JPH0355193B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a steam cleaning device that cleans objects to be cleaned, such as mechanical parts, with an evaporated solvent generated in a steam cleaning tank.

(Prior art) Conventional steam cleaning devices of this type include one that directly heats the solvent contained in a steam cleaning tank (hereinafter referred to as the "former device"), and one that directly heats the solvent contained in the steam cleaning tank (hereinafter referred to as the "former device"). There is a device in which the circulating solvent is heated outside the tank (hereinafter referred to as the "latter device").

That is, in the former device, as shown in FIG. 2, a heater 23 such as an electric heater is provided in the solvent reservoir 21a of the steam cleaning tank 21, and the solvent 22 in the tank 21 is directly heated by the heater 23. The cleaning section 21b in the upper part of the tank 21 is configured to form and maintain an evaporated solvent atmosphere. In addition, the cooling water is
By circulating between the cooling pipe 24 inside 1b and the cooling tower 25 outside the tank 21, the inside of the cleaning section 21b is kept cooled to an appropriate temperature.

In addition, in the latter device, as shown in FIG.
By disposing a heat pump 33 that sequentially circulates through an expansion valve 36, an evaporator 37, etc., and circulating a part of the solvent 32 in the tank 31 between the solvent reservoir 31a and the condenser 35 using the circulation pump 38. , the circulating solvent is heated in the condenser 35 by the latent heat of condensation of the refrigerant. Further, by circulating the cooling water between the evaporator 37 and the cooling pipe 39 in the cleaning section 31b, the surplus inside the cleaning section 31b is recovered, and the recovered heat is used to evaporate the refrigerant in the evaporator 37. In addition to being used as a heat source, the cleaning section 3
The inside of 1b is kept cooled to an appropriate temperature.

In such a steam cleaning device, when the object to be cleaned is brought to the cleaning portions 21b and 31b, the solvent vapor condenses and flows down the surface of the object to be cleaned, thereby causing water to flow onto the surface of the object to be cleaned. Adhering oil and fat, chips,
Other unnecessary substances are washed away, while
The condensed solvent after washing is collected together with impurities such as the above-mentioned oils and fats into the reservoirs 21a and 31a.

(Problems to be Solved by the Invention) However, in the former device in which the heater 23 is disposed inside the tank 21, it is extremely difficult to clean the inside of the tank 21 and to perform maintenance, inspection, and repair of the heater 23, etc. Yes, but less practical.

In addition, in the latter device which circulates the solvent outside the tank 31, there is no such inconvenience, but on the other hand, the circulation pump 38 may malfunction due to precipitation of dissolved substances in the circulating solvent or adhesion of mixed impurities. Anxiety cannot be avoided, and stable driving cannot be expected.

That is, in the case of the latter device, the circulation pump 3
8. In order to prevent liquid leakage, a closed type pump driven via a magnet is used, and the sliding part between the rotating part and the fixed part is lubricated by using the pump discharge pressure on the sliding part. This is usually done by directing a portion of the circulating solvent.
On the other hand, as described above, since the impurities removed from the object to be cleaned are collected together with the condensed solvent after cleaning, a large amount of impurities are dissolved and mixed in the circulating solvent. become. Therefore, due to the presence of dissolved substances and mixed impurities in the circulating solvent, the lubricating piping of the circulation pump 38 is likely to become clogged, and the sliding contact portions are likely to seize.
Furthermore, there is a risk that deposits may form on the pump blades, causing the balance to collapse, which may cause pump failure. Moreover, since the boiling point of the solvent 32 is low, cavitation may occur if the pump suction pressure is low. Thus, in the latter device, stable operation cannot be expected due to the presence of the circulation pump 38.

It is an object of the present invention to provide a steam cleaning apparatus that is highly practical and capable of stable operation by solving all of the problems with conventional apparatuses.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the steam cleaning apparatus of the present invention is provided with a heated solvent discharge pipe and a heated solvent inlet pipe provided at the upper and lower ends of the steam cleaning tank, respectively. An inclined solvent heating tube is connected to the solvent storage section of the steam cleaning layer via the solvent storage section, and is positioned below the liquid level of the solvent storage section, and the solvent in the solvent heating tube is heated. The system is equipped with a solvent heating means.

(Function) Since the solvent heating tube is located below the liquid level of the solvent reservoir, it is filled with the solvent in the tank. When the solvent in the heating tube (hereinafter referred to as "solvent in the tube") is heated by the solvent heating means, buoyancy is generated due to the volume expansion of the solvent in the tube, and the solvent in the tube is locally boiled. Bubbles are generated, and since the heating tube is inclined, these bubbles rise inside the heating tube and form an upward flow that also involves the surrounding liquid, and the specific gravity of the solvent inside the tube decreases. Therefore, the heated solvent in the tube is discharged from the heated solvent discharge pipe to the storage section, heating the solvent in the tank, and expands and evaporates due to the depressurizing effect accompanying the rise due to the difference in specific gravity, and the solvent liquid Generates large amounts of solvent vapor on surfaces. Further, in conjunction with this, the solvent is introduced from the reservoir to the heating tube via the heated solvent introduction tube, and the solvent is circulated between the reservoir and the heating tube.

