JPH06178965A - Device and method for regulating temperature of fluid - Google Patents

Abstract

PURPOSE:To regulate the temperature of fluid with equipment which is simplified and operates at a low running cost by providing an orifice installed on circulating piping and for increasing the temperature of fluid and a control mechanism for controlling the temperature of fluid. CONSTITUTION:An orifice 5 installed in circulating piping 18 and for increasing the temperature of fluid and a control mechanism for controlling the temperature of fluid are provided. Consequently viscous fluid is circulated through the piping 18 having the orifice 5, causing the temperature of the fluid to be increased by the self-friction of the fluid. That is, since without requiring an outside heat source, the temperature of the fluid is increased, the equipment is sharply simplified. And since the outside heat source is not required, running cast is remarkably decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature adjusting device and a temperature adjusting method for raising the temperature of a fluid, particularly a liquid, and is particularly suitable for keeping the temperature of a paint constant. Is the way.

[0002]

2. Description of the Related Art Various coatings are applied to automobiles for the purpose of protection and beauty. Spray coating is applied to paint by atomizing the paint. In this spray coating, uniform spraying is required, but for that purpose, the requirements such as the discharge amount of the paint, the spray pattern width, the fineness of grain, the relative linear velocity, and the spraying distance must be appropriate. It is required to keep it constant.

[0003]

The above requirements for good coating are easily influenced by the temperature of the coating material, and in particular, the discharge amount, spray pattern, and atomization are greatly influenced by the coating material temperature. Therefore, the coating mechanism is provided with a temperature adjusting device equipped with a heat source for keeping the temperature of the paint constant, and the paint temperature is managed by the temperature adjusting device. The temperature control device for controlling the temperature of the paint includes equipment for maintaining the temperature of the paint constant, for example, equipment for supplying an external heat source such as a temperature control tank, a heat exchanger, auxiliary piping, etc., for example, a heat source generator. , Heat storage tank, heat source supply circulation pumping device,
Attached piping is required. FIG. 2 shows a conventional example of the temperature adjusting device. The temperature control device 20 shown in FIG. 2 includes a temperature control tank 22, a pressure feed pump 24, a heat exchanger 26, and a temperature control tank 22.
And the pipe 28 for connecting the pressure pump 24 and the pressure pump 24.
And pipe 30 for connecting the heat exchanger 26, the pipe 32 for connecting the heat exchanger 26 and the temperature control tank 22, the heat storage tank 34, the pipe 40 for connecting the heat storage tank 34 and the heat exchanger 26, and the pressure feed provided for the pipe 40. The pump 36 and the heater 38, the pipe 42 connecting the heat exchanger 26 and the heat storage tank 34, the cold water generator 44, and the pipes 46 and 48 connecting the cold water generator and the heat storage tank 34 are roughly configured. The cold water generator 44 circulates cold water among the cold water generator 44, the pipe 46, the heat storage tank 34, and the pipe 48. The heater 38 heats the water flowing in the pipes 40 and 42, and the pump 36 circulates the water between the heat storage tank 34 and the heat exchanger 26. Further, the paint is stored in the temperature control tank 22, and the paint is circulated through the temperature control tank 22, the pipe 28, the pipe 30, the heat exchanger 26, and the pipe 32 by the pressure feed pump 24. That is, the water circulation system and the paint circulation system are the heat exchanger 26.
It is configured so that heat can be transferred and received via the. In this state, the paint temperature in the temperature control tank 22 is constantly measured,
Based on the result, the cold water generator 44 and the heater 38 are controlled so that the temperature of the water circulating in the heat exchanger 26 and the pipes 40 and 42 brings the paint temperature in the temperature control tank 22 close to the set temperature. Controlled. For example, when the paint temperature in the temperature control tank 22 is lower than the set temperature,
The temperature of the water circulation system is set to a high temperature. Conversely, when the paint temperature in the temperature control tank 22 is higher than the set temperature, the temperature of the water circulation system is set to a low temperature. At this time, since the temperature setting degree of the water circulation system is determined based on the result of the control device calculating the difference between the temperature in the temperature control tank 22 and the paint setting temperature by a method such as proportional / differential / integral, it is usually Repeat the fluctuations and continue to maintain the best condition. By adjusting the temperature of the water circulation system, the temperature of the paint circulation system is adjusted via the heat exchanger 26. Therefore, by controlling the cold water generator 44 and the heater 38, the temperature of the paint in the temperature control tank 22 can be maintained at the set value. The temperature control tank 22 has an output pipe 50 connected to a coating machine (not shown).
Is installed, and the paint of the desired temperature is adjusted to the temperature control tank 22.
Out through the output pipe 50.

