JP3059833B2 - Suction device for suspended matter above the liquid surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for sucking floating substances such as oils and paint residue floating on the liquid level of a storage tank for storing waste liquid and the like.

[0002]

2. Description of the Related Art In a conventional suction device, a suction pipe of a pump is flexibly extended from the liquid in a liquid storage tank toward a liquid surface, and a funnel-shaped suction pipe is provided at a tip of the suction pipe to suck floating substances on the liquid surface. The suction port is generally held at a liquid level by a float that follows a change in the level of the liquid level so that the suspended matter can be sucked in efficiently. No. 47-13215, No. 56-
No. 20074, Japanese Utility Model Laid-Open No. 57-9381,
No. 162093).

[0003]

However, the float floating on the liquid surface is liable to fluctuate under the influence of wind waves, and particularly when the liquid surface generates a large swell due to a strong wind such as a typhoon, the float is largely inclined to the left and right or violent. Since the vertical movement is repeated, the suction port may protrude upward away from the liquid level, and a large amount of air alone may be sucked from the suction port without floating substances on the liquid level being sucked. When a large amount of air is sucked in from the suction port, the inside of the suction pipe is completely hollowed out, and the entire suction pipe receives large buoyancy and floats on the liquid surface, thereby causing the float to fall over and so on. At the same time, the mouth may not return to the original state while projecting above the liquid surface, and at the same time, the pump may be emptied and the motor driving the pump may be burned.

In order to prevent the suction port from projecting above the liquid surface, it has been attempted to attach a weight to the suction pipe. However, if the weight is attached, the buoyancy of the float is reduced. There is a possibility that the suction port of the tube is completely submerged in the liquid and only a large amount of liquid is sucked, and the efficiency of sucking suspended matters on the liquid surface is reduced. Therefore, the present invention is to ensure that the suction port provided at the tip of the suction pipe does not fluctuate up and down even if the liquid level of the liquid storage tank swells, and that the liquid is reliably held at the liquid level position where the suspended matter can be efficiently sucked. Another object of the present invention is to prevent burnout of the motor due to empty pumping.

[0005]

In order to solve this problem, according to the present invention, a suction pipe of a pump is flexibly extended from the liquid in a storage tank toward a liquid surface, and is provided at the tip of the suction pipe. In a suction device for a floating substance above the liquid surface provided with a suction port for the floating substance above the liquid surface, a lifting drive device for raising and lowering the suction port to hold the liquid surface position, and vertically movable integrally with the suction port And a control device that outputs a level adjustment signal for raising and lowering the suction port in accordance with a level change of the liquid level detected by the level meter to the lifting / lowering drive device, and an empty pumping state of the pump. An empty-pumping detecting means for detecting, when the empty-pumping state of the pump continues for a certain period of time, only until the empty-pumping state stops, the control device sends the suction port to the lifting drive device. Lowering level adjustment signal Characterized in that it is made to be output.

[0006]

According to the present invention, the suction port provided at the tip of the suction pipe is held at the liquid level by the elevation drive device which raises and lowers the suction port in accordance with the level change of the liquid level. Therefore, unlike the conventional case where the float is held at the liquid surface position by the float floating on the liquid surface, there is no danger that the suction port protrudes above the liquid surface or sinks in the liquid due to the swell generated on the liquid surface. Disappears. In addition, the lifting drive raises and lowers the suction port according to the level change of the liquid level detected by the level meter that moves up and down integrally with the suction port, so that the suction port must be securely held at the liquid level position. Can be. Also, a sudden level change that cannot be immediately responded to by the elevation drive device occurs, and the distance between the level meter and the liquid level exceeds the measurable range of the level meter, and the level adjustment by the level meter becomes impossible. At the same time, when the suction port of the suction pipe protrudes above the liquid level and the pump is emptied, the lifting drive lowers the suction port of the suction pipe, so that the suction port returns to the liquid level position. At the same time, the distance between the level meter that moves up and down integrally with the suction port and the liquid level also returns within the measurable range of the level meter. Is also avoided in a short time.

