JPH0357899A - Gaseous medium transmitting apparatus - Google Patents

Abstract

PURPOSE: To provide a gas medium transmission device on a device having high fluid resistance with a rapid pressure/volume characteristic by curving a blade of an impeller the inside of which is sealed in a spiral case backward and providing a radially flowing fan a diameter of which is specific times as large as outlet width. CONSTITUTION: A case 1 of a radially flowing fan is closed by a cover 2, a sealing part 3 is inserted between them and they are screwed with each other on end parts. Thereafter, the case 1 has a spiral inside outline 12, and an impeller 6 having a blade 8 in the outline 12 is arranged so that the roughly same shortest distance between the outline 12 and the impeller 6 is performed between points A and B. Additionally, the blade 8 is curved backward seen from the rotating direction of the impeller 6 shown by an arrow 13, a diameter of the impeller 6 is 10 times larger than outlet width, and an inlet angle β1 and an outlet angle β2 of the blade 8 are the same value. Furthermore, on one hand, a transmission medium has comparatively high back pressure of about 400-450 pascal, and on the other hand, a large change of pressure is made only by a small change of capacity speed of fluid, that is, about 7-10 I/s at the time of gas medium density 1.2 kg/m<2> .

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas medium transmission device in a device with high fluid resistance.

BACKGROUND OF THE INVENTION Devices with high fluid resistance include, for example, ceramic zone burners, which are currently used in gas boilers. Gas boilers equipped with such ceramic zone burners are known (Journal "HLH, t{eizun
g, Lul'tung/KIima. Haustech
nlk；Zeltschr1 『t des Ver.
e! ns deutscher lngenleu
Lechnische Gebaudea
3os page, June 1989)
. It has a relatively high fluid resistance, on the order of 200 Pascals or more. The medium to be transmitted can be either air or a mixture of flammable gases.

[Problem to be Solved by the Invention] The technical problem to be solved by the invention is therefore that, on the one hand, the medium to be conveyed has a relatively high backpressure, and on the other hand, the pressure can be changed only by small changes in the volumetric velocity of the fluid. It is an object of the present invention to provide a gas medium transfer device in a device with high fluid resistance with abrupt pressure/volume characteristics producing large changes. The high backpressure should be approximately 400-450 Pascals and the exit velocity should be such that the gas medium density ρ is 1
．． 2Kg/1 should be about 7 to 10 p/s. In order that the structure in which the device is used does not take up too much space, the base occupied by the device must not exceed certain dimensions, for example 180 IIli x 180 mm.

Furthermore, the self-noise of the device must not exceed that of prior art gas medium transmission devices.

[Means for determining the target angle] According to the invention, the problem of this technique is that the case has a helical inner contour and is equipped with a closed impeller, the blades of which are curved backwards and have a diameter is solved by a radial flow fan that is much larger than the width of its outlet.

In the radiant fan according to the invention, the configuration is 17
0 mi2 (height x width), the transmitted gas medium has a pressure of 415 Pascals and an exit volume velocity of 6.9 R/s at the given operating point. The speed of the impeller was approximately 3800 revolutions/min.

[Example] As shown in Fig. 1, the case i of the convection fan is
is closed by. In the example shown, the case 1 and the cover 2 are die-cast aluminum.

They are screwed together at the ends with a seal 3 between them.

A drive motor 4 is flanged to the rear of the case 1 and its output shaft 5 extends into the case l. The drive motor is an electronically commutated direct current motor. It is also possible to use an alternating current motor. The impeller 6 is non-reliably and/or reliably fixed to the end of the output shaft 5 which projects into the case 1 . The width of the outlet of the impeller 6 is designed to be C. The impeller 6 consists of a rear part 7 with integrally shaped blades 8 and a cover 9. In the example shown, the length of the blade 8 at the rear end or portion 7 is greater than the length near the front end or shroud 9.

The impeller 6 can be made of metal or plastic.

The gaseous medium in the radial fan shown is absorbed in the axial direction, ie through the opening 10 of the cover 2, and is blown out radially (into the plane of the paper of FIG. 1). The outlet opening is
It is a square outlet of the circular flange l1.

FIG. 2 shows an effective type of radiant fan according to the invention. Case I has a helical inner contour l2. Within this internal contour, the impeller 6 with blades 8 is arranged such that an approximately equal minimum distance between the internal contour 12 and the impeller 6 is achieved between points A and B. In the example shown, this distance is the radius of the impeller (−
65 mm) and lengths a and b are 156 ms
It is. The blades 8 are bent rearward as seen from the direction of rotation of the impeller B, represented by the arrow 13.

The curvature of each blade 8 corresponds essentially to the arc of a circle.

The blade is arranged on the rear part 7 such that the artificial angle β1 has approximately the same value as the exit angle β2. In the example shown, the angle is 47 degrees.

In this type of radial flow, the distance between the impeller 6 near the outlet opening 14 and the inner contour 12 of the case l is called the "tongue area" and is denoted l5. In contrast, the tongue region in embodiments of the invention is wedge-shaped.

FIG. 3 shows the impeller 6 seen from the suction side. Through the opening 10 in the cover 2, the blade 8 of the rear part 7 can be seen.

FIG. 4 again shows that the curvature of the blade 8 is an arc of a circle. The centers of all these circles are located on circle 16. In the case of the impeller 6 having an outer diameter of 130 mm, the diameter of the circle l6 is 9glIn+.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of a radiant fan according to the invention. FIG. 2 is a side view showing the basic design of the radiant flow fan of FIG. FIG. 3 is a front view of the impeller. FIG. 4 is a basic design drawing of the impeller shown in FIG. 3. I...Case, 2...Cover, 3...Sealing part, 4.
... Drive motor, 5... Output shaft, 6... Impeller, 7... Rear part, 8... Blade, 9... Cover, lO... Opening, 11... Flange, 12...
Internal contour, l4...Blowout opening, l5...Tongue area.

Claims (9)

[Claims] (1) comprising a radiant flow fan whose case has a helical internal contour, has backwardly curved blades, and is equipped with a closed impeller whose diameter is much larger than the width of its outlet; A gas medium transmission device in a device with high fluid resistance characterized by: 2. The device of claim 1, wherein the diameter of the impeller is greater than ten times the width of its outlet. 3. The device of claim 1 or 2, wherein the curvature of each blade of the impeller essentially corresponds to an arc of a circle. 4. The device of claim 1, wherein the blades are arranged within the impeller such that the inlet and outlet angles are approximately equal. 5. A device according to claim 1, wherein the inlet angle and the outlet angle have values between 45 and 50 degrees. (6) Any one of claims 1 to 5, wherein the distance between the impeller and the internal contour of the case, that is, the tongue region is wedge-shaped.
Apparatus described in section. 7. The device according to claim 1, wherein the point of the shortest distance between the impeller and the internal contour of the case is displaced from the tongue region in the direction of rotation of the impeller. (8) Claims 1 to 7 in which the shortest distance between the circumference of the impeller and the internal contour of the case is equal to 4 to 8% of the radius of the impeller.
The device according to any one of the above. (9) The device according to any one of claims 1 to 8, wherein the impeller is driven by a direct current motor.