JP7497076B1 - Electric continuous baking oven - Google Patents

Abstract

[Problem] To provide an electric continuous baking furnace that renders pollutants contained in recovered polluted gas harmless by heating with a high-temperature electric heater and discharges the detoxified contaminants, and that can use the high-temperature exhaust gas as a primary heating source for inert gas sent into the baking furnace. [Solution] The baking furnace is provided with a gas supply source, a heater, a baking furnace, and a VOC removal device, and the baking furnace is provided with an outlet for discharging the inert gas heated by the heater into the baking furnace and an intake port for sucking in the exhaust gas at the bottom of the baking furnace and sending it to the VOC removal device, and the VOC removal device is provided with an inlet port for letting in the exhaust gas sent from the baking furnace, a supply port for letting in the inert gas generated by the gas supply source, a high-temperature electric heater that heats the exhaust gas to a high temperature and performs a VOC decomposition process, a heat exchanger that exchanges heat between the high-temperature exhaust gas sent from the high-temperature electric heater and the inert gas, an outlet port for sending the inert gas heated by the heat exchange to the heater, and an air supply port connected to an air supply pipe for sending clean exhaust gas to a utilization device. [Selected Figure] Figure 1

Description

The present invention relates to an electric continuous baking oven that uses electrically heated air to perform baking.

2. Description of the Related Art Conventionally, the baking process of articles (hereinafter referred to as workpieces) coated with baking paint, such as metal office equipment and automobile parts, has been carried out by a baking device equipped with a heat source for heating to a baking temperature.
The heat sources used in conventional baking devices include oil burners that use heavy oil or kerosene, and gas heaters that use LPG or city gas, and the emission of greenhouse gases such as carbon dioxide generated by the combustion of fuels has become a problem.
Therefore, there has been a demand for a baking furnace that performs baking processing using a heat source that can reduce greenhouse gas emissions.

In response to the above problem, the applicant developed a technology that enables continuous baking using an electric heater, and proposed the technology described in Patent Publication No. 7078299 (Patent Document 1). This technical proposal has the excellent effect of producing a high-quality baked-coated product by continuously transporting the coated workpiece into the baking chamber through an entrance blocked by a film-like gas flow while the inert gas heated by the electric heater is ejected uniformly and dispersedly into the baking chamber.

However, according to the technical proposal in Patent Document 1, because the gas outlet pipe for discharging contaminated gas is provided on the rear side of the baking furnace, it is conceivable that contaminated gas generated in the front and middle parts of the baking furnace may be dispersed by the ejection of inert gas introduced into the baking furnace, causing problems in baking the workpieces.

The applicant focused on the above-mentioned problems of the conventional method of recovering polluted gas remaining in a continuous baking furnace and of detoxifying the polluted gas, and came up with the idea of recovering the polluted gas remaining in the lower part of the baking furnace, detoxifying it, and then discharging it. He developed a baking furnace in which the pollutants contained in the recovered polluted gas are detoxified by heating with a high-temperature electric heater and then discharged, and the high-temperature exhaust gas can be used as a primary heating source for the inert gas sent into the baking furnace, which led to the proposal of the "electric continuous baking furnace" of the present invention.

Patent No. 7078299

In view of the above problems, the present invention aims to provide an electric continuous baking furnace that can render the pollutants contained in the collected polluted gas harmless by heating it with a high-temperature electric heater and then discharge it, and that can use the high-temperature exhaust gas as a primary heating source for the inert gas sent into the baking furnace.

