JPS5841433B2 - Yakitsuke Kansourosouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a baking drying oven apparatus for use in painting, etc., which discharges hydrocarbon-based organic gas.

Conventionally, in baking drying furnace equipment that discharges hydrocarbon-based organic gas for use in painting, etc., as is well known, a device for treating air polluting exhaust gas is installed separately, and the organic gas is discharged from the atmospheric exhaust hole of the drying furnace. Since the exhaust gas is guided to a treatment device for treatment, a heating device for exhaust gas treatment is required in addition to the heated combustion hot air supply system that supplies hot air to the drying furnace, and a separate location for installing it is also required. I had to.

In addition, new equipment has been added, including ducts, air blowers, filter devices,
An integrated facility consisting of a burner, combustion chamber, catalyst layer, and heat exchanger was required.

That is, the blower device, filter device, burner, etc. are duplicated with those of the hot air supply system, which increases the equipment cost and is very uneconomical.

In view of the above points, it is an object of the present invention to use a heated combustion hot air supply system as an organic gas combustion removal device, thereby significantly reducing initial costs and running costs.

The present invention will be described below with reference to the illustrated embodiments.
In the figure, reference numeral 1 denotes a drying oven, which is provided with an inlet conveyor 2 and an outlet conveyor 3 for carrying in spray-painted objects.

4 is a heated combustion hot air supply system that circulates and supplies hot air to the drying oven 1, which also serves as an organic gas combustion removal device;
It includes a filter device 6, a combustion device 7, a duct 8, a first blower device 9, and a heat exchanger 10.

The duct 5 is connected to the furnace outlet 11 of the drying furnace 1, and the enclosed combustion device 1 is composed of a burner 12 and a combustion chamber 13 in the case of direct combustion type exhaust gas treatment, and the combustion chamber 13 in the case of catalytic type exhaust gas treatment. A PT catalyst layer 14 is additionally provided within the combustion chamber 13 .

The combustion device 7 is provided with a fuel supply pipe 15 and a fresh air supply duct 16 for supplying fuel and combustion air from the outside.

The duct 8 connects the combustion chamber outlet 11 of the combustion device 7 and the drying oven 1.
The first air blower 9 and the heat exchanger 10 are sequentially provided in the duct B from the combustion device I side.

The heat exchanger 10 is for recovering heat from the hot air in the duct 8 and converting it into a fresh air crossflow introduced into the fresh air supply duct 16 from the outside. A contact heat exchanger is used.

A second blower device 19 is provided in the fresh air supply duct 16 .

Reference numeral 20 denotes an atmospheric exhaust duct, one end of which is connected to the duct 8 between the heat exchanger 10 and the furnace body inlet 18, and the other end is provided with an exhaust port 21 that opens to the atmosphere. A third blower device 22 is provided in the middle.

Next, the action will be explained.

The temperature inside the drying oven 10 is constantly maintained at a constant temperature of 140 to 200°C, and the spray-painted object is first carried into the drying oven 1 by the carry-in conveyor 2 and dried by heating and baking. The dried object to be coated is carried out as a finished product by a carrying-out conveyor 3.

Normally, for acrylic thermosetting paints, the baking time in the drying oven 1 is 20 minutes at 140 to 200°C, and the conveyance speed of the conveyors 2 and 3 is 2 to 5 m/min.

The drying oven 1 has a surface area of 1.5 to 2rr.
? It is common to dry an object to be coated with an iron plate thickness of 0.6 to 0.81 rrIn.

On the other hand, the heated combustion hot air supply system 4 supplies hot air for maintaining the temperature inside the drying oven 1 at a uniform temperature of 140 to 200°C, and also generates cured and decomposed paint resin of the object to be coated generated from the drying oven 1. The evaporation of organic solvents and evaporated organic solvents can cause foul odors and cause air pollution such as photochemical smog, so the design is designed to provide the heat of combustion oxidation hot air to treat this.

That is, exhaust gas hot air from the drying oven 1 (approximately 150 to 180°C
) is guided from the furnace body outlet 11 through a duct 5 to a filter device 6 for dust removal, and the dust-removed exhaust gas is supplied together with fuel and combustion air to the burner 12 of the combustion device 7, where it is combusted in the combustion chamber 13, resulting in direct combustion. In the type exhaust gas treatment, uniformly heated hot air is obtained at a temperature of 650 to 800°C, and in the catalytic type exhaust gas treatment, a temperature of 300 to 350°C is obtained.

The exhaust gas is combusted and oxidized while passing through the combustion chamber 13 to become N20. It is converted into non-polluting gases such as CO2, N2゜02, etc., and is heated from the combustion chamber outlet 17 by the suction action of the first blower 9 to approximately 700 to 850°C in direct combustion exhaust gas treatment, and approximately 400 to 450°C in catalytic exhaust gas treatment. The hot air is supplied to the duct 8 as hot air.

