JP2003320371A - Apparatus for cleaning and recovering coolant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus which eliminates foul odor in a coolant discharge vessel in such a way that oil floating on the surface of a coolant in the vessel is separated and recovered, and that the coolant is refluxed after aerobic and anaerobic bacteria propagating in the vessel are killed. <P>SOLUTION: The apparatus is constituted of a processing tank 9 with a built-in heater provided with a level gauge having a first and a second electrodes L1, L2 detecting an aqueous liquid layer 13 and an oil layer 14, and with an automatic relief valve FV; a coolant returning pipe 17 continuously feeding the upper layer liquid and the floating oil in the coolant discharge vessel 1 to the processing tank 9 and having a vertical part 19 and a horizontal part 20 for holding a liquid to be treated in the processing tank for a specified time; and a floating oil recovery pipe 21 which is opened at and connected to a position lower than the horizontal part of a returning pipe 17 and between the first and the second electrodes, and having an electromagnetic valve 22 which is opened for a specified period of time by an oil-layer detecting signal from the second electrode. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purification / recovery device for separating floating oil of a coolant contained in a receiving tank to prevent spoilage and bad odor.

[0002]

2. Description of the Related Art Machine oil mixed in the coolant (coolant) of a grinding machine or a cutting machine in a machining factory forms an oil film in the coolant drainage storage tank to cover the liquid surface, causing the coolant to spoil and produce a foul odor. Is known to do. That is, the liquid coolant in the storage tank consumes oxygen in the liquid by aerobic bacteria, and then anaerobic bacteria (sulfate-reducing bacteria) propagate, thereby causing a bad odor. As a device to prevent the bad odor and spoilage of the coolant, a device that adsorbs and removes floating oil by a belt, air aeration, filter filtration and separation by specific gravity difference, hollow fiber membrane filtration, etc. are used. Has not reached its purpose.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides an apparatus for recovering a coolant liquid by heating floating oil in the process of specific gravity separation to sterilize aerobic bacteria and anaerobic bacteria in the liquid and recover the coolant liquid. is there. Further, the present invention provides an apparatus capable of reducing energy cost by heat-exchanging a heat-sterilized coolant from which floating oil is separated and removed from a coolant to be treated supplied to a treatment tank.

[0004]

The device of the present invention is a level meter having a drainage tank for storing a coolant drainage from a machine tool or the like, and first and second electrodes for detecting a water liquid layer and an oil layer level. And a processing tank with a built-in heater equipped with an outside air release valve that closes at a predetermined water level in the tank, and a pump that is connected to a pump that sucks the upper layer liquid in the coolant drainage tank together with the floating oil and that opens above the processing tank. A processing liquid supply pipe and a vertical portion and a horizontal portion, which are opened at a lower portion in the processing tank and have a height for allowing the liquid to be treated to stay in the tank for a predetermined time, are connected to the coolant drainage tank. Floating oil provided with a coolant return pipe and a solenoid valve which is opened below the horizontal part of the return pipe and between the first electrode and the second electrode of the level meter and which is operated by an oil layer detection signal from the second electrode. Composed of a collection pipe By maintaining the liquid temperature in the treatment tank at a predetermined temperature and sterilizing aerobic and anaerobic bacteria in the drainage tank and returning it to the drainage tank by the natural fall method, the bad odor generated from the drainage tank is eliminated. This is to prevent and automatically collect the floating oil. A heating temperature of 70 to 90 ° C. is usually sufficient, and a drainage tank having an internal volume of up to 1000 L is effective for several tens hours of operation. The device of the present invention has an advantage of low power cost because the recovered coolant is returned by the natural dropping method, but the energy cost can be further reduced by connecting the supply pipe and the coolant return pipe through the heat exchanger.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a case where a heat exchanger is provided to improve the thermal efficiency of the apparatus. 1 is a used coolant drainage tank attached to a machine tool or the like, 2 is a coolant liquid layer, 3 is an upper layer liquid, 4 is floating oil, 5 is a suction float floating on the liquid surface, 6 is a suction hose, and 7 is A suction pump, 8 is a supply pipe connected to the pump and opens at an upper portion 10 of the processing tank 9. 11 is the temperature inside the tank 7
A heater for heating and holding at 0 ° C. or more, LG is an electrode type level meter, and is an earth electrode L0, a first electrode L1, a second electrode L2.
Is equipped with. The FV is a float type outside air release valve that operates at an operating water level of 16 or higher in the tank and shuts off the inside of the tank from the outside air. 12 is a drain valve.

