JPH07258876A - Washing device - Google Patents

Abstract

PURPOSE:To enhance an efficiency of separating a water-insoluble soln. and washing liquid, to enable continuous washing and to improve washing efficiency by providing a washing device for cyclically using an aq. detergent with an oil separating tank for separating the water-insoluble soln. included in the washing liquid and a filter for separating the emulsified water-insoluble soln. CONSTITUTION:The washing liquid 13 is filled into a washing tank 2 mounted at this washing device 1 and is heated and held. The contaminated washing liquid contg. the oil-components overflowing from the washing tank 2 are introduced into the oil separating tank 15 according to washing of the parts in a washing cage 12 immersed in this washing liquid 13, by which the greater part of the oil-components are removed. The washing liquid is thereafter sent to a filter house 4 by a pump 3 and the emulsified oil-components are passed through a filter cartridge 5 and are removed. The removed oil-components are recirculated to the washing tank 2. The washing liquid in such a case is formed of N-methyl-2-pyrrolidone contg. <=30% water. The washing tank 2 is preferably provided with an ultrasonic transmitter 8 to improve the washing effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an aqueous detergent, especially N-
Methyl-2-pyrrolidone (hereinafter referred to as "NMP") /
The present invention relates to a cleaning apparatus that uses a water-based cleaning agent to remove non-water-soluble liquids such as oils, fats, machine oils, and cutting oils that adhere to the surfaces of metal parts such as electric parts and precision parts.

[0002]

2. Description of the Related Art NMP / water-based cleaning agents have been proposed as an alternative cleaning agent for 1,1,1-trichloroethane for metal degreasing cleaning applications.
1-trichloroethane is a solution wash, whereas NM
It is considered that the P / water-based cleaning agent has a mechanism mainly for peeling oil stains from the surface of the object to be cleaned by physical force such as ultrasonic waves and fluid collision. Therefore, the NMP / water-based cleaning agent itself generally has a low dissolving power in a non-water-soluble oil, and most of the oil content needs to be separated and removed out of the cleaning system as a liquid or droplets, and partly as an emulsified cleaning liquid. is there. Therefore, how efficiently the cleaning liquid and the oil can be efficiently separated from the emulsion once formed directly affects the efficiency of the cleaning device. Therefore, a technique for quickly separating the cleaning liquid and the oil component is important.

Conventionally, when an NMP / water-based cleaning agent is used to remove oil stains or the like on an object to be cleaned, oil and impurities remain in the cleaning tank in the form of an emulsion. Therefore, it was necessary to update the cleaning liquid after treating a certain number of batches or a certain amount of the object to be cleaned. The method of renewal is to extract all or part of the cleaning liquid and refill it with new cleaning liquid, or to temporarily extract all or part of the cleaning liquid to an auxiliary tank, etc., and then install an external metal filter to separate the oil in the cleaning liquid. It was necessary to use a large-scale oil-water separator consisting of a pump, etc.

[0004]

However, these methods have a problem that the former is inferior in working efficiency and the latter cannot obtain sufficient oil separation property. Therefore, an object of the present invention is to efficiently separate a non-water-soluble liquid and a cleaning liquid in a cleaning device that circulates and uses an NMP / water-based cleaning agent to improve the workability of cleaning and improve the cleaning efficiency. .

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present inventors have introduced a contaminated cleaning liquid flowing out of a cleaning tank directly into an oil separation tank in a cleaning apparatus using a cleaning agent. By separating the oil, further emulsifying it with a filter provided in the latter stage of the oil separation tank, separating the oil that could not be separated in the separation tank, and returning the cleaning liquid to the cleaning tank, continuous cleaning work can be performed. The present invention has been achieved by finding that it is possible and that work efficiency is significantly improved.

