JP3030735B2 - Degreasing cleaning method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degreasing and cleaning method and apparatus, and more particularly, to a processing oil adhered in a previous step such as machining in a heat treatment step of metal or a quenching oil adhered in an oil quenching step. The present invention relates to a method and an apparatus for degreasing and cleaning oils such as oil.

[0002]

2. Description of the Related Art Conventionally, the following methods have been known as this kind of degreasing cleaning method, but each has various problems.

[0003] Cleaning method of chlorine-based organic solvent [0003] For example, by exposing the object to be treated in the vapor of a chlorine-based organic solvent such as 1-1-1 trichloroethane, trichloroethylene, etc., the adhering fats and oils are lifted up from the surface of the object to be cleaned. how to. Although this method is excellent in degreasing and cleaning power,
There are problems of polluting the working environment and destroying the ozone layer.

Alkaline solution washing method A method of immersing an object to be treated in an alkaline solution or spraying an alkaline solution onto the object to wash fats and oils, then washing the alkaline solution with clean warm water and drying. This method does not have sufficient degreasing and cleaning power and generates a large amount of sewage, so that a treatment facility is required and the cost increases.

Heat Degreasing Method A method of heating an object to be treated in a heating furnace to a temperature equal to or higher than the boiling point of the fat to be degreased, and burning the evaporated oil with a burner. In this method, since the object to be processed is heated to a high temperature of 480 to 530 ° C., there is no problem when the object to be processed is processed at a higher temperature in a subsequent step. In the case of a treatment at a temperature lower than the temperature, for example, a tempering treatment of heating to about 150 ° C., it cannot be applied.

Vacuum heating degreasing method In the above method, heating is performed in a vacuum atmosphere to reduce the heating temperature. In this method, since the heating is performed in a vacuum atmosphere, the boiling point of the fat to be degreased is low,
Low temperature processing becomes possible. However, the heating temperature was 150 ° C.
In order to reduce the pressure to about 10 ⁻² to 10 ⁻³ , the pressure must be reduced to about 10 ⁻² to 10 ⁻³ .

An object of the present invention is to provide a degreasing and cleaning method and apparatus which solve the above problems.

[0008]

The degreasing method according to the present invention is characterized in that, in heating an object to be treated with oil and fat in a vacuum atmosphere to degrease the object, an oil and a lighter oil than the oil to be treated are added to the object to be treated. And / or spraying a hydrocarbon organic solvent.

A degreasing cleaning apparatus according to the present invention comprises a vacuum vessel having a means for heating an object to which fats and oils are adhered, a vacuum exhaust device for depressurizing the inside of the vacuum vessel, and a lighter and lighter fat than the fats and fats in the vacuum vessel. Means for spraying oil and / or a hydrocarbon organic solvent.

[0010] In the above, as the oil lighter than the oil to be defatted and the hydrocarbon organic solvent, for example, kerosene, gasoline, toluene, alcohol and the like are used.

[0011]

When the object to be treated with the fat or oil is heated and degreased in a vacuum atmosphere, the object to be treated is sprayed with an oil and / or a hydrocarbon organic solvent which is lighter than the fat and oil to be defatted. And / or the organic solvent and the fat to be defatted form an azeotropic mixture, and its boiling point is lowered. Therefore,
The heating temperature can be lowered as compared with the conventional heat degreasing method, and the degree of vacuum can be lowered as compared with the conventional vacuum heat degreasing method. Moreover, since the oil to be defatted is dissolved by the lighter oil and / or the hydrocarbon-based organic solvent than the oil to be defatted, the degreasing and washing efficiency is improved.

Since the oil and / or organic solvent is sprayed in a vacuum atmosphere, there is no danger of ignition or explosion.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a degreasing and cleaning apparatus according to the present invention.

1 and 2, the degreasing cleaning device includes a vacuum vessel (1) having a door (2) which can be opened and closed, and a vacuum exhaust device (3) for reducing the pressure in the vacuum vessel (1). I have.

A heating device (4) is arranged in the vacuum vessel (1). A plurality of spray pipes (5) having a plurality of spray ports facing downward are formed in the upper part of the vacuum vessel (1). Further, a plurality of processing liquid spray pipes (6) having a plurality of upwardly directed spray ports are arranged at a lower portion in the vacuum vessel (1). These spray pipes (5) and (6) are connected to a processing liquid tank (8) via a processing liquid supply pipe (7). A supply valve (9) is provided in the middle of the processing liquid supply pipe (7). The processing liquid tank (8) contains oil and / or a hydrocarbon organic solvent which is lighter than the degreased fat or oil adhering to the processing object (W). The vacuum vessel (1) is provided with a leak valve (10).

The vacuum exhaust device (3) includes a vacuum pump (12) connected to the vacuum vessel (1) through a vacuum exhaust pipe (11), and a vacuum vessel (3) in the middle of the vacuum exhaust pipe (11). 1) It has a vacuum exhaust valve (13) and a trap (14) provided from the side.

