concrete washing residue to remove gravel GR and sand S, a cylindrical part 51 and a conical part 52 are integrally formed, and both ends are connected by bearings 53 and 54. An outer body bowl 5o that is rotatably supported and is provided with a first discharge port 56 on the large diameter side and a second discharge port 57 on the small diameter side, and a screw blade 61 that encloses the feed pipe 70 is fixed. A discharge port 62 is provided in the body, and an inner body screw 6 is rotatably supported within the cylindrical portion 51 and the conical portion 52.
0, and a gear box 80 that provides a rotational difference between the outer barrel bowl 5o and the inner barrel screw 60 in the same direction so that the rotational speed of the inner barrel screw 60 is slightly smaller than the rotational speed of the outer barrel bowl 5o; It is equipped with a casing 85 that encloses the outer bowl 5o and is provided with a separated liquid outlet 86 on the first discharge chamber 56 side and a high concentration sludge water outlet 87 on the second discharge chamber 57 side. be.

The characteristic first configuration is that a cutoff valve 90 is provided in the sludge water H supply conduit 26 connected to the feed vibe 7o to stop the supply of the sludge water H, and the casing 85 is provided with a A cleaning nozzle 91 directed toward the cylindrical portion 51 and the conical portion 52 of 50 is provided, and a cleaning conduit 92 is piped to supply pressurized cleaning water to the cleaning nozzle 91 and the feed vibe 70. A switching valve 93 is provided in the cleaning pipe line 92 to switch the cleaning water to either the cleaning nozzle 91 or the feed vibe 70 .

In addition, the characteristic second configuration is that a return pipe 94 is provided in the supply pipe 26, and when the sludge water pressure in the supply pipe 26 reaches a predetermined value, the sludge water H is returned to the return pipe 94.
There is a safety valve 95 that allows the water to flow to the water.

Moreover, the third characteristic configuration is that the cutoff valve 90 and the switching valve 93 are electromagnetic valves, and are program-controlled so that the cutoff valve 90 is periodically closed for a predetermined time and the switching valve 93 is switched. It is in.

A fourth feature of the configuration is that the cutoff valve 90 is a solenoid valve, and the gearbox 80 is provided with a load sensor 96, and when the load sensor 96 detects a load of a predetermined value or more, the cutoff valve 90 is activated. It is located where it is configured to close.

[Function] When cleaning the concentrator 20, the shutoff valve 90 is closed, the switching valve 93 is opened, and cleaning water is injected into the concentrator 20 to clean the concentrator 20. During this time, the sludge water H is returned to the previous process through the return pipe 94.

Further, when the load on the concentrator 20 becomes excessive, the shutoff valve 90 is closed to reduce the concentration load of sludge water in the concentrator of the gear box 80.

[Embodiment] Next, an embodiment of the present invention will be described in detail based on the drawings.

As shown in FIG. 1, fresh concrete washing water 12 generated when washing a fresh concrete transport vehicle or a fresh concrete mixer vehicle 11 is passed through a classifier 10 consisting of a wedge filter 13 and a spiral classifier 14 into gravel GR and sand. It is wet classified into S and sludge water H. That is, the wash water 12 is collected in a collection tank 15, and is supplied to the wedge filter 13 through a pipe 16 by a pump 15a provided at the bottom of the collection tank 15, and the gravel GR is removed. Gravel GR is stored in tank 13a.

The washing water from which the gravel GR has been removed is supplied to the spiral classifier 14 and is classified into sand S and sludge water H. Sand S is stored in tank 14b.

The sludge water H is a suspension in which water is used as a dispersion medium and sludge consisting of unhydrated cement and hydrated cement is used as a dispersed phase. The supernatant water of this sludge water H is pipe 1
4a and is returned to the recovery tank 15.

The supernatant water in the recovery tank 15 is sent to the sludge tank 24 through the pipe 17 and the cyclone 18 by the pump 15b. The remaining sand is separated by a cyclone 18 and returned to the spiral classifier 14.

A liquid level switch 15c is turned on when the water level in the recovery tank 15 reaches a predetermined level, driving the pump 15b to rotate.

While stirring the sludge water H in the sludge water tank 24 at a low speed with the agitator 24a to prevent the sludge water H from hardening, the sludge water I at the bottom with a sludge concentration of about 5 liters is passed through the supply pipe 26 by the pump 25 to the thickener 20. sent to. 24b is a liquid level switch, and when the sludge water tank 24 reaches a predetermined water level,
It turns on and drives the pump 25 to rotate.

