CN1172218A - Puddle with wheel rim - Google Patents

Abstract

The present invention relates to a propeller fan with wheel rim. It is characterized by that it consists of a number of blades, in which the end of each blade is equipped with a fixed circular wheel rim, attached to a central shaft. Its rotation drag is small, acting force is concentrated, directional property is good, and its blade end loss can be completely prevented so as to expand the main working zone of the blade from 0.7 blade length position to blade end and raise the conversion efficiency of true power of shaft converting to through-flow power of fluid by above 40%, and under the condition of supersonic speed, the rotating force of the shaft can be efficiently converted into thrust force, and its structure strength also can be raised.

Description

The slurry fan that the wheel limit is arranged

The present invention relates to a kind of slurry fan that is mainly used in initiatively convection cell work done.

Existing slurry fan generally is made up of rotating shaft and paddle fixed thereon.Its groundwork district is movement velocity the fastest zone from 0.7 leaf strong point to end of blade 0.7 leaf strong point, presses area, and this zone accounts for about half of whole slurry fan rotation area, and by the active force that produces, this zone accounts for more than 75%.Common propeller is in this zone, because tip loss, the pressure reduction of paddle pressure surface and suction surface descends on the contrary, almost drops to 0 at the end of blade place.End of blade is the fastest position of paddle movement velocity, but the contribution of common slurry fan loss maximum effective power is zero position, tip loss is serious, it is lower to the efficient of kinetic energy that the rotating energy of therefore existing slurry fan is converted into flow axis, and also have paddle thick, the raw material consumption is big, between the positive negative pressure of the end of blade blade face and and environment between all do not have the shortcoming that firm interface is subject to ambient conditions influence.

The purpose of this invention is to provide a kind of slurry fan that the wheel limit is arranged, it can remedy the above-mentioned deficiency of existing slurry fan.

Slurry fan of the present invention has a running shaft, and paddle is housed above, it is characterized in that fixing a circular wheel limit by the end of blade of each paddle.

Slurry fan rotational resistance of the present invention is little, force localization, good directionality, eliminated tip loss fully, make the groundwork district of paddle expand to end of blade from 0.7 leaf strong point, true merit in the rotating shaft is converted to the efficient of through-flow merit has improved more than 40% in the fluid, the rotating force with axle under the supersonic speed condition is converted to thrust efficiently, its efficient is high more about 60% than whirlpool spray turbofan engine, has also improved structural strength simultaneously.

Below by embodiment and description of drawings the present invention.

Accompanying drawing is a slurry fan structure schematic representation of the present invention.

Embodiment's 1 slurry fan of the present invention has running shaft (2), and paddle (3) is housed above, and corner is 45 °, is placed on stamping forming thin cylinder with corresponding internal diameter and promptly takes turns in the limit (1), and the latter is welded on the end of blade of each paddle (3).The width on wheel limit (1) is 0.1 meter, and internal diameter is 0.8 meter, and its plate face is parallel with running shaft (2), around the latter's one circle.Wheel limit (1) is a solid of rotation that the surface is very smooth, and it is concentric with the axle (2) that drives its rotation.Work hour wheel limit (1) only produces surface friction drag on sense of rotation, the power of latter's loss only accounts for the some thousandths of of slurry fan output power to a few percent.And with the raising of rotating speed, this part loss also can reduce relatively.Test verifiedly, the resistance of this product is less than the resistance of the common slurry fan of same size.

Product of the present invention is being axisymmetric in shape, so the power that acts radially on the wheel limit (1) is cancelled out each other, making a concerted effort is zero (except the gravity).Because paddle (3), wheel limit (1) and hub (2) have been linked to be a plurality of triangles and I-shaped, thereby structural strength, stability and bearing capacity that this slurry is fanned have been strengthened widely.With common propeller relatively, can attenuate paddle thickness, so both alleviated weight, reduce the wastage again.