In the temperature controller 20 having this structure,
Although the paint can be supplied to the coating machine while being kept at an appropriate temperature, it requires a lot of equipment, is complicated, and becomes large in size. In addition, not only a large amount of cost is required for equipment investment, but also the frequency of cleaning and maintenance increases. Moreover, since the heater and the cold water generator are used, the running cost is increased.
In particular, the use of an external heat source such as a heater or a cold water generator causes a significant increase in the coating process cost.

The present invention has been made to solve the above problems, and provides an apparatus and method for adjusting the temperature of a fluid with an apparatus having a simplified and low running cost.

[0006]

A fluid temperature adjusting apparatus of the present invention comprises a temperature control tank for storing the fluid, and a pump provided in the temperature control tank. The fluid in the temperature control tank circulates inside. And a control mechanism for controlling the temperature of the fluid.

In the method for adjusting the temperature of a fluid of the present invention, the fluid is circulated in a circulation pipe provided with an orifice, the temperature of the fluid is measured, and the measurement result is fed back to a control mechanism attached to the circulation pipe. It is characterized by adjusting the temperature of the fluid.

[0008]

The fluid temperature adjusting device and method according to the present invention circulate a viscous fluid in a pipe having an orifice to increase the temperature of the fluid by self-friction of the fluid. According to this method, the temperature of the fluid is raised without the need for an external heat source, so that the apparatus can be greatly simplified. In addition, since an external heat source is unnecessary, running costs can be reduced significantly. In particular, the temperature of the fluid can be kept constant by having a control mechanism that measures and feeds back the temperature of the fluid.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The temperature adjusting device 16 shown in FIG. 1 is provided in the coating device in order to keep the paint at an appropriate temperature.
The circulation pipe 18 and a control mechanism are roughly configured. The temperature control tank 1 is a container for storing paint, which is a fluid, inside. One end of the circulation pipe 18 is connected to the bottom surface of the temperature control tank 1, and the other end is connected to the upper surface.
It circulates inside. The circulation pipe 18 is provided with pressure feed pumps 2 and 2, and the pressure feed pump 2 circulates the paint. Further, the circulation pipe 18 is provided with an orifice 5. The passage diameter of the paint in the orifice 5 is formed small, and the circulating paint is rapidly agitated by passing through the orifice, so that self-friction occurs. The passage diameter of the orifice 5 is determined by the opening degree of a variable orifice valve provided inside the orifice 5, and is preferably variable by control from the outside. Further, the circulation pipe 18 is provided with a circulation fluid control valve 4. Further, the circulation pipe 18 is the branch portion 1
A supply pipe 10 is provided, which is branched at 9 and supplies the paint to a coating machine 11. A booster pump 9 for pumping the paint to the coating machine 11 without pulsation in the supply pipe 10,
An intake valve 7 and an outflow valve 8 are provided before and after the booster pump 9. The booster pump 9 is connected to a hydraulic pressure generator, a hydraulic valve, and a hydraulic pipe (not shown), and reliably supplies the pressure and flow rate of the paint required by the coating machine 11 using the hydraulic pressure. For this reason, the booster pump 9 employs a single-acting mechanism, which is a mechanism that does not cause the pressure fluctuation when reversing the operation, which is seen in the return pump. The intake valve 7 is used to supply paint to this hydraulic booster.
Is opened and the outflow valve 8 is closed, by an upward actuating force on the booster pump 9 of a hydraulic device (not shown) and an auxiliary pressure by the pressure feed pump 2. Due to this behavior, the booster pump 9 operates up to the upper limit end and the inside is filled with paint. Further, the coating material is supplied to the coating machine 11 by a downward actuating force of a booster pump 9 of a hydraulic device (not shown) with the suction valve 7 closed and the outflow valve 8 opened. Also,
The coating machine 11 and the temperature control tank 1 are also connected by a return pipe 12. A return valve 15 is provided on the return pipe 12.
Is provided.

The supply pipe 10 may not be provided so as to be branched from the circulation pipe 18 and may be directly provided in the temperature control tank 1.

