JPS6219912B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Use and Purpose The present invention provides a system for using outside air as cooling air.
To provide a method for cooling a high-temperature automobile body, etc. after baking and drying, by using water spray in combination to increase cooling efficiency and save energy, and to provide a cooling method that does not leave traces of water droplets due to water spray.

Prior Art An example of a conventional cooling device using outside air as cooling air is shown in FIGS. 10 and 11. The cooling chamber 1 is formed in the shape of a tunnel, and is configured such that an object 3 to be cooled, such as an automobile body, transferred from a baking paint drying furnace 2 can be transferred therein. An air supply chamber 4 and an exhaust chamber 5 are formed on the inner peripheral wall of the cooling chamber 1.
A plurality of air outlets 6 are formed at predetermined positions for blowing cooling air onto the object 3 to be cooled, and an air suction port 7 is formed in the exhaust chamber 5 for discharging cooled air. The air supply chamber 4 is communicated with the outside air via the air supply ducts 8a, 8b and the air supply fan 9, and by operating the air supply fan 9, cold outside air is forcibly used as cooling air from the air outlet 6. It's something to burst out into. Further, the exhaust chamber 5 is communicated with the outside air via exhaust ducts 10a, 10b and an exhaust fan 11, and is configured to exhaust warm air after heat exchange to the outside by operating the exhaust fan 11. There is.

The device configured as described above cools the object 3 to be cooled, such as an automobile body, to room temperature by forcibly blowing cold outside air as cooling air from the air outlet 6 onto the object 3 such as an automobile body. However, with such a method of blowing only cooling air, the cooling efficiency is not very high, so a large amount of air needs to be blown, and the air supply fan 9 and exhaust fan 11 require large power. Therefore, a method of improving cooling efficiency by adding water spray to the cooling air has been considered, but it is difficult to adjust the amount of spray, and more water than necessary is often sprayed. Because it leaves water droplets and traces on the surface of objects, it could not be used on painted products or other items with quality problems.

Composition of the Invention The present invention transports a high-temperature object to be cooled after baking and drying into a tunnel-shaped cooling chamber for a certain period of time.
In a cooling method in which the object to be cooled is cooled to a predetermined temperature by blowing cold outside air as cooling air onto the object from an air outlet provided in a cooling chamber, in the cooling air flow blown out from the air outlet. A predetermined amount of water is sprayed at predetermined intervals for a predetermined time according to a predetermined spray pattern, and cooling air containing no spray water and cooling air containing spray water are sprayed. The structure is such that the cooling material is alternately sprayed onto the object to be cooled.

Effects of the Invention The present invention sends water in the form of a mist on cooling air, and controls the spray amount, spray interval, and spray time according to a predetermined spray pattern depending on the cooling conditions of the object to be cooled. Therefore, the entire amount of sprayed water adhering to the surface of the object to be cooled quickly evaporates while cooling air that does not contain spray water is being blown, leaving water droplets and traces on the surface of the object to be cooled. This has the excellent effect of ensuring that no residue remains and ensuring good product quality. In addition, when the spray water attached to the surface of the object to be cooled evaporates, heat of vaporization is taken away from the object to be cooled, so cooling efficiency is significantly improved.
The power of the air supply fan and the exhaust fan can be significantly reduced, resulting in excellent energy savings.

Embodiment FIGS. 1 and 2 show a first embodiment of a cooling device constructed by applying the method of the present invention. In the figure, the 10th
The same reference numerals as in the figures and FIG. 11 indicate the same members.

A spray nozzle 12 that sprays water is located at the center of the front surface of each air outlet 6.
It is installed so as to spray water in the direction of the flow of cooling air blown out from the cooling air, and is configured to mix the sprayed water with the cooling air and blow it out. The spray nozzle 12 is controlled by a spray control device 13 and a control panel 14 according to a predetermined spray pattern as shown in FIG. 5 to spray water.