The concentrator 20 includes an outer bowl 50, an inner screw 60, a feed vibe 70, a gear box 80, and a casing 85.
It consists of a centrifugal sedimentation machine equipped with The feed vibe 70 is connected to the sludge water H supply pipe 26 described above, and the sludge water 1-I is introduced therein. Outer body bowl 50
A cylindrical portion 51 and a conical portion 52 are integrally formed, both ends are rotatably supported by bearings 53 and 54, and a first discharge port 56 is provided on the large diameter side and a second discharge port 57 is provided on the small diameter side, respectively. provided.

The inner barrel screw 60 is provided with a discharge port 62 in a body that encloses the feed vibe 70 and has a screw blade 61 fixed thereto, and is rotatably supported within the cylindrical portion 51 and the conical portion 52 . The casing 85 encloses the outer bowl 50 and has a separated liquid outlet 86 and a second discharge hole 5 on the side of the first discharge hole 56.
A high concentration sludge water outlet 87 is provided on each side.

Gear box 80 consists of a planetary gear set driven by pulley 81. As shown in detail in FIGS. 2 and 3, this gear box 80 connects the outer bowl 50 and the inner screw 60 so that the rotational speed of the inner screw 60 is slightly smaller than the rotational speed of the outer bowl 50. Drive in the same rotational direction while giving a rotational difference. As shown in FIG. 3, the sludge water H sent by the pump 25 during this drive is transferred from the feed vibe 70 of the concentrator 20 to the inner barrel screw 6.
When the sludge water is introduced into the sludge water, the sludge whose main component is unhydrated cement having a high specific gravity is deposited on the inner wall surface of the cylindrical portion 51 of the outer bowl 50 due to centrifugal force. The screw blade 6 of the inner barrel screw 60 is used for this sludge.
1, it moves to the conical part 52 as shown by the arrow,
The sludge water passes through the second discharge port 57 and is discharged from the outlet 87 in the form of highly concentrated sludge water KH having a sludge concentration of 60 to 70%.

Here, it is preferable that the centrifugal force generated by the rotation of the outer barrel bowl 50 and the inner barrel screw 60 is in the range of 100 to 4000 G. Particularly preferably 800 to 1500G. If it is less than 100G, it becomes difficult to separate sludge water H into high concentration sludge water KH and separation liquid B described below. When the force exceeds 4000G, the sludge K becomes cylindrical part 51.
Alternatively, it may adhere to the inside of each conical portion 52 and not be easily discharged. If the force is in the range of 800 to 1500G, even more efficient separation can be achieved.

Next, the characteristic configuration of the concentrating device of this embodiment will be explained.

A return pipe 94 is provided in the sludge water H supply pipe 26 connected to the feed vibrator 70.
4, a normally closed safety valve 95 is provided. safety valve 9
When the sludge water pressure in the pipe line 26 reaches a predetermined value, the valve 5 is opened to allow the sludge water H to flow back into the pipe line 26.

Further, the supply pipe 26 is provided with a cutoff valve 90 consisting of an electromagnetic valve that stops the supply of the sludge water H, and the casing 8
5 is provided with three cleaning nozzles 91 directed toward the cylindrical portion 51 and the conical portion 52 of the outer body bowl 50. These cleaning nozzles 91 have cleaning pipes 92a connected to the feed vibrator 7.
A cleaning pipe line 92b is connected to each of the cleaning pipe lines 92b through the pipe line 26. In this example, the conduit 92a communicates with the conduit 92b, and supplies pressurized cleaning water to the cleaning nozzle 91 or the feed vibe 70, respectively.

A switching valve 93a is provided in the cleaning pipe 92a, and a switching valve 93a is provided in the cleaning pipe 92a.
b has a switching valve 93b, and the supply pipe 26 has a switching valve 93b.
c are provided respectively. These switching valves 93a to 93
Reference numeral c is a solenoid valve, which is opened and closed together with the above-mentioned cutoff valve 90 by a control signal from a controller 97. The controller 97 has a built-in timer 98, and periodically closes the cutoff valve 90 for a predetermined period of time to close the switching valve 93a, 9.
Program control is performed to switch between 3b and 93c.

