The impeller of the fan
(57) Abstract:The impeller is designed for smoke exhausters sinter production. The impeller has a Central and lateral disks, between which set the main blade. At each input end of the main blades welded one-sided welded seam protective blade with tilt 20-30° to the working surface of the main blades. Protective blades have a trapezoidal shape with a height equal to 0.4-0.6 of the width of the input side of the main blades, and is adjoined by a large base to a Central disk. The elevation of the top edge of the protective blade above the work surface of the main blades is the Central disc of 0.015 to 0.02, and at the opposite end of the protective shoulder - 0,007-0.01 length of the main blades. The working surface and the ends of the protective blades deposited by the highly rigid alloy with a thickness of hardfacing layer constituting 0.1-0.2 thickness of the protective blades. This embodiment of the exhauster will allow for the possibility of multiple replacement of worn protective blades without damage to the main blades, i.e., increased maintainability, reliability of the wheel and extends its service life. 2 C.p. f-crystals, 3 ill. The invention relates to the field inpulsive mainly in the construction of smoke exhausters sinter production (exhausters).All of the exhaust gas exhaust ducts metallurgical production, kiln units, boilers, thermal power plants, etc. are most prone to wear exhausters sinter production, and are worn primarily vanes of the impeller.Dust in the wheel exhauster, as shown by repeated examination of worn impellers, is concentrated in a narrow cords and cut the blades from the Central disk stripe width of less than 20 mmKnown methods for the protection of impeller blades from abrasive wear by applying on the surface of the highly rigid metal inapplicable exhausters due to the high peripheral speed of the wheel, and therefore the larger the centrifugal forces that destroy the protective coating (see A. D. Brooke, Exhaust gas treatment facilities, Meters, mechanical engineering, 1984, S. 42, 55, 88).Transported the gas flow entering the impeller in the axial direction and, resting on okaloosae the Central area of the disk changes the direction of the velocity at radial, with dust particles, many orders of magnitude more inertia than the gas molecules, reach almost to the surface of the Central disk. At the entrance to milepost blades. The pressure force of the particles on the blade, as is known, is equal to the product of its mass and acceleration, reaching in the area of primary contact tens of thousands of m/s2.From this it follows that the preliminary acceleration of particles in the tangential direction on a smaller radius substantially reduces their impact on the rotor blades. This task technique is solved by setting before the rotor blades of additional protective blades on a smaller radius of the wheel, which perceive the primary impacts of dust particles and thus protects blades from severe wear.Known impeller of the centrifugal fan single-inlet, including suspension and front discs fastened between the rotor blades, in which the host drive is running in front of the rotor blades installed easily removable blade crown with a lattice having compared with workers in 2-3 times more protective of blades smaller width with angle output 22-25oexceeding the exit angle of gas flow with blades (see and.with. N 259315, CL 27, 12/02, IPC F 04 C).Dust particles, affecting mainly on the protective blades, dispersed them in angelopolis to the radius ensures the creation of the vortex zone along the surface of the support disc, what contributes to the dispersion of the particles in the interscapular area.The most significant drawbacks of this solution include:
vortex area, created a large number of protective blades, occupies a significant interscapular space, resulting in lower pressure gas flow:
- install the blade crown flat on your host drive is suitable only for low-power centrifugal fans for General purposes, as the high speed gas flow in this design of the impeller causes the separation of a gas stream to the front of the disk, forming a vortex zone, which increases aerodynamic drag wheels:
Thus, solving the task of protecting the blades from wear and tear, this design significantly reduces the generated pressure.In addition, when the vibration of the impeller due to uneven wear of the blades, the screw fastening parts is unreliable, and their separation from the wheel when the speed of rotation of 1000 rpm will inevitably lead to accidents.Thus, easy pealing protective blades reduces the reliability of the fan.It is known and accepted as a prototype Rabocheye main blades and protective blade, the number of which is equal to the number of main blades, in which the protective blades are arranged in the radial direction between the ends of the main blades, inclined in the direction opposite to the direction of the peripheral speed of the wheel and welded to the Central disk on