JPH0433992Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a cleaning device for cleaning printed circuit boards and the like using a solvent.

"Prior Art" This type of cleaning apparatus uses immersion cleaning, in which the object to be cleaned is immersed in a cleaning solvent such as Freon (registered trademark), or steam cleaning, in which the object is exposed to a solvent vapor atmosphere. The solvent vapor in the cleaning tank is cooled, condensed, and recovered by a cooling pipe provided at the top of the cleaning tank. For this reason, it is impossible to avoid moisture in the air from condensing at the same time and mixing into the recovered solvent liquid. Particularly, in devices where a refrigerant is passed through a cooling pipe for strong cooling in order to increase the recovery rate of the solvent, a large amount of water is mixed in. Therefore, a water separator is required to remove the water mixed in from the solvent solution.

In conventional water separators, the recovered solvent is retained in a separation tank, and water floating on the surface of the recovered solvent is separated and disposed of using the difference in specific gravity between the solvent and water.

However, depending on the object to be cleaned, an azeotropic mixed solvent such as Freon (R-113) and a small amount of alcohol may be used instead of a single solvent. When water is removed using such a solvent using the difference in specific gravity, there is a problem in that the alcohol in the solvent dissolves in the water and is discarded together, resulting in a change in the composition of the cleaning solvent. Therefore, a water adsorbent such as silica gel or synthetic zeolite is introduced into the separation tank, but there is a limit to the amount of water adsorbed, and there is a problem in that it is not known when the limit has been reached.

``Problems that the invention attempts to solve'' The present invention was made to solve the above problems, and can reliably detect when the moisture adsorbent has reached its adsorption limit, It is an object of the present invention to provide a cleaning device equipped with a water separator that can reliably remove water from water.

``Means for solving the problem'' Therefore, the present invention provides a cleaning device using a solvent, which is configured to temporarily retain the distilled solvent and return the solvent to the cleaning tank. a water absorbent immersed in the retention tank; and an electrode immersed in the solvent in the retention tank, and a voltage is applied to the electrode to cause the solvent to flow through the retention tank. A cleaning device is provided that includes a moisture detection circuit that detects the presence or absence of moisture in a solvent solution by detecting current.

"Operation" According to the above configuration, water mixed into the distilled solvent solution is adsorbed by the water adsorbent in the retention tank and removed. When the moisture adsorbent reaches its adsorption limit, the moisture that can no longer be removed begins to float on the surface of the solvent solution.
The adsorption limit can be detected because the current flowing through the electrode increases rapidly.

"Example" An example of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a sectional view schematically showing a cleaning device according to the present invention.

The cleaning tank 1 contains a cleaning solvent 2 based on Freon (R-113). A cooling pipe 3 is disposed along the inner circumference at the upper part of the cleaning tank 1, and cooling water is flowed through the cooling pipe 3 to cool and liquefy the vaporized solvent vapor, thereby preventing freon vapor from flowing out above the cleaning tank 1. ing. A gutter 4 is provided below the cooling pipe 3 to receive the solvent condensed and liquefied in the cooling pipe 3. An inflow pipe 5 is connected to the gutter 4 and sends the condensate to a water separator 6.

The water separator 6 will now be described. Fig. 2 is a plan view showing only the water separator portion.

The water separator has a double tank structure consisting of a retention tank 7 and an adsorbent basket 8. The retention tank 7 is divided into two chambers by a partition wall 10 provided with a through hole 9 in the lower part. The adsorbent basket 8 is accommodated in the first chamber 11, and an inflow pipe 5 from the gutter 4 is connected to the first chamber 11, into which the condensed solvent liquid 2 flows. The second chamber 12 , which communicates with the first chamber 11 through the through hole 9 at the lower end, is connected at the upper side to the cleaning tank 1 through an outflow pipe 13 and returns the overflowing solvent solution 2 to the cleaning tank 1 .

The adsorbent basket 8 is for accommodating the granular moisture adsorbent 14, and is provided with small holes 15 covered with a net at the bottom, so that only the solvent liquid 2 can freely pass therethrough. Crystalline synthetic zeolite is charged into the adsorbent basket 8 as a moisture adsorbent 14. The equilibrium water absorption rate of this water adsorbent 14 is
It is about 21%.

