JPH0398683A - Method and apparatus for vacuum washing of processed article - Google Patents

Abstract

PURPOSE:To complete a washing process within a short time by heating a vacuum hermetically closed container for degreasing and washing a processed article with an org. solvent. CONSTITUTION:A processed article 3 is placed in the degreasing/washing chamber 2 of a vacuum hermetically closed container 1 at a predetermined position. A jacket 5 circulating a heating medium is arranged to the periphery of the degreasing/washing chamber 2 as one example of a heating means. As the heating medium, hot oil, hot water, steam and Dowtherm(R) can be used and, especially, when the hot oil is used, it is prevented that rust is generated in the jacket or a flow passage and piping is closed by fur and said hot oil is easy to handle because it is liquid at room temp. A heater 9 for the heating medium is arranged to a line heater 10 and the heating medium is circulated by a pump 11. Since the processed article rises in temp. within a short time, a washing time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum cleaning method and a vacuum cleaning apparatus for cleaning workpieces such as metals, glass, ceramics, and plastics with organic solvents. [Prior Art] A conventional method and apparatus for cleaning a workpiece is disclosed in Japanese Patent Laid-Open No. 63-296881. This process involves the first step of creating a vacuum in the cleaning tank containing the workpiece in a cleaning tank isolated from the outside air and its path, and spraying a shower of organic solvent onto the workpiece in the cleaning tank. The second step, the third step of steam cleaning the workpiece in the cleaning tank, and the fourth step of vacuuming the inside of the cleaning tank again to dry the workpiece are performed, and the steps of the first to fourth steps are performed. The cycle is repeated one or more times. [Problems to be Solved by the Invention] However, in the above method and apparatus, the following problem occurred in the third step of steam cleaning the workpiece in the cleaning tank. That is, during the third step, the inside of the cleaning tank, which is brought into a vacuum state, is filled with organic solvent vapor (hereinafter referred to as solvent vapor).
As this happens, the temperature and pressure inside the tank begin to rise. However, since the outer wall surface of the cleaning tank is in contact with the atmosphere inside the factory where the equipment is installed, the temperature of the inner wall surface of the cleaning tank is almost the same as the room temperature inside the factory, and the generated solvent vapor is Since reliquefaction occurs repeatedly on the inner wall of the washing tank and the workpiece, especially on the inner wall of the washing layer, it takes a long time to raise the temperature and pressure inside the tank. In many cases, the mass of the workpiece to be cleaned (including the clamps that hold or house the workpiece) and the mass of the cleaning tank are approximately the same, so if the amount of solvent vapor generated is the same, then the In order to raise the temperature of an object to a specified temperature, it takes twice the energy to raise the humidity of the workpiece alone. But actually, washing? ! Since heat is radiated from the tank wall to the atmosphere, more energy is required, which causes the problem of significantly longer cleaning times. [Technical measures taken to solve the technical problem of the invention] The technical measures taken to solve the technical problem are: A method for heating the vacuum-tight container, and an apparatus for degreasing and cleaning a workpiece with an organic solvent in the vacuum-tight container, the vacuum cleaning device comprising a heating means for heating the vacuum-tight container. ．． [Function] In the present invention, since the vacuum sealed container that is the cleaning tank is heated, only the workpiece can be raised to the same temperature as the solvent vapor temperature in a short time, and the cleaning process can be completed in a short time. be able to. [Embodiments] To explain the present invention with reference to the embodiments shown in the drawings, FIGS. 1 to 3 are cross-sectional plan views of the apparatus of the present invention. An embodiment of the present invention will be described with reference to FIG. 1. A workpiece 3 is placed at a predetermined position in a degreasing and cleaning chamber 2 of a vacuum-tight container l. A jacket 5 for circulating a heat medium 4 as an example of heating means is disposed around the degreasing cleaning chamber 2. Here, hot oil, hot water, steam, or dowtherm can be used as the heat medium 4, and especially when hot oil is used, it may cause rust on the jacket 5 or the flow path or block the pipes like limescale. It also has the advantage of being easier to handle because it is liquid at room temperature, and the heating temperature can be controlled over a wider range. Further, in the figure, reference numeral 6 denotes a jacket including a heat insulating material, 7a, 7bt-k8, flow passages on the inlet side and outlet side of the medium, 8 is piping, and 9 is a heater for heating the heat medium. 1
0 is a line heater, and 11 is a pump for circulating the heat medium. Next, the embodiment shown in FIG. 2 uses a heater 12 as a heating means, and the vacuum sealed container and the heater can be attached by brazing or welding, or by using an adhesive. can. A sheathed heater is preferable as the heater 12, and if this sheathed heater is molded into a wave shape and fixed, the thermal efficiency per unit area can be improved.
The embodiment shown in FIG. 3 is a holder l3 for placing a workpiece.
In this example, the heater is installed inside or outside the
The holder l3 may be constructed from either a polygonal cylinder or a cylinder, and the cylinder surface may or may not have holes. It is preferable that the heating means described above completely surrounds the workpiece, but it is possible to change the heating means by, for example, excluding the door at the entrance/exit of the workpiece, and it is not necessarily necessary to completely surround the workpiece. [Effects of the Invention] Therefore, according to the present invention, since the vacuum sealed container is heated when cleaning the workpiece with an organic solvent, it is only necessary to heat the workpiece with solvent vapor to the solvent vapor temperature, which is a short process. It has the characteristic that the cleaning process can be completed in just a few hours. Additionally, since the vacuum-sealed container is heated, the workpiece is also heated from the vacuum-sealed container, allowing the temperature to rise even more quickly. Therefore, the cleaning time can be further shortened, the amount of cleaning per unit time can be increased, and excellent effects such as cost reduction can be obtained.

[Brief explanation of drawings]

Figures 1 to 3 are cross-sectional plan views of the device of the present invention. １・・・・・・・・・Vacuum sealed container 2・・・・・・Degreasing cleaning room ３・・・・・・・・・Processed product 4...Heating medium 5・・・・・・jacket 6.......coat 7a, 7b...... Distribution path 8...Piping 9・・・・・・・・・Heater O・・・・・・・・・Line heater l・・・・・・・・・Pump 2・・・・・・・・・Heater 3......Holding body Special patent applicant Yamazaki Chemical Industry Co., Ltd.

Claims (2)

[Claims] (1) A method for vacuum cleaning a workpiece in a vacuum sealed container, the method comprising: heating the vacuum sealed container. (2) An apparatus for degreasing and cleaning a workpiece with an organic solvent in a vacuum-tight container, characterized in that the device is equipped with a heating means for heating the vacuum-tight container.