JPH01191212A - Fluid temperature adjuster - Google Patents

Abstract

PURPOSE:To save a paint and to decrease a touchup by opening a connecting pipe by a three-way valve, and also, raising a temperature of a fluid by controlling a medium heater, when a fluid temperature is lower than a prescribed value, and supplying a heating medium of a heating medium tank to a heat exchanger by closing the connecting pipe, when the fluid temperature is higher than the prescribed value. CONSTITUTION:When a paint temperature which is measured by a temperature sensor 11a in the vicinity of a fluid gun 14 is low, a temperature controller 11 opens a connecting pipe 9 by turning a three-way valve 6, heats a heating medium by a medium heater 8, and contrives a temperature rise of a fluid by this heating medium. On the contrary, when a fluid temperature has becomes higher than a management value, the temperature controller 11 closes the connecting pipe 9 by switching the three-way valve 6, eliminates an applied voltage of the medium heater 8, and contrives cooling of the fluid by supplying a heating medium of a cold low temperature of a heating medium tank 3 to a heat exchanger 2. In such a way, spray width of a paint is made uniform, and an overlap and a painting omission can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a temperature regulating device for a fluid, and more particularly to a temperature regulating device for heating or cooling a high viscosity fluid such as a vinyl chloride resin paint to a desired temperature.

(Prior Art) The conventional technology will be explained using a painting line that handles high viscosity paint as an example. In the painting line, paint is sprayed onto a workpiece from a spray gun. Apply 80-150 paint to this spray gun.
Conventionally, the discharge pressure has been strictly controlled because it is necessary to pressurize it to about Kg/crd and the discharge amount is related to the discharge pressure.

In response to seasonal temperature changes, spray patterns have been managed by changing the viscosity of the paint by changing the proportion of solvent, and in the winter by raising the temperature with a heater to adjust the viscosity.

(Problem that the invention seeks to solve) However, when we measured the air temperature and the paint temperature at the spray gun inlet on the above-mentioned conventional painting line, we obtained the data shown in Figure 3, and the results are shown in Figure 4. As such, the spray width of some spray guns has expanded from 200+sm to 225+u+.

That is, the viscosity of the paint changes due to temperature changes between day and night, heat generation due to flow path resistance friction, heat absorption from the booster, and a combination of these effects.

Therefore, an increase in overlap or leakage occurs,
There was a problem of excessive consumption of paint or an increase in repainting.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes a heat exchanger, a heat medium tank, a heat medium supply pipe and a return pipe, and a three-way outlet valve interposed in the supply pipe.・The temperature of the fluid is determined from the pump and medium heater, the communication pipe connecting the three-way valve and the return pipe, the medium cooler attached to the heat medium tank, and the temperature controller that controls the three-way valve and the medium heater. Forming a regulating device.

(Function) When the temperature of the fluid is low, the three-way valve opens the communication pipe, the medium heater heats the heat medium, and the heat medium raises the temperature of the fluid.

When the temperature of the fluid is high, the communication pipe is closed with a three-way valve, and the cold and low temperature heat medium from the heat medium tank is supplied to the heat exchanger to cool the fluid.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a configuration diagram of a fluid temperature adjustment device according to the present invention, and the fluid temperature adjustment device 1 is roughly divided into a heat exchanger 2, a heat medium tank 3, and these heat exchangers 2. Heat medium tank 3
a supply pipe 4 and a return pipe 5 for circulating a heat medium between them, a three-way port valve 6 interposed in the middle of the supply pipe 4, a pump 7,
The medium heater 8, the remaining one of the three-way valve 6, and the return pipe 5
a communication pipe 9 that communicates with
and a temperature controller ll, which will be described in detail below.

The heat exchanger 2 exchanges heat between a fluid and a heat medium, and has first and second meandering pipes 2b, 2ct-
The supply pipe 4 and return pipe 5 are connected to the meandering pipes 2b and 2c, respectively.

The other end of each of the meandering pipes 2b and 2c is connected to a pipe for supplying and recovering a heat medium to a constant temperature jacket of a plunger pump of a fluid booster 12, which will be described later.

