JPS594843A - Interception of open air by air curtain - Google Patents

Abstract

PURPOSE:To prevent accurately the entry of the open air into a system and to control the releasing of gases in the system by a method wherein the two air curtains flowing in opposite directions are formed at a predetermined interval so that a swirling air stream is generated between the air curtains. CONSTITUTION:Air blown out from outside the system is transferred through a pipe 4 and divided into a part to be blown out from a blowout port 2 and a part to be blown out from a blowout port 3. Further, the air sucked into the system is discharged into the atmosphere from pipes leading from air intake ports 2' and 3' and brought together to be connected to an exhaust fan. The air enclosed by the two air curtains forms itself the swirling air stream to help increase the thickness of the air curtains on both sides thereof to thereby prevnet accurately the entry of the open air. Further, when the internal air curtain is made strong and the external air curtains is made weak by operating control valves 5 and 6, it is possible to discharge the gases within the system into the atmosphere while preventing the open air from entering into the system.

Description

[Detailed Description of the Invention] Air curtains remind the general public of the air flow at the entrances and exits of department stores, supermarkets, etc. where many people come in and out, but they are also often used in factory equipment.

For example, when metal workpieces to be heat treated are sent one after another by a conveyor to a tunnel-type heating furnace, or when molded products are continuously sent by cart to a refractory firing furnace, the entrance and exit of the furnace cannot be closed if the Ji is closed. Therefore, the air flow of the air curtain prevents heat from flowing into the furnace and cold outside air from entering.

However, the effectiveness of conventional air curtains in blocking internal and external air or gas cannot be said to be very good. Assuming that the air or gas inside and outside the air curtain is stationary and there is no object coming in or going out, we examine the operation status of the air curtain and find that the surface flow of the air curtain is as shown in Figure 2. The air or gas that comes in contact with the air or gas is drawn in to form a small vortex, resulting in a multi-turbulent flow that separates from the surface one after another and dissipates, and the air that remains in the main flow also slows down and forms a turbulent flow. This results in the passage of air or gas between the inside and outside.

In order to eliminate the above-mentioned drawbacks, the present invention uses two air curtains that flow in opposite directions, with a fixed distance between them. That is, one air curtain creates air flow from top to bottom, the other creates air flow from bottom to top, or right to left, left to right, etc., but now it creates air flow from top to bottom. Let us consider two air curtains. As shown in Figure 1, the two air curtains have the same surface flow that comes in contact with the outside air and the surface flow that comes into contact with the gas inside the furnace, but the air in the area surrounded by the two air curtains is It moves to form a large rotating airflow, and together with the air curtains on both sides, it becomes a thick air curtain. Therefore, their outside air blocking effect is significantly increased compared to a conventional double air curtain.

As mentioned above, the counterflow double air curtain has ensured the effect of blocking outside air, but depending on the furnace, if the gas generated inside is harmful, it is necessary to extract it midway through the furnace with a Gino Dive and dispose of it. If the gas is harmless, such as water vapor or carbon dioxide, it is often advantageous to release the gas sequentially through the furnace inlet and outlet. The present inventor has discovered a method for releasing internal gas while blocking outside air in such cases.

That is, by weakening the outer air curtain (downward flow) and strengthening the inner air curtain (upward flow), internal gas can be released to the outside, and the amount of released air can also be controlled to a large extent.

In addition, the blocking effect of the air curtain is significantly increased, and at the same time, the thickness of both air curtains can be made considerably thinner than the conventional one, and energy can be saved even more than the conventional one by using counterflow. I understand.

Next, an embodiment will be explained with reference to FIG. The figure shows a paint drying oven. In this embodiment, the generated gas is harmless. 1
is a furnace body, the rail 7 is supported on the lower surface by a support 8, the material to be dried 9 is suspended from movable hooks 10, and the movable hooks 10 are attached to chains 11 at equal intervals. A horizontally rotating chain wheel (not shown) is installed outside the furnace to move the chain 11 endlessly. Therefore, the objects to be heated move one after another in the direction of the arrow. 2 is a downward flow outlet, 3 is an upward flow outlet provided on the floor, and intake ports 2' and 3' are provided at opposing positions. The blown air is sent to the A' ear 64, and is branched into the respective blow-off ports 2 and 3 by the downward flow control valve 5 and the upward flow control valve 6. The intake air is discharged to the outside air by connecting piping from each intake port 2' and 3' to an exhaust fan (not shown). As shown in the figure, the air surrounded by the two curtains serves as a rotating airflow and thickens the air curtains on both sides to reliably prevent outside air from entering. This furnace uses infrared rays for drying, and the gas generated is harmless, but if it is harmful, it must be burned and vented to the outside air. If it is harmless as in this example, or if heating is being performed by blowing in combustion gas, the air curtain will be broken and outside air will enter unless the internal gas is removed one by one. 6 to make the inner air curtain stronger and the outer air curtain weaker, it is possible to prevent the intrusion of outside air while releasing the air inside to the outside world.

As mentioned above, the present invention is economically significant due to energy saving by reliably preventing the intrusion of outside air, the fact that the air curtain itself is energy saving compared to conventional ones, and the improvement of workability by controlling internal gas release. It is something that contributes.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a drying oven in accordance with an embodiment of the invention, showing a countercurrent air curtain according to the invention. FIG. 2 is a reference diagram showing a conventional air curtain. 1: Drying oven, 2: Downward flow outlet, 2'; Downward flow inlet,
3: Upward flow outlet, 3': Upward flow inlet, 5 and 6: Outlet control valve, 7: Rail, 9: Material to be dried, 11: Chain conveyor. Patent applicant Hino Motors Co., Ltd. Application agent
Patent Attorney Ito Strict Procedural Amendment (Method) October 72, 1980 Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 110836 of 1983 2, Name of the invention Air curtain outside air blocking method 3, Amendment Patent applicant address: 3-1-1 Hinodai, Hino-shi, Tokyo Name: Hino Motors Co., Ltd. Representative Director Masaji Arakawa 4 Agent address: 5-28-16 Kaijin, Funabashi-shi, Chiba 6. Subject of amendment Column 7 for a brief explanation of the drawings in the specification. Contents of the amendment: "Cross-sectional view" on page 5, line 20, is amended to "side sectional view." Correct to “Explanatory diagram” 〇1

Claims (2)

[Claims] (1) A method for blocking outside air from air curtains, which is characterized in that two air curtains are spaced apart from each other to form opposing flows, and a rotating airflow is created between them. (2) A patent claim in which two air curtains are spaced apart from each other to form countercurrent flows, and by changing the strength of these airflows, external air is blocked and internal gas dispersion to be released to the outside is controlled. The outside air blocking method for air curtains described in item 1.