In order to solve the above problems, the present invention provides an electric continuous baking furnace that is composed of a gas supply source, a heater that heats the inert gas generated by the gas supply source to a baking temperature and sends it into the baking furnace, a baking furnace equipped with a transport means that transports the workpiece from the entrance to the exit, and a VOC removal device, and in which the entrance and exit are located lower than the baking furnace and the transport path is inclined. The baking furnace is provided with multiple nozzles that release the inert gas heated by the heater into the baking furnace, and a device that sucks in the exhaust gas from the lower part of the baking furnace and sends it to the VOC removal device. The VOC removal device is equipped with an intake port, and is composed of an inlet port for the inflow of exhaust gas sent from the baking furnace, a supply port for the inflow of inert gas generated by the gas supply source, a high-temperature electric heater for heating the exhaust gas to a high temperature and decomposing the VOCs, a heat exchanger for exchanging heat between the clean, high-temperature exhaust gas sent from the high-temperature electric heater and the inert gas that flows in from the supply port, an outlet port for sending the inert gas heated by the heat exchanger to the heater, and an air supply port connected to an air supply pipe for sending the clean exhaust gas to the equipment that uses it.

The present invention also provides a ceiling fan on the ceiling of the baking oven.

Furthermore, the present invention employs a means for connecting a dust removal device to the air supply pipe.

Furthermore, the present invention employs a method in which the baking furnace has one end closed and the other end open, the loading entrance and the loading exit are provided at the same location, and the transport path within the baking furnace is U-shaped.

The electric continuous baking furnace of the present invention has the excellent effect of making it possible to keep the inert gas inside the baking furnace clean even during the baking process of the workpieces by sucking in the exhaust gas from the bottom of the baking furnace and sending it to a VOC removal device.
In addition, by providing a high-temperature electric heater in the VOC removal device, it is possible to convert the exhaust gas sucked from the baking furnace into high-temperature exhaust gas in which the VOCs in the exhaust gas have been rendered harmless.
Furthermore, by installing a heat exchanger within the VOC removal device, heat is exchanged between the high-temperature exhaust gas and the room-temperature inert gas generated in the gas supply source, making it possible to send the high-temperature inert gas to the heating heater and baking furnace, thereby contributing to the effective use of the heat source required to heat the inert gas from room temperature to a high temperature.

In addition, with the electric continuous baking oven of the present invention, the entrance and exit are located lower than the baking oven, so that high-temperature inert gas remains throughout the entire baking oven located at the top, forming a high-temperature air layer, which has the excellent effect of preventing outside air from entering through the entrance and exit located at the bottom.

Furthermore, the electric continuous baking oven of the present invention has the excellent effect of providing a ceiling fan on the ceiling of the oven, which agitates the air inside the oven, contributing to uniform baking temperature, and forming an air flow from the ceiling of the oven to the bottom, making it possible to suppress the diffusion of polluting gases generated inside the oven.

Furthermore, with the electric continuous baking oven of the present invention, a dust removal device is connected to the air supply pipe, which makes it possible to remove foreign matter such as dust and water vapor contained in the exhaust gas, thus providing the excellent effect of contributing to the supply of clean exhaust gas to the equipment connected downstream.

Furthermore, with the electric continuous baking oven of the present invention, the entrance and exit of the baking oven are located in the same place, and the conveying path inside the baking oven is U-shaped, which makes it possible to reduce the overall length of the baking oven by about half, which contributes to space saving of the equipment in the baking process, and also provides the excellent effect of facilitating the formation of a shielding layer against the outside air, since there is only one path for outside air to enter.

FIG. 1 is an explanatory diagram showing an embodiment of an electric continuous baking furnace according to the present invention. FIG. 4 is an explanatory diagram showing another embodiment of an electric continuous baking furnace according to the present invention. FIG. 4 is an explanatory diagram showing another embodiment of an electric continuous baking furnace according to the present invention.

The electric continuous baking furnace of the present invention is an electric continuous baking furnace in which the height of the loading/unloading port is provided lower than the baking furnace and the transport path is sloped.The greatest feature of this furnace is that the exhaust gas sent to the VOC removal device is rendered harmless by a high-temperature electric heater and the high-temperature exhaust gas is used as a primary heating heat source for the inert gas sent into the baking furnace.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an electric continuous baking furnace according to the present invention will be described with reference to the drawings.

