DE1898023U - SPIN FAN. - Google Patents

Description

Billners Handelsaktiebolag, Sk.eppsbroa 5 and 6,

Gothenburg: C (Sehweden)

The invention relates to a centrifugal fan, preferably for oil burners, with a central one Inlet-having impeller for radial Durehströmmtiag and a spiral-shaped housing accommodating the impeller and on whose end wall opposite the inlet of the impeller an air inlet is provided is ο

. " The purpose of the invention is _? To create a centrifugal blower with the maxi, while maintaining the usual drive motor with a speed of 1 * 450 revolutions per minute, a significantly higher working pressure ■ than what was previously possible even then, if the usual. "." drive motor with the mentioned number of revolutions is output against

I is exchanged, which corresponds to the desired pressure increase

t speaks · line such increase; is the sign of aspiration

f, however, undesirable as the for feeding fr «?» «-.

t! oil provided pump for economic reasons

j! directly voi? the drive motor with the gletcjteii

I speed like the impeller driven ιφ & ^ so

Γ that with a higher extension yes £ the service life

| l of the pump would be shortened while at the same time a

^ substantial recirculation of the oil in the fuel oil system

Jt is caused

For solving the problem resulting from the foregoing

the invention proposes that the geometric center of the air inlet of the fan housing within a

^: circle sector related to the circumference of the impeller

t, which is 90 ° in front of the shirt.

f a geometric location extends, 4 ^ r diametrically a »

! a radius related to the center of the impeller

(, _f which is related to the center of the wing

ί rads to the point where the impeller

\ ringst the distance to the inner circumferential surface of the Oßr

house has * drawn Badius in; a counterpart

¹ sets the angular range from k $ to 155 ° to the direction of rotation of the impeller «

With the fan according to the invention, a pressure increase can be achieved while maintaining the normal number of revolutions $ 20 to $ 30 can be achieved compared to the # loading

f ■■■ - ■

knew centrifugal blowers "

An exemplary embodiment of the invention is described below with reference to that which is essentially shown schematically Drawing described. There show: FIG. 1 a side view of the centrifugal blower according to the invention and

FIG. 2 shows a section along the line II-II of FIG. 1.

The centrifugal fan shown has a spiral housing 1 and an impeller 2 rotatably mounted in this, which has a central inlet opening 3 on one side and is provided with a number of blades 4 evenly distributed on its circumference. The housing 1 has two end walls , of which the one wall 5 on the inlet side of the impeller is provided with an air inlet 6, the geometric center of which lies diametrically (ie on the radius R3) to the radius Rl, which - seen opposite to the direction of rotation of the impeller - in the illustrated embodiment in is oriented at an angular distance of 90 ° based on a further radius ', R2, which runs through the point T, at which the impeller has its smallest distance to the inner circumferential surface of the housing. This point T is called the tangency point in the following. The angular distance

■■■ '.. .ν

vary between the two radii Rl and R2 may be at different configuration of the spiral housing as well as changes in location of the impeller in the housing between about 45 and 135 ° · "Further, the angular distance between the extension of the radius R to the wings' wheel center also located further radius R3, which is sucked through the geometric center of the air inlet 6, vary by approximately 90 ° in both directions without deviating from the inventive concept aimed at increasing the working pressure in the centrifugal fan.

In the exemplary embodiment shown, the air inlet 6 is delimited partly by an arcuate edge 6a of the housing 1, which is concentric to the inlet opening 3 of the impeller, and partly by an inner edge 6b of a screen 7 protruding into the inlet opening of the impeller Part of the lateral surface of a cone, the tip of which points into the impeller and its point which dips deepest into the impeller is oriented towards the radius Rl, where the screen is about half the depth of the impeller Spread of 240 °, which, however, can be varied within a range of 90 to 360 ° with appropriate adjustment of the axial spread and conicity of the screen, without the pressure-increasing effect of the screen

to prevent completely- The center of the impeller 2 am

* The next edge of the screen has with the above configuration

* guidance expediently a distance to the impeller track of 1

⁽ one fifth of the diameter of the inlet opening 3 of the

"Impeller · This dimension can also be changed, ί! Due to the eccentric design of the air inlet

a backflow of air through the air inlet in one

Prevents the zone in front of and around the tangency point T,

in its vicinity, otherwise, by the impeller again

'- emerging air would be blown out through the air inlet.

ΐ ■ ■ '

By preventing such a backflow of air through

the air inlet and by reintroducing this air fr
¹¹ flow into the impeller becomes a significant printer

1' -

^ft elevation, which is normally compared to the on

j standard centrifugal blowers on the market , blow between 20 and 30 $ and for blowers according to the

Ii- execution described in an earlier right between

$ 50 and $ 70. In the latter type of fan the return flow of the air is significantly stronger than with standardized blowers,

The invention is of course not limited to the above _'f * described and in the drawings illustrated examples game f, but may in its details and J "dimensions may be varied without the scope of the inventions

dung to leave.

-5-

Claims (4)

1. Centrifugal fan, preferably for oil burners, with an impeller having a central inlet for radial flow and a spiral housing which accommodates the impeller and on whose end wall opposite the inlet of the impeller an air inlet is provided, characterized in that the geometric center of the The latter air inlet (6) lies within a circle sector lying on the circumference of the impeller {2}, which extends in both directions by 90 ° from a geometrical location which is diametrically {on the radius R3) su a radius related to the center of the impeller (Rl), the radius fR2) drawn from the center of the impeller to the point (T) at which the impeller has the smallest distance to the inner peripheral surface of the housing (1) lies in an opposite direction of rotation of the impeller extending angular range from 45 to 135 ° is _β 2 _β centrifugal fan according to claim I ₅ dadureh characterized ₅ that the air inlet of the housing (1) of a preferably circular arc and with the inlet opening (3) of the impeller [Z) lconzentrischei * housing edge (6b) as well as by the inner edge (6a) of a shield (7) protruding into the inlet opening of the impeller, whose point protruding farthest into the impeller is within a Radius (R2) in both directions by 90 ° extending circular sector 3 centrifugal fan according to claim 2, characterized shows that the Abschirnpng (7) extends over an area extends from 90 to 360 degrees within the inlet port. 4. Centrifugal blower according to claim 2, characterized marked ^k is characterized in that the amount by which the Abschirmungin immersing the impeller, a fifth to a whole of the axial width of the impeller. 5 «centrifugal fan according to one or both of the claims 1 and 2, characterized in that the edge (6b) of the near the center of the impeller eccentric air inlet a distance between 0.1 and 0.4 of the diameter of the inlet opening of the Having the impeller from the center of the impeller, 6, centrifugal fan according to claim 2, characterized in that the shield (7) is the toilet of a dumbbell surface of a cone, the shielding tapers towards the impeller "7-