On the other hand, the tip of a main supply pipe 13a that leads fluid from a fluid supply source to this container 2a is inserted into the container 2a of the heat exchanger, and a conduit 13b that transports fluid to the fluid booster 12 branches from the container 2a. are doing.

That is, the heat exchanger 2 performs mutual heat exchange between the heat medium passing inside the meandering tubes 2b, 2c and the fluid passing outside the meandering tubes 2b, 2c.

The heat medium tank 3 is a storage tank for a heat medium connected to a return pipe 5 from the heat exchanger 2 and a supply pipe 4 heading toward the heat exchanger 2 .

This heat medium tank 3 is equipped with a medium cooler lO for cooling the heat medium therein. The medium cooler 10 is a cooler that circulates, compresses and expands a refrigerant such as Freon, absorbs heat from the heat medium, and releases this heat to the atmosphere from a heat radiating plate. The heat medium in the heat medium tank 3 is circulated between the heat medium tank 3 and the medium cooler 10 by the pump 10b until the measured value of the temperature sensor 10a inserted into the heat medium tank 3 reaches a predetermined value.

A remotely controllable three-way valve 6 is interposed in the middle of the supply pipe 4 that connects the heat medium tank 3 and the heat exchanger 2.
A pump 7 and a medium heater 8 are interposed on the heat exchanger z side.

Pump 7 is a line pump that pumps the heat medium in supply pipe 4 toward heat exchanger 2 .

The medium heater 8 is, for example, an electric heater whose applied voltage is continuously variable using a thyristor, and heats the heat medium.

A communication pipe 9 branching from the middle of the return pipe 5 is connected to the remaining one 6a of the three-way valve 6.

In addition, in the figure, 4a and 5a are connected to the heat medium tank 3 from the connecting pipe 9.
These are headers provided on the side supply pipes 4 and return pipes 5, respectively, and function to connect - heat medium tanks 3 and a plurality of heat exchangers 2... with piping.

The fluid booster 12 has a plunger 12b formed by a piston rod of a piston 12a, which is used to send a desired high-pressure fluid to the fluid gun 14, and which reciprocates under the action of switchingly supplied hydraulic oil.

12c alternately sucks fluid into the cylinders 12d and 12e and compresses it. 12f and 12g are jackets that enclose the cylinders 12d and 12e, and allow the heat medium to pass therethrough.

The temperature controller 11 receives a temperature signal from a temperature sensor lla that measures the temperature of the fluid near the fluid gun 14, and outputs a switching command signal for the three-way valve 6 and a control command signal for the medium heater 8.

The operation of the fluid temperature regulating device having the above configuration will be described below.

The fluid flows in the order of main supply pipe 13a→heat exchanger 2→conduit 13b→cylinders 12d and 12e+conduit 13cm+fluid gun 14, and is injected from fluid gun 14.

The circulating fluid returns to the heat exchanger 2 via conduit 13d.

That is, fluid enters the heat exchanger 2 through the main supply pipe 13a and the conduit 13d and exits to the conduit 13b.

The temperature adjustment effect of the present invention will be explained using a vinyl chloride resin paint as an example of this fluid.

The control value for the vinyl chloride resin paint is 30°C, and if the paint temperature measured by the temperature sensor lla near the fluid gun 14 is low, the temperature controller 11 rotates the three-way valve 6 to open the communication pipe 9. develop.

The heat medium is pressurized by the pump 7, heated by the medium heater 8, and then passed through the supply pipe 4 from the first meandering pipe 2b to the jacket 12f of the plunger cylinder 12d to the jacket 12g of the plunger cylinder 12e to the second pipe. It circulates in the order of meandering pipe 2C → return pipe 5 → communication pipe 9 → three-way port valve → 6-bump 7.

The temperature controller 11 changes the heating capacity of the medium heater 8 according to the difference between the reading of the temperature sensor lla and the control value. When there is no temperature difference, the voltage applied to the medium heater 8 becomes zero.

Conversely, when the fluid temperature becomes higher than the control value, the temperature controller 11 switches the three-way valve 6 to close the communication pipe 9 and makes the voltage applied to the medium heater 8 zero.