The electric continuous baking furnace of the present invention is not limited to the embodiment described below, but can be modified as appropriate within the scope of the technical concept of the present invention, i.e., within the scope of the shape, dimensions, materials, etc. that can achieve the same effect.

Fig. 1 is an explanatory diagram showing an embodiment of an electric continuous baking oven according to the present invention. Fig. 2 is an explanatory diagram showing an embodiment of an electric continuous baking oven according to the present invention, specifically showing an embodiment in which an inlet and an outlet are provided at the same location. Fig. 3 is an explanatory diagram showing an embodiment of an electric continuous baking oven according to the present invention, in which (a) shows a state in which a branch point is provided at the downstream of the dust removal device and merges with a pipe connected to an intake port, and (b) shows a state in which a branch point is provided at the downstream of the dust removal device and merges with a pipe connected to a gas supply source.
The electric continuous baking furnace 1 according to the present invention is composed of a gas supply source 2, a heater 3, and a baking furnace 4. There is no particular limitation on the workpiece W to be baked in the present invention, and examples of such workpieces include metal office equipment and automobile parts coated with baking paint, and beverage cans. Of course, piping is provided between each device in the electric continuous baking furnace 1. There is no particular limitation on the material used for the piping, and any material that can withstand the temperature of the gas sent in is used as appropriate.

(Gas supply source)
The gas supply source 2 is a device for generating gas to be supplied into the baking furnace 4 via the VOC remover 5 and the heater 3 .
The gas generated by the gas supply source 2 is an inert gas that will not cause discoloration due to oxidation of the baking paint used on the workpiece W. For example, inert gases such as argon gas and nitrogen gas can be used, but when nitrogen gas is used, it can be produced in a nitrogen gas production machine and used as the gas supply source 2. The structure of the device used as the gas supply source 2 is not particularly limited, and any device having conventionally known technology may be used.
The inert gas generated in the gas supply source 2 is heated by heat exchange in the heat exchanger 21 provided in the VOC removal device 5, and then adjusted to an appropriate baking temperature by the heater 3 and sent into the baking furnace 4.

(Heater)
The heater 3 heats the inert gas generated by the gas supply source 2 to a baking temperature and causes the gas to flow into the baking furnace 4 via a pipe.
The heater 3 is an electrically heated heater, and automatically or manually heats the gas heated by heat exchange in the heat exchanger 21 to a temperature suitable for baking the workpiece W. There is no particular limitation on the structure of the device used as the heater 3, and any conventionally known device may be used. The temperature set in the heater 3 may also be determined by the paint used for baking, and is set between 140°C and 180°C when an acrylic paint is used, for example.
Although not shown, a blower 16 may be provided at an appropriate position in the piping in order to stabilize the pressure of the gas flowing into the baking furnace 4.

(Baking oven)
The baking furnace 4 performs baking processing on the workpiece W using high-temperature gas whose temperature has been adjusted by the heater 3 .
The baking furnace 4 has a baking area of a size suitable for the workpiece W to be baked, and is equipped with an entrance 12 and an exit 13 at the front and rear of the baking furnace 4, which are open enough to allow the workpiece W to move in and out without being hindered, and one or more exhaust ports 10 and suction ports 11 are provided within the baking furnace 4.
During the baking process of the workpiece W, the high-temperature gas in the baking area becomes contaminated by containing solvent-derived substances that have changed due to the high temperature. Therefore, as shown in Figure 1, one or more suction ports 11 are provided that can suck in the contaminated high-temperature gas.
The baking furnace 4 is naturally equipped with a transport means 14 that supports the workpieces W in a line and in succession while transporting them in and out of the baking area of the baking furnace 4 via the carry-in entrance 12 and the carry-out exit 13. There are no particular limitations on the method of supporting the workpieces W in the transport means 14, and a belt conveyor, a suspended moving machine, or the like can be selected depending on the shape of the workpieces W and the baking mode.

