JPS6243264Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drying oven for coating, that is, a drying oven used for drying (including baking) articles after coating (materials to be dried).

The coating drying oven includes a drying oven main body having an inlet and an inlet for the material to be dried, and a hot air circulation mechanism that circulates hot air within the drying oven main body or a heat radiation duct disposed within the drying oven main body. In some drying ovens, the material to be dried that is transported inside the drying oven body is dried by the heat generated by the hot air circulation mechanism.

By the way, regarding this type of paint drying oven,
Hot air easily escapes from the entrance and exit of the drying oven and its vicinity, making it difficult to maintain high temperatures.
An area where the material to be dried can be effectively dried by the hot air circulation mechanism (hereinafter referred to as an effective drying area) is identified, and care is taken to maintain at least a predetermined temperature or higher in the effective drying area. (Although the effective drying area can be set in various ways by those skilled in the art, it should be understood here that it corresponds to an area where "stain" generation, which will be described later, is unlikely to occur.) Therefore, the hot air that is used to dry the material to be dried in the effective drying area and contains the volatile matter in the paint (hereinafter referred to as tar-forming substance because it forms the tar described later),
When the drying area moves to an area outside the effective drying area (hereinafter referred to as the entrance/exit area because it includes the entrance/exit area), it is cooled due to the relative temperature difference, and becomes "tar" and adheres to the inner wall of the drying oven body. It was expected that this would occur to a considerable extent. and,
This "tar" is located on the upper part of the inner wall of the drying oven main body.
If it adheres to the so-called ceiling, after a certain period of time, it may drip or fall onto the objects to be dried during transportation or the worker during inspection, resulting in poor quality of the objects to be dried or damage to the work. This was leading to environmental degradation.

Therefore, even in conventional paint drying ovens, various techniques have been proposed and put into practice, with emphasis placed on the problem related to "tar". The main technologies at present are the following two types. Specifically, one method is to install a "sand removal duct" above the entrance and exit area of the drying oven body, and indirectly heat the upper part of the entrance and exit area with hot air passing through the duct, thereby preventing the generation of "sand" itself. The second is that it is equipped with a tar-removing demister (something that absorbs tar) or a tar-removing oil pan (something that receives tar) at the top to remove the generated tar. By collecting it, it is possible to prevent the dripping or falling of tar. However, in the case of the former, heat loss is large and is not only a problem from the perspective of energy conservation, but also from the perspective of equipment costs.
On the other hand, in the case of the latter, it is necessary to periodically inspect and clean the "stain removing demister" or the "stain removing oil pan", which is problematic from a maintenance perspective.

The present invention has been made in view of these circumstances, and its purpose is to solve all the problems of the above-mentioned prior art at once.
The coating drying oven of the present invention has a drying oven main body having an inlet and an inlet for the material to be dried, and a heat radiation duct disposed within the drying oven main body or inside the drying oven main body to circulate hot air to dry the material. A painting drying oven is provided with a hot air circulation mechanism for drying, and an effective drying area is formed in the drying oven body by the hot air circulation mechanism, wherein hot air is supplied to an area of the drying oven body that is outside the effective drying area. A hot air discharge means having a discharge port is provided, the hot air discharge port is opened toward the effective drying area, and the opening position of the discharge port is at or above the entrance/exit. be. A preferred paint drying oven of the present invention further includes an exhaust gas purification mechanism for purifying exhaust gas from within the drying oven main body, and the hot air discharge means is connected to the exhaust side of the exhaust gas purification mechanism.

Hereinafter, embodiments of the present invention will be described based on the drawings.

In order to simplify the explanation, FIG. 1 shows only the inlet side of the drying oven main body of the coating drying oven. It should be noted that the configuration on the exit side is also understood to be substantially the same.

In the drawing, 1 is a drying oven main body;
This furnace is a so-called mountain-shaped furnace which is inclined downward toward the inlet 1a in an area 1A including the inlet 1a and outside the effective drying area 1B (hereinafter referred to as the inlet area). The main body 1 is provided with a hot air circulation mechanism X for drying objects to be dried (not shown) conveyed therein in an effective drying area 1B. First, this mechanism will be described.

Inside the main body 1, a discharge duct 2 and a suction duct 3 are arranged at the lower part and the suction duct 3 at the upper part along the extending direction of the main body 1 in the effective drying area 1B. The former 2 has a plurality of discharge ports 2a opened upward, and the latter 3 has a plurality of suction ports 3a opened downward. Further, an air jet discharge duct 4 is disposed slightly above the discharge duct 2 along the extending direction of the main body 1, and its plurality of discharge ports 4a are opened upward. ing. Therefore, the hot air discharge range of the discharge ducts 2 and 4 approximately corresponds to the effective drying area 1B.

