JPH0328347Y2 - - Google Patents

Description

[Detailed Description of the Invention] Generally, in a tank of water-soluble contaminated coolant liquid or a treatment tank of waste liquid or sewage, a large amount of foam is generated under certain conditions of the liquid. If these bubbles are left unattended, they will pollute drains and rivers, or be scattered by the wind, causing pollution. Therefore, the liquid in the treatment tank is filtered and an antifoaming solution mixed with an antifoaming agent is constantly added. A defoaming device is installed to spray water onto the liquid surface, or a device to detect the state of foam generation using an electric detection rod or a photocell is installed to automatically control the operation of the defoaming device. This method has the disadvantage of wasting liquid and pump driving power, and in the latter case, it has the disadvantage of not being able to accurately detect bubbles generated on the liquid surface, which constantly fluctuates and fluctuates due to the inflow of contaminated coolant liquid.

The present invention deals with this problem, and includes a liquid float 2 in which a hollow vertical rod 1 is installed, and a treatment tank for foaming liquid such as coolant liquid so as to guide the upper part of the hollow vertical rod so as to be able to move up and down. a guide means provided on the side;
It is provided with a guide bush 4 for operating a proximity switch in the center through which a hollow vertical rod 1 is slidably passed, and a plate-shaped float 3 made of foamed plastic that is pushed up and supported by the bubbles generated on the liquid surface of the processing tank. , a stopper means for supporting a plate-shaped float 3 fitted into the hollow vertical rod 1 so as to be able to rise and fall at a permissible height above the liquid surface of the generated bubbles is provided at the lower end of the hollow vertical rod, and is engaged with the stopper means. A space is provided between the disc-shaped float 3 and the liquid float 2 in which the generated bubbles can enter so that the disc-shaped float can be pushed up, and when the disc-shaped float 3 rises to the operating height of the defoaming device, the guide bush 4, an upper proximity switch 6 which issues an activation signal for the defoaming device; and a lower proximity switch 6, which issues a stop signal for the defoaming device by means of the guide bushing 4 when the disc-shaped float 3 engages with the stopper means. 7 is installed inside the hollow vertical rod 1.

In such a bubble generation state detection device, it is desirable to reduce the outer diameter of the float due to the strength and installation area of the foamed plastic disc float. Since the guide bush 4 for operating the proximity switch occupies most of the space, the weight of the disc-shaped float 3 with the guide bush is greater than the weight of foam having the same volume. Therefore, it should not be possible to levitate the disk-shaped float by the bubbles generated on the liquid surface, but various experiments have shown that it is possible to lift the disk-shaped float by the bubbles while it remains approximately horizontal. The floating state of the float hardly changes even when the liquid surface of the processing tank is undulated or stirred. This is understood to be because the bubbles generated on the liquid surface aggregate due to the adsorption force of the bubbles, and the disc-shaped float is lifted by the bubbles that are successively generated on the liquid surface due to wave motion or stirring.

Therefore, the amount of bubbles in the processing tank can be accurately detected by the proximity switches 6 and 7 installed above and below inside the hollow vertical rod 1. The proximity switch was used because if a micro switch is used, it requires a force of at least 10 grams to open and close the switch, which could cause the float to tilt and engage frictionally with the hollow vertical rod 1, reducing detection accuracy. This is due to the fact that it is difficult to make the switch watertight.

An embodiment of the present invention will be described below with reference to the drawings.
1 is a non-metallic hollow vertical rod installed on a spherical liquid float 2; 3 is a circular disc-shaped float molded from styrene foam resin with a guide bush 4 made of a thin metal plate attached to the center as a metal adjoining body; , and if no bubbles are generated on the liquid surface L of the processing tank 5, in which the guide bush 4 is fitted into the hollow vertical rod 1 so as to be able to move up and down,
The lower end of the guide bush of the disc-shaped float 3 is the liquid float 2
engages the upper end of the Therefore, the upper end of the liquid float 2 forms a stopper means for supporting the plate-shaped float 3 at an allowable height A above the liquid surface of the generated bubbles, and the size of the liquid float 2 is determined accordingly.

6 and 7 are upper and lower proximity switches installed in the hollow vertical rod 1, and the upper proximity switch 6 is the height H at which the disc-shaped float 3 is required to operate the defoaming device 8, as shown by the chain line C.
The lower proximity switch 7 is closed by the guide bush 4 when the plate-shaped float engages with the upper end of the liquid float 2 as shown by the chain line D. The antifoaming device 8 is configured to supply the antifoaming liquid in the tank T with a suction pump 11 through valves 10 to dispersion pipes 9 with porous nozzles arranged in parallel on the liquid surface in the processing tank 5. ,
Proximity switches 6 and 7 conduct or disconnect a starter operating solenoid 12 (FIG. 2) of pump 11.