That is, to explain the spray pattern in FIG. 5, the vertical axis indicates the temperature difference between the temperature of the object to be cooled and the blowing temperature of the cooling air, expressed on a logarithmic scale.
Note that the horizontal axis indicates elapsed time. In addition, the blowing temperature of cooling air (hereinafter referred to as blowing air temperature)
is θ ₀ , the wind speed is v ₁ , and the temperature of the object to be cooled at the start of cooling is θ ₁ .

First, the object to be cooled 3 placed in the cooling chamber 1 is air-cooled for a time T ₁ with cooling air at a wind speed v ₁ , and the temperature θ
Cool to ₂ . Then, for a time t ₁ , the amount of spray from the spray nozzle 12 is carried on the cooling air at a wind speed v _1.
Water spray is performed in _Q1 and the water spray is cooled to a temperature of _θ3 . Similarly, for time T ₂ , cooling air with a wind speed v ₁ is used to cool the temperature to θ ₄ , and for time t ₂ , water is sprayed on the cooling air with a spray amount Q ₂ to cool the temperature to θ ₅ . , air cooling to temperature θ ₆ with cooling air at a wind speed v ₁ for time T ₃ , water spraying at a spray amount Q ₃ on the cooling air for time t ₃ , water spray cooling to temperature θ ₇ , time T Temperature _θ with cooling air of wind speed v ₁ between ₄ and 8
air cooling until time t ₄ , spray volume on cooling air
Water spray cooling at Q ₄ to temperature θ ₉ , time
Air cooling is performed with cooling air at a wind speed v ₁ during T ₅ to a temperature θ ₁₀ . In this way, air cooling using only cooling air,
When water spray cooling, in which water is sprayed on cooling air, is performed alternately, the entire amount of sprayed water adhering to the surface of the object to be cooled 3 evaporates during the subsequent cooling period using only cooling air. At this time, the object to be cooled 3 is rapidly cooled by removing the heat of vaporization. By repeating this cooling operation, the cooling progresses in the form of a line graph, and as a result, a cooling effect equivalent to air cooling with cooling air at a wind speed v ₂ shown in FIG. 5 is exhibited. Therefore, each data T ₁ to _{T 5} , t ₁ to t ₄ , Q ₁ to Q ₄ , etc. shown in FIG. By doing so, it is possible to realize a cooling method with extremely high cooling efficiency even though the amount of air blown is small. It goes without saying that the spray pattern illustrated in FIG. 5 can be determined in advance through experiments or the like depending on the cooling conditions.

Examples of specific values for the spray pattern in FIG. 5 are: θ ₀ =25°C, θ ₁ =125°C, θ ₂ =109°C,
θ ₃ = 89℃, θ ₄ = 74℃, θ ₅ = 64℃, θ ₆ = 59
°C, θ ₇ = 52 °C, θ ₈ = 49 °C, θ ₉ = 45 °C, θ ₁₀
= 44℃, Q ₁ = 24c.c./min, Q ₂ = 14c.c./min, Q ₃ =
8.3cc/min, Q ₄ = 4.3cc/min, T ₁ = 20sec, T ₂ =
27sec, T ₃ = 17sec, T ₄ = 15sec, T ₅ = 5sec, t ₁ =
3sec, t ₂ = 4sec, t ₃ = 4sec, t ₄ = 5sec, T =
100 sec, v ₁ = 2.1 m/sec, V ₂ = 10 m/sec.

