CN202732463U

CN202732463U - Centrifugal fan sealing system

Info

Publication number: CN202732463U
Application number: CN 201220425678
Authority: CN
Inventors: 赵淑芬
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-08-24
Filing date: 2012-08-24
Publication date: 2013-02-13
Anticipated expiration: 2022-08-24

Abstract

A centrifugal fan sealing system is characterized in that an impeller front plate and an impeller rear plate are arranged on two sides of a fan impeller which is mounted on a spindle, small square blocks in a certain quantity is equidistantly welded to the outer edges of an inlet of each of the impeller front plate and the impeller rear plate, the lower half portions of the small square blocks are respectively welded onto the impeller front plate and the impeller rear plate, and the upper half portions of the small square blocks are connected with an arc cover plate through bolts. The arc cover plate is mounted on a cylinder which is arranged outside an outlet of a current collector, and an anti-eddy ring is additionally mounted between a volute and each of the impeller front plate and the impeller rear plate. A gap between the current collector and the impeller inlet can form a negative pressure area after the fan operates, gap turbulence is enhanced, leakage rate is decreased as far as possible, flow turbulence at the impeller inlet is weakened, uniformity of an internal flow field is improved, and accordingly fan efficiency is improved.

Description

The centrifugal blower sealing system

Technical field

The utility model relates to a kind of sealing system, is specifically related to a kind of centrifugal blower sealing system.

Background technique

Centrifugal blower is the principle that is converted to potential energy according to kinetic energy, utilizes the impeller of High Rotation Speed that gas is accelerated, and then slows down, changes the flow direction, makes kinetic energy convert potential energy (pressure) to.In the one-stage centrifugal blower fan, gas is from axially entering impeller, and gas flow changes over radially when impeller, then enters Diffuser.In Diffuser, gas and changing flow direction cause deceleration, this decelerating effect converts kinetic energy to pressure energy.Increased pressure mainly occurs in the impeller, and next occurs in the diffusion process.In Multi-stage centrifugal fan, make air-flow enter next impeller with return channel, produce more high pressure.

Centrifugal blower essence is a kind of variable-flow constant-voltage equipment, and when rotating speed one timing, the pressure-flow theoretical curve of centrifugal blower should be straight line, because internal losses, the actual characteristic curve is crooked.The pressure that produces in the centrifugal blower is subject to the considerable influence of intake temperature or variable density, to a given air inflow, the pressure that produces during the highest intake temperature (air density is minimum) is minimum, for a given pressure versus flow characteristic curve, a power and rating curve are just arranged.When blower during with constant-speed operation, for a given flow, required power raises with the reduction of intake temperature.

The loss of centrifugal blower mainly is divided into three parts: volumetric loss, mechanical loss and flow losses.At present, the research of centrifugal blower is concentrated on mostly structure and the flow field characteristic of impeller and spiral case both at home and abroad, and pay close attention to few to flow field characteristic and the blower fan volumetric loss of the area of space between slip ring, spiral case and the impeller shroud three, volumetric loss is owing to can flow back into by the gap between slip ring and the impeller inlet low pressure area of impeller inlet from the part of impeller effluent air, make the rate of discharge of blower fan less than inlet flow rate, and cause fan noise to increase.

For guaranteeing the blower fan safe operation, general slip ring and impeller radial clearance are controlled at 5-8mm, and slip ring puts in impeller the inside 20-30mm.Such as the centrifugal blower of 12Kpa D2=1160mm, gap control is at the about 6mm of design load, and gap leakage flow rate reaches 7000kg/h, and flow velocity is up to 90m/s.There is the air-foil fan fallback in a lot of centrifugal blowers in on-the-spot the use, and fan efficiency is lost 10 %～30 % and but do not caused widely attention.In manufacturing, installation and user maintenance process, the gap control between slip ring and the impeller inlet is bigger than normal, causes fan efficiency not reach design load.

Summary of the invention

For overcoming the problems referred to above, the utility model provides a kind of centrifugal blower sealing system, make the gap location between the rear slip ring of blower fan running and the impeller inlet can form negative pressuren zone, strengthen the gap disturbance, reduce leakage rate as far as possible, alleviate impeller eye air-flow disturbance, improve the uniformity in internal gas flow flow field, thereby reached the purpose that improves fan efficiency, for centrifugal fan, this technical innovation rear fan efficient can improve 3%-8%.