(Example) Hereinafter, the configuration of the present invention will be specifically explained based on the example shown in FIG.

In FIG. 1, reference numeral 1 denotes a steam cleaning layer, at the bottom of which there is formed a solvent storage section 1a containing a predetermined solvent 2 and a liquid level control section 1c communicating with this, and at the top of the solvent storage section 1a. A cleaning section 1b is formed to clean the object to be cleaned. The liquid level control unit 1c is provided with an appropriate liquid level control means 3, which maintains the solvent liquid level 2a in the tank 1 within a predetermined upper limit position (solid line position) and lower limit position (dashed line position). It is made possible to do so. The liquid level control means 3 detects the upper limit liquid level and the lower limit liquid level with liquid level detectors 4a and 4b, respectively, as shown in FIG. 1, and controls the opening and closing of the valve 5a of the solvent supply pipe 5 based on this. is configured to do so.

A solvent heating pipe 6 and a solvent heating means 7 are disposed outside the steam cleaning tank 1.

The solvent heating tube 6 is arranged in an inclined manner at the solvent liquid level 2a position, that is, below the lower limit position, and its upper and lower ends are connected to the solvent through the heated solvent discharge tube 8 and the heated solvent introduction tube 9, respectively. Storage part 1
It is connected to a. Therefore, the solvent heating tube 6 is always filled with solvent.

Incidentally, the inclination angle θ of the heating tube 6 is appropriately set so as to obtain the required amount of circulating solvent. That is, when the inclination angle θ is increased, the influence of buoyancy becomes greater, and the amount of circulating solvent can be increased. However, if the inclination angle θ is made larger than necessary, the amount of circulating solvent will increase, but at the same time, the boiling under reduced pressure of the ascending solvent will also become more intense, which is undesirable. This increases the amount of solvent required, which is undesirable in terms of equipment. Therefore, it is desirable to set the inclination angle θ of the heating tube 6 in consideration of such points.

Further, the solvent heating means 7 is also constituted by a heat pump. This heat pump 7 connects a compressor 10 to a condenser 1 driven by an engine or the like.
1. It is of a unit type, forming a refrigerant circulation path 14 that passes through an expansion valve 12, an evaporator 13, and reaches a compressor 10.

The condenser 11 is configured as a so-called inclined condenser, which includes the solvent heating tube 6 and a refrigerant flow tube 15 surrounding the solvent heating tube 6. Therefore, this condenser 11
Inside, the refrigerant vapor that has passed through the compressor 10 is condensed and liquefied while flowing through the refrigerant flow pipe 15 from the upper inlet 15a to the lower outlet 15b.
On the other hand, the solvent in the heating tube 6, that is, the solvent 2' in the tube, is heated and heated by the latent heat of condensation of the refrigerant and the sensible heat after condensation.

Further, a suitable heat source such as recovered heat is supplied to the evaporator 13, but in this embodiment, excess heat from the cleaning section 1b is recovered and the recovered heat is used as the heat source or as a part thereof. We are using. That is,
A cooling pipe 17 is disposed in the cleaning section 1b, and a circulation pump 18 circulates cooling water between the evaporator 13 and the cooling pipe 17, so that the refrigerant in the circulation path 14 is circulated within the evaporator 13. The cooling water is evaporated by the heat recovered in the cleaning section 1b, and the cooling water is cooled in the evaporator 13 and circulated through the cooling pipe 17, so that the inside of the cleaning section 1b is cooled and maintained at an appropriate temperature.

Furthermore, a liquid receiver 19 is interposed in the circulation path 14 from the condenser 11 to the expansion valve 12 directly below the liquefied refrigerant outlet 15b. It quickly flows out from the flow pipe 15 without being retained therein, and is stored therein.
The latent heat of condensation of the refrigerant can be fully utilized in the condenser 11 to effectively heat the solvent 2' in the pipe, and at the same time, it is devised to reliably prevent refrigerant vapor from entering the expansion valve 12. be.

Note that when the refrigerant condensate is well discharged from the refrigerant flow pipe 15, there is no short pass for refrigerant vapor, and a sufficient heat transfer area is secured in the condenser 11, the liquid receiver 19 is omitted. Of course, the refrigerant circulation path 14 may be equipped with an accumulator, an oil separator, a dryer, a filter, etc., as necessary, in addition to the above-mentioned equipment such as the compressor 10. Needless to say, it's a good thing.

