JPH0630299Y2 - Heat exchanger for paint drying oven - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a heat exchanger used for heating a drying gas circulated and supplied into a coating and drying furnace.

(Prior Art and Problems Thereof) Conventionally, in a device such as a coating drying oven, a coating film formed on a predetermined article is dried by circulating hot air into the oven.

A so-called indirect heating type hot air generator using a heat exchanger for generating hot air to be such a drying gas is conventionally known (Japanese Utility Model Publication No. 63-82476).

The heat exchanger used in this type of indirect heating type hot air generator is one in which a large number of metal plates are arranged in parallel in a wave pattern at a predetermined interval, and the gas to be heated is The gas that serves as a heat medium is ventilated so as to be orthogonal to each other and not mixed with each other.

However, when such a heat exchanger is used for heating the drying gas which is circulated in the coating drying furnace, the following problems occur.

That is, in addition to various kinds of dust and dust, paint components evaporate and mix into the coating film drying gas, so such components adhere to the metal plate wall of the heat exchanger to form a so-called tar.

Therefore, it is necessary to clean the heat exchanger at regular intervals. However, in this type of heat exchanger, in order to efficiently perform heat exchange, the metal plate has a wavy shape and the adhered paint components are Since it has a high viscosity and adheres strongly to the metal plate, its cleaning is extremely difficult.

Therefore, in the conventional apparatus as disclosed in the above publication, it was necessary to remove the heat exchanger from the apparatus in order to clean the heat exchanger.

(Means for Solving the Problem) That is, the present invention is intended to improve the cleaning property of a heat exchanger used in an indirect heating type hot air generator used in a coating film dryer.

That is, according to the present invention, a plurality of corrugated metal plates are arranged at a predetermined interval substantially in parallel, and the gas for the heat medium and the gas for drying to be circulated in the coating and drying furnace are respectively supplied to the metal. In a heat exchanger for a coating drying furnace for ventilating into a gap between plates to form hot air with the drying gas, a metal serving as a ventilation passage for the heating medium gas and a metal serving as a ventilation passage for the drying gas. The gaps between the plates are located alternately,
The mixture of both gases is prevented, and the heating medium gas and the drying gas are introduced into the gap between the metal plates in a horizontal crossing manner, and the gap between the metal plates serves as an air passage for the drying gas. Is configured so as to include a straight space that is not obstructed by the corrugated inner wall of the metal plate between the inlet and the outlet, and the metal plate has a ventilation gas flowing at a constant inclination angle with respect to the horizontal plane. The cleaning device provided with a large number of cleaning liquid supply nozzles arranged in a row toward the straight space has a higher position on either the inlet side or the outlet side in the ventilation direction of the drying gas. The heat exchanger is provided so as to be movable over the entire surface of the gap between the metal plates serving as a passage for the drying gas.

(Example) The heat exchanger of this invention is demonstrated based on the specific example shown in an accompanying drawing.

In FIG. 1, which briefly shows the heat exchanger of the present invention, this heat exchanger comprises a large number of corrugated metal plates 1 arranged in parallel at a predetermined interval.

The corrugated metal plate 1 is preferably made of stainless steel or the like from the viewpoint of heat conductivity, strength and corrosion resistance.

In the heat exchanger of the present invention, in the gap 1a of the metal plate 1,
Gas (hot air) 2 for the heat medium is introduced from one side, and this hot air 2 is discharged from the surface on the opposite side.

Further, the drying gas 3 is introduced into the gap 1b of the metal plate 1 from the adjacent side and is also discharged from the opposite side surface.

That is, the gaps 1a serving as the passages for the hot air 2 and the gaps 1b serving as the passages for the drying gas 3 are located alternately, and the mixing of the hot air 2 and the drying gas 3 is completely prevented, and the drying is performed. The working gas 3 is heated.

Further, this heat exchanger is equipped with a washer 6 in which a large number of nozzles 5 are arranged in a row with their injection ports facing the gap 1b, and this washer 6 slides on a rail 7 to form the gap 1b.
Is provided so as to be movable over the entire surface, and the cleaning liquid is sprayed from the nozzle 5 at a high pressure into the gap 1b serving as the passage of the drying gas 3.

In the heat exchanger of the present invention, the hot air 2 and the drying gas 3 cross horizontally, that is, the drying gas 3 flows horizontally into the gap 1b. First
Is a feature of.

