JPS60197889A - Method and device for adjusting liquid temperature - Google Patents

Abstract

PURPOSE:To utilize the stirring effect of foam and to adjust exactly the liquid temp. by blowing the pressurized air as it is or after heating or cooling into the liquid in a vessel thereby heating or cooling the liquid. CONSTITUTION:The air compressed by a compressor 1 is passed through a flow rate regulating valve 2 to a selector valve 3. On the other hand a temp. sensor S detectes the temp. of the liquid W' in a vessel W and feeds the detection signal thereof to a control part 10. When the control part 10 makes judgement that it is necessary to increase the temp. of the liquid W', said part changes over the valve 3 to the heater 4 side to heat the pressurized air by the heater 4. The air is thereafter blown through a conduit 7 and the aperture 8a of a nozzle pipe 8 to the liquid W' in the vessel W. When the control part makes judgement that it is necessary to decrease the temp., the control part changes over the valve 3 to the cooler 5 side to cool the pressurized air by the cooler 5. The cooled air is then fed through conduits 5g, 7 to the nozzle pipe 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to a method and apparatus for adjusting the temperature of pickling baths and other various chemical solutions.

[Prior art]

For example, when using a small iron tank, the temperature of a pickling bath is conventionally controlled by heating the iron directly with a burner, etc.
The through hole can be heated using an immersion type electric heater, a so-called internal heating method such as passing hot water through a pipe placed in the tank, or blowing heated steam, or using an external heat exchanger to pump the plating bath. The so-called external heating method, etc., which heats the material by guiding it to the outside, is used.

However, the above-mentioned direct heating method is applicable to a narrow range of applications, and the internal heating method requires chemical resistance for the equipment used when the bath liquid is, for example, strongly acidic or strongly alkaline, and there is also the problem that the inside of the bath becomes narrow. In addition, when using steam, there is a problem that the chemical solution changes, and in addition, the external heating method requires large equipment and requires a stirring device etc. inside the tank. [Purpose] This book The invention was made in view of the above circumstances, and its purpose is to efficiently and accurately control the temperature of a liquid by blowing heated or cooled air into the liquid, using the stirring effect of air bubbles. An object of the present invention is to provide a method and apparatus for controlling the temperature of a liquid that can be heated quickly.

〔composition〕

The liquid temperature control method according to the present invention is characterized in that pressurized air is blown into the liquid in the tank either directly or after being heated or cooled to heat or cool the liquid.

Further, the liquid temperature control device according to the present invention includes means for pressurizing air, means for heating and/or cooling the pressurized air, and a nozzle section for injecting the heated or cooled air into the liquid in the tank. It is characterized by including the following.

〔Example〕

Hereinafter, the present invention will be explained in detail regarding the case where the present invention is used for controlling the temperature of a pickling solution. The drawing is a schematic diagram showing a configuration in which the present invention is used to adjust the temperature of a pickling solution. In the drawing, W indicates a pickling bath, W' indicates a cleaning solution, and 1 indicates a compressor. The air compressed by the compressor 1 passes through a flow rate regulating valve 2 and is selectively introduced into either the heating N4 or the cooler 5 by a switching valve 3 provided at a branch point. The heater 4 is equipped with a burner 4b inside the housing 4a, and a pipe 4c for air circulation is spirally arranged above the housing 4a, and the air introduced into the pipe 4b passes through the pipe 4C. During the flowing process, it is heated by heat exchange with the combustion gas of the burner 4b.The heating temperature is determined by the fuel supply pipe 4 from the oil tank 4d to the burner 4b.
This is done by adjusting the flow rate control valve 4f installed at e. The configuration of the heater 4 itself is not particularly limited (any conventionally known configuration may be used as appropriate).

On the other hand, the cooler 5 is configured by arranging a pipe for refrigerant flow (not shown) in the housing 5a.
The air introduced into a is cooled while flowing through the pipe. The cooling temperature is set by adjusting a temperature control section 5b attached to the housing 5a.

Air heated by the heater 4 and air cooled by the cooler 5 are selectively introduced into the air supply pipe 7 through the pipes 4g, 5g and the switching valve 6. The air supply pipe 7 is arranged along one side wall of the pickling bath W, and has a nozzle pipe 8 at its tip. The nozzle pipe 8 is bent into an L shape and extends from the lower part of the side wall of the pickling bath W to near the lower wall, and from there extends along the lower wall to near the other side wall, and from the opening 8a, the cleaning liquid is directed to the side, Or - without blowing air upwards.

There are no particular limitations on the gangway on which the nozzle pipe 8 is arranged;
Alternatively, it may be arranged in a grid pattern so that the pickling bath W is blown out uniformly from the entire pickling bath W.

When heated air is blown into the pickling bath W, it forms fine bubbles in the air cleaning liquid, allowing efficient heat exchange with the cleaning liquid W'.
' is also prevented from being locally heated, heating to a predetermined temperature can be carried out quickly, and there is no risk of dilution of the chemical liquid compared to when steam is blown. The result is the same when cooled air is blown into the cleaning liquid.

The temperature of the cleaning liquid W' is detected by a temperature sensor S inserted into this liquid, and the detection signal is inputted to the indicator 9 and also manually inputted to the control section 10.

A set value for the temperature of the cleaning liquid is input into the control unit 10 in advance, and the temperature signal from the temperature sensor S is compared with this set value to determine an optimal control pattern to eliminate the difference.゛That is, the control unit 10 contains data such as the amount, specific heat, and heat capacity of the cleaning liquid W', as well as equations indicating the relationship between air pressure and air temperature when heating or cooling the cleaning liquid W' to a certain temperature, or A numerical table is entered,
When the temperature difference between the set temperature and the measured temperature is determined as described above, it is determined whether the heater 4 or the cooler 5 is to be driven, and the most efficient amount of air is determined to eliminate the temperature difference. , selects the air temperature, and outputs a predetermined control signal to the fuel flow control valve 4f in the compressor 1 and heater 4, or the temperature control section 5b in order to achieve this.