Although not shown, it is also possible to provide a temperature sensor in the baking area in the baking furnace 4. By adopting this mode, it is possible to control the heating temperature of the heater 3 based on the detected temperature, and to manually or automatically adjust the temperature of the high-temperature gas in the baking area so that it is maintained at a constant baking temperature.
It is also preferable to provide a pressure sensor in the baking area, which allows the amount of inert gas generated by the gas supply source 2 to be controlled by the detected pressure, and allows manual or automatic adjustment so that the high-temperature gas in the baking area is kept at a constant pressure.
Furthermore, it is also possible to provide oxygen concentration meters near both ends of the baking area. By adopting this mode, it is possible to grasp the intrusion of outside air into the baking area and prevent the oxidation phenomenon of the workpiece W. If an oxygen concentration above a certain level is detected, it is possible to issue a warning light or the like, stop the operation of the baking furnace 4 itself, identify the location of the intrusion of outside air, or replace the inert gas filled therein.

(Carry-in/carry-out entrance)
The carry-in entrance 12 is an entrance for carrying the workpiece W into the baking area of the baking furnace 4 , and the carry-out exit 13 is an exit for carrying the workpiece W out of the baking area of the baking furnace 4 .
There are no particular limitations on the size and shape of the loading entrance 12 and the unloading exit 13, and they will be determined appropriately depending on the shape and type of work W, but they will be at least as large as the work W and open to the extent that they do not interfere with the movement and ingress and egress of the work W.
Depending on the shape of the baking furnace 4, the carry-in entrance 12 and the carry-out exit 13 may be installed in the same location as shown in Fig. 2. When this configuration is adopted, the carry-in entrance 12 and the carry-out exit 13 are disposed adjacent to each other at one opening so that the workpieces W do not come into contact with each other.

(Spout)
The nozzle 10 ejects high-temperature gas heated by the heater 3, thereby maintaining the temperature in the baking area at a temperature suitable for baking.
A plurality of nozzles 10 are provided in a pipe extending in the longitudinal direction on the inner wall of the baking furnace 4 area, and the high-temperature gas adjusted in temperature by the heater 3 is ejected from each nozzle 10 into the baking area. There is no particular limitation on the installation position of the nozzles 10, but by arranging them on the top surface, side surface, or bottom surface, it is possible to eject high-temperature gas onto the workpiece W from one or more directions. In addition, there is no particular limitation on the shape of the nozzles 10, but a shape that ejects gas in a dispersed state into the baking area is preferable. Furthermore, there is no particular limitation on the number of nozzles 10, but by adopting a mode in which the nozzles 10 are provided at equal intervals on the top surface as shown in Figures 1 and 2, or a mode in which the nozzles 10 are provided at equal intervals on the top surface and side surface alternately (not shown), multiple vortex airflows are generated in the baking area, so that the surface of the workpiece W can be raised to the baking temperature while being covered by the vortex airflow.

(Intake port)
The suction port 11 sucks in high-temperature gas containing VOCs (volatile organic compounds) that has accumulated in the lower part of the baking area, and sends it to the VOC removal device 5 as a polluted gas.
In the baking area where baking processing is performed, contaminants such as VOCs, which are solvent-derived substances that are produced when the solvent is changed at high temperatures (hereinafter, simply referred to as "contaminants"), mix with the inert gas as the workpieces W are successively baked, generating contaminated gas (hereinafter, referred to as "contaminated gas"). This contaminated gas has a higher specific gravity than the inert gas filled in the baking area, and so remains below the baking furnace 4.
The intake port 11 is provided below the baking furnace 4 and sucks in polluted gas that contains pollutants and has accumulated below the baking area, and sends the gas to a VOC removal device 5 that can decompose and remove the pollutants, thereby preventing contamination inside the baking furnace 4.
1, it is preferable to provide a plurality of suction ports 11 capable of sucking in polluted gas at equal intervals in predetermined locations in the baking area where the concentration of pollutants in the inert gas is likely to increase, such as near the center or at the rear of the chamber where baking of the workpiece W is completed. It is also preferable to combine the piping connected to the suction ports 11 into one piping, and after the polluted gas sucked in from the suction ports 11 is joined, the flow rate of the polluted gas is increased by a blower 16 provided near the junction of the piping, and the gas is sent to a high-temperature electric heater 20 provided downstream.
By making the amount of inhalation through the suction port 11 the same as or less than the amount of inhalation through the outlet port 10, it is possible to maintain a state in which the inert gas filled in the baking area is constantly filled therewith.Furthermore, the excess inert gas filled in the baking area creates an airflow from the baking area toward the inlet 12 and outlet 13, which are the openings of the baking furnace 4, thereby providing the excellent effect of preventing the intrusion of outside air.

