JPH0732487U - DI can dryer oven - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a dryer oven for DI cans in which the circulating hot air for drying is made clean so that periodical cleaning of the inside of the oven becomes unnecessary and cleaning of the mesh belt conveyor becomes unnecessary. [Structure] The dryer oven for DI cans according to the present invention is
While placing the DI can A with the bottom on top on the mesh belt conveyor 5 and passing it through the dryer oven 1, circulating hot air for drying discharged from the circulation fan 2 is blown from above the can A. Also, in the DI can dryer oven of the type in which the mesh belt conveyor 5 is dried, a clean heating mechanism such as an electric heater unit 13 is installed in the hot air circulation return duct section 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a DI can dryer oven in which hot air is blown from the upper part of a can while the can is being placed on a conveyor belt conveyor and transferred. More specifically, the present invention relates to a can for drying a can. The present invention relates to a DI can dryer oven that uses a clean heating source as a heat source for heating circulating hot air.

[0002]

[Prior art]

 In a conventional DI can dryer oven, as shown in FIG. 5, a DI can A with the bottom part on top is placed on a mesh belt conveyor 5 through which gas and liquid can flow, and the DI can A is conveyed into the dryer oven 1 and fed from a hot air circulation fan 2. Circulating hot air for drying discharged is passed through the hot air circulation duct 3 and is blown from above the can as uniform and laminar hot air through the upper rectifying plate 4 to heat and heat the can A and the mesh belt conveyor 5. The attached water is evaporated.

The blown hot air absorbs the evaporated water and exchanges heat through a conveyor guide / lower exhaust rectifying plate 6 provided in the lower part of the mesh belt conveyor 5, and then becomes moist circulating hot air and becomes a hot air circulating fan. 2 and the exhaust fan 9 sucks downward, and a part of the moist circulating hot air is exhausted from the exhaust duct 7 to the outside of the oven by the exhaust fan 9 through the exhaust air volume control valve 8.

Further, the remaining part of the moist circulating hot air enters the return duct section 11 through the opening section 10 and passes through the dry air supply flow rate control valve 12 provided at the lower portion of the return duct section 11 to obtain a required amount. It is mixed with atmospheric fresh air taken into the oven and heated by the circulating hot-air heating burner 17 so that the temperature and humidity are suitable for use as circulating hot air for drying. It has a structure that circulates.

[0005]

[Problems to be solved by the device]

 However, in this conventional oven, since a direct-fired burner is used as a heat source for circulating hot air for drying, combustion exhaust gas is contained in the circulating hot air for drying, and although the amount is extremely small, the soot is changed due to changes in the combustion situation. There was a mixture of types.

This is because the mesh belt conveyor, which constantly passes through the oven as well as the dryer oven where circulating hot air for drying is present, is contaminated due to the accumulation of soot in the medium and long term, and cans of the material to be treated. Since the dirty soot adheres to the inside, regular cleaning of the oven is required, and the mesh belt conveyor that comes into direct contact with the cans must be cleaned almost at all times.

For this reason, there is a method in which a pure water cleaning device originally intended for the final cleaning of a can is also installed on the inlet side of the dryer oven, and the mesh belt conveyor is also used for cleaning. It was done.

Therefore, the amount of heat required to heat and heat the mesh belt conveyor is higher than the amount of heat required to heat and dry the wet can due to the weight of the mesh belt and the specific heat of the material. This is a major problem of thermal energy loss due to repeated heating and heating of the wet mesh belt conveyor by cleaning the mesh belt conveyor once heated and heated in the oven almost constantly. There was a point.

Further, since the temperature rise of the mesh belt conveyor is delayed compared to the temperature rise of the can, the temperature of the mesh belt conveyor causes the attached water to evaporate and dry the attached water at the contact portion between the mesh belt conveyor and the can. Since it has to be heated to a sufficient temperature, there is a problem that the time required for drying is significantly delayed.

