JPS61136478A - Method and device for preventing dissipation of solvent vapor in organic solvent vapor washer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for preventing the dispersion of solvent vapor into the atmosphere in an organic solvent vapor cleaning device, and a method for preventing dispersion of the solvent vapor used when carrying out this method. Regarding equipment.

[Prior Art] In organic solvent vapor cleaning equipment that uses organic solvents such as trichlorethylene, perchlorethylene, trichloroethane, and chlorofluorocarbons as cleaning liquids, these cleaning liquids are volatile, so solvent vapor There was a need to effectively deal with problems such as environmental pollution caused by the dissipation of water into the atmosphere, and wasteful consumption of relatively expensive cleaning fluids due to natural evaporation. For this reason, conventionally, a freeboard is connected to the top of the cleaning liquid tank, and a cooling coil is installed around the inner circumference of the freeboard.The cooling power of this cooling coil is used to confine the solvent vapor within the freeboard and create a vapor zone. The current situation is that the cleaning liquid is purified and recycled through a process of forming, condensing and recovering it, and reproducing it by distillation.

In order to effectively prevent solvent vapor from escaping into the atmosphere by reliably containing the solvent vapor within the freeboard, the height of the freeboard tends to be relatively high.
Therefore, the reality is that cleaning workability has to be sacrificed to some extent.

[Problems to be Solved by the Invention] As described above, as the height of the freeboard is made relatively high in order to prevent the dispersion of solvent vapor into the atmosphere, the working position during cleaning work has also changed. This made the work more expensive and the workability deteriorated, and there was a desire to improve the workability in this respect.

Regarding the temperature of the cooling coil, it is logical that the lower the temperature, the better the condensation efficiency of the solvent vapor, but as is clear from the conventional device shown in Fig. 2, the cleaning liquid heated by the heater 12 is free board. Since a vapor zone V is formed within the cooling coil 14 and the central portion bulges out, the upper cooling coil 13 comes into direct contact with the air, and the temperature of the cooling coil 13 and the room temperature change. It has been pointed out that if there is too much of a temperature difference between the two, moisture in the air will be drawn in due to condensation and drop into the cleaning liquid tank 11 as water droplets, resulting in an adverse effect on the cleaning liquid and the objects to be cleaned. Ta. For this reason, cooling coil 1
It is considered undesirable to flow a refrigerant directly into the interior of the tank for cooling, and generally, there is no choice but to use cold water of 10-15'C.

In view of such prior art, an object of the present invention is to improve workability by using a relatively low free board while preventing moisture from entering the cleaning liquid from entering the air. An object of the present invention is to provide a new method and apparatus that can also prevent solvent vapor from dissipating into the air.

[Means for Solving the Problems] The first invention, a method for preventing the dispersion of solvent vapor in an organic solvent vapor cleaning device, is such that the vapor of the cleaning liquid heated and evaporated in the cleaning liquid tank in the organic solvent vapor cleaning device is freeboard. The cooling power of the supercooling chamber installed within the vapor zone formed by staying in the vapor zone supercools the vapor zone without drawing in moisture from the outside air and efficiently condenses the solvent vapor. The purpose is to suppress the rise of the interface with the outside air, thereby preventing the solvent vapor from dissipating into the atmosphere, and also making it possible to reduce the height of the freeboard itself.

The second invention, the device for preventing the diffusion of solvent vapor, is
This is a device for carrying out the invention of the invention, in which the lower body side of the free board of the cleaning liquid tank in the organic solvent vapor cleaning device is made to protrude outward, thereby supercooling the surrounding internal space.
A supercooling chamber is formed by disposing a supercooling coil within the supercooling chamber, and the solvent vapor forming the vapor zone can be rapidly cooled and condensed.

[Function] When the vapor zone formed by the retention of solvent vapor is rapidly cooled at a low temperature, the solvent vapor can be liquefied with high condensation efficiency and recovered as a solvent.

This invention 16 focuses on and utilizes this phenomenon, and by disposing the supercooling coil in a supercooling chamber located within the vapor zone, the supercooling coil is brought into direct contact with the outside air. Since only the vapor zone can be rapidly cooled at a low temperature without any moisture being absorbed, only the solvent vapor can be efficiently condensed without drawing in moisture from the outside air. This can be achieved even with a relatively low freeboard height.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in FIG.