In the steam cleaning device configured in this way, the pipe solvent 2' is heated in the condenser 11 by the latent heat of condensation of the refrigerant and the sensible heat after condensing a part of the refrigerant, and the resulting pipe solvent Due to the buoyancy caused by the volumetric expansion of 2' and the bubbles caused by local boiling, a pressure difference is created between the upper and lower parts of the solvent heating tube 6, the solvent 2' in the tube flows upward, and the heated solvent is discharged from the discharge tube 8 into the reservoir. The solvent 2 is discharged into the storage section 1a, heats the solvent 2 in the storage section 1a, expands and evaporates due to the reduced pressure caused by the upward flow due to the difference in specific gravity, and generates a large amount of steam on the surface.
Along with this, the solvent 2 in the storage section 1a is introduced from the introduction pipe 9 to the heating tube 6, and the solvent 2 is circulated between the storage section 1a and the condenser 11.
1 to maintain the inside of the cleaning section 1b in a solvent vapor atmosphere.

By the way, when impurities are dissolved or mixed in the solvent 2, when the solvent 2 is evaporated, the contained impurities may precipitate in the evaporation part or adhere to members near the evaporation part. For this reason, when heating the solvent 2' in the tube, there is a so-called dry-out state in which the solvent 2' in the tube completely evaporates and no liquid is present in the heating tube 6, or there is a situation where no liquid is present in the heating tube 6, but no liquid is transmitted. It is necessary to avoid a so-called burnout condition in which large bubbles locally form on the hot surface. The reasons why this phenomenon occurs are that the amount of solvent retained in the steam cleaning tank is extremely small and a liquid level always exists in the heating tube 6, and that the heat transfer temperature of the heating tube 6 is extremely high, causing a drop on the heat transfer surface. It is thought that the solvent is boiling violently and that the amount of solvent circulating in the heating tube 6 is small compared to the amount of heating heat.

However, in the above-mentioned steam cleaning apparatus, the above-mentioned ~
It has been devised to eliminate all causes of this, and therefore the above-mentioned inconveniences do not occur at all.

That is, the steam cleaning tank 1 is controlled by the liquid level control means 3.
The above-mentioned cause is eliminated by controlling the solvent liquid level 2a so that the heating tube 6 is always filled with the solvent 2'. In addition, the solvent heating means is a heat pump 7.
The heating tube 6
The above-mentioned causes are eliminated by keeping the heat transfer surface temperature at an appropriate temperature. Moreover, since the solvent 2' in the tube is heated at the optimum temperature in this manner, the problem of solvent deterioration does not occur. Further, by adjusting the inclination angle θ of the inclined condenser 11 or the heating tube, the amount of circulating solvent can be adjusted, thereby eliminating the above-mentioned cause.

In the above embodiment, the heat pump 7 is used as the solvent heating means, and the condenser 11 of the heat pump 7 is used as the solvent heating means.
, a solvent heating pipe 6 and a refrigerant flow pipe 1 surrounding it.
5, the solvent heating means includes, for example, the solvent 2' in the solvent heating tube 6 and the hot water introduced into the outer peripheral area of the heating tube 6.
The solvent 2' in the pipe may be heated by exchanging heat with a heating fluid such as steam or heat transfer oil, or by attaching a heater such as an electric heater to the solvent heating pipe 6.
may be heated directly. Further, a plurality of heating tubes 6 may be installed.

(Effects of the Invention) As is clear from the above explanation, in the steam cleaning device of the present invention, unlike the former device, a heater is not provided in the steam cleaning tank, so cleaning the inside of the steam cleaning tank is easy. It is very practical, and existing equipment can be easily modified.

Moreover, since the solvent is circulated by applying the principle of an air lift pump, there is no need for a circulation pump like the latter device.
Stable operation is possible. In particular, by using a heat pump as the solvent heating means as in the above embodiment, it is possible to reliably prevent solvent deterioration, and in combination with not using a circulation pump, significant energy savings can be achieved. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of a steam cleaning apparatus according to the present invention, and FIGS. 2 and 3 are longitudinal sectional side views showing conventional steam cleaning apparatuses, respectively. 1...Steam cleaning tank, 1a...Solvent reservoir, 1b
...Cleaning section, 2...Solvent, 2'...Solvent in the tube (solvent in the solvent heating tube), 2a...Solvent liquid level, 6...
Solvent heating pipe, 7... Heat pump (solvent heating means), 8... Heated solvent discharge pipe, 9... Heated solvent introduction pipe, 11... Condenser, 15... Refrigerant flow pipe.

Claims (1)

[Scope of Claims] 1. Outside the steam cleaning tank, there is provided an inclined solvent heating pipe whose upper and lower ends are connected to the solvent reservoir of the steam cleaning tank through a heated solvent discharge pipe and a heated solvent introduction pipe, respectively. 2. A steam cleaning device, comprising: a solvent heating means disposed below the liquid level of the solvent reservoir and heating the solvent in the solvent heating tube. 2. Steam cleaning according to claim 1, wherein the solvent heating means is a heat pump, and the condenser of the heat pump is composed of the solvent heating tube and a refrigerant flow tube surrounding the solvent heating tube. Device. 3. The solvent heating means is configured to exchange heat between the solvent in the solvent heating tube and a heating fluid such as hot water, steam, or heat medium oil led to the outer peripheral area of the heating tube. A steam cleaning device according to claim 1, characterized in that: