JPH08159425A - Melting furnace - Google Patents

Abstract

PURPOSE: To prevent the endothermic reaction of carbon dioxide and coke and efficiently process industrial waste harmlessly by providing a grate formed with a refractory material in a melting furnace. CONSTITUTION: A grate 3 formed with a refractory material 2 is provided in a melting furnace 1. A heating part 4 for heating the grate 3 is provided in the vicinity of the lower part of the grate 3. A feed part 6 for feeding incineration ash 5 is provided on the upper part of the grate 3. A molten product take-out port 7 is provided on the bottom of the melting furnace 1 or in the vicinity thereof. The grate 3 is heated by the combustion gas of a burner 8 and the incineration ash 5 is molten by the heat of this grate 3, so that CO2 +C =2CO which is an endothermic reaction is not generated. Thus, a melting is efficiently carried out without heat loss.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste melting furnace for melting and treating incineration ash and fly ash obtained by incinerating municipal waste, sewage sludge and the like.

[0002]

2. Description of the Related Art Generally, most of incinerated ash such as industrial waste is landfilled.
However, since it is difficult to secure a landfill in recent years, useful utilization and volume reduction have been demanded.For example, a method of solidifying incinerated ash as it is with cement etc. is performed, but this method is In addition, there is a defect that the volume of the waste increases due to the use of the binder.

Therefore, in recent years, as a detoxification treatment by melting and solidifying the industrial waste, a melting and solidifying means using a cupola type coke bed melting furnace has been proposed.

This means is a means for injecting waste into a grate formed of coke which has been used for a long time, and heating and burning the coke to melt the waste.

However, this measure has drawbacks.

Carbon dioxide generated by the combustion of coke (C + O ₂ = CO ₂ ) reacts with the coke again (CO ₂ +
(C = 2CO), an endothermic phenomenon occurs and heat loss occurs, and the melting efficiency in the melting furnace deteriorates (CO ₂ + C = 2CO is an endothermic reaction as is well known). This is nothing but the fact that the grate was formed from coke (carbon).

The present invention solves such drawbacks and provides a melting furnace capable of efficiently detoxifying industrial waste.

[0008]

The gist of the present invention will be described with reference to the accompanying drawings.

A grate 3 made of refractory 2 is provided in the melting furnace 1, a heating part 4 for heating the grate 3 is provided near the bottom of the grate 3, and an incineration ash 5 is provided above the grate 3. The present invention relates to a melting furnace in which a supply unit 6 for supplying is provided and a melt take-out port 7 is provided at or near the bottom of the melting furnace 1.

In the melting furnace according to claim 1, the heating section 4
The burner 8 for injecting the combustion gas G is adopted as the above, and the area A ₁ of the plane cross section of the grate 3 near the lower end of the supply section 6 and the area A ₂ of the plane cross section of the grate 3 near the heating section 4 are , A ₁ ≧ A
As increased flow rate S ₂ of the combustion gas G of elevated flow rates S ₁ and an area A ₂ portion of the combustion gas G of a portion of the area A ₁ by configuring such that the _second relation is S ₂ ≧ S ₁ The present invention relates to a melting furnace characterized by being set.

[0011]

[Function] Since the grate 3 is made of the refractory 2, CO ₂
No endothermic reaction of + C = 2CO occurs and no heat loss occurs.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show one embodiment of the present invention.
This will be described below.

A cylindrical melting furnace 1 for melting and solidifying the incineration ash 5 is formed into a refractory structure by using a refractory material.

A burner 8 for mixing the air and the LPG and injecting the combustion gas G is provided around the lower portion of the melting furnace 1 (reference numeral 13 is a combustion air introducing portion).
Further, a melt take-out port 7 is provided near the bottom of the peripheral wall of the melting furnace 1. The melt take-out port 7 is composed of a slag tap 7a on the upper side and a metal tap 7b on the lower side.

A refractory 2 is filled up to a predetermined height in the melting furnace 1 to form a grate 3. In the melting furnace 1, a lower end opening 6 ′ is exposed to the inside of the melting furnace 1, and a cylindrical supply part 6 that continuously supplies the incineration ash 5 to the melting furnace 1 is hung down. The lower part of 6 is buried in the grate 3. The supply unit 6 is formed of a member having a good heat transfer property.

Combustion gas G (exhaust gas) is provided above the melting furnace 1.
Is provided with a secondary combustion chamber 9 (reference numeral 12 is a combustion air introduction portion), and an exhaust port 10 is provided at one side of an upper portion of the melting furnace 1.