Next, a method of performing a degreasing cleaning process on a workpiece (W) to which fats and oils have adhered using the above apparatus will be described with reference to FIG.

First, the door (2) is opened, the workpiece (W) is put in the vacuum vessel (1), and then the door (2) is closed. Then, supply valve
(9) and the leak valve (10) are closed, the workpiece (W) in the vacuum vessel (1) is heated by the heating device (4), and the vacuum pump (13) is opened to open the vacuum pump (13). The pressure inside the vacuum vessel (1) is reduced by 12). When the temperature of the workpiece (W) reaches a predetermined temperature (for example, 150 ° C.) and the inside of the vacuum vessel (1) reaches a predetermined degree of vacuum (for example, 10 Torr), the vacuum exhaust valve (13) is closed and the processing is started. Open the liquid supply valve (9),
An oil and / or a hydrocarbon organic solvent lighter than the fat to be degreased is sprayed from the spray ports of the treatment liquid spray pipes (5) and (6). Then, an azeotropic mixture is formed by the sprayed liquid and the fat and oil to be defatted, which azeotropically evaporates and is removed.
At this time, the pressure in the vacuum vessel (1) increases and the degree of vacuum decreases (for example, 50 to 100 Torr). Therefore, the processing liquid supply valve (9) is closed again, and the evacuation valve (13) is opened.
The pressure inside the vacuum vessel (1) is reduced by the vacuum pump (12). At this time, the steam generated by the azeotrope is also exhausted, and the trap (1
Aggregated and collected by 4). Then, evacuation valve (13)
, Open the leak valve (10), introduce air into the vacuum vessel (1) and return it to atmospheric pressure, then open the door (2) and open the door (2).
(W) is taken out. Thus, the degreasing cleaning process is completed.

In the above, in order to completely prevent ignition and explosion when the treatment liquid is sprayed and to enhance safety,
After reducing the pressure in the vacuum vessel (1), an inert gas may be supplied, and then the pressure may be reduced again, and the treatment liquid may be sprayed in the same manner as described above.

In the above, if sufficient degreasing and cleaning efficiency cannot be obtained by one spraying of the treatment liquid, the treatment liquid is sprayed again before opening the leak valve (10), Evacuate the container (1). Further, if necessary, such an operation is repeated.

Next, more specific examples of the degreasing method of the present invention will be described.

The treated material (W) to which the new oil of JIS Class 1 No. 2 cold quenching oil and the used oil adhered and the treated material to which the new oil of JIS Class 1 No. 2 hot quenching oil and the used oil adhered (W) was prepared. A heating temperature of 150 is applied to each workpiece (W).
A degreasing cleaning treatment was performed at a temperature of 10 ° C. and a degree of vacuum of 10 Torr. White kerosene was used as the treatment liquid to be sprayed.

For comparison, each of the above-mentioned objects (W) was subjected to a degreasing cleaning treatment by a conventional vacuum heating degreasing method. The degree of vacuum was 1 Torr, and the heating temperature was 220 ° C. and 150 ° C.

Table 1 shows the results.

[0026]

[Table 1] In Table 1, the degreasing rate (% by weight) was determined by comparing the weight of the object to be treated before oil adhesion and the weight before and after the degreasing and washing treatment after adhesion. The surface condition is
NG was determined when tar remained and discoloration was observed.

As is clear from Table 1, according to the method of the present invention, even when the heating temperature and the degree of vacuum are low, the same effect as when the heating temperature and the degree of vacuum are high can be obtained.

[0028]

According to the method and apparatus of the present invention, as described above, the heating temperature can be reduced as compared with the conventional heat degreasing method, and the vacuum can be reduced as compared with the conventional vacuum heat degreasing method. Since the degree can be reduced, equipment costs and maintenance costs are reduced. Moreover, since the oil to be defatted is dissolved by the lighter oil and / or the hydrocarbon-based organic solvent than the oil to be defatted, the degreasing and washing efficiency is improved. Further, since the oil and / or organic solvent is sprayed in a vacuum atmosphere, there is no danger of ignition or explosion. Further, since there is no need to use harmful chlorine-based organic solvents or alkaline solutions, equipment for these treatments is not required.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a degreasing cleaning device according to the present invention.

FIG. 2 is a vertical transverse sectional view of the same.

FIG. 3 is a graph showing a change in a heating temperature and a degree of vacuum in a vacuum vessel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 3 Vacuum exhaust device 4 Heating device 5 Spray tube 6 Spray tube

Claims (2)

(57) [Claims] When heating an object to be treated with a fat or oil in a vacuum atmosphere to degrease the object, spraying the object with an oil and / or a hydrocarbon-based organic solvent which is lighter than the fat or oil to be defatted. Characteristic degreasing cleaning method. 2. A vacuum vessel having a means for heating an object to be treated with fats and oils, a vacuum evacuation device for depressurizing the inside of the vacuum vessel, and an oil and / or lighter oil than fat to be defatted inside the vacuum vessel
Or a device for spraying a hydrocarbon organic solvent.