JP4199566B2 - Raw material supply apparatus and waste plastic supply method in iron-containing cold material melting furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a raw material supply apparatus and a waste plastic supply method in an iron-containing cold material melting furnace.
Specifically, the present invention relates to an apparatus for supplying waste plastic such as tire chips to an iron-containing cold material melting furnace that supplies iron-containing cold material into a melting furnace in which molten iron serving as seed water is present and melts to obtain high carbon molten iron.
[0002]
[Prior art]
In an iron-containing cold material melting furnace that melts by supplying iron-containing cold material into the melting furnace where the molten iron that is the seed hot water exists, instead of blowing pulverized coal from the top blowing lance, it is less expensive than the upper part of the furnace port Various proposals have been made in the past regarding iron-containing cold material melting methods that reduce the supply of expensive pulverized coal by supplying waste plastic such as tire chips into the furnace by natural dropping.
[0003]
For example, in JP 2000-17316 A, instead of blowing pulverized coal from an upper blowing lance, by supplying tire chips, the supply amount of expensive pulverized coal is reduced and almost no running cost is applied. Further, without generating C dust loss, the secondary combustion rate is controlled within a range of 20 to 30%, which is an effective secondary combustion rate range, and iron dust generation is suppressed to an extremely low level, thereby achieving a high molten iron yield. An iron-containing cold material melting method for melting an iron-containing cold material is disclosed.
However, when the waste plastic is supplied to the melting furnace, there is a risk that a flammable gas generated from the melting furnace may enter a waste plastic supply facility such as a conveyor to cause a fire.
Conversely, air, which is the atmospheric gas of waste plastic supply equipment such as conveyors, is mixed into the combustible gas generated from the melting furnace, so the amount of heat of the combustible gas decreases and the value as combustible gas decreases. There was also a problem of doing.
[0004]
As an apparatus for preventing such gas mixing, for example, Japanese Patent Laid-Open No. 6-346155 discloses a gas seal apparatus for shutting off the gas in the furnace of the continuous annealing equipment for strips from the outside air.
However, this gas seal device is a device that shuts off the gas in the furnace of the continuous annealing equipment of the strip from the outside air by sandwiching the strip with a seal roll and injecting nitrogen gas for sealing from above and below at high speed, Even if this method is applied to waste plastic such as solid tire chips, when supplying the waste plastic to the melting furnace, the combustible gas enters into the waste plastic supply equipment such as a conveyor, The problem of a decrease in the value of the combustible gas due to the mixture of the atmosphere gas (air) of the plastic supply facility into the combustible gas could not be solved.
[0005]
[Patent Document 1]
JP 2000-17316 A [Patent Document 2]
JP-A-6-346155
[Problems to be solved by the invention]
The present invention solves the problems of the prior art as described above, prevents the invasion of combustible gas into waste plastic supply equipment such as a conveyor, and flammability of atmospheric gas (air) in the waste plastic supply equipment It is an object of the present invention to provide a waste plastic supply device and a supply method in an iron-containing cold material melting furnace capable of preventing gas mixture.
[0007]
[Means for Solving the Problems]
The present invention uses an upward air ejector, nitrogen blowing or downward nitrogen ejector in combination to prevent entry of combustible gas into waste plastic supply equipment such as a conveyor, and for raw material supply equipment such as waste plastic. The present invention provides a raw material supply apparatus capable of preventing mixing of atmospheric gas (air) into a combustible gas and a waste plastic supply method in an iron-containing cold material melting furnace. It is the following contents as described.
(1) Supply waste plastic into the melting furnace where the molten iron used as the seed hot water exists and melt it to obtain high carbon molten iron. In the iron-containing cold material melting furnace or converter, electric furnace, waste incinerator, waste plastic is used as a raw material. A supply device for supplying ,
A hopper for storing the waste plastic;
A plurality of conveyors for conveying the waste plastic from the hopper to the exit side;
A seal chamber for sealing the plurality of conveyors;
A downward nitrogen ejector installed on the exit side of at least one of the plurality of conveyors;
A raw material supply apparatus having nitrogen blowing into a conveyor having the downward nitrogen ejector .
(2) It is characterized by having an upward air ejector installed on a conveyor upstream of at least one conveyor of the plurality of conveyors and upstream of the conveyor having the downward nitrogen ejector (1) The raw material supply apparatus as described in.
(3) The raw material supply apparatus according to ( 1 ) or (2), wherein the downward nitrogen ejector is installed on the exit side of the last conveyor in the conveying order among the plurality of conveyors.
(4) A waste plastic supply method, characterized in that the waste plastic is supplied to the iron-containing cold material melting furnace using the raw material supply apparatus according to any one of (1) to (3).
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a diagram illustrating an embodiment of a waste plastic supply apparatus of the present invention.
In FIG. 1, 1 is a furnace body, 2 is a lance, 3 is a projection injection tank, 4 is a bottom blowing nozzle, 5 is a bottom blowing coal injection tank, 6 is waste plastic supply equipment provided at the top of the furnace body, and 7 is a furnace body. Flue path through which exhaust gas is generated, 8 is an exhaust gas component analyzer, 9 is an exhaust gas flow meter, 10 is a dust sampling device, 11 is a calculator of these measured values, 12 is molten iron at the bottom of the furnace body, and 13 is iron Scrap 14 indicates a hopper.
[0009]
In FIG. 1, waste plastic such as tire chips supplied from a hopper 14 is conveyed to a furnace body 1 by a waste plastic supply facility such as a conveyor, and the interior of the furnace body 1 from a flue 7 through which exhaust gas generated in the furnace body passes. To be supplied.