If this hot air generated in the combustion chamber 13 is sent to its casing/drying oven 1, the temperature inside the drying oven 1 cannot be equalized, and when the burner 12 in the casing is adjusted to burn, the temperature becomes low, so the drying oven 1
It becomes impossible to treat the exhaust gas generated from the

In addition, for continuous operation, minimum combustion total gas and exhaust gas (combustible gas) are required.
It is necessary to keep the concentration below the explosive limit.

A part of the non-polluting gas that has become hot air is then discharged into the atmosphere through the atmospheric exhaust duct 20. In this case, in order to save the amount of heat discharged into the atmosphere and to facilitate temperature adjustment of the drying oven 1. , the fresh air supply duct 1 through heat exchange through different direction contact such as cross flow and counter flow in the heat exchanger 10.
The fresh air introduced into 6 is heated and heat is recovered, and the hot air is returned to the burner 12 as combustion air.

The heat exchanger 10 exchanges heat between the hot air after exhaust gas treatment and fresh air so that the heat balance of the drying oven 1 and the burner heat balance necessary for treating the exhaust gas are balanced. The heat is recovered to burner 12.

The hot air, whose temperature has been lowered by heat exchange in the heat exchanger 10, is supplied to the drying furnace 1 through the furnace body inlet 18 with its air volume adjusted, and a portion is discharged to the atmosphere through the atmosphere exhaust duct 20.

By appropriately distributing and adjusting the amount of heat and air volume of the heat exchanger 10, the atmospheric exhaust duct 20, and the fresh air supply duct 16, the temperature of the combustion chamber 13 (6
50-800℃, 300-350℃ for catalytic exhaust gas treatment
) and the temperature inside the drying oven 1 (140 to 200 degrees Celsius), and in the case of catalytic exhaust gas treatment, the hot air entering the furnace body inlet 18 is approximately 200 to 250 degrees Celsius, and the temperature inside the drying oven 1 (140 to 200 degrees Celsius) can be controlled. The combustion air supplied to the burner 12 is approximately 2
The temperature is 50°C.

Note that the first air blower 9 may be installed next to the heat exchanger 10.

In the above embodiment, all of the exhaust gas is treated, but as shown in FIG. If the configuration is such that the air is directly supplied to the mixing tank 23 via the circulation duct 24 without passing through it, and the combustion device 7 processes only the amount of air other than the amount necessary for exhausting into the atmosphere, fuel consumption can be further reduced. It is possible.

As described above in the embodiments, the present invention uses a heated combustion hot air supply system that circulates hot air to the drying furnace and also serves as an organic gas combustion removal device, and the heated combustion hot air supply system supplies the hot air from the drying furnace to the drying furnace. A combustion device capable of burning and oxidizing the discharged organic gas, a fresh air supply duct for supplying fresh air for combustion from the outside to the combustion device, and a heat recovery device for processing hot air from the combustion device to produce the fresh air. It consists of a heat exchanger that turns fresh combustion air in a supply duct into hot air, and an atmosphere exhaust duct that discharges a portion of the treated hot air that has been cooled in the heat exchanger to the atmosphere.

Therefore, according to the present invention, duplication of devices such as a blower device, a filter device, a burner, and a combustion chamber is eliminated.
In addition, the fresh combustion air supplied from the outside is heat-exchanged with the high-temperature processed hot air from the combustion equipment in a heat exchanger to become hot air, so the combustion efficiency in the combustion equipment is increased, and the amount of heat emitted to the atmosphere is increased. This makes it possible to save on initial costs and running costs.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet showing one embodiment of the present invention, and FIG. 2 is a flow sheet showing another embodiment. 1: Drying oven, 4: Heating combustion hot air supply system, 6: Filter device, T: Combustion device, 9: First blower device, 10: Heat exchanger, 12 burner 13: Combustion chamber, 16: Fresh air supply duct, 20:゛Atmospheric exhaust duct.

Claims (1)

[Claims] 1. A heating combustion hot air supply system that circulates and supplies hot air to the drying oven also serves as an organic gas combustion removal device, and the heating combustion hot air supply system is a combustion system capable of burning and oxidizing the organic gas discharged from the drying oven. a fresh air supply duct for supplying fresh air for combustion to the combustion apparatus from the outside; and a fresh air supply duct for recovering combustion air from the combustion apparatus to convert the fresh air for combustion in the fresh air supply duct into hot air. a heat exchanger,
A baking drying oven apparatus comprising: an atmospheric exhaust duct for discharging a part of the treated hot air whose temperature has been lowered by the heat exchanger to the atmosphere.