sites with a pseudo-spherical and flat surfaces in the zone of rotation from axial to radial flow velocity (see A. D. Brooke, Exhaust gas treatment facilities, Meters, mechanical engineering, 1984, S. 60).Protective blade of this design form the vortex zone is significantly smaller, i.e. less influence on the technological parameters of the exhauster.The disadvantage of the prototype is that when replacing the protective blades (most wearing parts of the impeller), inevitably damaged the surface of the Central disk in the most intense and responsible part, which significantly reduces the reliability of the wheel and reduces its service life.The basis for this invention is the task: by improving the design of the impeller to increase the reliability and extend the service life of the wheel without substantial deterioration of the technological parameters of the exhauster.The problem is solved in that Rami and protective blade, the number of which is equal to the number of main blades, according to the invention the protective blade having a trapezoidal shape with a height of 0.4 - 0.6 of the width of the input side of the main blades rigidly mounted on the input ends of the main blades angle = 20-30oto the working surface and adjacent to a large base to the Central disk, and the elevation of the top edge of the protective blade above the work surface of the main blades is the Central disc h = 0,015 - 0,02, and at the opposite end of the protective blades h = 0,007-0.01 length of the main blades.Moreover, the protective blades are welded to the ends of the main blades unilateral welded seam.Moreover, the working surface and the ends of the protective blades deposited by the highly rigid alloy with a thickness of hardfacing layer constituting 0.1 - 0.2 thickness of the protective blades.When the smoke exhauster highest abrasive wear are protective of the scapula. Their attachment to the ends of the main blades eliminates damage to the Central disk when replacing the protective blades. Fastening by welding provides reliable fixation, and the one-seam located at the end of the main blades, allows you to trim worn protective blades without Powerade without damaging the main elements of the impeller.Due to the fact that the dust particles due to their inertia when entering bezlopastny space are concentrated in the Central disk, protective blade adjacent to the Central disk and when their length, equal to 0.4 - 0.6 of the width of the main blades, almost the entire flow of dust gets on the protective blades, however, if their length exceeds 0.6 of the width of the main blades, it is not only useless in terms of protection, but also harmful, because it increases the voltage in the main blades from the centrifugal force.The location of protective blades with an angle to the working surface of the main blades provides education along the surface of the main blades of the vortex zone, necessary for scattering dust flow on the inter-layer space, with a decrease of the angle between the planes of the blades improves the flow of protective blades of the gas flow and increases their interaction on the dust particles in the recent acceleration in the tangential direction, but at the same time increases and the width of the protective blades, necessary for the formation of the vortex zone of optimum thickness, which in turn increases the weight of the protective blades, and hence the centrifugal force acting on the main blade. is Oh zone along the working surface of the main blades is determined primarily by elevation of the upper edge of the protective blades (h) above the working surface of the main blades.The Central disk, the concentration of dust particles in front of the blades is greatest, and therefore the thickness of the vortex zone should be the greatest, but with the increase in the thickness of the vortex zone, increases the volume it occupies megapastor space, and with it the energy costs of her education, which reduces the differential pressure created by the impeller, i.e., the pressure at the outlet of the fan.When the ratio (h) to the length of the main blades, more than 0.02 from the Central disk and 0.01 at the other end, with a sufficient degree of scattering dust loss of energy of the gas flow on the formation of the vortex zone would be unreasonably large, and with respect to, less than of 0.015 and 0.007, respectively, the scattering will be insufficiently effective.Thus, the optimum elevation of the upper edge of the protective blade above the work surface of the main blades is the Central disc h = 0,015 - 0,02, and at the end of the protective blades h = 0,007 - 0.01 length of the main blades.Due to the fact that the cross-sectional area of the vortex zones formed by the blades, does not exceed 4% of the area of the gas inlet in bezlopastny space, and the volume of these vortex zones is less than 1% of the volume megapastor space, negatiive abrasive particles impact mainly on the protective blades, giving them