That is, according to the present invention, a cleaning tank having a means for removing the non-water-soluble liquid from a part to which the non-water-soluble liquid adheres, a means for extracting a part of the aqueous cleaning liquid from the cleaning tank, and a circulating supply of the cleaning liquid. And a filter for separating the non-water-soluble liquid from the emulsified cleaning liquid, and an oil separation tank for separating most of the non-water-soluble liquid from the cleaning liquid accompanied by the non-water-soluble liquid. Is a cleaning device.

[0007]

When the object to be cleaned such as the metal parts to which the non-water-soluble oil adheres is cleaned by the cleaning apparatus of the present invention, the oil peeled off in the cleaning tank is liquid in the water-based cleaning liquid such as NMP / water-based cleaning agent. When mixed as a drop or an emulsion and a new object to be cleaned is put into the cleaning tank as it is, contamination is not removed and remains, or oil is separated and retained in the cleaning tank. Therefore, the cleaning liquid containing this emulsion or droplets is transferred to the oil separation tank, and is retained for a predetermined time to float most of the oil by the action of gravity, and the separated oil overflows from the upper layer of the cleaning liquid in the oil separation tank. Remove to outside of cleaning equipment. The emulsified cleaning solution containing oil that cannot be completely separated in the oil separation layer is further introduced into a filter house having a hydrophilic surface to permeate only the aqueous solution to block the oil content, thereby providing a transparent cleaning solution containing no oil content. Obtainable. The oil separated in the filter house is continuously or intermittently discharged to the outside of the cleaning device. The cleaning liquid from which the oil content has been removed in this manner is circulated again in the cleaning tank, so that the cleaning device can perform the cleaning operation without replacing the cleaning liquid.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the embodiment shown in FIGS. 1 and 2, but the present invention is not limited to this embodiment.

The cleaning tank 2 placed on the cleaning apparatus 1 is filled with the cleaning liquid 13 up to the upper side of the outer peripheral portion of the cleaning tank 2. The cleaning liquid is a water-based cleaning agent, preferably NMP / water-based cleaning agent. Further, the NMP / water-based detergent is NMP containing no water or containing 30% by weight or less of water, and an oil separation promoter and / or an antioxidant may be added. The oil separation promoter is an alkali metal salt of an aliphatic carboxylic acid, and for example, an aliphatic alkali metal salt of potassium acetate, sodium acetate, sodium lactate or the like can be used. The antioxidant is added to the NMP / water-based cleaning agent in order to obtain long-term stability of the cleaning solution.
Fatty acid metal soap, phenol-based antioxidant, sulfur-based antioxidant, phosphorus-based antioxidant, etc. are used. Specifically, zinc-based soap such as zinc stearate and zinc laurate, barium stearate, etc. Barium-based soap, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-
Butyl-4-ethylphenol, stearyl-β-
(3,5-di-t-butyl-4-hydroxyphenyl)
Monophenols such as propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-
t-butylphenol), 4,4'-thiobis- (3-
Methyl-6-t-butylphenol), 4,4'-butylidene- (3-methyl-6-t-butylphenol), and other bisphenol-based compounds, dilaurylthiopropionate, dimyristylthiodipropionate, distearylthiopro Examples include sulfur type antioxidants such as pionate, and phosphorus type antioxidants such as triphenyl phosphite, diphenyl isodecyl phosphite and phenyl diisodecyl phosphite.

