RU2805349C1 - Centrifugal gas fan for removal of methane-air mixtures (cgf) - Google Patents

Abstract

FIELD: centrifugal fans.

SUBSTANCE: centrifugal fans of high speed, with large impeller sizes, having an explosion-proof design, used in units intended for pumping methane-air mixture from coal mines. The creation of an explosion-proof fan with a high-pressure characteristic for use in units for pumping methane-air mixtures from coal mines, having a lightweight design, having low labor intensity in maintenance and repair. This goal is achieved by the fact that with identical volumetric process characteristics, the same electric drives and the presence of intrinsically safe seals, the CGF-10KM fan has its own design features: the impeller is made of lightweight high-strength alloy steel with filling of the blade cavities with rigid two-component high-density polyurethane foam with a closed cellular structure, as a result of which the weight of the impeller was reduced by 60-65% compared to the original design, which made it possible to exclude bearing supports from the fan design and install the impeller cantilevered directly on the motor shaft and make the spiral housing non-separable, a flange, which is part of the spiral housing, the electric motor is mounted on a subframe, made movable to remove the impeller from the spiral housing. Also, at the second end of the motor shaft, a current collector was fixed to remove static electricity.

EFFECT: presented design has smaller overall dimensions and reduced metal consumption by 10% compared to the original version, while having greater rigidity. The time and safety of repair work, with this design of the fan, are positively changed compared to the base case.

1 cl, 9 dwg

Description

The invention relates to the mining industry and, in particular, to devices and, in particular, to high-speed radial (centrifugal) fans with large impeller sizes, explosion-proof design, used as part of installations designed for pumping methane-air mixtures from coal mines.

A known draft machine contains a spiral housing with an outlet pipe, an impeller placed in it, mounted on the chassis shaft and consisting of an impeller, a cover disk and a hub, an electric motor, an inlet funnel adjacent to the spiral housing, an axial guide apparatus including a cylindrical shell with blades radially located in it [RF Patent for utility model No. 178824, M. Class. F04D 17/08 dated 09/11/2017].

A disadvantage of the known draft machine is the presence of a running gear shaft between the electric motor and the impeller, which is used to transmit torque from the electric motor to the impeller.

The closest in technical essence and achieved result is a centrifugal fan used in coal mines as part of installations for pumping a methane-air mixture from a goaf, including a spiral housing, an impeller, bearing supports, a main frame, an electric motor, an intermediate shaft and an electric motor subframe. [Ventiljator-uvcg-9 <https://www.lufter.ru/product/ventiljator-uvcg-9/>. (prototype)], the disadvantages of the known centrifugal fan are: a heavy impeller, a spiral casing that requires removal of the impeller only vertically upward and only after disassembling the casing, additional bearing supports with an intermediate shaft for transmitting torque from the electric motor to the impeller, a large number of components friction requiring control, high metal consumption and high labor intensity of maintenance and repair.

The technical objective of the invention is to create an explosion-proof fan with a high-pressure characteristic for use as part of installations for pumping methane-air mixtures from coal mines, simplifying the design and reducing the labor intensity during its maintenance and repair.

This goal is achieved by the fact that the impeller is made of lightweight high-strength alloy steel, with the cavities of the blades filled with rigid two-component high-density polyurethane foam with a closed cellular structure, the impeller is mounted in a cantilever directly on the electric motor shaft, and the spiral casing is made non-separable, a flange is attached to the electric motor, which is part of the volute casing, the electric motor is installed on the electric motor subframe, which is made movable to remove the impeller from the volute casing; a current-collecting device is attached to the other end of the electric motor shaft to remove static electricity.

The essence of the invention is illustrated by drawings, where in Fig. Figure 1 shows a general view of a centrifugal gas fan for removing methane-air mixtures (MCG), FIG. Figure 2 shows a centrifugal gas fan for removing methane-air mixtures (MCA) (side view), Fig. Figure 3 shows a VCG fan with the impeller removed; FIG. 4 shows the impeller of the VCG fan, Fig. Figure 5 shows the design of the current collecting device for the VCG fan.

The device of a centrifugal gas fan for removing methane-air mixtures (MCG) contains: a spiral housing - 1, an impeller - 2, an input confuser - 3, a main frame - 4, an electric motor - 5, the electric motor is mounted with mounting bolts - 6 on the electric motor subframe - 7, a mechanism displacement - 8, current collector - 9, subframe displacement screw - 10, limit nuts - 11, thrust plate - 12, threaded bushing - 13, guide screws - 14, sliding plates - 15, fixing bolts - 16, flange - 17, blades impeller - 18 filled with rigid two-component polyurethane foam - 19, contact washer - 20, clamping bolts - 21, metal-graphite brush - 22, fixed in the brush holder - 23.

