Gas induced draft fan

Abstract

The utility model discloses a coal gas induced draft fan which comprises a fan shell, a main shaft and a plurality of impellers are installed in the fan shell, the impellers are arranged in a spoke shape around the circumferential direction of the main shaft, and a fire extinguishing ring is installed between the impellers and the fan shell. The fire extinguishing ring is located on a ring surface track formed by rotation of the tail end of the impeller and fixedly connected with the fan shell, and the fire extinguishing ring and the impeller are coaxially arranged. According to the utility model, the fire extinguishing ring is additionally arranged on the rotating path of the impeller, so that the potential safety hazard of sparks caused by scraping of the blades and the casing when the blades in the fan rotate at a high speed is solved, and the escape phenomenon in the gas recovery process is reduced to a certain extent.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of steel smelting equipment, especially relates to a coal gas induced draft fan. BACKGROUND

[0002] A large amount of carbon monoxide is formed in the decarburization process of converter molten iron, and this part of carbon monoxide has high economic value, so converter gas recovery is needed. The current converter gas recovery process mainly includes: converter smelting → large flue → electric dust removal → coal gas induced draft fan → coal gas washing tower → coal gas tank → gas using unit.

[0003] Since the converter smelting is intermittent, the converter gas recovery is also intermittent, so the medium passing through the coal gas induced draft fan has air, coal gas and air-coal gas mixture, the coal gas is combustible, and when the impeller in the coal gas induced draft fan rotates at high speed, there is a safety hazard of spark generated by scraping between the impeller and the shell, and the coal gas also escapes to the next stage through the shell, affecting the recovery efficiency of the coal gas. In view of this, the structure of the coal gas induced draft fan on the production line needs to be modified. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims at providing a coal gas induced draft fan.

[0005] The technical scheme for realizing the utility model is: a coal gas induced draft fan, which comprises a fan shell, a main shaft and a plurality of impellers are installed in the fan shell, each impeller is arranged in a spoke shape around the circumference of the main shaft, a fire extinguishing ring is installed between the impeller and the fan shell, the fire extinguishing ring is located on the toroidal trajectory formed by the rotation of the end of the impeller and is fixedly connected with the fan shell, and the fire extinguishing ring is coaxially arranged with the impeller.

[0006] Further, the fire extinguishing ring comprises a plurality of arc-shaped fire extinguishing plates, each fire extinguishing plate is fixed on the fan shell, each fire extinguishing plate is spliced into a ring-shaped structure, and the adjacent fire extinguishing plates have an expansion gap. Since the temperature of the flue gas passing through the fan is between 150 DEG C and 180 DEG C, the fire extinguishing plate will be heated and expanded to bulge, which is easy to cause scraping between the blade and the impeller and cause equipment accidents. After the aluminum plate bulges, the airflow duct changes, causing surge, and the efficiency of the fan is reduced. Splitting the fire extinguishing ring into a plurality of fire extinguishing plates can solve the problem of bulging of the fire extinguishing plate.

[0007] Further, the expansion gap is 3-6 mm. The expansion gap cannot be too large, otherwise too much coal gas will escape to the next stage, affecting the recovery efficiency of the converter gas.

[0008] The utility model discloses a fire ring is additionally arranged on the rotation path of the impeller, solves the hidden danger of the spark produced by the scraping of the blade and the casing when the blade rotates at high speed in the fan, and reduces the escape phenomenon in the coal gas recovery process to some extent. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 It is the structure schematic diagram of the coal gas induced draft fan of the utility model embodiment;

[0010] Figure 2 It is Figure 1 The enlarged structure schematic diagram of part A. DETAILED DESCRIPTION

[0011] The specific implementation of the coal gas induced draft fan of the utility model will be explained in detail below in combination with the drawings:

[0012] As Figure 1 And Figure 2 Indicated, a kind of coal gas induced draft fan, it includes fan shell 1, the main shaft 2 and several pieces of impeller 3 are installed in the fan shell 1, each the impeller 3 around the circumferential of the main shaft 2 is arranged in spoke (uniform umbrella shape), the impeller 3 with the fan shell 1 between installation has a fire ring 4, the fire ring 4 is located on the annular track formed by the end rotation of the impeller 3 and is fixedly connected with the fan shell 1, the fire ring 4 with the impeller 3 coaxially arranged.

[0013] Further, the fire ring 4 includes several pieces of arc-shaped fire plate 41, each fire plate 41 is fixed on the fan shell 1, each fire plate 41 is spliced into annular structure, the expansion gap a between adjacent fire plate 41 has, the expansion gap a is 3-6mm the fire ring of the utility model can be a whole, but by several pieces of arc-shaped fire plate spliced into annular structure, can prevent the problem of drumming caused by fire plate in high temperature environment for a long time, reduces the replacement frequency of whole fire ring, reduces equipment maintenance cost, and prolongs the service life of coal gas induced draft fan;The expansion gap cannot be too big, and too much coal gas escapes to the next stage, which affects the converter coal gas recovery efficiency.

[0014] The above-mentioned is only the embodiment of the utility model, and does not limit the patent range of the utility model, and any equivalent process transformation using the utility model specification content, or direct or indirect application in other related technical fields, is also included in the patent protection range of the utility model.

Claims

1. A coal gas induced draft fan comprising a fan housing, a main shaft and a plurality of impellers mounted in said fan housing, each of said impellers being disposed in a spoke-like fashion around the circumference of said main shaft, characterized in that: A fire-extinguishing ring is mounted between the impeller and the fan shell, and is located on the annular locus formed by the rotation of the end of the impeller and is fixedly connected with the fan shell. The fire-extinguishing ring is coaxially arranged with the impeller.

2. A gas induced draft fan as claimed in claim 1 wherein: The fire-extinguishing ring comprises a plurality of arc-shaped fire-extinguishing plates, each of which is fixed to the fan shell, and each of which is spliced into an annular structure, and the adjacent fire-extinguishing plates have an expansion gap.

3. A gas induced draft fan as claimed in claim 2 wherein: The expansion gap is 3-6 mm.

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