Next, a method for controlling the amounts of water sprayed from the spray nozzles 12, _Q1 to _Q4 , will be explained with reference to FIG. Adjustment of the amount of water sprayed from the spray nozzle 12 is achieved by intermittent ON-OFF control, and is controlled by setting ON time t _a and OFF time t _b and changing the ratio of ta and tb. are doing. As an example, each spray amount Q ₁ ~ in FIG.
If we show a specific numerical example of ta and tb that gives Q ₄ , the fourth
In the case of q=0.14cc/0.1sec in the figure, Q ₁ =24c.c./
When min, ta = 0.2sec, tb = 0.5sec, Q ₂ = 14c.c./min
When ta = 0.2sec, tb = 1.0sec, Q ₃ = 8.3cc/min ta = 0.2sec, tb = 1.8sec, Q ₄ = 4.3cc/min
It is sufficient to set ta=0.2sec and tb=3.8sec.

An example of the configuration of the spray control mechanism portion of the spray nozzle 12 is shown in FIG. Spray time setting device 15
T _{1 to} T ₅ , t ₁ to _{t 4} , Q ₁ to _{Q 4} , etc. in FIG.
The above-mentioned ON-OFF times ta and tb are set respectively to give . By combining each of these data in the spray pattern generator 17,
A spray pattern signal as shown in FIG. 5 can be sent to the spray control device 13, thereby controlling the water sprayed from the spray nozzle 12 according to the spray pattern shown in FIG.

The apparatus of the first embodiment having the above-mentioned structure carries the high-temperature object 3 from the baking paint drying furnace 2 into the cooling chamber 1 and leaves it there for a certain period of time while following the spray pattern shown in FIG. Cooling air containing no spray water and cooling air containing spray water are alternately blown onto the object 3 to be cooled. The sprayed water that is sprayed together with the cooling air adheres to the surface of the object 3 to be cooled in the form of a mist, and the entire amount is evaporated by the subsequent spraying of the cooling air that does not contain the sprayed water. At this time, heat of vaporization is taken from the object to be cooled 3, and the temperature of the object to be cooled 3 decreases in the form of a line graph according to the cooling curve shown in FIG. 5, and after a certain period of time T has elapsed, the object to be cooled 3 is cooled to a predetermined temperature. When cooling is completed, the object to be cooled 3
is carried out from inside the cooling chamber 1 to the outside and carried to the next process.

As is clear from the above embodiments, according to the method of the present invention, although the velocity of the cooling air blown out from the air outlet 6 is v ₁ =2.1 m/sec, it is substantially v ₂ It is possible to achieve the same cooling effect as air cooling with cooling air having a wind speed of 10 m/sec. Therefore, as a result of reducing the wind speed to about 1/4, the fan power can be reduced to about 1/16. Also,
Since the spray nozzle 12 is controlled by adjusting the ON-OFF time ratio, the spray amount can be easily changed and the cooling system can be adjusted more easily than when using a variable flow rate pump or valve. The spray mechanism can be downsized. Furthermore, since no water droplets are generated on the surface of the object to be cooled, it is suitable for cooling items with strict product quality.

6 and 7 show a second embodiment of a cooling device constructed by applying the method of the present invention. The difference from the first embodiment (Figs. 1 and 2) is that the object to be cooled 3 is continuously transferred from the inlet to the outlet without stopping in the cooling chamber 1, and during the transfer, the above-mentioned water is It is configured to complete spray cooling. In order to achieve this, the inside of the cooling chamber 1 is divided into three areas: front stage, middle stage, and rear stage, and dedicated spray nozzle groups 12a, 12c, and 12b are provided for each area, so that the object to be cooled 3 is placed in each area. When the area reaches the target area, the water spray cooling mentioned above is performed using the spray nozzles in each area. FIG. 9 shows the spray pattern for this three-stage water spray cooling. The pattern itself is the same as that shown in _FIG .
However, the spray nozzle 12b is in charge of t ₂ and the spray nozzle 12c is in charge of t ₃ , and the 9th spray nozzle is in charge of t 3.
This achieves the spray pattern control shown in the figure.

