JPH08277412A - Apparatus for treating exhaust gas of electric furnace - Google Patents

Abstract

PURPOSE: To efficiently recover the energy from the exhaust gas of an electric furnace by arranging a scrap collecting vessel having a colliding plate in an exhaust gas duct part behind a combustion cylinder and an exhaust gas boiler having a contact part. CONSTITUTION: The scrap collecting vessel and the exhaust gas boiler 10 having the contact part are arranged in the duct 4 between the combustion cylinder 3 and a deodorizing cylinder 5 in an exhaust gas treating apparatus. The scrap scattered from the inner part of the electric furnace 1 collides against the colliding plate 9a arranged in the scrap collecting vessel 9 and dropped in the vessel and caught in a scrap receiver. The exhaust gas boiler 10 is provided with the contact part in direct contact with high temp. exhaust gas and has a structure arranged with many water tubes in the boiler body to exchange heat with the exhaust gas, and then, high temp. vaper is taken out. Since the exhaust gas is cooled to such degree as to be possible to be directly taken in a dust collector 8, a cooling cylinder can be omitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric furnace exhaust gas treatment apparatus, and more particularly to a processing apparatus capable of efficiently recovering energy from electric furnace exhaust gas.

[0002]

2. Description of the Related Art Conventionally, as shown in the exhaust gas treatment flow of FIG. 2, exhaust gas generated from an electric furnace during melting operation is
There was no energy recovery. That is, the electric furnace 1
The gas generated from the gas is introduced into the combustion tube 3 via the furnace lid direct drawing duct 2, where it is burned by the intake air, then passes through the exhaust gas duct 4, the deodorizing tube 5, the cooling tube 6, and then the dust collecting blower 7 Is sucked in through the dust collector 8 and reaches the dust collector 8, where it is dedusted and then released into the atmosphere.

In the conventional exhaust gas treatment flow described above, if energy is to be recovered, it is possible to install a boiler in the exhaust gas treatment system. Due to the effect of scraps that scatter, the current situation is that only a hollow exhaust gas duct type boiler with low recovery efficiency (boiler of the exhaust gas water cooling duct) can be installed. When a type of boiler with a water pipe with a high recovery efficiency is installed, scrap scraps charged into the furnace enter the boiler body along with the exhaust gas flow and damage the water pipe in the contact area and the suit blower. Another problem is the removal of scrap from the densely packed pipes. Further, in the current electric furnace operation in which the amount of exhaust gas is increasing more and more, large-sized scraps also fly in the duct, and damage to various devices in the exhaust gas treatment system is also becoming a problem.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to almost completely remove scraps scattered from a furnace before various equipments of an exhaust gas treatment system are damaged and to efficiently recover energy from the exhaust gas. An object is to provide an electric furnace exhaust gas treatment device capable of

[0005]

An electric furnace exhaust gas treating apparatus of the present invention for achieving the above object is such that an exhaust gas duct is connected to a direct drawing duct provided in a furnace lid of an electric furnace via a combustion cylinder, and further, In the electric furnace exhaust gas treatment device following the dust collector,
It is characterized in that a scrap collection tank having a collision plate and an exhaust gas boiler provided with a contact portion are arranged in the exhaust gas duct portion at the rear of the combustion cylinder.

[0006]

[Function] Since the scrap collection tank is provided in the exhaust gas line at the rear position of the combustion cylinder, the scrap that is sucked and scattered from the combustion cylinder hits the collision plate above the collection tank and falls to the lower part, where Most of the scrap is removed and recovered, so scrap does not scatter and enter the exhaust gas duct that follows it. As a result, it is possible to install an exhaust gas boiler having a contact part with the highest recovery efficiency in the subsequent position, and this exhaust gas boiler makes it possible to efficiently recover energy from exhaust gas, and also regarding other equipment. It will not cause damage.