Cleaning liquid W! t accommodates a cleaning liquid made of an organic solvent such as humin, and the heater 2 can heat this cleaning liquid. A freeboard 4 as a shield is connected to the upper part of the cleaning tank 1 in order to keep the solvent vapor generated when the cleaning liquid is heated as a vapor zone V without dissipating it into the atmosphere. A cooling coil 3 is provided around the inner circumference of the freeboard 4, through which water of 10 to 15''C is flowed in order to condense and recover the solvent vapor.The lower circumference of the freeboard 4 The side part has a space area formed by protruding outward, and a supercooling coil 5 for flowing a supercooling medium of around -10°C is disposed in this space area, and supercooling is performed. A chamber 6 is formed.As for the supercooling coil 5, in addition to indirect supercooling coil type in which a supercooling medium such as antifreeze that has been supercooled elsewhere is passed, there are also those in which a refrigerant as a supercooling medium is passed directly into the coil. A refrigerant direct cooling subcooled coil system may also be used.

Note that 7 is a water separator for separating water from the condensed and recovered liquid.

By providing the solvent vapor cleaning device in this way,
The cleaning liquid heated by the heater 2 turns into solvent vapor and evaporates. At this time, the solvent vapor is cooled by the action of the cooling coil 3 installed around the inner circumference of the freeboard 3, so it stays inside the freeboard 4 without being dissipated into the atmosphere outside the freeboard 3, and becomes vapor. Zone V is formed. Since a supercooling chamber 6 having a supercooling coil 5 is provided within this vapor zone (2), the solvent vapor that has entered the supercooling chamber 6 comes into direct contact with the supercooling coil 5. It is rapidly cooled, efficiently condensed and liquefied.

In other words, unlike the conventional device shown in Fig. 2, the center of the contact surface of the vapor zone V with the outside air does not bulge upward, and the height of the contact surface of the vapor zone V with the outside air is kept low. Therefore, even if the height of the freeboard 4 is reduced to about 3/4 to 1/2 of that of the conventional one, solvent vapor will not be released into the atmosphere.

Furthermore, since the supercooling chamber 6 itself is provided within the vapor zone so that it does not come out of the vapor zone V formed in the freeboard 4 and come into contact with the outside air,
There is no possibility that the supercooling coil 5 comes into direct contact with the outside air, condenses moisture in the air, and draws it into the cleaning liquid tank 1.

In addition, when the supercooling coil 5 is an indirect supercooling coil method in which antifreeze or the like is passed, it is easier to control the temperature of the supercooling medium such as antifreeze than in a subcooling coil method that directly cools the refrigerant. Since the set temperature can be changed as appropriate, it can be an energy-saving type that does not consume energy such as electric power unnecessarily.

[Effects of the Invention] As described above, according to the present invention, a supercooling chamber is provided at the lower peripheral side of the freeboard to rapidly cool the solvent vapor within the vapor zone, thereby reducing the height of the vapor zone. It is possible to efficiently condense solvent vapor while keeping the temperature low and preventing unnecessary moisture from entering. It becomes possible to replace the existing long freeboard with a compact one, and as a result, it is possible to obtain unprecedented effects in terms of workability and maintainability of the cleaning device itself.

[Brief explanation of the drawing]

In the drawings, FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional device. l-・Cleaning liquid tank, 2・φ・Heater, 3@・
φ Cooling coil, 4・Free board, 5＠−
・Supercooling coil, 6 @ II・Supercooling chamber, 7・
...Water separator, L...Washing liquid, V...Vapor zone

Claims (1)

[Claims] 1. The vapor zone is supercooled without drawing in moisture from the outside air by the cooling power of the supercooling chamber provided within the vapor zone that accumulates in the freeboard of the cleaning liquid tank in the organic solvent vapor cleaning device. A method for preventing the dispersion of solvent vapor in an organic solvent vapor cleaning device, characterized in that the dispersion of the solvent vapor is prevented by efficiently condensing the solvent vapor and suppressing the rise of the interface with the outside air in the vapor zone. . 2. In the organic solvent vapor cleaning device, the lower peripheral side of the free board of the cleaning liquid tank is made to protrude outward to provide a supercooling chamber,
A solvent vapor diffusion prevention device characterized in that a supercooling coil is disposed within the supercooling chamber.