In the case of a heat exchanger of the type in which this drying gas 3 flows in a vertical flow into the gap 1b, when this is used in a coating drying furnace, the height becomes extremely high, and This is extremely inconvenient in that the height becomes extremely large, and the maintenance of the apparatus becomes difficult.

The second feature of the present invention is that the gap 1b between the metal plates is configured so as to include a straight space which is not obstructed by the inner wall of the metal plate 1 between the inlet and the outlet thereof.

That is, in this type of heat exchanger, the shape of the metal plate 1 is corrugated in order to increase the heating efficiency, but the gap 1b is bent by the curved inner wall of the metal plate 1. If it is a gap, the gap 1 by the cleaning device 6
The cleaning efficiency of b is lowered and cleaning is substantially impossible.

Therefore, it is desirable that the gap 1b is a gourd type as shown in FIG. 2, and the parallel wave shape as shown in FIG. 3 is inappropriate.

Since the drying gas does not flow into the gap 1a, almost no foreign matter such as tars that is difficult to clean is generated on the inner wall.
The shape is arbitrary.

A third feature of the present invention is that the corrugated metal plate 1 is arranged such that the flow direction of the drying gas 3 is inclined with respect to the horizontal plane, and the cleaning device 6 is located on the higher side. In point.

By providing such an inclination, the cleaning liquid ejected from the cleaning device 6 naturally flows off, so that the device can be prevented from being damaged due to a steam explosion when the operation of the device is restarted, and the cleaning liquid can be prevented. It is possible to avoid the inconvenience that the components contained in remain and corrode the metal plate.
It becomes possible to effectively wash and remove tars and the like that firmly adhere to the inner wall of the metal plate 1.

The inclination angle θ is preferably 5 degrees or more, and particularly preferably in the range of 10 to 20 degrees.

The heat exchanger described above is used for heating the drying gas in the coating drying oven, and an example of an embodiment in which this is used in the drying oven is shown in FIG.

That is, in the coating and drying furnace including the drying chamber 10, the drying air is circulated and supplied to the drying chamber 10 by the blower F such as a fan to dry the coating film formed on the article to be treated 11. The above-mentioned heat exchanger of the present invention (indicated by 20 in FIG. 4) is installed in the circulation passage 12 for the drying air, and the filter 1 is provided upstream of the heat exchanger 20.
3 is provided.

On the other hand, below the heat exchanger 20, the drain pan 14 that receives the cleaning liquid is provided.

That is, the drying air passes through the filter 13 and the heat exchanger 2
0, heated, supplied again into the drying chamber 10, and the coating film is dried.

In cleaning the heat exchanger 20, as described above, the cleaning device 6 may be slid to inject the high-pressure cleaning liquid toward the gap 1b serving as a passage for the drying air.
It becomes possible to perform the cleaning very easily.

(Effect of the Invention) According to the present invention, the heat exchanger can be automatically cleaned without taking out the heat exchanger from the hot air generator, which is extremely useful in terms of maintenance and the like.

[Brief description of drawings]

FIG. 1 is a perspective view of a heat exchanger of the present invention, FIG. 2 is a view showing a preferable shape of a metal plate, FIG. 3 is a view showing an improper shape of a metal plate, and FIG. It is a figure which used the heat exchanger of FIG. 1 for the coating-drying furnace.

Claims (1)

[Scope of utility model registration request] 1. A plurality of corrugated metal plates arranged substantially parallel to each other at predetermined intervals, wherein a gas for a heat medium and a gas for drying to be circulated in a coating and drying furnace are provided between the metal plates. In a heat exchanger for a coating and drying furnace, which ventilates the gap to turn the drying gas into hot air, between a metal plate that serves as a ventilation passage for the heating medium gas and a metal plate that serves as a ventilation passage for the drying gas. The gaps are located alternately and
The mixture of both gases is prevented, and the heating medium gas and the drying gas are introduced into the gap between the metal plates in a horizontal crossing manner, and the gap between the metal plates serves as an air passage for the drying gas. Is configured so as to include a straight space that is not obstructed by the corrugated inner wall of the metal plate between the inlet and the outlet, and the metal plate has a ventilation gas flowing at a constant inclination angle with respect to the horizontal plane. The cleaning device provided with a large number of cleaning liquid supply nozzles arranged in a row toward the straight space has a higher position on either the inlet side or the outlet side in the ventilation direction of the drying gas. And the cleaning device is provided so as to be movable over the entire surface of the gap between the metal plates serving as a passage for the drying gas.