JPH0245798B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a heating furnace that is incorporated into a part of a conveyor line and is used to dry and bake articles to be conveyed.

(Prior Art) In this type of heating furnace, an appropriate heat source is selected in consideration of thermal efficiency, stability, uniformity, safety, etc. A heating furnace that burns liquid or gaseous fuel using a burner device as a heat source, and heats the furnace by directly introducing hot air from the combustion gas into the furnace, is economical because it has a high heat calorie, is simple to install, and is easy to use. There are advantages. However, on the other hand, since heat is carried into the furnace by the combustion gas to heat the article, it is necessary to introduce a large amount of combustion gas into the furnace. This results in the same amount of gas being discharged from the furnace, which wastes fuel if it is not metabolized efficiently. Particularly problematic is the handling of the entrances and exits for goods on the conveyor line.

Conventionally, as a heating furnace with good thermal efficiency, a heating furnace described in Japanese Patent Publication No. 58-12513 and Japanese Patent Publication No. 59-42225, both of which were filed by the same applicant as the present applicant.
There is a mountain-shaped furnace as shown in Figure 1. This mountain-shaped furnace has a burner device c installed in the lower floor part b of the furnace body a configured in a tunnel shape, and a conveyor line d that conveys goods e.
The upper edges f' and g' of the inlet f and outlet g are set at approximately the same height as the lower floor part b.

That is, the inside of the furnace is shaped like a bowl, hot air generated from the burner device c rises due to convection, and low temperature gas is pushed out from the upper edges f' and g' of the inlet f and outlet g. The mechanism is that the gas that fills the furnace is at a higher temperature, and the lower temperature gas is exhausted by natural convection. Therefore, the thermal efficiency is good and the temperature inside the furnace is also averaged.

(Problem to be solved by the invention) However, since the entrances f and g of the conventional heating furnace are inclined, the overall height of the furnace body a becomes high, making it impossible to install due to space constraints, or depending on the type of product. However, there are some people who dislike slopes during transportation, and there was a fear that such a mountain-shaped furnace could not be used.

In view of the above-mentioned points, the present invention provides a heating furnace having a horizontal furnace body and having the advantages of a mountain-shaped furnace.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above-mentioned object, the heating furnace according to the present invention has a substantially horizontal tunnel-shaped furnace body having a conveying device such as a rail, and a burner device in the lower floor. An air curtain device is installed at the entrance and exit, and an exhaust port that opens near the bottom of the furnace body is installed to guide the hot air generated by the heat source directly into the furnace body by natural convection. , the air is exhausted from the exhaust port.

(Function) This heating furnace is equipped with an air curtain device at the entrance and exit of the almost horizontal tunnel-shaped furnace body, so the hot air generated from the heat source such as the burner device is confined by the air curtain device. The heated air is discharged from the exhaust port that opens near the bottom floor due to natural convection, so the mechanism is exactly the same as that of a conventional mountain-shaped furnace, resulting in high thermal efficiency and stable and uniform heat distribution within the furnace. is obtained.

(Example) Hereinafter, an example of a heating furnace according to the present invention will be described with reference to the accompanying drawings.

FIG. 2 shows an embodiment of a heating furnace according to the present invention, and this heating furnace has a tunnel-shaped furnace body 1 that is substantially horizontal. In the furnace body 1, rails 3 are laid on the lower floor surface 2, and the articles 4 are passed through the furnace by a conveyance device such as a cart (not shown). A pit 5 is provided at a suitable location on the lower floor surface 2, and a heat source such as a gas burner 6 or an electric heating device is placed. Also. An exhaust passage 7 that opens at a position close to the lower floor surface 2 is arranged.

An air curtain device is provided at the article entrances and exits 8 and 9 of the furnace body 1. The air curtain device has a plurality of air blowing slits 10 on one side, and opposing air suction slits (not shown) on the opposite side. The interval between the slit openings 10, 10 is appropriately set in consideration of the vertical width (length in the transport direction) of the article 4, and is selectively used by the opening/closing valve 11.

Next, the operation of the heating furnace will be explained.

Items 4 are placed on a transport device such as a trolley that runs on rails 3 and are carried in one after another from the article inlet 8 of the furnace body 1.The articles 4 that have been carried in pass through the furnace and are directed toward the article outlet 9. You will be guided there.

While the imported items 4 pass through the furnace, the hot air released from the heat source such as the gas burner 6 has high-temperature gas at the top, and low-temperature gas that has been cooled by baking and drying the items 4 naturally. It is guided to the lower part by convection and is discharged through an exhaust passage 7 that opens near the lower floor surface 2.

That is, the hot air generated from the heat source such as the gas burner 6 is confined by the air curtain, and due to the convection phenomenon, the hotter gas stays at the top, and the lower temperature gas passes through the exhaust passage 7 and is released into the atmosphere. is dissipated inside. Therefore, the mechanism is exactly the same as that of a mountain-shaped furnace, and the temperature inside the furnace is averaged with high thermal efficiency.

Note that the conveying device may be a conventional conveyor line shown in Japanese Patent Publication No. 58-12513.

〔Effect of the invention〕

As described above, the heating furnace according to the present invention is a nearly horizontal tunnel-shaped furnace body having a conveyor device such as a rail, a heat source such as a burner device installed in the lower floor, an air curtain device at the entrance and exit, and ,
An exhaust port that opens near the bottom of the furnace body is arranged, and the hot air generated by the heat source is guided directly into the furnace body by natural convection, and the air is exhausted from the exhaust port, so that the furnace body is almost horizontal. , it can be configured to perform exactly the same function as a direct heating type mountain furnace that uses natural convection, and can easily achieve the thermal efficiency of a mountain furnace. The overall height of the furnace body can be set low, which is advantageous in terms of space, and the horizontal lower floor allows for easy use of transport means such as carts.Moreover, it has good thermal efficiency, so it is extremely effective when incorporated into baking painting lines.

In addition, the gas in the furnace is lowered in temperature by natural convection and is discharged from the exhaust port that opens near the bottom floor, so it is constantly metabolized and there is no accumulation of gas. It is also possible to prevent harmful effects on the coating and the risk of explosion due to increased concentration. Therefore, this furnace has good thermal efficiency, saves fuel, is easy to use, has low equipment costs, is extremely economical, and has excellent functions.

Furthermore, this heating furnace uses a natural convection method,
Since the article to be treated is carried in from one side of the furnace body and taken out from the other side, the article to be treated can be heat-treated continuously and efficiently.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing an example of a conventional heating furnace as a mountain-shaped furnace, and FIG. 2 is a longitudinal side view showing an embodiment of the heating furnace according to the present invention. 1...Furnace body, 2...Subfloor surface, 3...Rail, 4
... Goods, 6 ... Gas burner, 7 ... Exhaust passage,
10...Air blowout slit opening.

Claims (1)

[Claims] 1 A nearly horizontal tunnel-shaped furnace body with a conveyor device such as a rail, a heat source such as a burner device installed in the lower floor, and an article inlet on one side of the furnace body and an article outlet on the other side. , an air curtain device is provided at the article inlet and outlet, and an exhaust port that opens near the bottom of the furnace body is disposed in the middle of the furnace body, and the hot air generated by the heat source is transferred into the furnace body by natural convection. A heating furnace characterized in that air is guided directly and exhausted from the exhaust port.