JP2527519B2 - Molten slag crystallization furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten slag crystallization furnace used for producing a crystallized product from molten slag such as sewage sludge.

[0002]

2. Description of the Related Art It has been conventionally known to produce aggregate having excellent strength by crystallizing molten slag such as sewage sludge. However, the conventional molten slag crystallization furnace has a method of driving the crystallization container at a constant speed with a roller chain, or a method of pulling a trolley equipped with the crystallization container with a chain at a constant speed. The speed of movement was uniform from start to finish.

On the other hand, in order to successfully perform crystallization, it is necessary to control the crystallization temperature (heat curve) in correspondence with the composition variation of the molten slag, and practically, it is 1300 to 1500 ° C. It is necessary to consider that the chain etc. will not deteriorate due to high temperature slag. However, in the above-mentioned conventional molten slag crystallization furnace, since the moving speed of the crystallization container is constant, the adjustment of the heat curve is performed only by heating with a burner or supply of cooling air, and an appropriate heat curve is obtained. Adjustment was difficult. Further, in the conventional molten slag crystallization furnace, it is unavoidable that the chain or the like that drives the crystallization container is thermally deteriorated.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and enables the heat curve to be adjusted widely in accordance with the composition variation of molten slag, and the mechanical equipment of high temperature slag can be used. It was completed in order to provide a molten slag crystallization furnace with little deterioration and excellent heat resistance.

[0005]

The present invention, which has been made to solve the above-mentioned problems, provides a temperature rising zone for raising the temperature of a crystallization vessel to a predetermined temperature, a constant temperature zone for receiving and crystallizing molten slag, and a subsequent temperature zone. The furnace body whose inside is divided into the cooling zone for cooling the molten slag, the temperature rising zone of the furnace body, the constant temperature zone, and the crystallization container in the cooling zone can be specialized for each zone and transported at different speeds. It is characterized in that it is provided with a different carrier.

[0006]

According to the molten slag crystallization furnace of the present invention, the crystallization container that receives the molten slag from the slag melting furnace is moved at different speeds in each zone of the furnace body by the carrier provided in each zone. Therefore, it is possible to expand the adjustable range of the heat curve as compared with the conventional device that has to rely solely on heating by a burner or supply of cooling air. Therefore, it is possible to set an appropriate heat curve corresponding to the composition variation of the molten slag.

[0007]

The present invention will be described below in more detail with reference to the illustrated embodiments. In FIG. 1, 1 is a slag melting furnace that melts sewage sludge and the like to form slag, and 2 is a tunnel-shaped furnace body formed below the slag melting furnace. The furnace body 2 is installed so as to extend in front of and behind the slag melting furnace 1. The inside of the furnace body 2 is divided into a plurality of zones by some shield plates 3. In the embodiment, the temperature rising zone 4, the adjusting zone 5,
There are a constant temperature zone 6, a control zone 7, and a cooling zone 8. Here, the adjustment bands 5 and 7 are zones that can be changed to any of the front and rear bands, but they are not essential.

In each of these zones inside the furnace body 2, an independently driven carrier 9 is laid. In the embodiment, the conveyor 9 is a roller unit, and each of the temperature rising zone 4, the adjusting zone 5, the constant temperature zone 6, the adjusting zone 7 and the cooling zone 8 can be independently driven at different speeds. ing. As the roller, a ceramic roller having excellent heat resistance used for high temperature firing of various ceramic products is attached, and a mechanism for driving the roller from outside the furnace is adopted.

Reference numeral 10 denotes a crystallization container which is moved in the furnace body 2 by these conveyors 9, is placed on the setter 11, is supplied from the inlet side, and is taken out from the outlet side. In addition,
Movable shield plates 12 and 13 are provided at the entrance and exit of the furnace body, and are opened and closed only when the crystallization container 10 is taken in and out.

Further, as shown in the lower part of FIG.
In addition, combustion burners 14 are provided above and below the rollers in the zones of the adjustment zones 5 and 7 before and after the zone to control the temperature inside the furnace.
Further, cooling nozzles 15 are provided above and below the rollers in the cooling zone 8 to cool the inside of the furnace. Further, a heating zone exhaust fan 16 and a cooling zone exhaust fan 17 are provided above the furnace zone 2 to heat the crystallization vessel 10 while moving the high temperature gas generated in the constant temperature zone 6 to the inlet side, It can be discharged to the outside by the temperature rising zone exhaust fan 16.

In the molten slag crystallization furnace of the present invention thus constructed, the crystallization vessel 10 is put into the furnace from the inlet side of the furnace body 2, and the carrier 9 moves the temperature rising zone 4 for crystallization. Preheat container 10. And the crystallization container 10 has a constant temperature zone 6
When the temperature reaches, the molten slag is poured into the crystallization container 10 from the slag melting furnace 1. After that, the crystallization container 10 is moved in the constant temperature zone 6 by the carrier 9 and crystallizes the slag while passing through the cooling zone 8.

As described above, in the crystallization process, it is necessary to appropriately set the heat curve in correspondence with the composition variation of the slag, but in the molten slag crystallization furnace of the present invention, the crystallization container 10 is provided in each zone. Each can be driven independently at different speeds. Therefore, as shown in FIG. 2, the temperature holding time of the slag can be changed by changing the moving speed of the crystallization container 10 in the constant temperature zone 6. Further, as shown in FIG. 3, the cooling speed of the slag can be changed by changing the speed of the carrier 9 of the cooling zone 8. Further, if the adjustment bands 5 and 7 are provided as in the embodiment,
The heat curve can also be adjusted by changing this to the constant temperature zone 6 or the cooling zone 8. Therefore, according to the present invention, it becomes possible to appropriately set the heat curve in correspondence with the composition variation of the slag and the like.

[0013]

As described above, according to the molten slag crystallization furnace of the present invention, the heat curve can be widely adjusted in accordance with the composition variation of the molten slag, and the crystallization of the molten slag is sufficiently performed. Can be done. In addition, by using a roller unit as a carrier and moving the crystallization container with a ceramic roller having excellent heat resistance as in the embodiment, deterioration of mechanical equipment due to high temperature slag can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating an embodiment of the present invention.

FIG. 2 is a graph showing a change in a heat curve by changing the speed of a carrier in a constant temperature zone.

FIG. 3 is a graph showing a change in a heat curve by changing a speed of a carrier in a cooling zone.

[Explanation of symbols]

 2 furnace body 4 temperature rising zone 6 constant temperature zone 8 cooling zone 9 carrier 10 crystallization vessel

Claims (2)

(57) [Claims] 1. A furnace body whose inside is divided into a temperature rising zone for raising the temperature of the crystallization container to a predetermined temperature, a constant temperature zone for receiving and crystallizing the molten slag, and a cooling zone for cooling the molten slag thereafter. A molten slag crystallization furnace, characterized in that the crystallization containers in the temperature rising zone, the constant temperature zone, and the cooling zone of the furnace body are individually provided for each zone and can be transported at different speeds. 2. The molten slag crystallization furnace according to claim 1, wherein a control zone capable of changing to any of the front and back zones is provided at least at one place between the temperature rising zone, the constant temperature zone and the cooling zone.