JPH046708Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a dry cleaning machine, and particularly to a structure for detecting solvent froth that prevents boiling of the solvent inside a distiller.

[Conventional technology]

Figure 1 shows the circuit structure of a dry cleaning machine. Cleaning in such a dry cleaning machine involves pumping solvent from base tank 2 into basket 1.
The cleaning process is carried out in such a way that the basket 1 is rotated forward and backward to mix the solvent and soap with the items to be washed inside, thereby removing dirt from the items to be washed.

When cleaning is completed, the dirty solvent is drained into the distiller 3, where it is indirectly heated by a steam heat source. Due to this heating, the solvent boils at 121°C at normal pressure (atmospheric pressure) in the distiller 3, and the evaporated solvent vapor enters the condenser 5 via the standpipe 4, where it is liquefied and then passed through the water separator. In step 6, the solvent and water are separated by specific gravity and collected in the base tank 2.

[The problem that the idea aims to solve]

By the way, if the removed solvent is mixed with dirt, water, soap, etc., the solvent may boil inside the distiller 3 during distillation.

When the solvent boils down in the distiller 3 in this way,
The solvent becomes foamy and grows toward the top of the distiller 3, and as boiling continues, the foam of the solvent flows into the condenser 5.
The solvent penetrates into the water separator 6 and base tank 2, and the soap, dirt, water, etc. contained in the froth mix into the solvent. When cleaning is performed by circulating the solvent mixed with soap, dirt, etc. into basket 1 in this way,
This has negative effects such as shrinking the laundry and making the laundry discolored or stained.

For this reason, traditional dry cleaning machines
A photoelectric switch is provided inside the distiller 3, and the amount of foam in the boiled solvent is detected by this photoelectric switch. That is, when the amount of froth reaches a predetermined amount, heating of the distiller 3 is stopped to prevent the solvent froth from leaking from the distiller 3.

However, since there is a lot of soap and dirt inside the distiller 3 along with the solvent, the detection structure using a phototube mistakenly detects the soap and dirt attached to the inner wall of the distiller 3. This has the disadvantage that detection may become unstable.

Therefore, this invention aims to provide a detection structure that can stably detect the amount of foam in a solvent without causing malfunctions due to soap, dirt, etc.

[Means to solve the problem]

In order to solve the above problems, this invention installed a capacitance type level switch inside the distiller that heats and distills the solvent removed from the basket, and the tip of the electrode of the level switch is stored in the distiller. The electrode is formed into a planar shape that is parallel to the solvent liquid surface and has a predetermined spread, and the amount of foam in the boiled solvent is detected by the change in capacitance that occurs at the tip of this electrode. It is.

In other words, capacitance type detectors measure changes in the capacitance of a substance interposed between two electrodes, and since the electrodes are hardly affected by oil or insulating dirt, it is possible to accurately measure the capacitance. Detection becomes possible.

〔Example〕

The dry cleaning machine according to this invention has the same circuit configuration and operation as described in the section of the prior art, and the characteristic parts of this invention will be explained here.

As shown in FIG. 2, the distiller 3 is provided with a heating plate 7 at the bottom, and a steam pipe 8 at the bottom of the heating plate 7.
is provided, and this steam pipe 8 has an on-off valve 9
The steam supply is opened and closed by the

A vapor outlet 10 to the condenser 5 is provided at the corner of the top surface of the distiller 3, and a vapor outlet 10 is provided at the center of the top surface.
A capacitive level switch 11 is installed to detect bubbles of boiling solvent.

This level switch 11 is formed by attaching a disk-shaped electrode 14 to the tip of an oscillator 12 via a stay 13. By making the electrode 14 larger in this way, detection sensitivity can be improved.

In the above level switch 11, when the solvent is boiled and bubbles come into contact with the electrode 14, the electrode 14 detects the change in capacitance that occurs between the wall of the distiller 3 and the electrode 14 due to the increase in bubbles. , the capacitance change is converted into an electrical signal by an oscillator 12 connected to the electrode 14 and output. The cable of this oscillator 12 is connected to a controller 15 that operates the steam pipe opening/closing valve 9, and when an electric signal is input from the oscillator 12, the controller 15 opens/closes the opening/closing valve 9.

In the dry cleaning machine with the above structure, the level switch 1 is switched during the cleaning operation.
1 to detect the amount of foam. When the solvent boils and bubbles grow in the distiller 3 and reach the electrode 14, the controller 15 closes the on-off valve 9 based on the output signal of the level switch 11, and steam is supplied to the steam pipe 8. stop. As a result, heating to the heating plate 7 is eliminated, boiling of the solvent is suppressed, and further growth of bubbles is prevented.

On the other hand, when boiling is suppressed and the amount of foam in the solvent falls below a predetermined amount, the controller 15 opens the on-off valve 9 in response to a signal from the level switch 11, whereby steam is supplied to the steam pipe 8 and the heating plate 7 heat the
Boil off the solvent.

In this way, based on the detected amount of froth, the steam pipe 8
By repeatedly cutting off the supply of steam to the distiller 3, it is possible to prevent foam from leaking from the distiller 3, and to suppress a decrease in the distillation efficiency of the solvent.

[Effect of idea]

As described above, this invention uses a capacitance type level switch to accurately detect the amount of solvent foam regardless of soap or dirt. It is possible to completely prevent the inconvenience of contamination in the tank 2, and there is an effect that a stable cleaning finish can always be obtained.

In addition, the tip of the electrode of the capacitive level switch has a flat shape parallel to the solvent liquid level, and the amount of foam is detected by the change in capacitance that occurs at the tip of the electrode. It is possible to reliably detect bubbles that boil from any position and grow irregularly, and a large change in capacitance can be obtained when the bubbles come into contact with the electrode, greatly improving the detection sensitivity of the amount of bubbles. There are advantages that can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the circuit structure of a dry cleaning machine, and FIG. 2 is a partially longitudinal side view showing the main parts of this invention. 1...basket, 2...base tank, 3...
... distiller, 5 ... condenser, 6 ... water separator,
8... Steam pipe, 9... Opening/closing valve, 11... Capacitance type level switch, 12... Oscillator, 14...
…electrode.

Claims (1)

[Scope of utility model registration request] A capacitance type level switch is installed inside the distiller that heats and distills the solvent removed from the basket, and the tip of the electrode of the level switch is set parallel to the liquid surface of the solvent stored in the distiller and with a predetermined spread. What is claimed is: 1. A dry cleaning machine, characterized in that the dry cleaning machine is formed into a planar shape with an electrode, and the amount of foam of boiled solvent is detected by a change in capacitance occurring at the tip of the electrode.