(Ceiling fan)
The ceiling fan 15 agitates the inert gas within the baking area and creates an air current directed downward from above the baking area.
The ceiling fan 15 has a propeller shape and is installed on the ceiling of the burning area. There are no particular limitations on the size, number, or installation location of the ceiling fan 15, and these are determined appropriately taking into account the distance and height of the burning area.
By stirring the inert gas in the baking area by rotating the ceiling fan 15, the temperature of the high-temperature inert gas filled in the baking area can be made uniform, and by forming an air current from the ceiling of the baking oven toward the bottom, it is possible to suppress the diffusion of contaminant gases generated in the baking oven.

(Shielding Means)
Since the entrance 12 and the exit 13 are always open, air may flow in through the openings, lowering the temperature of the inert gas filled in the baking furnace 4, and the oxygen contained in the air may oxidize the workpiece W during baking, which may adversely affect the baking quality of the workpiece W. For this reason, it is preferable to provide an automatic door that automatically opens and closes in conjunction with the workpiece W being transported in and out of the baking furnace near the openings of the entrance 12 and the exit 13, or to provide a shielding means 17 that forms an air curtain that separates the inside and outside of the baking area as shown in FIG.
2, the gas discharged from the shielding means 17 in a film shape is supplied by the gas supply source 2 and turned into a high-temperature inert gas via the heater 3, thereby preventing the intrusion of outside air from the openings of the inlet 12 and outlet 13 and preventing a drop in the temperature of the inert gas filled in the baking furnace 4. There are no particular limitations on the location of the shielding means 17, but possible locations include a location where the shielding means 17 can be provided vertically in one direction from the top or bottom of the opening as shown in the figure, or a location where the shielding means 17 can be provided above and below the top and bottom of the opening to enable vertical discharge from two directions, top and bottom.

(VOC removal device)
The VOC removal device 5 heats the VOCs contained in the polluted gas sucked in from the intake port 11 to a high temperature to decompose and render them harmless, and also exchanges heat between the high-temperature, harmless polluted gas (hereinafter referred to as "exhaust gas") and the inert gas supplied from the gas supply source 2.
The VOC removal device 5 is a box-shaped body having a hollow portion, and is equipped with an inlet hole 22 that allows the polluted gas sucked in from the baking area by the suction port 11 to flow into the VOC removal device 5, a high-temperature electric heater 20 that heats the polluted gas that flows in from the inlet hole 22 to a high temperature to decompose the VOCs contained in the polluted gas, a supply hole 23 that allows the inert gas supplied from the gas supply source 2 to flow into the VOC removal device 5, a heat exchanger 21 that exchanges heat between the room temperature inert gas that flows in from the supply hole 23 and the exhaust gas that has been heated to a high temperature by the high-temperature electric heater 20, an outlet hole 24 that sends the inert gas that has been heat exchanged in the heat exchanger 21 and has been heated to a high temperature to the heating heater 3, and an air supply hole 25 that sends the exhaust gas that has been heat exchanged in the heat exchanger 21 and has been cooled to a subsequent stage.

(Inlet hole)
The inlet hole 22 is a hole through which the polluted gas sucked in from the suction port 11 flows into the high-temperature electric heater 20 .
There is no particular limitation on the diameter of the inlet hole 22, but by making it larger than or equal to the diameter of the piping through which the polluted gas is delivered, it is possible to allow the polluted gas to flow into the high-temperature electric heater 20 without losing its pressure.

