JPH0118323B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is designed to prevent heavy metals from flowing out when various industrial wastes such as sewage sludge, or intermediately processed products obtained by drying, incinerating or pulverizing them as necessary, are used in landfills. Regarding the method of incinerating and melting industrial waste or its intermediate products to prevent it from burning or to make it usable as construction aggregate, etc. Regarding a waste melting method, the waste is supplied to a bed, incinerated and melted, and the combustion exhaust gas is discharged into an ascending channel formed above the high-temperature hearth, the purpose of which is to easily remove clinker attached to the inner surface of the ascending channel. The aim is to enable sufficient removal in a short time and with a simple operation.

More specifically, in the above waste melting method, as a means to suppress clinker from adhering and accumulating on the inner surface of the ascending channel, combustion exhaust gas is cooled or the cross-sectional area of the ascending channel is increased. Although measures such as lowering the linear velocity of the exhaust gas can be considered, these methods have an economical disadvantage in that thermal energy cannot be used effectively, and are therefore difficult to put into practical use. For this reason, in the past, adhering clinker was manually crushed and removed, but in this case, the work had to be done at a dangerous height, and the furnace temperature had to be lowered to a temperature where the work could be done. Because the furnace temperature must be raised again after the clinker removal work, the waste melting work must be stopped for a long time during the clinker removal work, and in addition, the entire clinker must be removed properly. There are various drawbacks, such as the fact that it is difficult to do so, and it is an object of the present invention to eliminate these drawbacks all at once.

Next, embodiments of the present invention will be described with reference to illustrative figures.

A high-temperature hearth 2 made of carbon-based combustible material is formed in a cupola-type melting furnace 1, and dampers 4a and 4b are alternately opened and closed to transfer industrial waste or its intermediate processed materials from a hopper 3 to the high-temperature hearth 2. , supplied in a mixed state or alternately with carbon-based combustible materials,
A packed bed 5 of carbon-based combustible substances and industrial waste or intermediate treatment thereof is formed on the high-temperature hearth 2, and oxygen-containing gas such as air is supplied to the high-temperature hearth 2 from the first tuyere 6 below. Then, industrial waste or its intermediate treatment is burnt in the upper part of the high-temperature hearth 2.
The combustion exhaust gas is discharged into an ascending passage 7 formed above the high-temperature hearth 2 and a lower passage 8 connected to the lower part of the high-temperature hearth 2, and the molten material is discharged into the lower flow passage 7. The combustion exhaust gas generated from the high-temperature hearth 2 is taken out of the furnace through the passage 8, and the ascending passage 7 is configured to combust and decompose odor components and harmful components generated when the combustion exhaust gas is passed through the packed bed 5.
After-combustion is carried out inside the furnace by oxygen-containing gas such as air supplied from the second tuyere 9, and the side wall for the two portions of the high-temperature hearth is constructed with a double pipe structure to form a water-cooled jacket 10. .

The combustion exhaust gas from the ascending passage 7 is discharged into the atmosphere through an exhaust duct 11 connected to the top of the furnace, a dust removal cyclone 12, a heat exchanger 13, and a first blower 14, and further, the first The oxygen-containing gas supplied to the second tuyeres 6 and 9 by the second blower 15 is heated by the heat exchanger 13.

Further, in a state where the supply of industrial waste or its intermediate treated product to the high-temperature hearth 2 is stopped or reduced, a Adjustment of flow control valves V ₁ and V ₂ ,
By adjusting the supply rate of the carbon-based combustible material to the high-temperature hearth 2, etc., the temperature of the combustion exhaust gas discharged from the high-temperature hearth 2 into the ascending channel 7 is lowered to the inner surface of the ascending channel 7. Melting point of attached clinker (1000
The clinker adhering to the inner surface of the ascending flow path 7 is melted and flowed down by burning for 30 minutes to 1 hour at a temperature of 50 to 100 degrees Celsius (1210 degrees Celsius) plus 50 degrees Celsius.

In short, the clinker adhering to the inner surface of the ascending channel 7 can be removed by a simple operation of burning the high-temperature hearth 2 as described above, and the clinker can be removed without lowering the furnace temperature. The clinker removal work can be carried out in a short time without the inconvenience of having to stop the waste melting work for a long time during the removal work, and in addition, the entire adhered clinker can be heated evenly while the entire surface of the adhered clinker is evenly heated. It can be completely removed without any problems.

In addition, when removing the adhered clinker using the present invention, if the part of the clinker located near the inner surface of the ascending channel 7 is removed, heat loss to the forming member of the ascending channel 7 can be avoided. It's good to be what you can be.

In addition, although raising the temperature of the flue gas above the melting point of the clinker can remove clinker more quickly, on the other hand, there is a risk of heat loss to the walls of the furnace used. The temperature may be raised depending on the composition of the clinker and the properties of the clinker.

In addition to sewage sludge, the present invention can treat various industrial wastes such as tire scraps, municipal waste incineration ash, and waste catalysts, as well as intermediate products thereof, and the specific configuration of the melting furnace used is Various modifications are possible, such as one without the water-cooling jacket 10, and furthermore, it is preferable to mainly use coke as the carbon-based combustible material forming the high-temperature hearth 2.
Various materials such as briquettes such as anthracite, black smoke electrode scraps, etc. may be used.

In summary, the present invention, in the above-mentioned waste melting method, stops or reduces the supply of industrial waste or its intermediate processed material, and removes clinker adhering to the inner surface of the ascending channel 7 to the high-temperature hearth 2. It is characterized by causing the melt to flow down by combustion exhaust gas from.

That is, while the supply of industrial waste or its intermediate treatment product is stopped or reduced, the temperature of the combustion exhaust gas from the high-temperature hearth 2 is maintained at a temperature higher than the melting point of the clinker, and the ascending flow path 7 is Since the purpose is to melt and flow down the clinker adhering to the inner surface of the high-temperature hearth 2, the supply of industrial waste or its intermediate products is stopped or reduced.
The adhering clinker can be removed by simply burning the flue gas so that the temperature of the flue gas is above the melting point of the clinker. Moreover, the clinker can be removed without lowering the furnace temperature, making the clinker removal work easier. The clinker removal work can be carried out in a short time without the inconvenience of having to stop the waste melting work for a long time, and in addition, the entire surface of the adhering clinker can be heated evenly and thoroughly. Eventually, it became possible to remove adhering clinker very effectively.

[Brief explanation of drawings]

The drawing illustrates an embodiment of the waste melting method according to the present invention and is a schematic cross-sectional view of a furnace used. 2...High temperature hearth, 7...Rising channel.

Claims (1)

[Claims] 1. Industrial waste or its intermediate treatment product is supplied to a high-temperature hearth 2 formed of carbon-based combustible material, incinerated and melted, and combustion exhaust gas is transferred to the high-temperature hearth 2.
A waste melting method in which the waste is discharged into an ascending channel 7 formed above, and clinker adhering to the inner surface of the ascending channel 7 is removed by stopping or reducing the supply of industrial waste or its intermediate treatment products. A waste melting method characterized in that the waste is melted and flowed down by combustion exhaust gas from the high temperature hearth 2.