JP3408464B2 - Clean oven - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot air circulation type clean oven, and more particularly to a clean oven in which circulating hot air is always cleaned by an internal filter and circulated in a constant temperature bath. Is.

[0002]

2. Description of the Related Art Conventionally, large and small constant temperature baths have been widely used when heat-treating or drying test samples in a laboratory or products in a manufacturing process at a predetermined temperature.

[0003] In such a constant temperature bath, a type in which warm air is circulated has conventionally been generally used in a constant temperature inner bath for treating a sample or a product at a constant temperature. In many cases, the constant temperature atmosphere is of a so-called clean oven type, which is always cleaned.

Most of the clean ovens are used in a temperature range of about 100 to 350 ° C., and therefore, the high temperature hot air heated by the internal heater is usually kept at a constant temperature. It is being circulated to the tank.

Further, the circulating hot air is normally passed through an internal filter loaded to collect and remove dust and the like contained in the atmosphere, for example, having a particle size of 0.01 to 100 μm. Make (clean).

[0006] As a filter of this type, normally, particles having a diameter of 0.15 µm and 99.97 at a blowing speed of 0.5 m / s are used.
A glass fiber filter having heat resistance that can be cleaned with a collection rate of not less than 10% is widely used.

Therefore, as a conventional constant temperature oven (or clean oven), in JP-A-10-185427 and Japanese Utility Model Laid-Open No. 2-20323, a constant temperature inner vessel is set in an outer vessel, and an internal filter and a heater ( There is described a clean oven in which purified hot air is blown and circulated through a constant temperature inner tank by a circulation fan via an internal heater or an external heater.

The clean oven shown in FIG. 4 is the clean oven proposed in Japanese Utility Model Laid-Open No. 2-20323 mentioned above, in which the outer tank 48 and the inner tank 41 each have an intake port and an exhaust port with automatic dampers. Install a gas sensor in the tank and open / close the automatic dampers at the intake and exhaust ports to keep the concentration of combustible gas below the set value, and then prevent explosion / combustion when used in a sealed type. It is a clean oven that circulates purified warm air for the purpose.

The warm air circulation path in the conventional example shown in FIG. 4 is formed from an intake port (or a ventilation port) at the bottom of the constant temperature inner tank 41.
A circulation fan 46 sucks and blows air into the internal heater 45.
And then passed through the internal filter 43,
The purified warm air is introduced into the constant temperature inner tank 41.

Further, in FIG. 4, the gas is exhausted from an exhaust port with a damper which is directly connected to the lower part of the constant temperature inner tank, and although not shown, in the proposal of JP-A-10-185427, An exhaust duct having a damper is provided on the upper side of the outer tub which is directly connected to the warm air passage between the outer tub and the outer tub.

[0011]

Under the circumstances as described above, when handling the clean oven, when the test sample or product is taken in and out, the user opens and closes the closed constant temperature inner tank. You have to open the door.

However, as already described above, in the conventional clean oven which is used at a high temperature and is circulated by blowing hot air into the constant temperature inner tank,
When this opening / closing door is opened, the user is properly exposed to the hot air.

Further, depending on the purpose of use, this warm air is
A high temperature gas stream with various harmful or offensive odors,
It cannot be ignored from the viewpoint of occupational safety and health. Therefore, in such a work, it is actually required to wear a set of protective equipment such as protective gloves, protective glasses and a mask.

Therefore, in the above-mentioned conventional example, although the exhaust port or the exhaust duct having the opening / closing damper is provided, the heater power is once turned off, the temperature is lowered, the opening / closing door is opened, It is the actual situation that the target processing body is taken in and out, which raises the energy cost and lowers the utilization efficiency or the productivity.

Therefore, an object of the present invention is to provide a clean oven without the user having to wear the above-mentioned set of protective equipment on his / her body, and to avoid high-temperature hot air, harmful harmful or harmful air. It is an object of the present invention to provide a clean oven which is excellent in occupational safety and health without exposing the face and hands to the odorous hot air and which can improve the utilization efficiency.

[0016]

In view of the above-mentioned problems, the present inventor has diligently studied and found that the internal heater and
By paying attention to the layout of the circulation fan and the shape of the inner tank that serves as the constant temperature part, the constant temperature inside tank can be effectively heated to a high temperature by opening or closing the opening / closing door of the constant temperature tank installed in the outer tank. The present invention has been completed by finding a circulation method that can blow the air and can solve the above-mentioned conventional problems.

That is, according to the present invention, it comprises an inner bath having a constant temperature part and an outer bath, and hot hot air is circulated in the constant temperature inner bath to keep various test samples and various products under a predetermined constant temperature. It is a clean oven (or closed type constant temperature chamber) that heats or dries, especially when the user opens and closes the constant temperature chamber when the test sample or the product is put in or taken out of the constant temperature inner chamber. A clean oven characterized in that a user is not exposed to high-temperature hot air or the like as in the conventional case.