Then, the heat medium is supplied from the heat medium tank 3 to the supply pipe 4 → the header 4a
→ Three-way valve 6 → Pump 7 → Supply pipe 4 → First meandering pipe 2b
→ jacket) 12f → jacket 12g → second meandering pipe 2C → return pipe 5 → header 5a → return pipe 5 → heat medium tank 3.

Incidentally, a sufficient amount of heat medium is stored in the heat medium tank 3,
The medium cooler 10 acts independently of the command from the temperature controller 11 to maintain a constant low temperature.

Figure 2 shows the action data of this device, where the horizontal axis is time;
The vertical axis shows the temperature, the horizontal line A is the control value of 30°C, the curve B is the temperature recorded value of the heat medium in the supply pipe 4, and the curve C is the temperature sensor l
This is the recorded temperature value of the paint according to la.

In the figure, temperature adjustment device 1 is activated at Pl, and the paint temperature is 22.
Since the temperature was as low as 0.degree. C., the medium heater 8 was activated to heat the heat medium and warm the paint. Since the paint temperature reached 30° C. at P2, the heat medium begins to pass through the heat medium tank 3. Although the temperature of the heat medium in the supply pipe 4 drops rapidly, the curve C becomes gentle because the heat medium itself absorbs heat and the operation of the medium cooler 10 is delayed.

At P3, the three-way port valve 6 is switched again and the switching medium heater 8 is activated.

The paint is deceptively kept near a controlled temperature.

In this embodiment, the cylinder 12d of the plunger pump is heated by sliding friction heat and is at a low temperature at startup.

It also has the feature that temperature is maintained by passing a heat medium through jackets 12f and 12g that enclose 12e.

In addition, since the medium cooler 10, which uses a refrigerant such as Freon and is a complicated piece of equipment, is attached to the heat medium tank 3 without being interposed in the supply pipe 4, the medium cooler 10 can be operated even during heating operation. Therefore, the capacity can be reduced. That is, the device is characterized in that a simple heating means is interposed in the supply pipe 4, and a complicated cooling means is attached to the heat medium tank 3.

(Effects of the Invention) As described above, the present invention maintains the temperature of the fluid at a predetermined temperature by selectively using a medium heater and a heat medium tank with a medium cooler, even if the temperature changes in the four seasons and during the day and night. This makes it possible to maintain a uniform paint spray width and prevent overlapping and paint leakage, thereby saving paint and reducing the need for repair painting.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a fluid temperature regulating device according to the present invention, Fig. 2 is a diagram showing changes in paint temperature by the device of the present invention, and Fig. 3 is a diagram showing changes in paint temperature by the device of the present invention.
The figure shows the change in paint temperature using a conventional device, and FIG. 4 shows the relationship between paint temperature and spray width. In addition, in the drawing, 1 is a fluid temperature adjustment device, 2 is a heat exchanger,
3 is a heat medium tank, 4 is a supply pipe, 5 is a return pipe, 6 is a three-way valve, 7 is a pump, 8 is a medium heater, 9 is a communication pipe, 10 is a medium cooler, 11 is a temperature controller, 12 is a fluid booster, 1
2f and 12g are jackets. river/busu p

Claims (1)

[Claims] A heat exchanger that exchanges heat between a fluid and a heat medium, a supply pipe/return pipe that supplies and recovers a heat medium from a heat medium tank to this heat exchanger, and a three-sided pipe installed in the middle of this supply pipe. a port valve, a communication pipe connecting the remaining port of the three-way port valve to the middle of the return pipe, a pump and a medium heater provided on the heat exchanger side of the three-way port valve of the supply pipe, and the heat medium. A medium cooler attached to the tank keeps the heat medium in the heat medium tank at a predetermined low temperature, and when the fluid temperature is lower than a predetermined value, a three-way valve opens the communication pipe and controls the medium heater to cool the fluid. and a temperature controller that increases the temperature and closes the communication pipe with the three-way port valve to supply the heat medium in the heat medium tank to the heat exchanger when the fluid temperature is higher than a predetermined value. Temperature control device.