Note that the above-described control unit 10 is not limited to an automatic control type; it goes without saying that the control unit 10 may be configured to be manually controlled by an operator while monitoring the indicator 9.

Examples of the present invention will be described below with numerical values.

[Example 1] Width 2500++++, length 5000mm, height 2000mm
Add 201-ton of pickling solution containing 15% nitric acid, 5% hydrofluoric acid, and 80% water to a +u bathtub and heat it to 60°C with 830r+ hot air at 220'C. / I was able to accomplish this in about 30 minutes. During the heating process, the mixed pickling solution had a good stirring effect, and although the temperature was measured diffusively during the heating process, an average temperature rise was observed, and no special stirring work was necessary.

In addition, when stainless steel that has been annealed from the beginning is immersed in liquid, the oxidized scale on the surface is completely removed by the bubble process, resulting in a beautiful finish. This required physical brushing, but this work was also completely unnecessary.

[Example 2] In order to pickle (chemical milling) a titanium alloy product, a pickling solution containing 30% nitric acid, 5% hydrofluoric acid, and 65% tap water was placed in the same bath as in Example 1, After heating, when the object was immersed in this, the temperature rose to over 60°C due to a rapid reaction between the pickling liquid and the titanium alloy, creating a risk of hydrogen brittle cracking. By stopping the burner 4c, operating the switching valve 3, and operating the cooler 5, the temperature could be easily maintained at 60°C or lower.

In the past, it was not possible to keep up with the rapid temperature rise of the pickling solution, and there were many interruptions in the pickling process, such as temporarily stopping the pickling process and restarting it after waiting for the pickling solution to descend.However, in the above example, The interruption of work was completely unnecessary. Furthermore, since the cooling air was blown into the pickling bath in the form of bubbles, the temperature could be lowered uniformly due to its stirring effect, and local temperature differences were also extremely small.

[Example 3] A degreasing solution made of chlorine or other solvent was placed in a bathtub made of acid-resistant resin polypropylene, objects such as mechanical parts were immersed in this, and compressed air heated to 120°C (3 When air pressure) was blown into the tank, sufficient degreasing treatment was achieved. Conventionally, when performing this type of degreasing treatment, a stainless steel ultrasonic cleaner was placed in a bathtub to perform ultrasonic cleaning, but in this type of ultrasonic cleaning, the ultrasonic waves are absorbed by the resin, so the resin Although it was not possible to use a bathtub made of
This example did not cause any inconvenience.

[Example 4] In order to remove animal and vegetable oils and mineral oils adhering to the surfaces of mechanical metal parts, these can be used at room temperature, and unlike chlorinated solvents, they do not have a negative impact on the human body (halogen ions). After cleaning, the machine metal parts are cleaned using isopropyl alcohol, and hot air of 170°C and 3 atmospheres is supplied from the heater 4 to the machine metal parts using an appropriate nozzle. Since there was no open flame, the work could be carried out safely without any fear of combustion or explosion.The flash point of isopropyl alcohol is 21.
．． 1℃, but lower flash point than this: Methyl alcohol: 15.6℃, Ethyl alcohol: 15.8℃
Alcohols such as , n-propyl alcohol: 15℃, benzene at 11.1℃, toluene: 4.4℃, xylene: 34.4℃, etc. are also used to remove animal and vegetable fats and mineral oils. , the target mechanical metal parts were dried with air at 170° C. supplied from the heater 4, but no combustion occurred.

[Example 5] Applying paint containing organic solvent (thinner) to mechanical parts,
Similarly, drying was carried out by blowing hot air at 170° C. supplied from the heater 4, but the drying could be carried out efficiently without ignition or combustion.

In addition, although the above embodiment describes the case where room temperature air is heated or cooled, in relation to the liquid to be heated or cooled, it is possible to heat or cool the target liquid even if room temperature air is used as it is. Of course.

〔effect〕

As described above, in the method and apparatus of the present invention, heated and cooled air is used to adjust the temperature of the liquid, so there is no need to disturb the mixing ratio of the target liquid, and there is no risk of combustion, explosion, etc. What's more, the agitation effect of air bubbles allows for uniform and quick adjustment of the liquid temperature without local changes.Furthermore, since no special equipment is installed inside the tank, the inside of the tank can be widely used, and the temperature of the cleaning liquid can be adjusted evenly. When used for temperature control, the present invention has excellent effects such as being able to improve the cleaning effect on objects by using air bubbles at the same time as temperature control.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing a configuration in which the present invention is applied to temperature control of a pickling solution. W... Pickling bath Wl... Cleaning liquid S... Temperature sensor... Compressor 2... Flow rate adjustment valve 3...
・Switching valve 4... Heater 5... Cooler 6... Switching valve 7... Air supply pipe 8... Nozzle pipe 8a...
Air outlet 9...Indicator 10...Control unit Patent applicant: Nishiyama Stainless Chemical Co., Ltd. Patent attorney: Noboru Kono

Claims (1)

[Scope of Claims] A method for adjusting the temperature of a liquid in summer, which comprises blowing pressurized air directly or after heating or cooling into the liquid in a tank to heat or cool the liquid. 2. It is characterized by comprising means for pressurizing air, means for heating and/or cooling the pressurized air, and a nozzle section for injecting the heated or cooled air into the liquid in the tank. Liquid temperature control device.