The waste plastic supplied to the furnace body 1 burns in contact with the molten iron 12 at the bottom of the furnace body 1 and is used as a heat energy source for melting the iron scrap 13.
Thus, by using waste plastic for melting iron scrap 13, pulverized coal, CaO powder supplied from the projection injection tank 3 to the furnace body 1 via the lance 2 and bottom blowing from the bottom blowing coal injection tank 5 are used. The amount of pulverized coal supplied to the furnace body 1 through the nozzle can be significantly reduced.
The type of waste plastic used in the present invention is not limited. For example, a normal passenger car tire is cut to about 1/32, a cut tire having a size of about 200 mm × 200 mm, or a plastic is crushed and then solidified. A plastic having a size of about 30 mmφ × 500 mm is preferable.
Moreover, the waste plastic supply apparatus of this invention is applicable also about a general converter, an electric furnace, and a garbage incinerator other than FIG.
[0010]
FIG. 2 is a detailed view illustrating an embodiment of the raw material supply apparatus of the present invention.
In FIG. 2, 14 is a hopper, 15 is a conveyor, 16 is an upward air ejector, 17 is nitrogen blowing, 18 is a downward nitrogen ejector, and 19 is a seal chamber.
Waste plastics stored in the hopper 14 are sequentially conveyed to a melting furnace by a conveyor 15 provided with a plurality of units.
The type and number of conveyors to be installed may be appropriately selected according to the installation environment. In the present embodiment, four belt conveyors are installed. The belt conveyor is entirely covered with a seal chamber 19.
Moreover, in this invention, the downward nitrogen ejector installed in the delivery side of at least 1 conveyor among several conveyors is installed.
Here, as shown in FIG. 2, the downward nitrogen ejector refers to a device that prevents flammable gas from flowing upward by injecting nitrogen downward with a nozzle.
Further, in the present invention, when the sealing performance of the seal chamber 19 is poor, it is desirable to blow nitrogen into the conveyor on which the downward nitrogen ejector is installed by the nitrogen blowing 17.
In addition, in the present invention, when the sealing performance of the seal chamber 19 is further poor, it is also effective to install the upward air ejector 16 on the exit side of at least one of the plurality of conveyors.
Here, the upward air ejector means an apparatus that prevents the atmospheric gas of the waste plastic supply device from flowing downward by injecting air upward by a nozzle as shown in FIG.
[0011]
Furthermore, it is preferable that the downward nitrogen ejector is installed on the delivery side of the last conveyor in the conveying order among the plurality of conveyors, and nitrogen blowing is installed on the conveyor.
Furthermore, the upward air ejector is installed on the outlet side of the second conveyor from the last in the conveying order among the plurality of conveyors, and the downward nitrogen ejector is the last conveyor in the conveying order among the plurality of conveyors. It is preferable to install on the exit side of the.
The effect of blocking gas by creating a buffer area to block atmospheric gas and flammable gas by sandwiching the last conveyor in the transfer order closest to the melting furnace with an upward air ejector and a downward nitrogen ejector Can be further increased.
As described above, by using the raw material supply device such as the waste plastic of the present invention, the waste plastic supply device can be cut off from the atmosphere gas and the combustible gas by supplying the waste plastic to the iron-containing cold material melting furnace. It is possible to achieve both disaster prevention measures such as fire and measures to lower the value of fuel.
[0012]
【The invention's effect】
According to the present invention, by using an upward air ejector and a downward nitrogen ejector together, intrusion into a raw material supply facility such as waste plastic such as a combustible gas is prevented, and a raw material supply facility such as waste plastic It is possible to provide a raw material supply device such as waste plastic and a supply method in an iron-containing cold material melting furnace that can prevent the atmospheric gas (air) from being mixed into the flammable gas, and has a remarkable industrially useful effect. To do.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an embodiment of a raw material supply apparatus such as waste plastic according to the present invention.
FIG. 2 is a detailed view illustrating an embodiment of a raw material supply apparatus such as waste plastic according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Furnace body, 2 ... Lance, 3 ... Projection injection tank, 4 ... Bottom blowing nozzle, 5 ... Bottom blowing coal injection tank, 6 ... Waste provided in upper part of furnace body Plastic supply equipment, 7 ... Flue through which exhaust gas generated in the furnace passes, 8 ... Exhaust gas component analyzer, 9 ... Exhaust gas flow meter, 10 ... Dust sampling device, 11 ... Measurement Value calculator, 12 ... Molten iron at the bottom of the furnace, 13 ... Iron scrap, 14 ... Hopper, 15 ... Conveyor, 16 ... Upward air ejector, 17 ... Nitrogen blowing 18 ... Downward nitrogen ejector, 19 ... Seal chamber

Claims (4)

Supplying waste plastics as raw materials to iron-containing cold material melting furnaces or converters, electric furnaces, and garbage incinerators that supply high-carbon molten iron by supplying iron-containing cold materials into the melting furnace where the molten iron used as seed water exists A device ,
A hopper for storing the waste plastic;
A plurality of conveyors for conveying the waste plastic from the hopper to the exit side;
A seal chamber for sealing the plurality of conveyors;
A downward nitrogen ejector installed on the exit side of at least one of the plurality of conveyors;
A raw material supply apparatus having nitrogen blowing into a conveyor having the downward nitrogen ejector . It has an upward air ejector installed in a conveyor which is an exit side of at least one conveyor among the plurality of conveyors and is upstream of the conveyor where the downward nitrogen ejector is installed. Raw material supply equipment. The raw material supply apparatus according to claim 1 or 2 , wherein the downward nitrogen ejector is installed on the outlet side of the last conveyor in the conveying order among the plurality of conveyors. A waste plastic supply method, characterized in that waste plastic is supplied to an iron-containing cold material melting furnace using the raw material supply device according to any one of claims 1 to 3.

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