Calculating by known following formula theoretically below, present embodiment is the static thrust F of medium with the atmosphere:

F=PAV _FlatV _Flat

P is 0.125 kilogram of second of air density in the formula ²/ rice ⁴, A is 0.5 meter of the area of wheel shape slurry fan ²(diameter of slurry fan is 0.8 meter), V _FlatBe the air mean velocity.Establish tip speed V at present embodiment _PointBe 550 meter per seconds, this is the speed of the gas compressor blade tip that reaches of American I RPTET plan.Do not consider the influence of gas compressibility in the calculating.Tip speed maximum in the present embodiment, center are zero, and wherein speed should be got its mean value during therefore with above-mentioned formula calculating F, can prove V in the case _Flat ²=0.5V _Point ²So draw

F=0.5PAV _Point ²=9453 (kgfs)

Use known flat-plate drag formula { with reference to being permitted to tie up moral work " fluid mechanics " (National Defense Industry Press publishes in December, 79) P253 P259 surface friction drag formula } to calculate the resistance Z that this device wheel limit produces again, account for the percentage of output power so that estimate wheel limit loss:

Z＝0.5CPVVM

C is a resistance coefficient in the formula, and P is an air density, and V is V _Point, M is wheel limit area, the wheel limit launches to be a rectangular slab, its long L=2 π R=2.5 rice, long-pending sum M=0.5 square metre of its inner and outer surface.Resistance coefficient in the following formula can be obtained by following formula $C=\frac{0.455}{\left(\mathrm{lgR}\right)2.58}=0.0021$

Wherein R is that reynolds' number can be obtained by following formula: $R=\frac{L\×V}{1.45\×0.00001}=\frac{2.5\×550}{1.45\×0.00001}=94827586$

So Z=0.5CPV _Point ²M=0.5 * 0.0021 * 0.125 * 550 ²* 0.5=19.85 (kgf)

As not considering the moment factor, then take turns the ratio of limit resistance and gross thrust:

Be not difficult to reach a conclusion from above rough estimation, though the wheel limit resistance ratios with upper estimate greatly to 10 times, its resistance is 2.1% of gross thrust only.

Embodiment 2 is in tank, and fanning with the seawater with the slurry of diameter 150MM is that medium is done experiment, and make with the thick metal stamping of 0.5MM on the wheel limit of slurry fan, no weld seam, the paddle end of blade is fixed with soldering with the wheel limit, wheel hem width 20MM, 1400 rev/mins of wheel shape slurry fan rotating speeds can draw V in view of the above _Point=10.8 meters, so can calculate with following formula

F=0.5PAV _Point ²=107 (kgfs)

Wherein P is 104 kilograms of seconds of density of sea water ²/ rice ⁴, A is the area of slurry fan, in the present embodiment The resistance Z that the wheel limit of copying embodiment 1 to calculate this slurry fan below produces:

Z=0.5CPV _Point ²The M=0.388 kgf,

Take turns 0.15 meter=0.47 meter of the length L=π on limit in the present embodiment, wheel limit area M=2 * 0.47 meter * 0.020 meter=0.0188 meter ²

At last, copy embodiment 1 to estimate the ratio of wheel limit resistance and gross thrust

In other words, be under the situation of seawater at medium, the thrust on wheel limit only accounts for 3.6 ‰ of gross thrust.

When slurry fan of the present invention is used as fan, on wheel limit (1), be provided with fan vent (4).

Claims (3)

1. the slurry fan that the wheel limit is arranged has a running shaft (2), and paddle (3) is housed above, it is characterized in that fixing a circular wheel limit (1) by the end of blade of each paddle (3).

2. as claim 1 described slurry fan, it is characterized in that the described limit (1) of taking turns is a ganoid circular turned body, it is concentric with running shaft (2).

3. as claim 1 described slurry fan, it is characterized in that described the wheel has vent (4) on the limit (1).