[0007]

1 is a flow sheet diagram showing an example of a suction device according to the present invention, FIG. 2 is a front view of a suction port provided at the tip of a suction pipe, and FIG. 3 is a side view of the suction port. In the suction device of the present embodiment, the suction pipe 2 of the pump 1 is flexibly extended from the liquid in the storage tank 3 into which the waste liquid of the paint or the like flows toward the liquid surface. There is provided a suction port 4 for sucking a floating substance such as paint residue floating on the surface. In addition,
The suction port 4 is formed with an inverted conical guide slope 6 for facilitating suction of suspended matter from above to below an opening 5 having an opening height of about 200 mm, and is connected to the suction pipe 2. A weight 7 for suppressing the swing is provided on the lower end side.

In the drawing, reference numeral 8 denotes a lifting drive device for vertically moving the suction port 4 so as to maintain the suction port 4 at the liquid level.
A hoist 10 is used to hang the hoist 10 up and down with a chain 9. At the upper end of the suction port 4 suspended by the chain 9, a horizontal member 11 extending parallel to the liquid surface protrudes, and at the tip of the horizontal member 11, a sound wave or an ultrasonic wave emitted from the sound source is stored. A sound wave level meter 12 is provided which measures the time required for the light to reflect off the liquid surface of the liquid tank 3 and returns, and utilizes the fact that the required time is proportional to the level to detect a change in the liquid surface level. I have. 13 is a level meter 12
The level control signal CP for raising and lowering the suction port 4 in accordance with the level change of the liquid level detected by the
The control device 14 for outputting to 0 is an ammeter for detecting the pumping state of the pump 1 by a change in the current value of the motor 15 for driving the pump 1. When the detected current value of the motor 15 continuously falls below the set value for a certain period of time, the control device 13 connects the suction port 4 to the hoist 10 of the lifting / lowering drive device 8 until the current value returns to the set value. A level adjustment signal CQ to be lowered is output.

The control device 13 sets the current value of the motor 15 when the pump 1 is not in the idle pumping state in the storage device in advance, and stores the set value and the current value of the motor 15 detected by the ammeter 14. The value is compared by the arithmetic unit to the motor 1
The microcomputer is configured to output a level adjustment signal CP when the current value of No. 5 is equal to or greater than the set value, and to output a level adjustment signal CQ when determined that the current value is equal to or less than the set value. In addition, the suspended matter on the liquid surface sucked into the suction pipe 2 from the suction port 4 together with the waste liquid in the liquid storage tank 3 is transferred to the filtering device 16 and separated and recovered from the waste liquid. The liquid is returned to the liquid storage tank 3 again through the pipe 17.

When the level of the liquid in the storage tank 3 changes due to the inflow or outflow of the waste liquid, the level change is detected by the level meter 12, and the controller 13 sends the level to the hoist 10 of the lifting drive 8. A level adjustment signal CP corresponding to a change in the liquid level is output, and the signal CP causes the chain 9 of the hoist 10 to unwind or wind up by a required length capable of holding the suction port 4 at the liquid surface position. In this way, the suction port 4 is protruded above the liquid surface under the influence of a wave or the like generated on the liquid surface of the liquid storage tank 3 or is completely immersed in the liquid. And the danger of sucking only liquid is eliminated.

In particular, a level meter 1 utilizing sound waves and ultrasonic waves
No. 2 measures the time required for the sound radiated from the sound source to reach the surface of the measurement level and returns by reflection, and measures the time using the fact that the time required is proportional to the level. The reflectance of sound between the liquid and the liquid is almost 100%, and the level detection accuracy of the liquid level is extremely high, so that the suction port 4 can be reliably held at the liquid level. Moreover, the suction port 4 is formed with an inverted conical guide slope 6 from above to below the opening 5, so that the liquid sucked into the suction pipe 2 from the suction port 4 generates a vortex and the vortex Thus, the suspended matter on the liquid surface is absorbed so as to be involved, so that the efficiency of absorbing the suspended matter is remarkably improved.

However, since the measurable range of the level meter 12 is limited, for example, while the hoist 10 winds the chain 9 with the rise of the liquid level, the liquid level may cause a large swell, For example, when a large amount of waste liquid flows into the liquid storage tank 3 and the liquid level changes from rising to suddenly decreasing, the distance between the level meter 12 and the liquid level becomes so large that the level meter 12 cannot measure it. There is a possibility that the level adjustment signal CP for raising and lowering the suction port 4 in accordance with the level change of the liquid level may not be output, and in that case, the pump 1 may be idle.