(High temperature electric heater)
The high-temperature electric heater 20 heats the polluted gas that has flowed into the VOC removal device 5 from the inlet 22 to a high temperature, thereby decomposing and rendering harmless the VOCs contained in the polluted gas.
The high-temperature electric heater 20 heats the polluted gas sucked in through the suction port 11 and introduced through the inlet hole 22 via a pipe to a high temperature with an electric heater, thereby decomposing the VOCs and making the polluted gas into a harmless exhaust gas. There is no particular limitation on the structure of the device used as the high-temperature electric heater 20, and any device having a conventionally known technology may be used. In addition, the temperature set in the high-temperature electric heater 20 is preferably set to a temperature of approximately 800 to 900 degrees with an electric heater in order to decompose the VOCs in the polluted gas discharged from the baking furnace 4. By adopting this mode, the VOCs in the polluted gas are decomposed into water and carbon dioxide, and the detoxified high-temperature exhaust gas is sent to the heat exchanger 21 in the subsequent stage.

(Supply hole)
The supply hole 23 supplies the inert gas generated by the gas supply source 2 to the heat exchanger 21 .
There is no particular limitation on the diameter of the supply hole 23, but by making it larger than or equal to the diameter of the piping for the inert gas supplied from the gas supply source 2, it is possible to allow the inert gas to flow into the heat exchanger 21 without losing pressure.

(Heat exchanger)
The heat exchanger 21 exchanges heat between the high-temperature exhaust gas sent from the high-temperature electric heater 20 and the room-temperature inert gas flowing in through the supply hole 23 .
The heat exchanger 21 is a device in which the high-temperature exhaust gas delivered from the high-temperature electric heater 20 and the room-temperature inert gas generated in the gas supply source 2 and delivered through the supply hole 23 each flow into the heat exchanger 21, and the thermal energy contained in the high-temperature exhaust gas is transferred to the room-temperature inert gas, thereby lowering the temperature of the high-temperature exhaust gas and raising the temperature of the room-temperature inert gas.
The structure of the heat exchanger 21 may be any known technology, for example, a double-tube system using a coil shape or a U-tube shape may be used.
In addition, since the discharge temperature of the high-temperature exhaust gas from the heat exchanger 21 is determined based on the heat resistance temperature and adsorption efficiency of the adsorbent and filter used in the foreign matter removal device 30 arranged downstream, it is possible to consider, for example, an additional heat exchanger capable of exchanging heat with the atmosphere to further reduce the discharge temperature of the exhaust gas.

(Outlet hole)
The outlet hole 24 supplies the inert gas, which has been heated to a high temperature by heat exchange in the heat exchanger 21 , to the heater 3 .
There is no limitation on the diameter of the outflow hole 24, but by making it equal to or larger than the diameter of the supply hole 23, it is possible to allow the inert gas to flow into the heater 3 without losing its pressure.
The high-temperature inert gas flowing into the heater 3 is adjusted to a temperature required for use as the inert gas in the baking furnace 4 and then sent thereto.

(Air supply hole)
The air supply hole 25 supplies the exhaust gas, the temperature of which has been reduced by heat exchange in the heat exchanger 21 , to the foreign matter removal device 30 .
There is no limitation on the diameter of the air supply hole 25, but by making it equal to or larger than the diameter of the inlet hole 22, it is possible to allow the exhaust gas to flow into the foreign matter removal device 30 without losing its pressure.