The present invention aims to solve the above-mentioned problems, and by making the circulating hot air for drying clean, it is possible to eliminate the need for periodic cleaning in the oven and the cleaning of the mesh belt conveyor. The main purpose is to provide a DI can dryer oven.

Still another object of the present invention is to employ an indirect heating method for cleaning the circulating hot air in the oven to suppress the temperature drop of the mesh belt conveyor heated and heated as the mesh belt conveyor cleaning becomes unnecessary. When the mesh belt conveyor returns to the receiving side of the can, it is necessary to raise the temperature of the mesh belt conveyor not only by preventing the temperature of the mesh belt conveyor from falling by passing through the oven on the return. An object of the present invention is to provide a DI can dryer oven capable of reducing various heat energy and contributing to early heating of the can by preheating the mesh belt conveyor and prevention of softening of the can.

[0012]

[Means for Solving the Problems]

 As a means for solving the above problems and achieving the object, in the present invention, while a DI can with a bottom portion on top is placed on a mesh belt conveyor, it is discharged from a circulation fan while passing through a dryer oven. A DI can dryer characterized by having a clean heating mechanism installed in the hot air circulation return duct in a DI can dryer oven in which circulating hot air for drying is blown from above the can to dry the can and mesh belt conveyor. Developed and adopted the oven.

Further, the present invention is a DI can dryer oven configured as described above, in which an electric heater unit is installed as a clean heating mechanism, and an indirect heating as a clean heating mechanism. We have developed and adopted DI can dryer ovens, which are characterized by installing a heat exchanger such as a radiant tube burner of the type and a recuperator of the indirect heating type as a clean heating mechanism.

[0014]

[Action]

 Circulating hot air for drying discharged from the circulation fan is blown from the circulation duct through the upper blowing straightening vane to the bottom of the can with moisture adhering to the mesh belt conveyor and the outer wall surface to evaporate and dry the adhering moisture. Let The hot air absorbs the evaporated water and flows to the conveyor guide / lower exhaust baffle plate provided on the lower surface of the mesh belt conveyor.

The circulating hot air that has passed through the lower exhaust baffle plate has a high moisture dew point due to the evaporation of moisture adhering to the cans and conveyors, and is sucked downward by the exhaust fan and the circulating hot air fan. Part is discharged from the exhaust duct to the outside of the oven, and the remaining moist circulating hot air flows through the opening to the circulation return duct on the other side and is mixed with the fresh air introduced from the lower part of the part to obtain a humidity suitable for drying. .

[0016] The mixed circulating hot air has a temperature suitable for being used as a circulating hot air for drying in which the amount of water contained in the combustion exhaust gas does not enter as in the case of an open flame type, and a hot air for electric heating so that the humidity becomes dry It is heated by the heat source of the heat exchanger such as the heater unit, radiant tube burner or recuperator, and clean hot air is circulated, which not only cleans the inside of the oven but also the mesh belt conveyor frequently moves inside the oven. Even if it passes through, there is no dirt due to the adherence of soot.

Further, since it is not necessary to wash the mesh belt conveyor, it is not necessary to lower the temperature by heating the mesh belt conveyor that is heated at the same time as the can and reheat the temperature of the wet mesh belt conveyor for washing. As a result, the heat energy loss necessary for heating the mesh belt conveyor can be suppressed, and the mesh belt conveyor can be preheated easily and the can drying time can be shortened.

[0018]

【Example】

 Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIGS. 1 and 2, reference numeral 1 is a dryer oven, in which a hot air circulating fan 2 is arranged above the inside thereof, and a hot air duct 3 is provided at a discharge port of the fan 2. The hot air circulation duct 3 is composed of an upper duct 3a that partitions the interior and a lower duct 3b that does not have a partition.