However, when the pump 1 is pumped empty,
When the current value of the motor 15 for driving the pump 1 continuously falls below the set value for several seconds to several tens of seconds, the control device 13 unwinds the chain 9 to the hoist 10 and lowers the suction port 4 by the level adjustment signal CQ. Is output, and the suction port 4 automatically returns to the liquid level position at which the pump 1 does not pump, and the distance between the level meter 12 that moves up and down integrally with the suction port 4 and the liquid level is accordingly increased. It returns to within the measurable range of the level meter 12. Then, when the suction port 4 returns to the liquid level position, and the empty state of the pump 1 is eliminated and the current value of the motor 15 for driving the pump 1 exceeds the set value, the control device 13
From the hoist 10 to the level adjustment signal C
Instead of Q, a level adjustment signal CP for raising and lowering the suction port 4 in accordance with the level change of the liquid level detected by the level meter 12 is output. Therefore, there is no possibility that the motor 15 will be burned out by the empty pumping of the pump 1, and the reliability of the suction device is significantly improved.

In the above embodiment, the ammeter 14 for detecting a change in the current value of the motor 15 is used as the empty-pump detecting means. However, the empty-pump detecting means of the present invention is not limited to this. Or a pressure gauge for detecting a change in the internal pressure of the suction pipe 2. A lifting drive 8 for raising and lowering the suction port 4;
May use a cylinder instead of the hoist 10.

[0015]

As described above, according to the present invention, the suction port provided at the tip of the suction pipe is securely held at the liquid surface position without being affected by the swell generated on the liquid surface. In addition, there is an excellent effect that the efficiency of sucking suspended matter on the liquid surface is significantly improved as compared with the conventional case. Also, should the suction port protrude above the liquid level and the pump is in an empty pumping state, the empty pumping state is immediately avoided and the burnout of the motor driving the pump is reliably prevented. There is also an excellent effect.

[Brief description of the drawings]

FIG. 1 is a flow sheet diagram showing an example of a device for sucking suspended matter on a liquid surface according to the present invention.

FIG. 2 is a front view of a suction port provided at a distal end of a suction pipe of the suction device.

FIG. 3 is a side view of a suction port.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pump 2 ... Suction pipe 3 ... Liquid storage tank 4 ... Suction port 8 ... Elevating drive device 12 ... Level meter 13 ... Control device 14 ... Ammeter ( Empty pumping detection means) 15 Motor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C02F 1/40 B01D 17/00-17/12 B01D 21/24

Claims (3)

(57) [Claims] 1. A suction pipe (2) of a pump (1) is flexibly extended from the liquid in a liquid storage tank (3) toward the liquid surface, and floats on the liquid surface at the tip of the suction pipe (2). In a device for sucking suspended matter on the liquid surface provided with a material suction port (4),
A lifting / lowering drive (8) for raising and lowering the suction port (4) to maintain the liquid surface position, a level meter (12) integrally and movably provided with the suction port (4), Total (1
A control device (13) for outputting a level control signal (CP) for raising and lowering the suction port (4) to the lifting / lowering drive (8) in accordance with a level change of the liquid level detected in 2); ) And an empty-pumping detecting means for detecting the empty-pumping state of the pump (1). When the empty-pumping state of the pump (1) continues for a certain period of time, the control device (13) is used only until the empty-pumping state is stopped. ), A level control signal (CQ) for lowering the suction port (4) is output to the lifting drive device (8). . 2. An on-liquid level according to claim 1, wherein said empty pumping detecting means is an ammeter (14) for detecting an empty pumping state by a change in a current value of a motor (15) for driving said pump (1). Floating material suction device. 3. The empty-pumping detecting means is a flow meter that detects an empty-pumping state by a change in the flow rate in the suction pipe (2) or a pressure gauge that detects an empty-pumping state by a change in the pipe pressure. The apparatus for sucking suspended matter on a liquid surface according to claim 1.