JPH0635892U - Continuous scrap charging equipment - Google Patents

Abstract

(57) [Summary] [Purpose] In a continuous charging device for scrap that introduces furnace exhaust gas and supplies it to the arc furnace while preheating the scrap, the scrap preheating efficiency is high, and the invasion of outside air is prevented and dust collection is performed. An object is to provide a highly efficient continuous charging device for scrap. [Structure] (1) An exhaust gas passage hole is provided at the bottom of the transfer device, and an exhaust gas suction duct is provided below the bottom of the transfer device. A scrap receiving hopper provided with an open / close lid and a cutting device for the conveying device provided under the receiving hopper, and the periphery of the receiving hopper, the cutting device and the conveying device are covered with a gas seal cover. Is characterized by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a scrap charging device in an arc furnace used for melting metal materials and refining molten metal.

[0002]

[Prior art]

 Charging of scrap into an arc furnace used for melting metal materials, refining molten metal, etc. is usually performed as follows. That is, scrap is loaded in advance in a container called a bucket and is transported to the vicinity of the arc furnace by an overhead crane. The arc furnace has a furnace lid that can swivel. When scrap is charged, the furnace lid is swiveled and opened, then the bucket is moved onto the furnace, the bottom of the bucket is opened, and the scrap is thrown into the furnace. Scrap is thrown into the arc furnace by so-called batch charging 2-3 times per heat. However, this method has a problem in that the furnace lid is always opened when scrap is charged, so that the heat dissipated from the furnace is large and that the work environment deteriorates due to the generation of dust and the like.

Therefore, various methods for continuously charging scrap have been proposed as a method for charging scrap into the furnace without opening the furnace lid. In the furnace operation in this case, the next melting operation is started with the appropriate amount of molten steel left in the furnace during the previous tapping operation, so the operation is in the conventional refining period from the initial melting stage. In the refining stage of operation, it is important to maintain an appropriate slag thickness on the molten steel in order to increase the thermal efficiency of the arc, but this is generally done by the generation of CO gas due to the reaction of carbon and oxygen. Because of this, the amount of gas generated from the furnace will also increase compared to the past. Therefore, technology for efficiently recovering the heat of exhaust gas is important, and this exhaust gas is introduced into the scrap conveying device that forms the flue, and the scrap is preheated by flowing it in opposition to the scrap movement. However, a technique of charging into the furnace is disclosed, for example, in Japanese Examined Patent Publication No. 4-42452.

[0004]

[Problems to be solved by the device]

 However, in this method, since the exhaust gas passes through the upper part of the scrap inside the conveying device that forms the flue and is discharged from the rear end of the flue, the preheating is limited to the surface part of the scrap and the lower part of the scrap is There is a problem that it cannot be done effectively. Further, it is difficult to seal the gas in the portion where the scrap on the transfer device enters the flue, and the outside air is sucked at the same time as the exhaust gas is sucked, so that there is a problem that the dust collection efficiency is reduced. Therefore, it is an object of the present invention to provide a scrap continuous charging device which has a high scrap preheating efficiency on the transfer device, prevents external air from entering, and has a high dust collecting efficiency.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the scrap continuous charging apparatus according to the present invention is (1) introducing scrap gas supplied to an arc furnace while preheating the scrap gas by introducing furnace exhaust gas into a scrap transport device having a flue. In the continuous charging device, an exhaust gas passage hole is provided at the bottom of the scrap transfer device, and an exhaust gas suction duct is provided below the bottom of the transfer device on the downstream side of the flue.

(2) In the scrap continuous charging device for introducing the exhaust gas of the furnace into the scrap transfer device having the flue and supplying it to the arc furnace while preheating the scrap, regarding the scrap loading part to the transfer device , A scrap receiving hopper with upper and lower gas-sealable opening / closing lids, and a cutting device to the conveying device at the bottom of the receiving hopper, and further surrounding the receiving hopper, the cutting device, and the conveying device. It is characterized in that it is configured to be covered with a gas seal cover.

[0007]

[Action]

 The high-temperature exhaust gas generated in the furnace is introduced into the scrap conveyor that forms the flue, preheats the surface layer of the scrap on the conveyor, and then on the downstream side of the flue, to the bottom of the conveyor. Through the exhaust gas passage holes provided, it flows into the exhaust gas suction duct provided below the bottom of the transport device. At this time, gas flows in the layer thickness direction not only between the surface layer of the scrap on the transfer device but also between the scraps, so that the scrap in the lower layer is also preheated. In addition, at the scrap loading section of the transfer device, scrap is loaded by opening the upper lid with the lower lid of the receiving hopper closed, and loading into the cutting device with the upper lid of the hopper closed. Open the bottom lid with. Furthermore, since the surroundings of the receiving hopper, the cutting device, and the transfer device are covered with a gas seal cover, the outside air entering the transfer device from the receiving hopper during scrap loading can be minimized. It is done.