Furthermore, the gear box 80 is provided with a load sensor 96,
The detection output of this load sensor 96 is connected to a controller 97. The controller 97 controls the shutoff valve 90 to close when the load sensor 96 detects a load equal to or greater than a predetermined value.

On the other hand, the separated liquid B separated by the sludge content contains the low hydration components of cement with low specific gravity and components that are considered not to be hydrated in the sludge water.
The first discharge port 5
6 and is discharged from the outlet 86 and sent to the separation liquid storage tank 37 through the conduit 27.

The high concentration sludge water KH discharged from the outlet 87 is transferred to the conduit 3.
1 and stored in the concentration adjustment tank 30 located directly below the outlet 87. The supernatant water of the separated liquid in the separated liquid storage tank 37 is supplied by the pump 33 through the pipe line 34 to the concentration adjustment tank 30, and is stirred by the agitator 30a to dilute the high concentration sludge water KH to sludge water J of a predetermined concentration. be done.

In this example, the sludge concentration is 30% to 40% based on the measured value of the sludge concentration at the outlet 30b of the adjustment tank 30.
Adjusted within the range of %. When the sludge concentration reaches a predetermined concentration, the pump 35 sends sludge water J having a predetermined concentration to the vibrating ball mill 40 through the pipe line 36.

This sludge water J is vibrated and pulverized by a vibrating ball mill 40. In this example, the vibratory ball mill 40 consists of a first stage mill 40a and a second stage mill 40b. The vibration-pulverized slurry M is sent to the slurry storage tank 42, and is stored therein while being prevented from hardening by an agitator 42a. The dispersed phase of this slurry M becomes sludge fine particles with a higher content of unhydrated cement. By sending the required amount of the sludge particles to the plant mixer using the metering pump 43 and adding them to new cement to prepare fresh concrete, the washing residue of the fresh concrete can be effectively used.

The separated liquid stored in the separated liquid storage tank 37 is pumped by a pump 38.
It passes through a conduit 39 and is used for cleaning fresh concrete deposits on a ready-mixed concrete transport vehicle or a ready-mixed concrete mixer vehicle 11 or the like. Here, the hydrated components of the cement contained in the separated liquid and the components considered not to be hydrated are adsorbed to gravel and sand and stored in the tank 13a or 14a, respectively.

Next, the characteristic operation of the concentrating device of this embodiment will be explained.

(a) A timer 98 in the cleaning controller 97 of the concentrator is used to periodically close the cutoff valve 90 for a predetermined period of time and switch valve 93a;
The operating intervals and operating times of these valves 90.93a, 93b, and 93c are set so as to switch between valves 93b and 9.3c. The operation interval and operation time are determined as appropriate depending on the concentration amount of the sludge water H, etc.

When the gear box 80 is in operation, the controller 97 closes the cutoff valve 90 for a predetermined time, opens the switching valve 93a, and switches the two switching valves 93b,
93c at the same time or either one. As a result, as shown in FIG. 2, the cleaning water is jetted from the cleaning nozzle 91 toward the outside of the outer bowl 50 through the cleaning conduit 92a, and the solid content of the accumulated sludge water is washed away.

Further, the cleaning water also flows vigorously into the feed pipe 70 via the cleaning conduit 92b and the supply conduit 26, and the discharge port 62
Discharge from the screw vane 61 and inner body screw 6
Clean the inside of 0.

When the cutoff valve 90 is closed, the water pressure in the supply pipe 26 increases, the safety valve 95 opens, and the sludge water H is returned to the sludge water tank 24 via the return pipe 94.

When the predetermined time for cleaning has elapsed, the controller 97
closes the switching valves 93a and 93b and opens the cutoff valve 90 and the switching valve 93c.

(b) Overload prevention of the thickener When the thickener 20 is in steady operation, the rotational resistance of the outer bowl 50 or the inner barrel screw 6o increases due to variations in solid content in the sludge water, etc. When a load of a predetermined value or more is applied to the gear box 8o, the controller 97 closes the cutoff valve 90 based on a detection signal from the load sensor 96, and continues driving the gear box 80. Since sludge water H does not flow in from the feed pipe 70, the load is reduced. If necessary, the switching valves 93a, 93b, and 93c are opened to inject cleaning water into the concentrator 20 from the cleaning nozzle 91 or the feed pipe 70.