13 is a liquid layer in the tank, 14 is an oil layer, 15
Is an interface and 16 is a liquid surface. Reference numeral 17 denotes a return pipe, the lower end 18 of which is opened at the lower part of the tank and has a vertical portion 19 and a horizontal portion 20 each having a predetermined height, and communicates with the drainage tank 1 via the heat exchanger H. The height of the horizontal part, that is, the length of the vertical part is such that the liquid to be treated is retained in the tank for a sufficient time and the level of the returning liquid 1 during operation
6 is defined. That is, the return liquid flows when the liquid level reaches the horizontal portion, and the return liquid does not flow out when the liquid level becomes low. Reference numeral 21 denotes a floating oil recovery pipe, which is opened and connected 21a at a position communicating with the oil layer 14 between the first electrode and the second electrode, and the solenoid valve 22 is opened by the output of the second electrode L2 of the level meter for a predetermined time. It will be closed later. 23 is a floating oil recovery tank.

[0007]

[Example] Coolant drainage from a cutting machine (19-2
2 ℃) Drainage from the tank (capacity 300 L) at 10 L / 1 hour while the processing machine is operating, continuously empty processing tank (effective volume 7
L). The heater was energized at the water level D in FIG. 2, the temperature reached 80 ° C. after about 40 minutes, the water surface 16 was moved to the A position, and the float valve FV was activated to seal the inside of the tank. In the initial state, the floating oil and the coolant liquid are not separated in layers, but while the coolant liquid from the return pipe is being returned, they are gradually separated and the thickness of the oil layer 14 increases, and the interface B
From C to C or less, the first electrode detects the liquid layer and the second electrode detects the oil layer.
2 was activated and the floating oil was discharged. Solenoid valve 2 after about 2 minutes
2 automatically closes. The float valve FV opens due to the decrease in the liquid level A, and the inside of the tank becomes atmospheric pressure. The return coolant does not flow out because the liquid level A is lower than the horizontal position of the return pipe 20, but the coolant drainage is continuously supplied, so the liquid level rises again and the above operation is repeated.

Operation for 6 hours a day (60 L treatment) was continued for 5 days. After 10 hours, 0.5 L of floating oil was collected and 3
On the day, the floating oil film on the surface of the coolant drainage tank was no longer visible and the rotting odor was reduced. After 5 days (30 hours),
The rotten odor was almost completely removed. During this time, the temperature of the processing tank was maintained at 80 degrees, and the heat exchanger (6000 Kca
The temperature of the supply liquid from 1) was maintained at 60 ° C, and the temperature of the liquid returned to the drainage tank 1 was maintained at 40 ° C.

Pretreatment liquid (liquid temperature 20
C.) and a treatment liquid (liquid temperature 32.degree. C.) after 1 hour and 30 minutes of operation, the sulfate-reducing bacteria were measured by the clean water test method (2001) VIII-4, 3 and 2, and the pretreatment liquid was 2.4. × 1
0 ⁸ MPN / 100 mL at which was, a processing liquid 1.7 ×
It was 10 ⁵ MPN / 100 mL.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of the device

FIG. 2 is a configuration diagram of a main part showing a liquid level change.

[Explanation of symbols]

1 Coolant drainage tank 2 Coolant liquid layer 3 Upper layer liquid 4 floating oil 5 suction float 6 hose 7 suction pump 8 supply pipes 9 Processing tank 10 Tank top 11 heater 12 drain valve LG level meter L0, L1, L2 electrodes FV float type air valve 13 liquid layers 14 oil layer 15 Interface 16 Liquid level A, B, C, D Fluctuating liquid level 17 Return tube 18 bottom 19 Vertical part 20 Horizontal part 21 Floating oil recovery pipe 22 Solenoid valve

Claims (3)

[Claims] 1. A processing tank with a built-in heater, comprising a coolant drainage tank, a level meter having first and second electrodes for detecting a water liquid layer and an oil layer level, and an outside air release valve for closing at a predetermined water level, A liquid to be treated supply pipe which is connected to a pump for sucking the upper layer liquid in the coolant drainage tank together with the floating oil and which is opened to the upper part of the treatment tank, and which is opened to the lower part in the treatment tank to store the liquid to be treated in the tank A coolant return pipe having a vertical portion and a horizontal portion having a height for retaining for a predetermined time and communicating with the coolant drainage tank, a first electrode of the level meter and a first electrode of the level meter which are below the return pipe horizontal portion. A coolant liquid purification and recovery device comprising a floating oil recovery pipe provided with a solenoid valve which is opened between the two electrodes and which is activated by an oil layer detection signal from the second electrode. 2. The coolant liquid purifying and collecting apparatus according to claim 1, wherein the supply pipe and the coolant return pipe pass through the heat exchanger. 3. The coolant liquid purifying and recovering apparatus according to claim 1 or 2, wherein the liquid temperature in the processing tank is maintained in the range of 75 to 90 ° C.