FIG. 2 shows an example of the control electric circuit for the solenoid 12, including an operating circuit (a) for a relay 1CR controlled by a switch 6, a solenoid circuit (b) held and conducted by the relay, and a solenoid cutoff relay 2CR controlled by a switch 7. includes an operating circuit c.

A switch operating piece 13 is attached to the upper end of the hollow vertical rod 1, which is supported by a guide means 5a appropriately attached to the treatment tank 5 side so as to be able to rise and fall while maintaining a vertical state at all times. Upper and lower micro-switches 14 and 15, which are respectively switched by the switch actuating pieces 13 at the upper and lower limits, are attached to the processing tank side, and a device etc. for increasing or decreasing the filtration capacity of contaminated coolant liquid by the signals emitted by the switches 14 and 15, respectively, is provided. Under automatic control, the hollow vertical rod 1 and its supporting float 2 function as a liquid level gauge that keeps the vertical fluctuations of the liquid level L within a permissible fluctuation range.

According to the above configuration, when the height of the generated bubbles B above the liquid level is less than the allowable height A, the float 3 is moved to the lower limit position D.
Since switch 7 is closed in the event of
CR conducts and opens the normally closed relay contact 2CR of circuit A, and even if the upper switch 6 is accidentally closed, the defoaming device 8
This eliminates the fear that the system will operate. From this state, the height of the generated bubbles B above the liquid level increases, and the lower switch 7
When the float 3 is pushed up by the bubbles until it opens,
The relay 2CR of circuit C becomes non-conductive, and the relay contact 2CR of circuit A returns to the normally closed position as shown. Therefore, when the float 3 floats up to the upper limit position C and closes the upper switch 6, the relay 1CR of circuit A becomes conductive and is self-held by closing the normally open relay contact 1CR of circuit B, and the solenoid 12 becomes conductive. to start the defoaming device 8.

When the float 3 is lowered by its own weight from the upper limit position C to the lower limit position D by the operation of the defoaming device 8 and the lower switch 7 is closed, the relay 2CR becomes conductive as described above and opens the normally closed relay contact 2CR of circuit A. , stop the antifoam device from operating.

The plate-shaped float 3 in the illustrated embodiment is a molded product of styrene foam resin.

According to the present invention, the plate-shaped float 3 and the liquid float 2
During this time, bubbles that aggregate due to the bubble adsorption phenomenon can constantly enter the disk-shaped float to push it up, until the disk-shaped float 3 with the guide button for actuating the proximity switch becomes heavier than the same volume of bubbles. By making the outer shape of the disc-shaped float small, the defoaming device can be automatically controlled by the upper and lower proximity switches 6 and 7, and it is truly effective as a device that can directly and accurately detect the amount of foam generated regardless of fluctuations in the water level. It is.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of an embodiment of the present invention, and FIG. 2 is an electrical circuit diagram thereof. 1...Hollow vertical rod, 2...Liquid float, 3...
Disk-shaped float, 4... guide bush, 5... treatment tank,
6, 7...Proximity switch, 8...Defoaming device, L...
...Liquid level, B...Bubble generated.

Claims (1)

[Scope of utility model registration request] A liquid float 2 in which a hollow vertical rod 1 is installed, a guide means provided on the side of a processing tank for a foaming liquid such as a coolant liquid so as to guide the upper part of the hollow vertical rod so that it can move up and down, and a hollow vertical rod. 1 is provided in the center with a guide bush 4 for operating the proximity switch that is slidably penetrated therethrough, and a plate-shaped float 3 made of foamed plastic that is pushed up and supported by the bubbles generated on the liquid surface of the processing tank. A stopper means is provided at the lower end of the hollow vertical rod to support the disk-shaped float 3 fitted on the rod 1 so as to be able to rise and fall at a permissible height above the liquid surface of generated bubbles, and the disk-shaped float engaged with the stopper means. 3 and the liquid float 2, a space is provided in which the generated bubbles can enter to push up the plate-shaped float 3, and when the plate-shaped float 3 rises to the operating height of the defoaming device, the guide bush 4 an upper proximity switch 6 which issues an activation signal for the defoaming device, and a lower proximity switch 7 which issues a stop signal for the defoaming device by means of the guide bush 4 when the disc-shaped float 3 engages with the stopper means. A device for detecting a bubble generation state on a liquid surface, characterized in that it is installed inside a hollow vertical rod 1.