The discharge duct 2 is connected to a burner 6 via a pipe 5.
A filter 7 and a fan 8 are sequentially installed in the pipe 5 from the burner 6 side. and,
The piping 5 and the air jet discharge duct 4 are connected via a piping 10 provided with an air jet fan 9. On the other hand, the suction duct 3 is connected to the burner 6 via a pipe 11. Also,
A blower 13 and further a suction filter 14 are connected to the burner 6 via a pipe 12. In addition,
Reference numeral 15 denotes an exhaust pipe whose one end is connected to the pipe 5 and the other end is opened to the outside of the system.

The main body 1 is also provided with an exhaust gas purification mechanism Y for purifying exhaust gas from within the main body 1. Next, this mechanism will be described.

This consists of a purification catalyst 16 and related members 17 to 25. The purification catalyst 16 is connected to the main body 1 via a pipe 17, and a prefilter 18 and a fan are connected in order from the main body 1 side. 19, a heat exchanger 20 and a burner 21 are installed. A blower 23 and a suction filter 24 are connected to the burner 21 via a pipe 22. Further, 25 is an emergency exhaust pipe which has one end connected to the pipe 17 and the other end opened to the outside of the system, and 26 has one end connected to the purification catalyst 16 via the heat exchanger 20 and the other end. This is an exhaust pipe opened to the outside of the system.

Along with the above-mentioned hot air circulation mechanism 1
It is arranged to extend in a direction perpendicular to the direction in which it extends. Then, the duct 27 includes the main body 1
A plurality of discharge ports 28 for those located at the top...
is opened, and the direction of this opening is directed toward the effective drying area 1B side and in the direction of inclination in which the main body 1 extends. Here, the duct 27 is connected to a pipe 29 that branches off and extends from the exhaust pipe 26 of the exhaust gas purification mechanism Y.

Further, 30 is a hood provided in the main body 1 at the main body inlet 1a, and the hood 30 and the outside of the system are connected to a pipe 32 equipped with a fan 31 and branched on the side of the hood 30 from the fan 31. connected via.

In FIG. 1, 33 and 33' are dampers, and 34 is a differential pressure gauge.

Next, the operation of the coating drying oven having such a configuration will be described.

First, according to the hot air circulation mechanism Furthermore, the air is discharged through the air jet fan 9 from the discharge ports 4a of the air jet discharge duct 4 into the effective drying area 1B of the main body 1, thereby heating the material to be dried that is being conveyed within the effective drying area 1B. Much of this discharged hot air is sucked into the suction duct 3 through the suction ports 3a and returned to the burner 6 through the piping 11, thereby making the hot air circulate.

Further, according to the exhaust gas purification mechanism Y, the exhaust gas inside the main body 1 (containing the above-mentioned tar-forming substances, and the substances are also present) is collected by the prefilter 18, the fan 19, the heat exchanger 20, and Burner 2
After the temperature is raised through step 1, purification catalyst 1
6, where it undergoes a purifying action. Thereafter, this purified exhaust gas passes through a heat exchanger 20 to exchange heat with the exhaust gas from inside the main body 1, and is then supplied to the duct 27 in the inlet area 1A through pipes 26 and 29. And this duct 2
At 7, the hot air is discharged from the discharge ports 28, and flows toward the effective drying zone 1B while following the upper part of the inlet zone 1A (in other words, the inclined upper wall of the main body 1).

Here, looking at the hot air (containing a large amount of tar-forming substances) α existing in the effective drying zone 1B, some of it moves from the effective drying zone 1B to the entrance zone 1A and tries to generate "tar". do. However, as described above, since the hot air β discharged from the hot air discharge ports 28 is flowing in the opposite direction to the direction in which the hot air α tends to move, the movement of the hot air α is prevented as much as possible. In addition, even if the hot air α escapes this and moves to the inlet area 1A, there is hot air β in a high temperature state and purified (because it has passed through the purification mechanism) above it. The hot air α maintains its high temperature state and the concentration of tar-producing substances is diluted.
The above-mentioned generation of tar in the upper part of the entrance area 1A is suppressed. Although the parts other than the upper part are in a relatively low temperature state, since the concentration of the tar-generating substance is diluted as in the upper part, almost no "tar" is generated in these parts as well. Further, even if "stin" occurs in parts other than the upper part, the above-mentioned problem related to dripping or falling does not occur because the phenomenon of dripping or falling does not occur as in the upper part.

