PL235103B1 - Axial fan - Google Patents

Description

Description of the invention

The invention relates to an axial fan. Fans, next to pumps, belong to the group of working machines characterized by high energy consumption. The above is due to:

- a wide range of applications,

- relatively high power of drive motors.

There are basically different types of fans, that is:

- radial fans,

- axial fans.

Both types of fans are commonly used in various industries such as:

- energetics,

- mining,

- metallurgy,

- chemistry and petrochemistry and others.

Axial fans in comparison to centrifugal fans are distinguished by:

- more favorable dimensions,

- easier integration into the network,

- more favorable methods of parameter adjustment by changing the angles of the rotor blades and the steering wheel, both when stationary and in motion,

- high efficiency values.

Unfortunately, axial fans also have disadvantages in the form of higher production costs resulting from the required high accuracy of execution of both the flow systems, i.e. the rotor and the stator, as well as the housing. The problem comes down to the necessity to obtain an optimal over-blade gap and the accuracy of the palisade profiles and surface smoothness. For reasons of movement, it is quite common, inter alia, to exclude the possibility of mechanical sparking, the size of the scapular gap is much higher than the optimal value. Moreover, during the operation of the fan, the gap is enlarged due to natural wear. It manifests itself in increased gap losses, which directly reduces the fan efficiency and increases the power consumption of the drive motor. For the above reasons, it becomes necessary to look for design solutions for axial fans that will eliminate the influence of an increased overblock gap. This is evidenced by the present invention concerning the use of special rings at both the inlet and outlet in the housing.

The application of the solution according to the invention ensures higher efficiency of the axial fan and improvement of its certainty of movement. The above results in obtaining specific economic effects in the operation of the axial fan. The aim of the project is to develop a structure of a new type of axial fan, adapted for various reasons to the size of the blade gaps much higher than the optimal values. An axial fan according to the invention is characterized in that in front of the impeller, at a distance Ii from the blade edge equal to 1 to 5 times the blade gap size, it has a ring with a thickness g of 0.5 to 3 times the value δ of the blade gap, while on the inlet side the ring is thinned up to a thickness g1 equal to 0.1 to 1 of the magnitude δ of the scapular gap. Preferably, in the housing behind the rotor at a distance I2 from the blade edge equal to 1 to 5 of the blade gap size δ, it has a ring with a thickness g equal to 0.5 to 2 times the blade gap δ, while from the outlet side the ring is thinned to a thickness g2 equal to from 0.1 to 2 sizes δ of the scapular gap.

Preferably, in the case of multi-stage fans in a casing in front of the rotor, at a distance Ii from the blade edge equal to 1 to 5 of the blade gap size δ, it has an embedded ring with a thickness g equal to 0.5 to 3 of the blade gap δ size, while from the inlet side the ring is thinned up to a thickness g1 equal to 0.1 to 1 of the magnitude δ of the scapular gap.

Preferably, in the case of multi-stage fans in a casing downstream of the impeller, at a distance I2 from the blade edge equal to 1 to 5 of the blade gap size δ, it has an embedded ring with a thickness g equal to 0.5 to 2 times the blade gap size δ, while from the outlet side the ring is thinned up to a thickness g2 equal to 0.1 to 2 times the magnitude δ of the scapular gap.

The axial fan according to the invention, due to the use of additional elements, will be partly more expensive to produce, but due to its higher efficiency it will be cheaper to operate. The subject of the invention is illustrated by an exemplary embodiment in the drawings, in which Fig. 1 shows by

Fig. 2 - axial section of a two-stage axial fan, Fig. 2 - view of the blade palisade on the casing in the developed two-stage version, Fig. 3 - axial section of the ring from the impeller inlet side, Fig. 4 axial section of the ring from the impeller outlet side.

An axial fan in the casing of which 1 in front of the impeller 2 at a distance li from the edge 3 of the blade 4 equal to 1 to 5 of the size δ of the blade gap 5, has an embedded ring 6 with a thickness g equal to 0.5 to 3 of the magnitude δ of the blade gap, while on the side of the inlet, ring 6 is thinned to a thickness g and equal to 0.1 to 1 of the magnitude δ of the over-vane gap 5. In the housing 1, behind the rotor 2, at a distance I2 from the edge 7 of the blade 4, which is 1 to 5 of the size δ of the 5 super-blade gap, there is an embedded ring 8 with a thickness g equal to 0.5 to 2 of the size δ of the 5 super-vane gap, while on the outlet side, a ring 8 is thinned to a thickness g2 equal to 0.1 to 2 of the magnitude δ of the supercapillary gap.

In the case of multi-stage fans in the casing 1 in front of the impeller 9, at a distance li from the edge 10 of the blade 4, which is from 1 to 5 of the size δ of the super-blade gap 5, it has a ring 11 with a thickness g of 0.5 to 3 of the magnitude δ of the gap 5 in the super-blade, while from on the inlet side, the ring 11 is thinned to a thickness gi equal to 0.1 to 1 of the magnitude δ of the superscapular gap 5.

In the case of multi-stage fans in the casing 1 after the rotor 9, at a distance b from the edge 12 of the blade 4 equal to 1 to 5 of the size δ of the 5 super-blade gap, there is an embedded ring 13 with a thickness g equal to 0.5 to 2 of the size δ of the 5 super-blade gap, while from on the outlet side, the ring 13 is thinned to a thickness g2 equal to 0.1 to 2 of the magnitude δ of the supercapillary gap 5.

Claims (4)

Patent claims 1. Axial fan, characterized in that in the housing (1) in front of the rotor (2) at a distance li from the edge (3) of the blade (4) equal to 1 to 5 of the δ size of the over-blade gap (5), it has a ring (6) with with a thickness g equal to from 0.5 to 3 of the magnitude δ of the super-scapular gap (5), while on the inlet side, the ring (6) is thinned to a thickness gi equal to 0.1 to and the size δ of the supercapillary gap (5). 2. Axial fan according to claim 1 and, characterized in that in the housing (i) downstream of the rotor (2) at a distance l2 from the edge (7) of the blade (4) equal to 1 to 5 of the size δ of the super-vane gap (5), it has a ring (8) with a thickness g equal to from 0.5 to 2 sizes δ of the super-scapular gap (5), while from the outlet side, the ring (8) is thinned to a thickness g2 equal to 0.1 to 2 sizes δ of the super-scapular gap (5). 3. An axial fan according to claim 1 and or 2, characterized in that in the case of multi-stage fans in the housing (i) in front of the rotor (9) at a distance li from the edge (i0) of the blade (4) equal to 1 to 5 of the magnitude δ of the over-blade gap (5), it has a ring ( 11) with a thickness g equal to 0.5 to 3 of the magnitude δ of the super-scapular gap (5), while on the inlet side the ring (11) is thinned to a thickness g and equal to 0.1 to 1 of the magnitude δ of the supercapillary gap (5). 4. Axial fan according to claim 1 and or 2 or 3, characterized in that in the case of multi-stage fans in the housing (1) behind the impeller (9) at a distance b from the edge (12) of the blade (4) equal to 1 to 5 of the size δ of the over-blade gap (5) a ring (13) with a thickness g equal to 0.5 to 2 of the magnitude δ of the super-scapular gap (5), while on the outlet side, the ring (13) is thinned to a thickness g2 equal to 0.1 to 2 of the magnitude δ of the supercapillary gap (5).