Reference numeral 4 is an upper blowing straightening vane incorporating a honeycomb laminar flow plate and blowing hot air of uniform and vertical laminar flow. Reference numeral 5 is a metal mesh belt for carrying the inverted can A with the bottom part facing upward. The conveyor travels in the direction of the arrow in the oven 1 and exits from the outlet 1b. The belt conveyor 5 finishes the transfer of cans (not shown), enters the bottom of the oven 1 again, and returns to the inlet 1a of the oven 1. It is stretched endlessly.

Reference numeral 6 denotes a conveyor guide / lower exhaust rectifying plate disposed on the lower surface of the belt conveyor 5, 7 denotes a duct for exhausting a part of the moist circulating hot air, and a part of the moist circulating hot air controls an exhaust air volume control valve 8 After being discharged to the outside of the oven 1 by the exhaust fan 9, the remaining moist circulating hot air flows from the opening 10 to the circulation return duct 11 on the other side.

Reference numeral 12 denotes an air fresh air supply flow rate control valve provided at a lower portion of the circulation return duct 11 on the other side, and introduces air fresh air into the oven in an amount corresponding to the mass exhausted from the blower 9. Reference numeral 13 denotes a heating electric heater unit used as a clean heating mechanism, which is configured to be heated to a temperature suitable for being used as the circulating hot air for drying and to be sucked into the hot air circulating fan 2.

The use mode of the present invention having the above-described structure will be described. When the can A with the bottom is placed on the mesh belt conveyor 5 and conveyed into the dryer oven body 1, the hot air circulating fan 2 Circulating hot air for drying discharged through the hot air circulation duct 3 is blown with uniform vertical laminar hot air from above the can A by the upper blowing straightening plate 4 to heat and heat the can A and the mesh belt conveyor 5. Then, the attached water is evaporated and dried.

The hot air blown from the upper part of the can A absorbs the evaporated water, and passes through the conveyor guide / lower exhaust rectifying plate 6 provided at the lower part of the mesh belt conveyor 5 to perform the wet heat circulation after the primary heat exchange. After the secondary heat exchange after heating the return part 5a of the mesh belt conveyor 5 that further passes underneath it as hot air, it is sucked downward by the circulation fan 2 and the exhaust fan 9 as wet circulating hot air.

A part of the moist circulating hot air after the secondary heat exchange sucked downward is discharged to the outside of the oven 1 as the exhaust moist circulating hot air by the exhaust fan 9 through the exhaust duct 7 and the exhaust air volume control valve 8. The remaining circulating moist circulation hot air flows through the opening 10 to the circulation return duct 11 on the other side.

The moist circulating hot air that has entered the circulation return duct 11 on the other side is taken into the oven by the amount of mass exhausted from the exhaust fan 9 from the atmospheric fresh air supply flow rate control valve 12 provided below it. After being mixed with the fresh air in the atmosphere, it is heated by the circulating hot air heating electric heater unit 13 so that the temperature and humidity are suitable for being used as the circulating hot air for drying, and is then guided to the hot air circulating fan 2.

FIG. 3 and FIG. 4 show another embodiment. The difference from the above embodiment is that an indirect heating method is adopted instead of the electric heater unit 12 as a clean heating mechanism. The radiant tube burner 14 is used as a clean heating mechanism, and the heat exchanger 15 such as a recuperator is used as a clean heating mechanism in FIG.

When the heat exchanger 15 such as a recuperator is used, the hot air generator 16 is provided in order to introduce excess air and create a heating-side fluid having an appropriate temperature and volume. Is as follows.

That is, when the heating side fluid of the heat exchanger is only the combustion exhaust gas of the normal air-fuel ratio combustion by the burner, since the heat receiving side fluid circulation flow rate is considerably large, the heating side fluid becomes a small amount of high temperature. Therefore, it is necessary to use an expensive material for the heat exchanger, and in some cases the water equivalent ratio in the heat exchanger design may become unbalanced and it may not be possible to deal with it. This is because the flow rate is low and uniform heating cannot be performed on the heat-receiving fluid that causes uneven flow when passing through the heat exchanger.