By the way, since the configuration is such that the hot air discharged from the discharge ports 28 of the duct 27 flows toward the effective drying area 1B, the hot air α tends to flow toward the inlet area 1A, which is the opposite. Also, regarding the hot air β (due to the inertial force of the hot air discharged from the discharge ports 28), the effective drying area 1B
It is possible to move to Therefore, when maintaining the effective drying zone 1B at the set temperature, the thermal energy of the hot air β existing in the inlet zone 1A is utilized very effectively.

Furthermore, in the above embodiment, the hot air purified by the exhaust gas purification mechanism Y is supplied to the duct 27 and discharged into the main body 1, so that the concentration of tar-forming substances in the main body 1 is sufficiently reduced. It contributes to the prevention of tar generation by diluting it to
A separate hot air supply mechanism for supplying hot air to the duct 27 is not required.

For reference, an example of a conventional coating drying oven (corresponding to the above embodiment and based on the above-mentioned "stain removing duct") is shown in FIG. In the figure, 35 is a tar removal duct, and the duct 35 is formed to extend in the direction in which the main body 1 extends in the inlet area 1A (it does not have a discharge port). Note that 36 is a pipe that connects the duct 35 and the exhaust gas purification mechanism Y, and 37 is a pipe that connects the duct 35 and the outside of the system. The present invention is not limited to the above embodiments, but includes the following modifications, for example.

a The hot air supplied to the hot air discharging means 27 may be one that circulates through a hot air circulation mechanism, or a hot air supply mechanism exclusively for the hot air discharging means 27 may be provided separately, and the hot air from the mechanism may be used. You may.

b The hot air discharge means 27 may be disposed at any location as long as it is in the entrance/exit area. For example, it may be arranged closer to the effective drying area 1B or further down than in the above embodiment. Furthermore, these may be combined.

c In accordance with the above b, the opening positions of the hot air discharge ports 28 can also be selected as appropriate. However, the hot air discharged from the hot air outlet 28...
The opening location is required to be at the top of the doorway area so that the flow is at least along the top of the doorway area.

d The hot air discharge ports 28... may have variable opening areas.

e Heating of the drying oven body by the hot air circulation mechanism may be performed indirectly. That is, a heat radiation duct may be provided in the drying oven body, hot air from a hot air circulation mechanism may be circulated within the radiation duct, and the heat radiated from the radiation duct to the drying oven body may be utilized. .

f The only exhaust gas purification mechanism Y may be used as both the effective drying area 1B on the inlet side and the effective drying area 1B on the outlet side.

g. The paint drying oven may be a flat oven equipped with an air curtain.

As described above, according to the present invention, all the problems related to the prior art described above can be solved, and the hot air from the hot air discharge port of the hot air discharge means can be used to maintain the temperature in the effective drying area of the drying oven body. This has the effect of reducing the burden on the hot air circulation mechanism, which in turn leads to energy savings.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing one embodiment of the present invention;
The figures are a plan view showing the main parts of the above example, FIG. 3 is a side view, and FIG. 4 is a configuration diagram (corresponding to FIG. 1) showing a conventional example. 1... Drying oven main body, 1a... Inlet (entrance/exit),
1A... Entrance area (entrance/exit area), 1B... Effective drying area, X... Hot air circulation mechanism, Y... Exhaust gas purification mechanism, 27... Duct (hot air discharge means), 28
...Hot air outlet.

Claims (1)

[Claims for Utility Model Registration] (1) A drying oven body having an inlet and an inlet for drying materials, and a method for drying materials by circulating hot air through the drying oven body or a heat radiation duct provided in the drying oven body. A painting drying oven is provided with a hot air circulation mechanism for drying objects, and has an effective drying area formed by the hot air circulation mechanism in the drying oven main body, wherein an area of the drying oven main body that is outside the effective drying area is , characterized in that a hot air discharge means having a hot air discharge port is provided, the hot air discharge port is opened toward the effective drying area, and the opening position of the discharge port is at the top of the entrance/exit or the vicinity thereof. Paint drying oven. (2) Claim 1 of the Utility Model Registration Claim characterized in that the drying furnace is provided with an exhaust gas purification mechanism for purifying the exhaust gas from within the drying oven main body, and the hot air discharge means is connected to the exhaust side of the exhaust gas purification mechanism. Drying oven for painting.