In the temperature adjusting device 16 of this embodiment, in order to raise the temperature of the fluid, that is, the paint, the pressure pump 2 is driven with the circulating fluid control valve 4 open to circulate the paint in the temperature control tank 1. It is circulated in the pipe 18. Since the circulation pipe 18 is provided with the orifice 5, the paint pressure-fed to the orifice 5 at high pressure generates heat due to self-friction. Regarding the heat generation phenomenon of the fluid at the orifice, the heat generation temperature increases as the viscosity of the fluid increases. Therefore, if the paint has a resin component, a pigment and the like and has a high viscosity, the temperature can be sufficiently raised to a suitable temperature for coating. The paint circulating in the circulation pipe 18 is heated every time it passes through the orifice 5,
Eventually, a suitable temperature for coating is reached. The temperature control tank 1 is provided with a temperature measuring device 13, and the temperature of the paint in the temperature control tank 1 is constantly measured. After the temperature of the paint reaches an appropriate temperature, the intake valve 7, the outflow valve 8 and the booster pump 9 are interlocked with each other to feed the paint to the coating machine 11, as described in the description of the operation of the booster pump 9. Excessive or residual paint after painting is returned to the temperature control tank 1 via the return pipe 12 by opening the return valve 15. Further, the temperature data of the paint measured by the temperature measuring device 13 is transmitted to the controller 14. Controller 1
4 is connected to the circulating fluid control valve 4. The circulating fluid control valve 4 can control the flow rate of the paint circulating in the circulation pipe 18. Therefore, the controller 14 can control the circulating fluid control valve 4 to control the amount of fluid circulating in the circulation pipe 18. That is, in the temperature adjusting device 16 of this embodiment, the temperature measuring device 1 for measuring the temperature of the fluid is used.
3, a controller 14 to which temperature data is transmitted from the temperature measuring device 13, and a circulating fluid control valve 4 controlled by the controller 14 constitute a control mechanism for controlling the temperature of the fluid. The controller 14 compares the preset temperature input in advance with the temperature data transmitted from the temperature measuring device 13, and if the measured temperature is lower than the preset temperature, the circulation pipe 18
The flow rate of the fluid circulating inside is increased, and if the measured temperature is higher than the set temperature, the amount of fluid circulating inside the circulation pipe 18 is reduced. In this way, by measuring the temperature of the fluid and feeding back the measurement data to operate the control mechanism, the fluid can be maintained at the set temperature. Further, the operation of the temperature adjusting device 16 and the coating device incorporating the temperature adjusting device 16 of the present embodiment will be described. When the paint temperature is lower than the set temperature without coating, the suction valve 7 is closed, the circulating fluid control valve 4 is opened, and the pressure feed pump 2 is driven to circulate the paint in the temperature control tank 1. 18
Circulate inside. Since the paint passes through the orifice 5, the temperature of the paint is gradually raised. If the paint temperature is higher than the set temperature,
The circulating fluid control valve 4 is closed to stop the paint circulation. The paint gradually drops depending on the ambient temperature. When the paint temperature is lower than the set temperature during coating, the circulating fluid control valve 4 is opened to circulate the paint in the circulation pipe 18, and the suction valve 7 is used as described in the description of the operation of the booster pump 9. , Outflow valve 8 and booster pump 9
The paint of suitable temperature is sent to the coating machine 11 by interlocking with each other.
When the paint temperature is higher than the set temperature, the circulating fluid control valve 4
To prevent paint from circulating in the circulation pipe 18,
The paint temperature is lowered by the ambient temperature. The operations of these valves and pumps can be automatically controlled by the controller 14.

The temperature of the fluid can be controlled by changing the passage diameter of the orifice 5. The amount of heat generated by self-friction of the fluid passing through the internal passage of the orifice is
It becomes higher as the passage diameter of the orifice becomes smaller. Therefore, in order to further raise the temperature of the fluid, the passage diameter of the orifice 5 may be narrowed, and in order to suppress the temperature rise of the fluid, the passage diameter in the orifice 5 may be widened. The passage diameter of the office 5 can be controlled by controlling the opening degree of a variable orifice valve provided inside the orifice 5. Therefore, the controller 14 controls the orifice 5
It is possible to control the opening of the variable orifice valve and to control the orifice 5 based on the measured temperature of the fluid to adjust the temperature of the fluid. further,
By constructing a fluid temperature control mechanism in which the adjustment by the orifice 5 and the adjustment by the circulating fluid control valve 4 are combined, a more precise and quick fluid temperature adjustment can be performed.

With a coating apparatus incorporating the temperature adjusting apparatus 16 of the present embodiment, it is possible to always apply a paint having an appropriate temperature, so that it is possible to perform the application while keeping the discharge amount, spray pattern and atomization optimum. it can.

Further, a fluid having a high viscosity has a characteristic (thixotropy) that its viscosity is lowered by giving a continuous flow, but according to the method of this embodiment, the fluid is circulated in the circulation pipe 18. The applied fluid is the coating machine 11
Therefore, the paint can be sent to the coating machine 11 in a state where the viscosity is lowered. Therefore, the energy required for pumping the fluid, that is, the pumping load can be reduced, and the load on the pump that pumps the fluid can be reduced. Therefore, if the coating apparatus incorporates the temperature adjusting apparatus of this embodiment, the coating process cost can be further reduced.