In the present invention, the term "exhaust gas boiler having a contact portion" means that the heat transfer portion in the boiler body, for example, the meandering water pipe portion, is in direct contact with the introduced high temperature exhaust gas to exchange heat with the water pipe. It is a type that can be recovered as high-temperature steam at the outlet side, and its structure is known. In addition to the water pipe type, there is also a smoke pipe type.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments will be described below with reference to the drawings.
FIG. 1 shows an outline of the exhaust gas treating apparatus of the present invention from an electric furnace to a dust collector. The electric furnace 1, the ducts 2, 4, the combustion cylinder 3, the deodorizing cylinder 5, and the dust collecting blower 7 having the same symbols as those in FIG. The dust collector 8 is the same. A feature of the present invention is that the exhaust gas boiler 10 provided with a scrap collection tank (scrap catcher) 9 and a contact portion with good recovery efficiency is arranged in the duct 4 between the combustion cylinder 3 and the deodorization cylinder 5. .

A concrete example of the scrap catcher 9 is shown in FIG.
Shown in The scrap scattered from the electric furnace collides with the collision plate 9a installed in the scrap collection tank over one to several stages. The scrap 11 that has collided falls in the tank and is collected by a grid-shaped scrap receiver 12. The collected scrap is recovered from the recovery port 13. The scrap pieces, dust, etc. that have passed through the scrap receiver are collected in the dust bin below the scrap receiver, and the dust carry-out port 14
Is more exhausted.

The exhaust gas boiler 10 is of a type having a contact portion that comes into direct contact with high temperature exhaust gas. For example, the exhaust gas boiler 10 has a structure in which a large number of water pipes are provided inside the boiler body, and can be taken out as high temperature steam by exchanging heat with the exhaust gas. It is a thing. The exhaust gas recovers energy in this boiler,
As a result, the exhaust gas is cooled to such an extent that it can be directly taken into the dust collector, and the cooling cylinder which has been essential in the past can be omitted.

(Operation example) capacity 120t, melting time 60mi
As shown in Fig. 1, a scrap catcher 9 and an exhaust gas boiler 10 were placed in a DC electric furnace facility of n, and molten steel was melted.
Saturated steam of kg (pressure 10 kg / cm ² ) could be recovered. Further, no damage due to scrap was observed in the boiler, the deodorizing cylinder, the dust collector, etc., which are located after the scrap catcher 9.

[0012]

As described above, according to the exhaust gas treating apparatus of the present invention, the scrap pieces scattered in the duct can be almost completely collected immediately after the combustion cylinder, and the damage to the equipment thereafter can be prevented. In addition to being able to prevent, efficient energy recovery from electric furnace exhaust gas is also possible. Further, the cooling cylinder, which has been indispensable in the conventional exhaust gas flow, can be omitted, which has a great advantage in terms of equipment.

[Brief description of drawings]

FIG. 1 is an equipment layout diagram showing an embodiment of an exhaust gas treatment apparatus according to the present invention.

FIG. 2 is a layout diagram of a conventional exhaust gas treatment facility.

FIG. 3 is a front sectional view (a) and a plan sectional view (b) showing a specific example of the scrap catcher in FIG.

[Explanation of symbols]

 1 Electric Furnace 2 Direct Duct 3 Combustion Cylinder 4 Exhaust Gas Duct 5 Deodorizing Cylinder 6 Cooling Cylinder 7 Dust Blower 8 Dust Collector 9 Scrap Catcher 9a Collision Plate 10 Exhaust Gas Boiler with Contact 11 Scrap 12 Scrap Receptor 13 Recovery Port 14 Dust Transport Exit

Claims (1)

[Claims] 1. In an electric furnace exhaust gas treatment apparatus, wherein an exhaust gas duct is connected to a direct drawing duct provided in a furnace lid of an electric furnace via a combustion cylinder, and further in an electric furnace exhaust gas treatment device following a dust collector, the exhaust gas duct at the rear of the combustion cylinder, An electric furnace exhaust gas treatment apparatus comprising a scrap collection tank having a collision plate and an exhaust gas boiler provided with a contact portion.