the working surface of high hardness (HU = 1000) greatly increases their lifespan, and therefore the overhaul life of the exhauster.However, in the weld brittle carbide layer, the number of microcracks in proportion to the square of the thickness of the hardfacing layer. When the voltage from the action of centrifugal forces, which impellers exhausters value 1500-1800 kg/cm, microcracks lead to spalling of the surface layer, if the thickness of more than 0.2 thickness of the blade, and when the relative thickness of the deposited layer, a lower 0,1, - the effectiveness of protective blades from abrasive wear is markedly reduced.The optimum thickness of the carbide layer is 0.1 - 0.2 thickness of the protective blades.Since the radius of the location of protective blades in the present invention is approximately half the outer radius of the impeller, which limits the magnitude of the stresses from centrifugal forces in the deposited layer of protective blades within the allowable values.Thus, the present invention provides frequent replacement of worn protective blades without damaging the main elements of the impeller, which poses the Oia disks, and increases maintainability and reliability.The essence of the invention is illustrated by the attached drawings, which shows:
Fig. 1 - General view of the impeller of the smoke exhauster;
Fig. 2 - section a-a of Fig. 1;
Fig. 3 is a section along B-B of Fig. 1.The impeller of the smoke exhauster includes a Central disk 1 and the two side disk 2, between which set the main blade 3. To the input ends of the main blades welded protective blade 4 angle = 30oto the working surface 5 of the main blades. Protective blades have a trapezoidal shape and is adjoined by a large base to the Central disk 1. Length of protective blades (the altitude of the trapezoid) is 0.6 of the width of the input side of the main blades. The elevation of the top edge of the protective blades above the working surface 5 of the main blades is the Central disc - h = 0,02, and at the end of the protective shoulder - h = 0.01 length of the main blade 3.Protective blades 4 are welded one-sided welded rear-side blades.The working surface of the protective blades 4 deposited by the highly rigid alloy electrode of brand T-620. The thickness of the hardfacing layer 6 is 0.2, the thickness of the protective blades.Coming from the gas stream dust particles as well as gas, are inhibited in the axial direction, but slower due to the much greater mass of the particles, therefore, reach almost to the Central disk 1. Carried by a stream of gas to the main blades 3, dust particles hit moving in the circumferential direction of the protective blades 4 mounted on the input ends of the main blades 3, are accelerated to the peripheral speed of the input ends of the main blades and are made in bezlopastny space.Due to the inclination of the protective blade 4 relative to the main blade 3, and the elevation of the upper edges of the protective blades above the working surface 5 of the main blades, the most significant in the Central disk - along-thirds of the length of the main blade 3 and a half its width is formed a narrow vortex zone, russei and with the working surface of the main blades, in addition, a further increase in the peripheral speed of dust particles occurs due to the interaction with the accelerating gas stream, and the working surface of the main blades 5 are practically not subjected to abrasive wear.During operation of the exhauster is periodically inspection of the impeller. When the wear of the blades is greater than the allowed value, they are cut and replaced with new ones, aimed carbide layer. When the main blades are practically not damaged.Thus, the proposed design of the impeller substantially improves its maintainability and reliability, with repeated replacement of protective blades without damaging the main parts of the impeller ensures a significant increase in its operating life. 1. The impeller of the fan, the contains of the Central and lateral disks installed between the main blades and protective blade, the number of which is equal to the number of main blades, characterized in that the protective blade having a trapezoidal shape with the height component of 0.4 - 0.6 of the width of the input side of the main blades rigidly mounted on the input ends of the main blades with m elevation of the upper edge of the protective blade above the work surface of the main blades is the Central disc of 0.015 - 0,02, and at the opposite end of the protective shoulder - 0,007 - 0.01 length of the main blades.2. The impeller of the fan under item 1, characterized in that the protective blades are welded to the front ends of the main blades unilateral welded seam.3. The impeller of the fan under item 1, characterized in that the working surface and the ends of the protective blades deposited by the highly rigid alloy with a thickness of hardfacing layer constituting 0.1 - 0.2 thickness of the protective blades.
