JPH01119367A - Drying furnace - Google Patents

Abstract

PURPOSE:To attain a stabilization of quality and an improvement of workability by arranging a heating-up zone using far infrared ray and a soaking zone using hot air successively from a carry-in port in a body of a drying furnace, wherein coated matters of complicated shapes are dried while they are conveyed. CONSTITUTION:A heating-up zone 4 using far infrared ray and a soaking zone 5 using hot air are arranged successively from a carry-in port in a body 2 of a drying furnace A, wherein coated matters 1 of complicated shapes are dried while they are conveyed. It is possible, as a result, to attain a stabilization of quality by preventing dispersion of coating film properties through uniformly heating the coated matters as a whole and also to improve a workability by utilizing far infrared ray efficiently.

Description

[Detailed description of the invention] [Industrial application field]

TECHNICAL FIELD The present invention relates to a drying oven for drying a painted object having a complicated shape while being transported.

[Conventional technology]

Drying ovens that use far infrared rays have been known for some time, but
As shown in FIG. 4, it was difficult to uniformly heat the painted object 1 which had a complicated shape. This is because far-infrared rays are a type of electromagnetic waves, and because they travel in a straight line, the temperature of the part 1a perpendicular to the far-infrared rays increases quickly.
This is because the temperature rise of the portion 1b parallel to the far infrared rays is delayed. On the other hand, although hot air drying ovens provide uniform heating, the heating rate of the coating as a whole is slow, and
The workability was poor. For this reason, the present inventors have already developed a drying furnace that has a heating zone using far infrared rays in the upper or lower part of the furnace body, and a soaking zone using hot air in the lower or upper part. is in the heating temperature zone and has a relatively high temperature (temperature 3
The far-infrared heater heated to a temperature of approximately 50 to 400 degrees Celsius is cooled by hot air (temperature of approximately 130 degrees Celsius) in the soaking zone, and the rate of temperature rise of the coating object 1 does not become so fast, making the effect of far-infrared rays effective. was not available.

Problem to be Solved by the Invention 1 The present invention has been made in view of the above circumstances, and it solves the problem of poor coating film performance caused by non-uniform heating of the painted object and delay in temperature rise in various parts in the conventional technology. The aim is to improve variations and poor workability. [Means for Solving the Problems] The drying oven of the present invention is a drying oven that dries a painted object 1 having a complicated shape while conveying it, and in which far-infrared rays are sequentially introduced into the oven body 2 from the loading port 3. It consists of a heating temperature rising zone 4 and a scorching zone 5 using hot air, and this structure solves the above-mentioned problems. (Function) When the painted object 1 is brought in through the loading port 3, the painted object 1 is heated by far infrared rays in the heating temperature rising zone 4.
Although there are local variations, the temperature can be raised quickly as a whole, and then the hot air from the scorching heat zone 5 compensates for the variation in temperature rise in the heating temperature rising zone 4, so that the object to be coated 1 can be uniformly heated as a whole. It is possible to prevent variations in coating film performance by heating, and by effectively utilizing far infrared rays, overall workability is improved.