Therefore, excess air is introduced in order to reduce the temperature of the combustion exhaust gas from the burner to an appropriate temperature for the heating side fluid, and the flow rate is set so as not to cause uneven flow when passing through the heat exchanger. Therefore, in some cases, a hot air generator that mixes cold air with the burner combustion exhaust gas to obtain a proper temperature and flow rate may be installed. Replace them to save energy. After that, the exhaust gas is released to the atmosphere.

[0030]

[Effect of device]

 As described above, the present invention uses a heat exchanger such as an electric heater unit, a radiant tube burner, or a recuperator as a clean heating mechanism in the hot air circulation return duct to heat the circulating hot air for drying to generate the circulating hot air for drying. By making it clean, it is not necessary to stop the line for regular cleaning in the oven, and at the same time the labor cost for cleaning can be reduced.

Further, since the mesh belt conveyor is not polluted, it does not need to be cleaned. Needless to say, the cleaning equipment and the cleaning liquid for cleaning the mesh belt conveyor are not required, and the mesh belt conveyor is dry, The heat energy required to heat the conveyor to a certain temperature can be reduced, and the time required for heating and heating can be shortened.

Furthermore, when the mesh belt conveyor is heated to a certain temperature when the can is dried, the can is transferred to the next facility and then returned from the oven outlet side to the oven inlet side. Not only can the temperature of the mesh belt conveyor be prevented from falling, but the cooled conveyor can be heated up and down at the outlet of the oven, so preheating of the conveyor is effective in preventing early drying and softening of cans.

Further, if the electric heater unit is used, since it uses electricity, there are few accessories as a facility, it is compact, the handling is very simple, it looks good, and the facility cost is very cheap and there are few failures. Also, the responsiveness of the control of the set temperature is good, and it is not necessary to consider handling of combustion exhaust gas such as burner combustion.

When a radiant tube burner is used, a heat exchanger is used for the combustion air and the tube exhaust gas. Since the indirect heating method is used in the drying furnace, the apparent fuel consumption will increase, but the actual running cost will be low due to the heat exchange between the exhaust gas and the combustion air described above and energy saving such as mesh belt conveyor preheating. .

Further, when the heat exchanger is used, it is used for heating the cleaning liquid in the cleaning process of the previous process, as compared with the case where the radiant tube burner is used, so that the temperature of the combustion exhaust gas is lowered and energy is saved. The cost is low.

[Brief description of drawings]

FIG. 1 is a simplified vertical sectional side view of a dryer oven of the present invention.

FIG. 2 is a vertical cross-sectional view taken along the line II of FIG.

FIG. 3 is a simplified vertical sectional front view showing another embodiment of the present invention.

FIG. 4 is a simplified vertical sectional front view showing still another embodiment of the present invention.

FIG. 5 is a simplified vertical sectional front view of a conventional dryer oven.

[Explanation of symbols]

 1 Dryer Oven 2 Circulation Fan 5 Mesh Belt Conveyor 11 Hot Air Circulation Return Duct 13 Electric Heater Unit 14 Radiant Tube Burner 15 Heat Exchanger

Claims (4)

[Scope of utility model registration request] 1. While a DI can having a bottom portion on top is placed on a mesh belt conveyor and passed through a dryer oven, circulating hot air for drying discharged from a circulation fan is blown from above the can, A DI can dryer oven in which a mesh belt conveyor is dried, and a clean heating mechanism is installed in a hot air circulation return duct section. 2. The DI according to claim 1, wherein an electric heater unit is installed as a clean heating mechanism.
Can dryer oven. 3. The DI can dryer oven according to claim 1, wherein an indirect heating type radiant tube burner is installed as a clean heating mechanism. 4. The DI can dryer oven according to claim 1, wherein a heat exchanger such as an indirect heating type recuperator is installed as a clean heating mechanism.