In the fluid, the first solution (resin content (PVC): 2
4%, plasticizer: 25%, adhesive agent: 6%, pigment: 37%,
Calcium oxide: 4%, solvent: 4%) and second solution (resin content (PVC): 28%, pigment: 39%, additive: 3
%, Solvent: 30%), and the temperature rising / falling characteristics were measured. The measurement was performed by raising the temperature of both the first solution and the second solution at 22 ° C. using the temperature adjusting device of the present embodiment. still,
The ambient temperature was 19 ° C. The results are shown in Fig. 3. (In the figure, ◯-◯: first solution, □ --- □: second solution) From FIG. 3, the first solution was heated to 30 ° C. in about 1 hour,
It can be seen that the solution was heated to 30 ° C. in about 6 hours. still,
The measurement test is to circulate each solution in the circulation pipe 18 after the temperature of each solution reaches 30 ° C. (about 1 hour after the first solution and about 6 hours after the second solution). After stopping, the temperature was naturally cooled by the ambient temperature and the temperature lowering characteristics were also examined.

Further, a test of keeping the temperature constant for 19 hours was conducted using the first solution and the second solution. The first solution was set at 25 ° C. and the second solution was set at 29 ° C., and the temperature change of each solution was measured. The measurement results are shown in FIG. It can be seen from FIG. 4 that the temperatures of both the first solution and the second solution are kept constant within an allowable range around the set temperature.

According to the temperature adjusting device of this embodiment, the equipment is simple and the size can be greatly reduced. In addition, the cost of equipment investment is low, and cleaning and maintenance are easy. Furthermore, since no heater or cold water generator, that is, an external heat source is required, running costs can be significantly reduced. In particular, eliminating the need for a facility for supplying an external heat source can significantly reduce the installation area of the temperature control device and the use of external energy, which is very advantageous for cost reduction. Therefore, if the temperature adjusting device and the adjusting method of the present embodiment are applied to, for example, a coating device,
It is possible to significantly reduce the coating process cost.

The fluid temperature adjusting apparatus of the present invention is not limited to the one used in a coating apparatus, but may be applied as a heating apparatus for various fluids as long as the fluid has a certain degree of viscosity. For example, it can be used as a temperature adjusting device for fats and oils, foods and the like.

[0019]

The fluid temperature adjusting apparatus and method according to the present invention circulate a viscous fluid in a pipe having an orifice, and utilize the temperature rise characteristic of the fluid due to self-friction of the fluid. . According to this method, the temperature of the fluid can be raised without the need for an external heat source, so that the apparatus can be greatly simplified. Therefore, it is possible to significantly reduce the size of the device, reduce the cost required for equipment investment, and reduce the frequency of cleaning and maintenance. In addition, since an external heat source is unnecessary, running costs can be reduced significantly. In particular, the temperature of the fluid can be kept constant by having a control mechanism that measures and feeds back the temperature of the fluid. Also,
Since fluids with high viscosity have thixotropic properties,
By circulating the fluid in the circulation pipe, the viscosity of the fluid can be reduced. Therefore, the pumping load required for pumping the fluid can be reduced, and the load on the pump that pumps the fluid can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a temperature adjusting device of the present embodiment.

FIG. 2 is a configuration diagram showing a conventional temperature adjusting device.

FIG. 3 is a graph showing test results of temperature rising / falling characteristics of a fluid.

FIG. 4 is a graph showing test results of temperature control characteristics of fluid.

[Explanation of Codes] 1 Temperature Control Tank 2 Pressure Pump 4 Circulating Fluid Control Valve 5 Orifice 11 Coating Machine 13 Thermometer 14 Controller 16 Temperature Control Device 18 Circulation Piping 20 Temperature Control Device 22 Temperature Control Tank

Claims (2)

[Claims] 1. A temperature control tank for storing a fluid, a circulation pipe provided in the temperature control tank and having a pump for circulating the fluid in the temperature control tank, and a temperature of the fluid provided in the circulation pipe. And a control mechanism for controlling the temperature of the fluid, the fluid temperature adjusting device. 2. A fluid is circulated in a circulation pipe provided with an orifice, the temperature of the fluid is measured, and the measurement result is fed back to a control mechanism attached to the circulation pipe to adjust the temperature of the fluid. A method for adjusting a temperature of a fluid, comprising: