JPS5862491A - Heat exchanger for semifused solid grain - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for recovering heat from molten slag.

Molten slag discharged from blast furnaces and the like has a high temperature of about 1500° C., and various means have been proposed to recover this retained heat. As one of the highly efficient heat recovery methods from melted materials,
By granulating the molten slag using an appropriate method such as air atomization, and then bringing it into direct contact with a refrigerant, etc.),
There is a way to exchange heat. One method of heat exchange with the granulated grains is a fluidized bed heat exchange device. As shown in FIG. 1, a conventional fluidized bed heat exchanger has a flat bottom perforated plate 17 and is provided with an overflow pipe 18 for discharging fluid. Now, the atomized slag grains have adhesive strength in a semi-solid state at high temperatures. When such slag grains are collected in a general fluidized bed, before they are sufficiently cooled and solidified and lose their adhesive strength, the semi-solidified slag grains come into contact with each other and fuse together, forming granular lumps and settling. It accumulates on the bottom plate, impairs fluidization, and finally blocks the bottom plate fumarole 17, paralyzing the fluidized bed function.

The present invention has been made to easily restore the fluidized bed function in response to the occurrence of such abnormal conditions.The present invention is characterized by the fact that the perforated plate at the bottom of the fluidized bed has a convex arc shape. In addition, an adjustment mechanism that can be opened around the periphery is provided to enable discharge of the re-fused granular mass.

The present invention will be explained below with reference to the drawings.

FIG. 2 illustrates the invention. The atomized semi-solidified slag grains 1 fly through the closed wind tunnel 2 and directly fall into the fluidized slag grain fluidized bed 4 or 14113. Some of the fallen particles fuse with each other on the side wall 3 or the particle fluidized bed 4 due to changes in conditions during atomization, changes in cooling conditions in the wind tunnel, changes in fluidization conditions, etc., and form particle agglomerates. 5°6 may be formed. These particle agglomerates are thicker than normal particles, so they are not fluidized sufficiently.
The particles either slide down along the inclined wall or settle within the particles in the fluidized bed 4 and reach the arc-shaped bottom perforated plate 8 . Here, the gas is moved to the periphery due to the ejection velocity energy of the gas ejected from the holes in the perforated plate. A perforated plate 10 that is opened and closed by, for example, an air cylinder 9 is installed around the arcuate perforated plate 8, and maintains a constant distance from the perforated plate 8, normally functioning as an overflow path for fluids. . When the particle agglomerate reaches point 7, the cylinder 9 opens the syblate 10 and the particle agglomerate falls. Note that the grate 10 may be opened and closed at regular intervals. The fallen particle groups and particle agglomerates are removed from the packed bed heat exchange section 11 installed at the bottom.
After exchanging heat and being sufficiently cooled, it is discharged to the outside of the system through the discharge pipe 13. In addition, a refrigerant such as air is sent from the blower 12 to the lower heat exchanger 11, where it undergoes heat exchange and becomes hot air. The air rises from the gap between the perforated plate 8 and the perforated grate 10 and serves as a source of fluidizing air, and at the same time, it also exchanges heat with the slag particles to reach an even higher temperature and is exhausted from the exhaust pipe 20.

Since this invention is configured as described above, it is possible to easily and smoothly restore the fluidized bed function in response to the occurrence of an abnormal state caused by refusion between slag particles, and therefore it is extremely useful industrially. It is an invention.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional semi-solid grain heat exchange device at, and FIG. 2 is a diagram showing a semi-solid grain heat exchange device according to the invention. 1: Cow solidified slag grains, 2: Closed wind tunnel, 3: Side wall, 4: Fluidized bed, 5.6.7: Fused particle mass, 8: Arc porous plate, 9:
Air cylinder, 10: Porous grate, 11: Packed bed heat exchange section, 12: Air blower, 13: Discharge pipe, 14: Damper, 15: Cold slag grain group, 16: Air header, 1
7: Perforated flat plate, 18: Overflow pipe, 19: Control valve, 20: Hot air exhaust pipe. Patent applicant Nippon Steel Corporation (5) First page 2θ

Claims (1)

[Claims] In a semi-solid heat exchanger using a fluidized bed method, which atomizes high-temperature molten slag discharged from blast furnaces etc. into semi-solid granules in a space and recovers the retained heat, the bottom part with gas fumaroles is A semi-solid particle heat exchange device characterized by having a convex arc shape with curvature and having a pore size variable adjustment mechanism provided around the periphery thereof.