[0008]

【Example】

 An embodiment according to the present invention will be described with reference to an example diagram. FIG. 1 is an overall vertical cross-sectional view of the present invention, FIG. 2 is a cross-sectional view of the transfer device taken along the line AA in FIG. 1, and FIG. 3 is a detailed exhaust gas passage hole provided at the bottom of the transfer device. In this example, the apron conveyor system is adopted as the transport device. The high-temperature exhaust gas generated from the furnace 1 is introduced into the conveying device 2 having the flue 13 through the expandable connecting pipe 15, and mainly radiates and convects the surface layer 3 of the scrap in the conveying device 2. Preheat with heat. After that, in the installation zone of the exhaust gas suction duct 6 provided in the lower part of the transfer device 2, the exhaust gas passage hole 5 provided in the bottom plate part 4 is passed through, and the scrap of the lower layer part 7 in the transfer device 2 is mainly disposed therebetween. Preheat by convective heat transfer to. The bypass damper 16 and the exhaust gas damper 17 adjust the amount of the exhaust gas introduced into the carrier device 2.

It is also possible to divide the exhaust gas suction duct 6 into a plurality of zones and provide an air flow rate adjustment damper for each zone to control the preheating temperature of the scrap. The shape of the exhaust gas passage holes 5 is shown as a slit shape in the example diagram, but it may be a lattice shape. The gas seal between the bottom plate 4 of the carrier device and the exhaust gas suction duct 6 is a seal inside the carrier device, and is simple because no outside air enters. Reference numeral 8 denotes a dust discharge hole that accumulates inside the exhaust gas duct and inside the transfer device.

On the other hand, loading of scraps is performed by opening the upper lid 10 of the receiving hopper 9 with a crane equipped with a riff mag (not shown) or the like. In this case, the lower lid 11 is closed. After the scrap loading is completed once or a plurality of times, the upper lid 10 is closed, then the lower lid 11 is opened, and the scrap is put into the cutting device 12. Scraps are cut out from the cutting device 12 to the transfer device 2 in a fixed amount. The receiving hopper 9, the cutting device 12, and the transfer device 2 are surrounded by the gas seal cover 14, and by performing the scrap loading work according to the procedure described above, it is possible to minimize the invasion of outside air. .

[0011]

[Effect of device]

 As explained above, in the scrap continuous charging device according to the present invention, the exhaust gas of the furnace generated from the initial melting stage to the refining period is used to continuously convey the surface layer of scrap in the conveying device. Not only that, the lower layers can be preheated, which greatly improves the thermal efficiency, improves productivity and reduces energy costs. In addition, the amount of suction gas can be controlled by adjusting the exhaust gas damper, so that the preheating temperature of scrap can be easily controlled and the degree of freedom in operation can be improved. In addition, since the ingress of outside air is suppressed to a minimum, the dust collection efficiency can be improved, the working environment can be improved, and the dust collection power can be reduced.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view of the present invention,

FIG. 2 is a cross-sectional view of the carrying device taken along the line AA in FIG.

FIG. 3 is a view showing details of an exhaust gas passage hole provided in a bottom plate portion of a transfer device.

[Explanation of symbols]

 1 Furnace 2 Conveying Device 3 Surface Layer Scrap 4 Bottom Plate 5 Exhaust Gas Passing Hole 6 Exhaust Gas Suction Duct 7 Lower Layer Scrap 8 Dust Discharging Hole 9 Receiving Hopper 10 Upper Lid 11 Lower Lid 12 Cutting Device 13 Flue 14 Cover 15 Connecting Pipe 16 Bypass damper 17 Exhaust gas damper

Claims (2)

[Scope of utility model registration request] 1. A continuous charging device for scrap, which introduces the exhaust gas of a furnace into a scrap carrier having a flue and supplies it to an arc furnace while preheating the scrap, wherein an exhaust gas passage hole is provided at the bottom of the scrap carrier. Provided, in addition,
An apparatus for continuously charging scrap, characterized in that an exhaust gas suction duct is provided below the bottom of the transfer device. 2. A scrap continuous charging device for introducing exhaust gas from a furnace into a scrap transporting device having a flue and supplying the same to an arc furnace while preheating the scrap. A scrap receiving hopper provided with an opening / closing lid capable of gas sealing, and a cutting device for a conveying device provided under the receiving hopper, and a gas seal cover around the receiving hopper, the cutting device, and the conveying device. A continuous charging device for scrap, characterized by being configured to be covered with.