The melting furnace 1 is formed with a small diameter near the lower portion (where the burner 8 is present), and the rising velocity S ₂ of the combustion gas G in the small diameter portion 1a rises in the large diameter portion 1b. It is designed so as not to become slower than the flow velocity S ₁ . Rising flow velocity S of combustion gas G in the large diameter portion 1b
_{When 1} is faster than the rising velocity S ₂ of the combustion gas G in the small diameter portion 1a, the relatively light incineration ash 5 supplied from the supply portion 6 does not move to the lower side of the melting furnace 1 but immediately moves to the upper side. Because it ends up.

Since this embodiment is constructed as described above, the incineration ash 5 is introduced from the supply section 6 into the grate 3 in the melting furnace 1,
When the grate 3 is heated by the burner 8 (about 1500 ° C.), the incineration ash 5 is melted by the heat of the grate 3.

The melt 2 is dropped in the gaps between the refractory materials 2 forming the grate 3 and is accumulated at the bottom of the melting furnace 1 as metal or slag.

The slag collected at the bottom is the slag tap 7a.
Boil more hot water, treat with slag treatment equipment (not shown), and reuse. On the other hand, the metal is discharged from the metal discharge port 7b, poured into the mold 11 or the like and reused.

This embodiment does not burn and consume the coke as in the conventional example, but heats the grate 3 with the combustion gas G of the burner 8, and this grate 3 is used.
Since the incineration ash 5 is melted by the heat of, no CO ₂ + C = 2CO, which is an endothermic reaction, naturally occurs, and therefore, efficient melting without heat loss is performed.

Further, in the case of the present embodiment, the combustion gas G generated by the burner 8 rises in the grate 3 and preheats the incineration ash 5 in the supply section 6, so that the incineration ash 5 is melted accordingly. Is promoted and efficient melting is achieved.

Further, the supply unit 6 of this embodiment is embedded in the grate 3 and, for example, no gap is provided between the lower end of the supply unit 6 and the top surface of the grate 3. Therefore, the incineration ash 5 supplied from the supply unit 6 is prevented from being scattered by the combustion gas G, and thus the incineration ash 5 is reliably melted by the heated grate 3.

Further, the combustion gas G of this embodiment is secondarily burned in the secondary combustion chamber 9 provided in the upper part of the melting furnace 1 to burn the unburned substances and decompose the organic chlorine substances, and then to the discharge port. Since it is discharged from 10, cleaned by a gas melting processing device (not shown), detoxified and released into the atmosphere, there is no fear of pollution problems.

Further, since the melting furnace 1 of this embodiment is provided with the small diameter portion 1a near the bottom, the rising velocity S ₂ of the combustion gas G in the small diameter portion 1a and the rising of the combustion gas G in the large diameter portion 1b are increased. The flow velocity S ₁ is naturally faster in the former case. Therefore, the scattering of the incineration ash 5 supplied from the supply unit 6 can be minimized. Even if there is scattered incineration ash 5, it adheres to the upper grate 3 and is melted, so the incineration ash 5 will not be scattered into the gas system, and the load on the gas supply facility will be reliably prevented. To be done.

If necessary, the incinerated ash 5 may be mixed with an auxiliary material (for example, CaCO ₃ or CaO) for adjusting the basicity (CaO / SiO ₂ ) of the slag and supplied to the melting furnace 1. .

[0027]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, it is possible to suppress heat loss as much as possible, and therefore, a melting furnace which can efficiently slag incinerated ash and make it a detoxified and reusable resource.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view of the present embodiment.

[Explanation of symbols]

A ₁ area A ₂ area G Combustion gas S ₁ Ascending velocity S ₂ Ascending velocity 1 Melting furnace 2 Refractory 3 Grate 4 Heating part 5 Incineration ash 6 Supply part 7 Melt outlet

Claims (2)

[Claims] 1. A grate made of refractory material is provided in a melting furnace, a heating part for heating the grate is provided near a lower part of the grate, and a supply part for supplying incineration ash is provided on an upper part of the grate. A melting furnace provided with a melt take-out port at or near the bottom of the melting furnace. 2. The melting furnace according to claim 1, wherein a burner for injecting a combustion gas G is used as a heating part, and the area A ₁ of the plane cross section of the grate near the lower end of the supply part and the vicinity of the heating part are adopted. Combustion gas G in the area A ₁ is configured by configuring the area A ₂ of the plane cross section of the grate so that A ₁ ≧ A _2.
Of the combustion gas G in the area of area A ₂ and the ascending flow rate S _{1 of} S ₂ are set such that S ₂ ≧ S ₁ .