2 to the moisture adsorbent 14 in the adsorbent basket 8.
Electrodes 16 and 17 made of two metal plates are inserted facing each other. The two electrodes 16 and 17 are inserted so that their upper portions are exposed above the liquid level of the solvent liquid 2, and each electrode 16 and 17 is connected to a moisture detection circuit 20 by lead wires 18 and 19. The moisture detection circuit 20 applies an AC voltage of about 24 V between the electrodes 16 and 17, and outputs an alarm signal when the current value exceeds a predetermined value.

The operation will be explained based on the above configuration.

The moisture-containing solvent liquid flowing into the retention tank 7 from the gutter 4 via the inflow pipe 5 has its moisture adsorbed and removed by the moisture adsorbent 14 in the adsorbent basket 8, and only the solvent liquid from which moisture has been removed is removed. It moves to the second chamber 12 via the through hole 9 and returns to the cleaning tank 1.

When the moisture adsorbent 14 adsorbs a large amount of moisture and reaches its adsorption limit, the moisture mixed into the solvent liquid 2 in the retention tank 7 cannot be removed completely, and a small amount of moisture floats on the surface of the solvent liquid 2. For this reason, the electrode 16,
The current flowing through 17 increases rapidly, and moisture detection circuit 20 detects the current and outputs an alarm signal. By turning on an alarm signal, for example, by lighting an indicator lamp, the cleaning operator can easily know the adsorption limit of the moisture adsorbent 41, and can reliably remove the moisture adsorbent at the appropriate time without relying on the cleaning operator's intuition. 14 replacement operations can be performed. Since the electrodes 16 and 17 have exposed portions on the surface of the solvent solution 2, the presence or absence of moisture that cannot be removed by adsorption can be detected with high sensitivity.

In the embodiment described above, two metal plate electrodes 1
As shown in FIG. 3, one metal plate electrode 21 is used to conduct electricity between the adsorbent basket 8 or the retention tank 7 made of metal to determine the presence or absence of water. may be detected. In this example, the metal plate electrode 21 is formed in an inverted U shape to facilitate insertion into the moisture adsorbent 14.

In addition, independent metal plate electrodes 16, 17, and 21 are not particularly provided, and the adsorbent basket 8 and the first chamber 11 of the retention tank 7 are arranged to be electrically insulated, so that the adsorbent basket 8 and the retention tank 7 themselves are not provided. By using both as electrodes, it is also possible to detect moisture by passing current between the two.

In addition, when using silica gel as the moisture adsorbent, it is also possible to provide a window in the adsorbent basket 8 and the retention tank 7 that can be observed from the outside, so that it is possible to visually check that the blue silica gel changes from blue to red. be.

``Effect of the invention'' As explained above, the present invention has the above structure and is equipped with an electrode that is immersed in the solvent solution, so it is possible to ensure that the moisture adsorbent has reached its adsorption limit. It has the excellent effect of being able to reliably remove water in the solvent without relying on the intuition of the cleaning operator.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing the first embodiment;
FIG. 2 is a plan view of the water separator portion, and FIG. 3 is a perspective view showing the second embodiment. 1...Cleaning tank, 2...Solvent solution, 7...Retention tank,
8...Adsorbent basket, 14...Moisture adsorbent,
16, 17, 21... electrode, 20... water detection circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A cleaning device using a solvent, comprising: a retention tank configured to temporarily retain a distilled solvent and return the solvent to the cleaning tank; and an interior of the retention tank. and an electrode immersed in the solvent in the retention tank, and by applying a voltage to the electrode and detecting the current flowing through the solvent in the retention tank, the solvent is removed. A cleaning device comprising: a moisture detection circuit that detects the presence or absence of moisture in a liquid; 2. The utility model according to claim 1, wherein the retention tank is made of metal, and the presence or absence of water is detected by applying a voltage between the retention tank and the electrode. cleaning equipment.