FIELD: mechanical engineering; air blowers, compressors and outer vane machines.
SUBSTANCE: invention relates to electric compressors, turbocompressors for supercharging internal combustion engines, air blowers and other vane machines. Proposed high-speed rotor of blower provides practically complete elimination of rotor unbalance owing to provision of minimum tolerable deformation of shaft when rotor parts pack is tightened by nut, thanks to which vibration and noise of turbocompressor in operation are considerably reduced, service life of bearings is increased and rubbing of impeller or turbine of compressor against base members is prevented which improves operating capabilities and reduces energy consumption. For this purpose, according to first design version, rotor is furnished with plates, each placed between end face of compressor impeller bushing and nut. Said plate has concave spherical surface at one side adjoining convex spherical surface of nut, and at other side, flat surface adjoining flat end face of bushing of compressor impeller. Ring groove is made on each bushing of compressor impeller between blades and end face of compressor impeller bushing. According to second version, ring groove is made on each bushing of compressor impeller between blades and end face of compressor impeller bushing provided with concave spherical surface adjoining convex spherical surface of nut.
EFFECT: improved operating capabilities, reduced energy consumption.
3 cl, 2 dwg
FIELD: mechanical engineering.
SUBSTANCE: rotor (10) of multi-stage compressor comprises axial section (12) of the rotor followed by the centrifugal section (14) of the rotor. Axial section (12) of the rotor and centrifugal section (14) of the rotor are interconnected by means of a diffusion junction to define a unit working wheel having blades (22) and (36). The sections of the axial stage and centrifugal stage go one into the other without discontinuities.
EFFECT: improved design.
21 cl, 1 dwg
FIELD: power machine engineering, possibly production of large-size pumps with complex-shape spatial interval of inter-blade ducts, mainly main circulation pumps used in nuclear power plants in nuclear electric power stations.
SUBSTANCE: impeller is formed of two parts; each part includes two mutually joined members. One member is in the form of protrusion formed on main disc as one piece with it. Other member is formed on covering disc as one piece with it. Members of each blade are milled in order to provide possibility of their joining by butt welding and to realize quality control of their joining by irradiating with penetration irradiation. After joining before welding, portions of impeller are geometrically divided by means of surface of revolution. At movement along said surface from inlet to impeller towards its outlet the least angle between rotation axis of impeller and line normal to said surface of revolution does not increase.
EFFECT: enhanced quality of product due to increased strength of welded seam and elimination of distortion of shape of inter-blade ducts.
5 cl, 9 dwg
FIELD: mechanical engineering; fans and ventilators.
SUBSTANCE: invention relates to improved centrifugal fan. Proposed fan with single of double intake has enclosed type impeller formed by rotating bladed wheel 10 with at least one cover member 13. Blades 11 of fan impeller are flat, tilted backwards relative to direction of impeller rotation, and cover member 13 is provided with section 13A on truncated cone surface, first curvilinear section 13B on surface and second curvilinear section 13C on surface in direction of flow. Radius of curvature of first curvilinear section of surface is less than radius of curvature of second curvilinear section of surface.
EFFECT: increased efficiency of centrifugal fans owing to use of optimum combination of parameters, for instance, number, shape and arrangement of blades of fan impeller and form of cover member.
8 cl, 9 dwg
FIELD: mechanical engineering; compressors.
SUBSTANCE: invention relates to impellers of centrifugal machines. Proposed impeller has disk with blades fitted on disk. Layer of material is attached to surface of disk opposite to blades in which ratio of modulus of elasticity to density is less than that of disk material, for instance, glass plastic can be used for this purpose. Layer of similar material is arranged near outer diameter of plate of cover and main disk in zone of interblade channels. At elastic vibrations of disks of impeller in places of contact of material, internal friction, dissipation of energy of vibrations and reduction of their amplitude in places of contact of material appear, which has favorable effect on resistance of impeller to cyclic loads and provides required dynamic strength characteristics of impeller at relatively high peripheral velocities.
EFFECT: increased strength of impeller and high peripheral velocities.
