JPH05332522A - Method of igniting waste food containing salt - Google Patents

Abstract

PURPOSE:To enable food containing salt to be ignited while its bad odor or soot smoke being removed by a method wherein chlorine gas of primary combustion and discharged gas containing carbon are secondary ignited and passed through a dechlorine catalyst. CONSTITUTION:As a dried noodle to be wasted is ignited, chlorine gas generated under decomposition of salt contained in the noodle is guided to a secondary combustion chamber 14 together with generated gas in a combustion furnace 6, carbon is ignited by an air blowing fan 15 and a heavy oil burner 16 to generate carbon oxide gas A. contact decomposing chamber 17 having refractory materials lined up in its inner surface is cooperatively arranged at the secondary combustion chamber 14. Dechlorine catalyst 18 is filled in it. The dechlorine catalyst 18 is made such that iron oxide powder and crushed zeorite are mixed and made into sphere particles and they are applied as raw baked and mixed catalyst having many voids in the baked surface. Hydrochloric acid gas is decomposed while dechlorine catalyst 18 being contacted and passed, and then chlorine is fixed to the catalyst 18 through its ion exchange. Accordingly, the discharged gas got from the contact decomposing chamber becomes non-pollution and non-smoke state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for incinerating salt-containing waste food such as noodles, pickles and the like collected from food counters.

[0002]

2. Description of the Related Art Conventionally, a part of waste food is used as feed, but most of it is currently landfilled, which causes pollution problem due to putrid odor. Therefore, it has been tried to incinerate waste food, but it is difficult to burn it because the contained salt acts as a flame retardant, which promotes the formation of carbon and produces toxic hydrochloric acid gas. I can't find a proper incineration method. Particularly, in noodles, the starch contained therein is gelatinized to form an adhesive glue film to block air, so that it is more difficult to burn, and it is considered difficult to incinerate it.

[0003]

Therefore, according to the present invention, noodles containing a large amount of starch and other salt-containing foods can be burned, and corrosion of the incinerator due to hydrochloric acid gas, air pollution, etc. can be eliminated, and harmful effects of bad odor and soot can be solved. It is intended to provide an incineration method that can eliminate the problem.

[0004]

Therefore, according to the present invention, salt-containing waste food is dried with hot air, and the dried waste food is
A part of the hot air exhaust gas is burned in the primary combustion furnace to remove the incineration ash, and the exhaust gas containing chlorine gas and carbon of the primary combustion is secondarily burned to convert carbon to carbon dioxide gas, and copper and Alternatively, chlorine is fixed and removed by passing iron through a dechlorination catalyst obtained by mixing iron with zeolite and calcination, and exhausting. It is optimum that the temperature of the primary combustion furnace is maintained at 700 to 900 ° C and the dechlorination catalyst installation part is maintained at 300 to 500 ° C. Also,
It is desirable that the secondary combustion exhaust gas that has passed through the dechlorination catalyst be washed with clean water and then released into the atmosphere.

Here, the reason why the salt-containing waste food is dried with hot air before being burned in the primary combustion furnace is to improve the combustion, and the hot-air drying makes it easier to break the salt-containing waste food into smaller pieces. In noodles, the tackiness of starch is released to prevent the formation of a glue film.

Further, it is desirable to maintain the temperature of the primary combustion furnace at 700 to 900 ° C, and burn the dried waste food by burner injection. At this time, since the waste food is dried and shredded, it can be incinerated well. Further, by sending a part of the hot air exhaust gas for drying to the primary combustion furnace, the primary combustion furnace can maintain a high temperature state by the residual heat of the dry hot air.

The primary combustion exhaust gas is secondarily burned by a burner or the like and passed through the dechlorination catalyst. Carbon contained in the exhaust gas is secondarily burned into carbon dioxide gas, and further chlorine gas is removed by the dechlorination catalyst. This is because. Here, as the dechlorination catalyst, a mixed catalyst obtained by mixing copper and / or iron with zeolite and bisque-molding is to fix chlorine well in contact with copper or iron. And to make it cheap. It is optimal to keep the temperature of the installation site of the dechlorination catalyst at 300 to 500 ° C.

Further, the secondary combustion exhaust gas that has passed through the dechlorination catalyst is washed with clean water in order to remove it in consideration of the worst situation in which carbon or the like remains slightly, and as a pollution-free gas. It diffuses into the atmosphere.

[0009]

[Operation] The drying time is shortened by drying with hot air, and a part of the hot air exhaust gas is sent to the primary combustion furnace to utilize the residual heat, and the dried waste food is burned in the primary combustion furnace and dropped from the rustle. Take out the incineration ash. The exhaust gas of the primary combustion contains chlorine gas and carbon, and by secondary combustion of this gas and passing it through a dechlorination catalyst, chlorine is fixedly removed, and carbon is exhausted as carbon dioxide gas.

[0010]

The details of the present invention will be described below with reference to the illustrated apparatus. In this example, waste noodles such as udon noodles and buckwheat noodles are mixed and used as waste food. The discarded stock feeder 1 is put into a rotary hot air dryer 2 and the waste noodles are dried while rotating in a dryer. Is done. The temperature inside the dryer is controlled so that the exhaust gas maintains 260 to 300 ° C. As a result, the wet waste noodles containing salt are dried and dropped onto the conveyor 4.