For achieving the above object, the utility model is by the following technical solutions:

A kind of centrifugal blower sealing system, comprise blockage, the circular arc cover plate, main shaft, slip ring, volute, anti-vortex ring, the impeller shroud, impeller hub disk and draught fan impeller, it is characterized in that, the draught fan impeller both sides that are installed on the main shaft arrange respectively impeller shroud and impeller hub disk, blockage in the equidistant welding some in the import outer ledge place of impeller shroud and impeller hub disk, described blockage Lower Half is welded in respectively on impeller shroud and the impeller hub disk, the first half adopts bolt to be connected with the circular arc cover plate, described circular arc cover plate is installed on the cylindrical shell in the outside, slip ring outlet port, installs anti-vortex ring additional between fan impeller front disc and impeller hub disk and volute.

As preferred version of the present utility model:

Described anti-vortex ring is to 15～20 ° of blower fan impeller outer section lopsidedness, and described circular arc cover plate outer ring width can cover blockage fully.

The utility model beneficial effect:

1, reduces gap leakage flow rate between slip ring and the impeller inlet, install anti-vortex ring in the draught fan impeller outlet additional with the spiral case place, improve the uniformity in internal gas flow flow field, thereby improve fan efficiency.

2, the sealing system is applicable to single double-suction centrifugal fan, and is applied widely, reduces consuming during blower fan work, makes profit maximization; Aspect energy-conservation, reach requirements at the higher level.

3, reduce noise, make the work employee physical and mental health of blower fan annex obtain certain protection, reduce occupational disease data.

Description of drawings:

Fig. 1 is for installing the double-suction centrifugal fan sectional view of sealing system.

Fig. 2 is for installing the double-suction centrifugal fan plan view of sealing system.

Fig. 3 is the sealing system plan view.

Fig. 4 is the sealing system sectional view.

Among the figure: the anti-vortex ring 10-fan airflow outlet of 1-impeller shroud 2-draught fan impeller 3-impeller hub disk 4-blockage 5-circular arc cover plate 6-main shaft 7-slip ring 8-volute 9-11-bolt 12-impeller inlet 13-face of weld.

Embodiment:

Embodiment

Shown in Fig. 1-4: this sealing system is comprised of circular arc cover plate 5 and blockage 4, at 24 or 36 blockages 4 of the equidistant welding in the import outer ledge place of impeller shroud 1 and impeller hub disk 3, then make a whole circle circular arc cover plate 5, be installed on the cylindrical shell in the slip ring 7 outlet outsides, blockage 4 Lower Halves adopt and are welded to connect on impeller shroud 1 and impeller hub disk 3, the first half adopts bolt 11 to be connected with circular arc cover plate 5, circular arc cover plate 5 outer ring width can cover blockage 4 fully, gap location after the blower fan running between slip ring 7 and the impeller inlet 12 forms negative pressuren zone, strengthen the gap disturbance, reduce leakage rate as far as possible, alleviate impeller inlet 12 air-flow disturbances, at slip ring 7, the three-dimensional diverse location that spiral case 8 and impeller shroud 1 and impeller hub disk 3 form, the vortex that has different scale and different rotary intensity, because the existence of vortex can consume the energy of flow of gas in the blower fan, is unfavorable for its internal flow situation, and can produces vortex noise.After fan impeller front disc 1 and impeller hub disk 3 installs anti-vortex ring 9 additional with spiral case 8 places, its interior flow field is more even, the large scale vortex obtains effective fragmentation, the vortex spin intensity obviously reduces, simultaneously volumetric loss also greatly reduces, the leakage loss of blower fan obviously descends, its leakage rate decreased average 35%-45%, thus reached the purpose that improves fan efficiency.

Claims

1. centrifugal blower sealing system, comprise blockage (4), circular arc cover plate (5), main shaft (6), slip ring (7), volute (8), anti-vortex ring (9), impeller shroud (1), impeller hub disk (3) and draught fan impeller (2), it is characterized in that, draught fan impeller (2) both sides that are installed on the main shaft (6) arrange respectively impeller shroud (1) and impeller hub disk (3), blockage (4) in the equidistant welding some in the import outer ledge place of impeller shroud (1) and impeller hub disk (3), described blockage (4) Lower Half is welded in respectively on impeller shroud (1) and the impeller hub disk (3), the first half adopts bolt (11) to be connected with circular arc cover plate (5), described circular arc cover plate (5) is installed on the cylindrical shell in the outside, slip ring (7) outlet port, installs anti-vortex ring (9) additional between fan impeller front disc (1) and impeller hub disk (3) and volute (8).

2. centrifugal blower sealing system according to claim 1 is characterized in that, described anti-vortex ring (9) is to 15～20 ° of the outside lopsidedness of draught fan impeller (2).

3. centrifugal blower sealing system according to claim 1 is characterized in that, described circular arc cover plate (5) outer ring width can cover blockage (4) fully.