That is, this clean oven has an internal filter for cleaning the circulating hot air introduced into the constant temperature part of the inner tank.

Further, an internal heater and a circulation fan are provided between the inside of the outer tank and the thermostat of the inner tank, and hot air is supplied to the thermostat inner tank so as to face the internal filter. An openable shutter is provided to blow or block air.

Further, an exhaust duct provided with an openable exhaust damper is provided in the upper part of the outer tank.

Therefore, when the object is put in or taken out of the constant temperature inner tank, first, after opening the exhaust damper,
Then, after closing the open / close shutter, the opening / closing door of the constant temperature bath provided in the outer bath is opened, and the target object is taken in and out.

Further, in use, when the object is subjected to constant temperature treatment or drying, the open / close door is closed and the open / close shutter is opened to shut off the exhaust damper.

As a result, even when the user opens and closes the open / close door of the thermostatic chamber when the test sample or the product is put in or taken out of the thermostat internal bath, the hot hot air is not blown into the thermostatic chamber and the outer bath is opened. Since it is discharged from the exhaust duct provided in the upper direction, the user is not exposed to this high-temperature hot air or strange odor and harmful hot air as in the conventional constant temperature bath.

Therefore, the clean oven is excellent in work safety and occupational hygiene, and the user does not have to take the trouble of installing a set of protective equipment as in the prior art, and the heat energy cost is reduced. It is also possible to provide a clean oven capable of improving utilization efficiency.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, referring to FIGS.
The embodiment of the clean oven according to the present invention will be further described.

Therefore, in the present invention, the internal filter to be used has a heat resistance and, depending on the sample or product to be subjected to the isothermal treatment, the particle size contained in the normal atmosphere is 0.01 to Dust in the range of 100 μm, for example, at a blowing rate of 0.5 M / s and a collection rate of 99.97 to 99.9.
An air filter made of glass fiber of 9998% is suitably used.

These air filters are usually MEPA filters, HEPA filters, depending on the collection rate grade.
It is used as an air filter for clean rooms and units as filters and ULPA filters.
If necessary, an activated carbon filter or a prefilter such as a non-woven fabric can be used in combination.

An embodiment of the clean oven according to the present invention will be described with reference to FIG. 1. The constant temperature inner tank 1 is provided in the outer tank 13. Hot air is blown to the constant temperature inner tank 1 through an internal filter 3. In this case, the opening / closing shutter 4 provided on the back surface of the internal filter 3 is pulled up and opened, and the exhaust duct 8 provided at the upper portion of the outer tank is in a closed state. At the bottom of the constant temperature inner tank 1, an internal heater 5
Further, an intake port 15 is provided in the lower portion of the constant temperature inner tank 1, and a circulation fan 6 is installed so as to face the intake port. The circulation fan is linked to the external motor 7.

Further, in the clean oven according to the present invention, dry air can be introduced into the tank through the conduit 16 through the dry air valve 12 provided outside.
If necessary, nitrogen gas or argon gas can be introduced into the tank through the nitrogen gas valve 14 and similarly through the conduit 16 to purge (replace) the tank with an inert atmosphere.

In the present invention, the internal filter 3 shown in FIG. 1 may be installed in the rear surface portion of the constant temperature inner tank 1 (see FIG. 1), or in the side surface portion of the constant temperature inner tank 1. It may be provided, and there is no particular difference in effect depending on the installation site.

Further, as shown in FIG. 1, the opening / closing shutter 4 provided facing the internal filter 3 is vertically oriented toward the opening / closing door 10 which is a door of a constant temperature bath provided in the outer bath. The hot air can be blown or blocked by either the horizontal or horizontal direction. In the present invention, although not shown in the drawings, it is preferable to use the horizontal method for taking the articles in and out, rather than the vertical method shown in FIG. The opening and closing is not necessarily limited to the opening and closing method, and for example, a blind method is also suitable.

Further, the exhaust duct 9 with the exhaust damper 8 provided in the upper direction portion of the outer tub 13 is provided in the upper part of the outer tub 13 (see FIG. 1) already mentioned above, or the side portion of the upper direction portion is also provided. It may be provided on the outer tank 13 and is preferably provided on the upper portion of the outer tank 13 from the viewpoint of easy exhaust.

Further, in the present invention, when the circulating fan sucks warm air from the internal heater and effectively sends the hot air to the back surface of the internal filter, as shown in FIG. It is preferable that the inner tank is partitioned into two stages, an upper stage and a lower stage. This upper part is a constant temperature inner tank 1, and an internal heater 5 can be installed in the inner tank of the partitioned lower part 2, which causes peeling foreign matters such as rust due to oxidative deterioration. The easy heater part can be completely isolated from the constant temperature inner tank 1 in the upper part, which is always required to be clean.