【Example】

A heat insulating material is provided on the peripheral wall of the furnace main body 2, and an inlet 3 is provided at one end in the longitudinal direction, and an outlet 6 is provided at the other end. The furnace body 2 is installed on a base 8 of a conveyor 9, and the conveyor 9 runs inside the furnace body 2 from an inlet 3 to an outlet 6. A hot air generator 12 equipped with a sparker 10 is installed on the outer surface of the clay wall of the furnace body 2.
A 7-ring 13 is attached to the end of the hot air generator fi12 facing the sburner 10. Inside the furnace body 2, a heating zone 4 using far infrared rays and a soaking zone 5 using hot air are installed sequentially from the loading port 3. The heating temperature rising zone 4 is constructed by hot air heating type far infrared heaters 15 installed at predetermined intervals so as to form hot air channels 14 on the inner surface of the soil wall and the inner surface of the lower wall in the furnace body 2, respectively. It is something that The upper and lower hot air channels 14 are connected by a hot air duct 16 at the front and rear of the heating temperature raising zone 4, and the hot air generated by the hot air generator fi12 by the fan 13 is circulated through the hot air duct 16 and the hot air channel 14. The far-infrared heater 15 is heated, and far-infrared rays are generated from above and below within the furnace body 2. The hot air temperature is controlled by the large burner 10 by measuring the temperature of the hot air in the rear hot air duct 16. In the scorching heat zone 5, a part of the hot air from the heating temperature increasing zone 4 is sucked by the fan 18 through a communication duct 17 connected to the hot air duct 16 at the rear of the heating temperature increasing zone 4.
This hot air serves as a heat source and is sent downward through the hot air duct 19 and circulated within the soaking zone 5. In this way, a part of the hot air in the heating temperature rising zone 4 is transferred to the soaking zone 5.
Since it is used as a heat source, it is possible to save energy. The hot air temperature is controlled by a control valve (not shown) by measuring the temperature near the fan 18. The temperature of the hot air is preferably 5 to 10° C. higher than the final temperature of the coated object 1. In addition, a preheating chamber 20 and an annealing chamber 21 are attached to the inlet 3 and the outlet 6 of the furnace body 2, respectively, and the inlet 22 of the preheating chamber 20 can be freely turned in the R direction with N23 to prevent heating and temperature rise. The heat in the zone 4 is blocked from escaping to the outside, while the carry-out port 6 and the outlet 24 of the slow cooling chamber 21 can be opened and closed by 523, and the heat in the soaking zone 5 is blocked from escaping to the outside. That's what I do. An exhaust pipe 27 is provided in the upper part of the preheating chamber 20 and the slow cooling chamber 21. Therefore, this drying oven A produces aW as shown in Fig. 4.
When drying the treated product 1, when the painted product 1 is carried into the furnace body 2 by the conveyor 9, it is irradiated in the vertical direction from the upper and lower far infrared rays and a part 15 in the heating temperature rising zone 4. Due to the far infrared rays, the temperature of the portion 1a of the coating object 1 perpendicular to the far infrared rays is mainly increased, and the temperature rise of the portion 1b parallel to the far infrared rays, which is in the shadow of the far infrared rays, is delayed. Next, in the soaking zone 5, the coated article 1 is uniformly heated as a whole by hot air, and the temperature of the coated article 1 is raised uniformly throughout, so that each part 1a of the coated article 1, The final temperature reached by lb will be the same. The temperature changes in each part of the painted object 1 are shown in FIG. ta
The time required to leave the soaking zone 5 is shown as tb. Note that the chain line indicates heating only by the heating temperature rising zone 4.1 For example, if the total length of the furnace body 2 is 6111, the heating temperature rising zone 4
When the coated object 1 is processed in the drying oven A with a length of 4 m and a soaking zone 5 of 2 m, the temperature of the far infrared heater 15 in the heating temperature rising zone 4 is set to 350 to 400°C. When the hot air temperature in the soaking zone 5 is set to 125 to 130°C and the fi temperature of the painted object 1 is set to 120 to 130°C, ta is 3 to 7 minutes, and tb is 9 to 10 minutes. there were. As shown in FIG. 6, in the heating temperature rising zone 4, a far-infrared radiator 26 is provided on the inner wall surface of a cylindrical body 25 such as a corrugated tube by thermal spraying, and an outer tube is attached to this cylindrical body 25. 28
The gap between the cylindrical body 25 and the outer tube 28 may be configured as the hot air flow path 14 by fitting the hot air into the outer tube. Far-infrared rays can be irradiated from the infrared irradiator 26, and the hot air is flowed through the hot-air channel 14 formed in a spiral shape on the outer wall of the cylindrical body 26, so far-infrared rays can be irradiated from the entire inner wall of the cylindrical body 25. By doing so, it is possible to compensate for the straight propagation of far infrared rays and to more uniformly raise the temperature of the object to be coated 1.

【Effect of the invention】

In the present invention, a heating zone using far infrared rays and a soaking zone using hot air are formed in the furnace main body sequentially from the loading port, so that when the object to be coated is transported through the loading port, the heated temperature increasing zone By heating with far infrared rays, it is possible to quickly raise the temperature of the painted object as a whole, although there are local variations, and then the hot air from the soaking zone compensates for the variations in temperature rise in the heating zone. , it is possible to uniformly heat the entire coating process to prevent variations in coating film performance and stabilize quality, and in this way, effective use of far infrared rays improves overall workability. It is possible to significantly improve the

[Brief explanation of the drawing]

! @ Figure 1 is a side sectional view showing one embodiment of the present invention, Figure 2 is a plan view of the same as above, Figure 3 is a sectional view taken along the line X-X of Figure 1, and Figure 4
The figure is a perspective view showing an example of a painted object, FIG. 5 is a graph showing the treatment of the painted object according to the above, and FIG. 6 is a side sectional view showing the heating temperature rising zone on the other side of the present invention, A
1 is the drying oven, 1 is the painted product, 2 is the oven body, 3 is the loading port,
4 is a heating temperature rising zone, and 5 is a soaking zone. Agent Patent Attorney Ishi 1) 艮
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Claims (1)

[Claims] (1) A drying oven that dries a painted object with a complex shape while being transported, and consists of a heating zone using far infrared rays and a soaking zone using hot air, which are successively constructed from the loading entrance into the oven body. .