(Foreign matter removal device)
The foreign matter removal device 30 separates and removes foreign matter, such as impurities such as dust and water vapor, remaining in the exhaust gas whose temperature has been reduced by the heat exchanger 21 (hereinafter, sometimes simply referred to as “foreign matter”).
The foreign matter removal device 30 separates and removes impurities such as dust and harmful substances such as VOCs contained in the polluted gas discharged from the baking furnace 4, substances that could not be removed by the high temperature of the high-temperature electric heater 20, and water vapor generated by the decomposition of VOCs, and sends the separated gas to the subsequent stage. The structure of the foreign matter removal device 30 is not particularly limited, but for example, it can be considered that the exhaust gas is sent to and passed through an air dryer that removes water vapor from the exhaust gas, a dust and water removal filter that uses a centrifugal separation mechanism, and a foreign matter removal filter whose hollow part is filled with an adsorbent using activated carbon, zeolite, or the like. By adopting this embodiment, the foreign matter in the exhaust gas is removed, so that the exhaust gas can be sent to the subsequent stage as clean exhaust gas, and can be used in devices such as a pre-treatment drying furnace.

As shown in FIG. 3, the exhaust gas that has been purified by passing through the foreign matter removal device 30 can be branched off into a pipe that sends the gas to a downstream device, and can be connected and merged with a pipe arranged as the electric continuous baking furnace 1, so that a portion of the gas used can be circulated within the electric continuous baking furnace 1. For example, it can be merged with the contaminated gas sucked in from the intake port 11 as shown in (a), or with the inert gas sent out from the gas supply source 2 as shown in (b). By adopting these embodiments, it is possible to cover a portion of the gas used in the entire electric continuous baking furnace 1 with clean exhaust gas, which has the excellent effect of contributing to a reduction in the amount of new inert gas generated.

The main operations and functions of the electric continuous baking furnace 1 consisting of the above components will now be described.
(Mainly gas)
First, the inert gas generated in the gas supply source 2 passes through a heat exchanger 21, and then, if necessary, is heated to a high temperature by a heater 3 to become a high-temperature gas, which is then sent to the nozzle 10 in the baking furnace 4.
The high-temperature gas sent to the nozzle 10 is blown onto the workpiece W transported into the baking area of the baking furnace 4 to perform baking processing, and then is sucked in from the suction port 11 as contaminated gas. The sucked in contaminated gas is heated by the high-temperature electric heater 20 disposed in the VOC removal device 5 to decompose the VOCs, and then the gas is heat-exchanged with the inert gas sent from the gas supply source 2 via the heat exchanger 21, thereby lowering the temperature. The foreign matter removal device 30 then separates and removes dust, moisture, and the like from the exhaust gas, and the exhaust gas is sent as clean exhaust gas to a utilization device disposed downstream.

(Work subject)
As shown in FIG. 1, the entrance 12 side and the exit 13 side have a symmetrical structure from front to back, so the entrance 12 side will be described in detail below, and the exit 13 side will be briefly described.
First, the workpiece W is transported by the transport means 14 and enters the baking area of the baking furnace 4 through the carry-in opening 12. At this time, since the carry-in opening 12 is located below the baking furnace 4 and high-temperature gas is constantly supplied in the baking area, an air current is generated from the baking area toward the carry-in opening 12. Therefore, the workpiece W, surrounded by high-temperature gas, moves up the slope of the transport means 14 and is transported into the baking furnace 4.
In the baking area, the workpiece W is baked by high-temperature gas blown out from a plurality of nozzles 10, and the workpiece W after baking is transported toward the discharge port 13.
Like the inlet 12, the outlet 13 is located lower than the baking furnace 4, so the workpiece W is gradually cooled from the state in which it is surrounded by high-temperature gas as it descends the incline of the transport means 14, and is then transported out through the outlet 13 and transported to the subsequent equipment.

Although the main operation and action of the electric continuous baking furnace 1 according to the present invention have been described above, the present invention is not limited to the structural aspects shown in the above embodiment. For example, by arranging another heat exchanger after the heat exchanger 21 and exchanging heat between the high-temperature exhaust gas and the room-temperature inert gas generated by the gas supply source 2, the temperature of the exhaust gas can be further lowered, and the inert gas that is higher than the room temperature and lower than the baking area can be sprayed from the air curtain installed as the shielding means 17, thereby making it possible to change the temperature of the workpiece W in stages.
The electric continuous baking furnace 1 is equipped with various instruments (thermometer, air pressure gauge, anemometer, air flow meter, nitrogen concentration meter, workpiece transport speed meter, etc.) as necessary. For example, a thermometer is used not only inside the baking furnace 4 and on the discharge side of the heat exchanger 21, but also to measure the temperature of the workpiece W itself during the baking process and when it is carried in and out, and depending on each measured value, the gas temperature is adjusted by the heater 3 to the appropriate temperature, and an alarm is issued when an abnormal temperature is detected.