As a result, as shown in FIG. 2, a conically narrowed intake port 15 can be provided at the bottom of the lower stage, and the circulation fan 6 is installed so as to face the intake port. can do.

Therefore, when the hot air is circulated when the open / close door 10 is closed, the exhaust damper 8 is closed and the open / close shutter 4 is pulled open to open the hot air to the internal heater 5-intake port 16. Circulation fan 6 through
-Internal filter 3-It can be circulated in the regular path of the upper part of the constant temperature inner tank 1-internal heater 5.

Furthermore, as shown in FIG. 3, when the object treatment object is put in or taken out from the constant temperature inner tank in which high temperature hot air is circulated, that is, when the opening / closing door 10 is used, in the present invention, The warm air is shut off by opening the exhaust damper 8 and then pulling down the open / close shutter 4, so that a procedure such as opening the open / close door 10 can be appropriately performed.

As a result, as in the prior art, for example, the heater is turned off, the fan is also turned off, and the exhaust valve 1
While discharging hot air from 1 and leaving it for a while to lower the temperature appropriately, put in or take out the target treatment object, or, as already mentioned above, attach a set of protective equipment to hands, face, etc. It is possible to completely eliminate complicated procedures such as work.

[0038]

As described above, according to the present invention, the opening / closing shutter for blowing or blocking the circulating hot air is provided so as to face the internal filter provided in the constant temperature inner tank, so that the exhaust duct with the exhaust damper is linked. The user is prevented from being exposed to high-temperature hot air from a constant temperature bath or hot air containing offensive odors and harmful components when putting in or taking out test samples or products, and also equipped with a set of protective equipment as in the past. It is possible to secure the safety of work without doing.

Further, since the inner tank can be divided into two stages and an internal heater can be installed in the lower part, and the heater part is completely isolated from the constant temperature inner tank in the upper part, the heater can be oxidized more than before. The mixture of deteriorated foreign matter is reduced, and the cleaning of circulating hot air is facilitated.Also, through the intake port provided at the bottom of the lower stage, the route of warm air circulation or warm air exhaust is simplified, Circulates or is exhausted smoothly without difficulty.

Furthermore, unlike the prior art, the user does not have to carry out the work of mounting a set of protective equipment, and when the target processing body is taken in and out, the heater power is turned off as in the prior art to lower the temperature. Since there is no waiting time, it is possible to provide a clean oven that can reduce heat energy cost and improve utilization efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a clean oven according to the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of warm air circulation in a clean oven according to the present invention.

FIG. 3 is a cross-sectional view showing a disclosed embodiment when the opening / closing door of the clean oven according to the present invention is opened.

FIG. 4 is a cross-sectional view showing an example of a conventional clean oven.

[Explanation of symbols]

1,41 Inner layer constant temperature part 2 Lower part of inner tank 3,43 Internal filter 4 openable shutter 5,45 Internal heater 6,46 Circulation fan 7,47 External motor 8 Open / close type exhaust damper 9 exhaust duct 10 openable door 11 Exhaust valve 12 Dry air valve 13,48 outer tank 14 Nitrogen valve 15 air intake 16 conduits

Claims (6)

(57) [Claims] 1. A closed type constant temperature tank comprising an inner tank having a constant temperature section and an outer tank, wherein hot air is circulated in the inner tank, and an opening / closing door is provided in the outer tank, which is introduced into the inner tank. Having an internal filter for cleaning the circulating hot air, and having an internal heater and a circulation fan between the inner side of the outer tub and the constant temperature part of the inner tub, facing the surface of the inner filter. There is an openable shutter that blows or blocks hot air to the inner tank, and an exhaust duct that installs an exhaust damper is provided in the upper direction part of the outer tank, and when the opening and closing door is opened or closed during use. Correspondingly, a clean oven characterized in that the exhaust damper is opened or shut off, and the openable shutter is shut off or opened. 2. The clean oven according to claim 1, wherein the internal filter is provided on a rear surface or a side surface of a constant temperature portion of the inner tank toward the opening / closing door. 3. The opening / closing shutter is moved in and out in parallel in a horizontal or vertical direction toward the opening / closing door to blow or block warm air to the inner tank.
Or the clean oven according to 2. 4. The inner tank is partitioned into an upper temperature-controlled part and a lower temperature part, and the lower heater is provided with the internal heater. Clean oven. 5. When the opening / closing door is closed and hot air is circulated, the exhaust damper is closed and the hot air is passed through the internal heater-the circulation fan-the internal filter-the constant temperature part of the inner tank-the above-mentioned. The clean oven according to any one of claims 1 to 4, wherein the clean oven is circulated in a normal path of an internal heater. 6. When the opening / closing door is opened and the target processing body is put in or taken out from the constant temperature part of the inner tank, the exhaust damper is opened, and then the opening / closing shutter is shut off.
The clean oven according to claim 1, wherein the opening / closing door is opened.