Next, the dried waste noodles are sent to the primary combustion furnace 6 by the conveyor 4 via the intermediate hopper 5. After the exhaust gas of the dryer 2 is removed by the dust collector 7, a part of the exhaust gas is returned to the hot air generating furnace 3 of the dryer 2 by the circulation fan 8 and the rest is blown into the combustion furnace 6. Also, the combustion furnace 6
Is equipped with a combustion air fan 9 and a heavy oil burner 10 to control the furnace temperature to 800 ° C.

Combustion of the dry waste noodles in the combustion furnace 6 is in a chopped shape before the dry waste noodles are charged into the combustion furnace 6, and therefore the air fan 9 and the circulation fan 8 eject the dry waste noodles into the furnace. It is burned well by the disturbance. Therefore, the dried waste noodles are incinerated and turned into ash and fall down from the grate, and are carried out from the cooling conveyor 11 via the feeding conveyor 12 and the bunker 13.

On the other hand, the hydrochloric acid gas generated by the decomposition of sodium chloride is introduced into the secondary combustion chamber 14 together with the gas generated in the combustion furnace 6, and carbon is burned by the air feeding fan 15 and the heavy oil burner 16 to become carbon dioxide gas. .. In the secondary combustion chamber 14, a catalytic cracking chamber 17 having an inner surface lined with refractory bricks is continuously provided, and a dechlorination catalyst 18 is filled inside. The dechlorination catalyst 18 is
Approximately 25 mm by mixing equal amounts of iron oxide powder and crushed zeolite
This is a bismuth-mixed catalyst that has a large number of voids on the surface and is formed into a spherical shape and baked at 1000 to 1200 ° C. The catalytic decomposition chamber 17 has a diameter of 300 mm and a height of 1500 mm, and its temperature is kept at about 400 ° C. by the burner 16.

Hydrochloric acid gas is decomposed by passing through the dechlorination catalyst 18, and chlorine is fixed to the catalyst 18 by ion exchange. Therefore, the exhaust gas from the catalytic cracking chamber 17 becomes smokeless and pollution-free. For this reason, a large amount of air may be mixed and cooled and diffused into the atmosphere, but in this example, the exhaust gas is sucked into the water tank 20 whose pressure has been reduced by the water jet scrubber 19 and circulated by the circulation pump 21. It is washed with water and then diffused from the discharge cylinder 22 into the atmosphere.

The dust collected by the exhaust gas dust collector 7 from the hot air dryer 2 and the exhaust gas dust collector 23 from the catalytic cracking chamber 17 is collected on the feed conveyor 12 and carried out through the bunker 13. Of.

Table 1 shows the measurement results of the contained substances such as dust.
The results of dust concentration measurement are shown in Table 2, and the results of the composition amount of the exhaust gas from the catalytic cracking chamber 17 are shown in Table 3. From these, normal results were obtained.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

As described above, according to the method of this example, the noodles in a wet state containing starch are dried by hot air drying to a state suitable for incineration, and the dried noodles are shredded to be effectively incinerated. Then, chlorine gas generated by combustion of the contained salt is dechlorinated by the dechlorination catalyst 18, and carbon also becomes carbon dioxide gas by secondary combustion.

Although the method of the present example is configured as described above, the method of the present invention is not limited to this. For example, salt-containing waste foods include udon noodles, ramen noodles, noodles such as spaghetti and macaroni, and crepes and okonomiyaki that use wheat flour as the main raw material are most suitable, but salt-containing pickles, etc. It is possible to incinerate various waste foods.

In the hot air drying step, the waste food may be cut into pieces beforehand. Further, although the mixing ratio of the dechlorination catalyst is not limited, it is appropriate to use 50% by volume of zeolite and 50% by volume of copper and / or iron alone as a simple substance.

[0023]

EFFECTS OF THE INVENTION According to the present invention, since the starch content of salt-containing waste foods is decompressed by hot air drying, it is easy to incinerate the same, and chlorine gas generated by the burning of the contained salt is chlorinated by a dechlorination catalyst. After that, carbon also becomes carbon dioxide gas in the secondary combustion and becomes pollution-free exhaust gas. According to the second aspect, the combustion effect of the salt-containing waste food and the dechlorination effect by the catalyst are improved, and in the third aspect, the exhaust gas can be made more pollution-free.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an incineration system illustrating the method of the present invention.

[Explanation of symbols]

 1 stock feeder 2 hot air dryer 3 hot air generating furnace 4 conveyor 6 primary combustion furnace 7,23 dust collector 9 combustion air fan 10,16 heavy oil burner 11 cooling conveyor 14 secondary combustion chamber 17 catalytic cracking chamber 18 dechlorination catalyst 19 water jet Scrubber 20 Water tank 22 Discharge cylinder

Claims (3)

[Claims] 1. A salt-containing waste food is dried with hot air, the dried waste food is burned in a primary combustion furnace to which a part of the hot air exhaust gas is sent, and the incinerated ash is taken out. Secondary combustion of exhaust gas containing gas and carbon turns carbon into carbon dioxide, and copper and / or iron is mixed with zeolite and passed through a dechlorination catalyst that is calcinated to fix and remove chlorine. A method for incinerating salt-containing waste food, characterized by exhausting air. 2. The incineration method according to claim 1, wherein the temperature of the primary combustion furnace is maintained at 700 to 900 ° C., and the installation portion of the dechlorination catalyst is maintained at 300 to 500 ° C. 3. The incineration method according to claim 1, wherein the secondary combustion exhaust gas that has passed through the dechlorination catalyst is washed with clean water and then diffused into the atmosphere.