The installation of a centrifugal gas fan for removing methane-air mixtures (MCG) is illustrated with drawings:

In fig. Figure 1 shows a general view of a centrifugal gas fan for removing methane-air mixtures (MCG), where a spiral casing - 1 with an input confuser - 3 is rigidly fixed on the main frame - 4, an electric motor subframe - 7 is installed with a movement mechanism - 8 and an electric motor - 5 with a flange - 17, screwed to the spiral housing - 1. On the electric motor shaft - 5, on one side there is an impeller - 2, and on the other side a current collector - 9, which ensures the removal of static electricity.

In fig. Figure 2 shows a centrifugal gas fan for removing methane-air mixtures (MCG), where (A) is a front view, (B) and (C) is an image of the movement mechanism - 8 of the electric motor subframe - 7. The movement mechanism - 8 is formed by the following elements: subframe movement screw - 10, limiting nuts - 11, thrust plate - 12, fixed to the frame - 4, threaded bushing - 13, welded into the electric motor subframe - 7.

In fig. Figure 3 shows a centrifugal gas fan for removing methane-air mixtures (MCG) with the impeller removed. Work on the VCG fan to remove the impeller - 2 from the volute casing - 1 for inspection or replacement is carried out as follows: after disconnecting the flange - 17 from the volute casing - 1 and loosening the fixing bolts - 16, rotate the displacement screw - 10, limit nuts - 11 rest against the thrust plate - 12, thereby ensuring either pushing the electric motor subframe - 7 towards the spiral housing - 1, or pulling the electric motor subframe - 7 from the spiral housing - 1 through the threaded bushing - 13, depending on the direction of rotation of the displacement screw - 10. When rotation of the movement screw - 10 the electric motor subframe - 7 moves along the sliding plates - 15, which are part of the main frame - 4, while the linearity of movement and control of the movement of the electric motor subframe is ensured using guide screws - 14 located on the main frame - 4 on both sides of electric motor subframe - 7. Upon completion of work related to movement, the electric motor subframe -7 is attracted to the main frame -4 with fixing bolts -16.

In fig. Figure 4 shows the impeller - 2, where (A) is a general view of the impeller, (B) is an enlarged view of the impeller blade - 18, filled with rigid two-component polyurethane foam - 19.

In fig. Figure 5 shows the design of a current collector - 9 for removing static electricity, made in the form of a metal-graphite brush - 22, fixed in a brush holder - 23 and pressed by it to a contact washer - 20, made of brass or copper and attached to the end of the second end of the electric motor shaft - 5 clamping bolts - 21.

The operation of a centrifugal gas fan for removing methane-air mixtures (MCG) is carried out as follows: when power is supplied, the electric motor - 5, installed on the subframe of the electric motor - 7 on the main frame - 4, begins to rotate the impeller - 2 in the spiral casing - 1. Under the influence of centrifugal force the methane-air mixture located in the impeller - 2 between the blades of the impeller - 18 and rotating with it, tends to leave the impeller - 2 through the outlet of the spiral casing - 2, creating excess pressure inside the spiral casing - 1, and in the central part of the impeller - 2 vacuum. Under the influence of rarefaction, the methane-air mixture moves from the confuser - 3 to the impeller - 2, then through the spiral housing - 1 it leaves the centrifugal gas fan to remove methane-air mixtures (MCG).

The presented design has smaller overall dimensions and reduced metal consumption by 10% compared to the original version, while having greater rigidity. The time and safety of repair work with this fan design are positively changed compared to the basic version, and when the blade cavities are filled with rigid two-component high-density polyurethane foam with a closed cellular structure, the weight of the impeller is reduced by 60-65%.

Claims (1)

Centrifugal gas fan for removing methane-air mixtures (MCG), consisting of a spiral casing, a main frame, an electric motor subframe attached to it, an electric motor, an impeller, characterized in that the spiral casing is made non-removable and is rigidly fixed to the main frame, the electric motor subframe is equipped with a moving mechanism , consisting of a subframe moving screw, limiting nuts, a thrust plate attached to the frame, a threaded bushing welded into the subframe of the electric motor, the impeller is made of lightweight high-strength alloy steel, the cavities of the blades of which are filled with rigid two-component high-density polyurethane foam with a closed cellular structure, while the impeller is mounted directly on the electric motor shaft, a flange is attached to the electric motor, which is part of the volute casing, the electric motor is installed on the electric motor subframe, and the current-collecting device for removing static electricity is made in the form of a metal-graphite brush, fixed in the brush holder and pressed by it to a contact washer made of brass or copper and attached to the end of the second end of the electric motor shaft with clamping bolts.