The cleaning liquid 13 is heated and maintained at the cleaning temperature by a heater 9 provided at the bottom of the cleaning tank 2. The washing temperature is not particularly limited and may be in the range of 0 to 100 ° C, but is usually 25 to 70 ° C. There is no merit in cooling the cleaning liquid in the cleaning tank, and it is preferable to avoid excessively high temperature from the viewpoint of safety. Further, a cooling pipe 11 is provided above the cleaning tank 2 to prevent evaporation of the cleaning liquid. The cleaning tank 2 can be connected to a mechanism (not shown) such as an air cylinder, an oil cylinder, or a chain device,
A cleaning basket 12 that allows the object to be cleaned to be formed so as to be vertically or horizontally movable or swingable is immersed. An object to be cleaned (not shown) is placed in the cleaning basket 12. The object to be cleaned is not particularly limited, but metal, plastic, glass,
These include mechanical parts, precision parts, optical parts, and electrical / electronic parts made of ceramics and their composite materials.
The non-water-soluble liquid adhering to the object to be cleaned is a liquid at the operating temperature of the cleaning device, and is oil or fat that does not dissolve in the cleaning liquid, and specific examples include spindle oil, refrigerator oil,
Dynamo oil, turbine oil, machine oil, internal combustion engine lubricating oil for ships, internal combustion engine lubricating oil for land, cylinder oil, marine engine oil, gear oil, cutting oil, insulating oil, automatic transmission oil, compressor oil, hydraulic oil, rolling Oils, lubricating oils for sliding guide surfaces, etc. may be mentioned. Further, the cleaning tank 2 is provided with an ultrasonic oscillator 8 to improve the cleaning effect.

The contaminated cleaning liquid 13 containing oil that overflows from the cleaning tank is introduced into the first oil separation tank chamber 15a through the communication pipe 14. The oil separation tank 15 is composed of three chambers as shown in FIGS. 1 and 2, and its volume may be the same as that of the cleaning tank. In the oil separation tank first chamber 15a, the oil component is separated into the upper layer and the emulsified cleaning liquid is two-phase separated into the lower layer, and the upper layer oil is discharged out of the system by the waste oil pipe 7 installed in the upper part of the oil separation tank first chamber 15a. It On the other hand, the cleaning liquid that has been emulsified by the remaining oil is introduced into the oil separation tank second chamber 15b through the opening provided in the lower bottom portion, and from the liquid surface of the oil separation tank second chamber 15b to the oil separation tank third chamber 15c. Overflow. Oil separation tank No. 3
A liquid level gauge 17 for detecting a liquid level drop is installed in the chamber 15c, and is interlocked with a power switch of the pump 3 to prevent an idle operation of the pump 3, and a warning sound, a warning lamp and the like (not shown). A device to warn the operator is attached.

The cleaning liquid from which most of the contaminated oil content has been removed by the oil separation tank 15 is supplied to the filter house 4 by the pump 3, and the oil content that has been emulsified in the cleaning liquid and entrained therein is separated and removed by the filter cartridge 5. The filter used is preferably a hydrophilic glass fiber-based material, a cellulose fiber-based material, an acetyl cellulose-based material, etc. Among them, the cellulose fiber-based material has good performance,
It is also inexpensive. The shape of the filter is not limited, but it is a woven fabric or a non-woven fabric, and a cartridge made of a non-woven fabric formed into a cylindrical shape is preferable because it is easy to handle. The throughput can be increased by installing one or more cartridges in the filter house 4. A waste oil valve 6 that is opened or closed manually or automatically is provided on the upper part of the filter house 4, and the waste oil is discharged out of the system continuously or intermittently.
A pressure gauge 16 is connected between the pump 3 and the filter house 4, and by monitoring the instruction, the contamination status of the filter cartridge 5 can be judged and the necessity of filter replacement or cleaning regeneration can be known. The pressure gauge 16 is linked to the opening / closing or opening of the waste oil valve 6, and when the pressure exceeds a certain pressure, the waste oil valve 6 opens and the filter cartridge 5
It is possible to discharge pollutants and oil attached to the outside of the system. By doing so, the filter cartridge 5 can be used continuously for a long period of time. The transparent cleaning liquid that has passed through the filter house 4 is connected to the communication pipe 10 and the cleaning liquid return pipe 1.
It is supplied again to the cleaning tank 2 through 8.

In the cleaning apparatus constructed as described above, the oil separation tank and the filter are installed in the circulation system of the cleaning solution, and the cleaning solution can be easily regenerated and circulated. As a pre-process or a post-process of this cleaning device, a spray, a shower cleaning device, and a dryer can be combined.