FIG. 8 shows the spray nozzle 12a in FIG.
An example of the configuration of the spray control mechanism portions 12b and 12c is shown. Each spray nozzle 12a, 12b, 12
c, each corresponding spray control device 13
a, 13b, 13c, spray time setting device 15
a, 15b, 15c are provided, and the data for the spray nozzle 12a is provided by the spray time setting device 1.
5a, the data for the spray nozzle 12b is sent to the spray time setting device 15b, and the data for the spray nozzle 12c is sent to the spray time setting device 15b.
The data for each is set in the spray time setting device 15c, and the spray pattern generator 17 creates a spray pattern signal dedicated to the spray nozzle from each data according to the moving position of the object to be cooled 3, and each spray control device 13a , 13b, 13c
It is configured to be sent to.

Specific numerical examples of the spray pattern in Figure 9 are: θ ₀ = 25°C, θ ₁ = 125°C, θ ₂ = 118°C,
θ ₃ = 85℃, θ ₄ = 69℃, θ ₅ = 59℃, θ ₆ = 50
°C, θ ₇ = 45 °C, θ ₈ = 44 °C, Q ₁ = 24 c.c./min,
Q ₂ = 8.3cc/min, Q ₃ = 4.3cc/min, T ₁ = 10sec,
T ₂ = 35sec, T ₃ = 35sec, T ₄ = 5sec, t ₁ = t ₂ = t ₃ =
5sec, T=100sec, v ₁ = 2.1m/sec, v ₂ = 10m/
sec.

According to the second embodiment, the baking paint drying oven 2
While the high-temperature object 3 is carried into the cooling chamber 1 and passes through, water is sprayed from the corresponding spray nozzles 12a, 12b, 12c depending on the passing position, and as a result, the object 3 to be cooled is While passing through the cooling chamber, the whole is cooled according to the cooling curve shown in FIG.

In addition, in Figures 5 and 9, the amount of water sprayed
The reason why Q ₁ to _{Q 4} decrease as the temperature of the object to be cooled θ ₁ to _{θ 10} decreases is because as the surface temperature of the object to be cooled decreases, the evaporation rate of the spray water adhering to the surface of the object decreases. This is because if the amount of spray is large, excessive moisture will adhere to the surface of the object to be cooled, and water droplets may be generated. Therefore, the spray amount Q ₁ to _{Q 4}
is the cooling air blowing time following the water spray.
T ₁ , T ₂ , ......T ₅ ) are selected so that the entire amount can evaporate from the surface of the object to be cooled.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a first embodiment of a cooling device constructed by applying the method of the present invention, FIG. 2 is a schematic longitudinal sectional view of the same, and FIG. 3 is a configuration diagram of a spray control mechanism. Figure 4 shows spray ON to adjust the spray amount.
OFF control time chart, FIG. 5 is a spray pattern diagram, FIG. 6 is a schematic side view of a second embodiment of a cooling device constructed by applying the method of the present invention, and FIG. 7 is a schematic longitudinal sectional view of the same. , FIG. 8 is a configuration diagram of the spray control mechanism portion, FIG. 9 is a spray pattern diagram, FIG. 10 is a schematic side view showing the structure of a conventional cooling device, and FIG. 11 is a schematic longitudinal sectional view of the same. . 1: cooling chamber, 3: object to be cooled, 6: air outlet,
9: Air supply fan, 11: Exhaust fan, 12, 12
a, 12b, 12c: spray nozzle, 13, 1
3a, 13b, 13c: spray control device, 1
4: Control panel.

Claims (1)

[Claims] 1. A high-temperature object to be cooled after baking and drying is carried into a tunnel-shaped cooling chamber for a certain period of time, and cold outside air is blown onto the object as cooling air from an air outlet provided in the cooling chamber. In the cooling method, water is sprayed into the cooling air stream blown out from the air outlet, and a predetermined amount of water is sprayed at predetermined intervals according to a predetermined spray pattern. A water spray cooling method characterized by spraying water for a predetermined period of time and alternately spraying cooling air that does not contain spray water and cooling air that contains spray water onto an object to be cooled.