When this load becomes less than a predetermined value, the controller 97 opens the cutoff valve 90 based on the detection signal from the load sensor 96.

Although three switching valves are provided in the above example, the number can also be reduced by using a three-way valve or the like. Further, the cleaning conduit may be provided separately for the cleaning nozzle and the feed pipe.

Further, although an example has been shown in which the cutoff valve and the switching valve are configured with electromagnetic valves, valves that can be opened and closed manually may also be used.

[Effects of the Invention] As described above, in the past, the entire regeneration equipment for cleaning residue from fresh concrete had to be periodically stopped for maintenance, but according to the present invention, the entire regeneration equipment can be stopped. It is possible to wash the solid content of sludge water accumulated in the thickener without having to do so. As a result, the sludge water can be concentrated continuously and to a high concentration, so that the sludge water concentration efficiency is high, the concentration can be easily adjusted, and the regeneration efficiency of the entire apparatus can be improved.

Furthermore, since the system is configured to automatically stop the supply of sludge water when the rotational load on the thickener becomes excessive, the service life of the thickener can be extended.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a fresh concrete washing residue regeneration device including a concentration device according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view of the main part of the concentrator during cleaning. FIG. 3 is an enlarged sectional view of the main part of the concentrator during concentration. H: Sludge water, KHz high concentration sludge water B: Separated liquid, L: Supernatant water, J: Sludge water of specified concentration, 0 0 6 0 7 0 0 1 2 53°6 7 0 1 2 0 0 5 6 Slurry classification machine, concentrator, supply pipe, concentration adjustment tank, separated liquid storage tank, vibrating ball mill, outer shell bowl, cylindrical part, conical part, 54: bearing, first discharge port, second discharge port, inner shell Screw screw vane, discharge port, feed pipe, gear box, casing, separated liquid outlet, 7 0 1 2 3 4 5 6 7 High concentration sludge water outlet, shutoff valve, cleaning nozzle, cleaning pipe, switching valve, return pipe road, safety valve, load sensor, controller. 324

Claims (1)

[Scope of Claims] 1) A feed pipe that introduces sludge water obtained by wet-classifying fresh concrete washing residue to remove gravel and sand, and a cylindrical portion and a conical portion are integrally formed, and both ends are rotated by bearings. an outer body bowl that is supported by the main body and has a first discharge port on the large diameter side and a second discharge port on the small diameter side, and a discharge port in the body that encloses the feed pipe and has a screw blade fixed to it an inner barrel screw rotatably supported within the cylindrical portion and the conical portion; A gear box that provides a rotation difference so as to be slightly smaller than the speed, and a gear box that encloses the outer bowl and has a separated liquid outlet on the first discharge port side and a high concentration sludge water outlet on the second discharge port side. A concentrator for regenerating washing residue of fresh concrete, comprising: a cutoff valve installed in a sludge water supply conduit connected to the feed pipe to stop the supply of the sludge water; a cleaning nozzle provided in the outer body bowl and directed toward the cylindrical portion and the conical portion of the outer body bowl; a cleaning pipe piped to supply pressurized cleaning water to the cleaning nozzle and the feed pipe; and the cleaning water. 1. A concentrating device for regenerating fresh concrete washing residue, comprising: a switching valve for switching the supply of fresh concrete to either the washing nozzle or the feed pipe. 2) The product according to claim 1, wherein a return pipe is provided in the supply pipe, and a safety valve is provided to allow the sludge water to flow into the return pipe when the sludge water pressure in the supply pipe reaches a predetermined value. Concentration equipment for recycling concrete washing residue. 3) The fresh concrete according to claim 1 or 2, wherein the cutoff valve and the switching valve are electromagnetic valves, and are program-controlled so as to periodically close the cutoff valve and switch the switching valve for a predetermined period of time. Concentration device for washing residue regeneration. 4) The cutoff valve is a solenoid valve, and the gearbox is provided with a load sensor, and the cutoff valve is configured to close when the load sensor detects a load of a predetermined value or more. Concentration equipment for recycling fresh concrete washing residue. 5) The concentrator according to claim 1, wherein the centrifugal force generated by the rotation of the outer barrel bowl and the inner barrel screw is 10
A concentrating device for regenerating fresh concrete washing residue, characterized in that it has a power of 0 to 4000G.