As described above, according to the electric continuous baking furnace 1 of the present invention, the inert gas generated in the gas supply source 2 is heated by the heat exchanger 21 and the heater 3 and sent into the baking furnace 4 as a high-temperature gas, and is blown out from the nozzle 10 provided in the baking furnace 4 to bake the workpiece W brought into the baking area. While this gas is being baked, a part of the high-temperature gas is transformed into a contaminated gas containing the contaminants generated during the baking process and remains at the bottom of the baking area. It is then sucked in from the suction port 11 and sent to the high-temperature electric heater 20. After the VOCs in the contaminated gas are decomposed and rendered harmless by the high-temperature heating by the high-temperature electric heater 20, the gas flows into the heat exchanger 21 as a high-temperature exhaust gas, making it possible to provide an electric continuous baking furnace 1 that exchanges heat with the room-temperature inert gas generated in the gas supply source 2.

The electric continuous baking furnace of the present invention uses an electric heater to heat and bake the workpiece and neutralize the VOCs generated during the baking process, but the objects to be heated are not limited to metal products; it can also be applied to baking process equipment in printing facilities and adhesive-using facilities where VOCs may be generated. Therefore, it is believed that the "electric continuous baking furnace" of the present invention has great industrial applicability.

REFERENCE SIGNS LIST 1 Electric continuous baking furnace 2 Gas supply source 3 Heater 4 Baking furnace 5 VOC removal device 10 Jet port 11 Suction port 12 Carry-in entrance 13 Carry-out exit 14 Conveying means 15 Ceiling fan 16 Blower 17 Shielding means 20 High-temperature electric heater 21 Heat exchanger 22 Inlet hole 23 Supply hole 24 Outlet hole 25 Air supply hole 30 Foreign matter removal device

Claims (4)

A continuous electric baking furnace comprising a gas supply source, a heater for heating an inert gas generated by the gas supply source to a baking temperature and feeding the inert gas into the baking furnace, a baking furnace equipped with a transport means for transporting a workpiece from an entrance to an exit, and a VOC removal device, the entrance and exit being located lower than the baking furnace and the transport path being inclined,
The baking furnace is provided with a plurality of outlets for discharging inert gas heated by a heater into the baking furnace, and an intake port for sucking in exhaust gas from the lower part of the baking furnace and sending it to a VOC removal device.
The suction port is installed below the baking furnace that is formed above the carry-in entrance and the carry-out exit,
The VOC removal device is an electric continuous baking oven characterized in that it comprises an inlet port through which exhaust gas sent from a baking oven flows in, a supply port through which inert gas generated by a gas supply source flows in, a high-temperature electric heater that heats the exhaust gas to a high temperature and performs a VOC decomposition process, a heat exchanger that exchanges heat between the clean, high-temperature exhaust gas sent from the high-temperature electric heater and the inert gas that flows in from the supply port, an outlet port through which the inert gas heated to a high temperature by the heat exchanger is sent to the heating heater, and an air supply port connected to an air supply pipe that sends the clean exhaust gas to a utilization device.
The electric continuous baking oven according to claim 1, characterized in that a ceiling fan is provided on the ceiling of the baking oven. The electric continuous baking furnace according to claim 1, characterized in that a dust removal device is connected to the air supply pipe. 2. The electric continuous baking furnace according to claim 1, characterized in that the baking furnace has one end closed and the other end open, an inlet and an outlet are provided at the same location, and a transport path within the baking furnace is U-shaped.