Next, the contamination of the cleaning liquid and the recycling of the cleaning liquid when the metal parts are cleaned by using the cleaning device shown in FIGS. 1 and 2 will be described. A cleaning liquid in which NMP and water were mixed at a weight ratio of 80/20 was poured into a 20 L cleaning tank, and cutting oil (Lubecut B-35 manufactured by Kyodo Petroleum Co., Ltd.) was accurately applied about 0.5 g per sheet of SUS. Parts made (50 x 50
40mm x 2mm) in a cleaning basket and immerse in a cleaning tank for 60
Ultrasonic cleaning was performed at 3 ° C for 3 minutes. The contaminated cleaning liquid mixed with the oil adhering to the object to be cleaned flowed into the oil separation tank from the outer peripheral portion of the cleaning tank, and about 90% or more of the oil was separated from the cleaning liquid due to the difference in specific gravity. The oil that was emulsified in the washing liquid and could not be completely separated in the oil molecule tank was introduced into a filter (TC-1 manufactured by Advantech Toyo Corp.) and forcibly separated and removed. The oil content in the cleaning liquid circulated to the cleaning tank was 1% by weight or less (corresponding to the solubility).

Repeated washing to obtain 20% by weight in the washing device.
Even when the above oil was retained, the oil content in the cleaning liquid circulated to the cleaning tank was 1% by weight or less, and the cleaning effect was not reduced. At this time, the increase in the amount of oil in the cleaning device and the cleaning performance are shown.

[0016]

[Table 1]

[0017]

By using the cleaning apparatus of the present invention, when cleaning with an aqueous cleaning agent, especially NMP / aqueous cleaning agent,
The oil content is separated from the oil component and the emulsion formed containing the oil component that have been washed and removed in the cleaning tank in the oil separation tank and the filter, so that the cleaning liquid can always be kept in a clean state, so that the cleaning operation is always stable and continuous. Can be implemented.

[Brief description of drawings]

FIG. 1 shows a top view of a cleaning device.

FIG. 2 shows a side view of the cleaning device. 1 Cleaning Device 2 Cleaning Tank 3 Pump 4 Filter House 5 Filter Cartridge 6 Waste Oil Valve (Filter) 7 Waste Oil Pipe (Oil Separation Tank) 8 Ultrasonic Oscillator 9 Heater 10 Communication Pipe 11 Cooling Pipe 12 Cleaning Basket 13 Cleaning Liquid 14 Communication Pipe 15 Oil separation tank 15a Oil separation tank first chamber 15b Oil separation tank second chamber 15c Oil separation tank third chamber 16 Pressure gauge 17 Liquid level gauge 18 Cleaning liquid return pipe

Claims (5)

[Claims] 1. A cleaning tank having a means for removing the non-water-soluble liquid from a part or the like to which the non-water-soluble liquid adheres, a means for extracting a part of an aqueous cleaning liquid from the cleaning tank, and a means for circulatingly supplying the cleaning liquid. A cleaning device comprising: an oil separation tank for separating most of the non-water-soluble liquid from the cleaning liquid accompanied by the non-water-soluble liquid; and a filter for separating the non-water-soluble liquid from the emulsified cleaning liquid. Cleaning equipment. 2. The cleaning liquid is N-methyl-2-pyrrolidone containing 0 to 30% by weight of water.
The cleaning device described. 3. The cleaning apparatus according to claim 1, wherein the means for withdrawing part of the cleaning liquid is such that the cleaning liquid overflows from the vicinity of the liquid level in the cleaning tank. 4. The cleaning apparatus according to claim 1, wherein the filter is a filter material having a hydrophilic surface. 5. The cleaning apparatus according to claim 1, wherein the means for removing the non-water-soluble liquid comprises a means for heating the cleaning liquid and an ultrasonic oscillator.