2 cl, 1 dwg
FIELD: mechanical engineering; compressors.
SUBSTANCE: layer of composite material is applied to surface of impeller disk. Ratio of modulus of elasticity to density of said material is less than material of disk. Layer of glass plastic can be used for this purpose. Layer of composite material featuring smaller ratio is arranged in ring groove found of periphery in disk body. At elastic vibrations of impeller disk internal friction interaction effect appears in place of contact of materials. As a result, vibration energy is dissipated and vibration amplitude is reduced which contributes to resistance of impeller to cyclic loads.
EFFECT: provision of required dynamic strength characteristics at relatively high peripheral speeds of rotation.
FIELD: ventilation system.
SUBSTANCE: invention relates to main unit of centrifugal fans used for ventilation of industrial and living rooms and servicing of different technological processes where liberation of hot gases, smoke and harmful admixtures takes place. Invention is aimed at reduction of area of heat transfer from hub of impeller to shaft of centrifugal fan motor and creation of air flow to cool front end plate of motor and hub. According to invention, impeller of centrifugal fan consists of hub, main and cover flat disks and working blades. Hub is provided with cylindrical boss from side of mounting of main disk and through holes located around axle of rotation of impeller. Axes of through holes are parallel to axle of rotation of impeller, and their number and diameter are chosen so that summary area of said holes is equal to 0.1-3.0% of area of intake hole of centrifugal fan, and axes of said through holes are arranged over circumference of diameter equal to Dh+2.5d±10%. Distance between two adjacent axes of through holes is 1.5d±10%.
EFFECT: increased thermal stability, reliability and reduced cost of operation of centrifugal fans.
FIELD: ventilator engineering, namely, construction of centrifugal smoke exhauster, which may be used in gas cleaning systems in metallurgy and during production of building materials, and also for kitting steam boilers of heat and power stations.
SUBSTANCE: centrifugal smoke exhaust consists of spiral body, input branch pipe, guiding machine and working wheel. Working wheel has 24 radially terminating blades with exit angle equal to 90°, circles drawn along an arc with a radius equal to 34% of external diameter of working wheel, measured along exit edges of blades. Diameter of entrance into working wheel equals 62% of external diameter of working wheel. Width of working wheel at exit equals 13% of external diameter of working wheel. Angle of inclination of surface of covering disk to rotation plane of working wheel equals 15°.
EFFECT: ensured increase of efficiency from 70% to 77% for smoke exhauster with radially terminating blades, which is used for moving substances with dust, prone to sticking to blades of working wheel, which is achieved due to optimal selection of dimensions of working wheel of smoke exhauster.
FIELD: mechanical engineering; turbomachines for aircraft.
SUBSTANCE: invention relates to rotors of turbomachines used, particularly, in aviation, in which drum 124 in form of cylindrical solid of revolution rotation around longitudinal axis is manufactured of metal alloy, and it has curvilinear profile between front and rear ends 124b. Said profile is formed by ring shell arranged around said longitudinal axis, being located in radial direction to both sides from surface of rotation, with generatrix 134. Rear end 124b is provided with stiffening element. Said stiffening element is provided with at least one composite element 140 fitted on rear end 124b of drum and having fibers, and matrix made of polymeric material. Drum is designed for forming rotor of low-pressure compressor.
EFFECT: enlarged operating capabilities.
4 cl, 5 dwg
FIELD: mechanical engineering; fans and ventilators.
SUBSTANCE: invention relates to impeller of centrifugal fan with blades 2 tilted opposite to direction of rotation 8 (backwards tilted impeller) in which outer edge areas 14, 7 of front and rear disks 3, 1 project behind outer diameter DAs of blades. Diffusion space, thus set between rear and front disks 1, 3 and output diameter DAs of blades and outer diameter DN of blades, provides effective conversion of kinetic energy of fluid medium into pressure potential (transformation of kinetic energy into static pressure). Profile of cross section of diffusion space is made rectangular or trapezium widened radially outwards.
EFFECT: increased efficiency of centrifugal fan.
10 cl, 9 dwg