DE1210635B - Flow diffuser with a boundary wall consisting of an auxiliary flow medium curtain - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

F061

German KL: 47 F-1/01

Number: 1210 635

File number: S 79952 XII / 47 f

Filing date: June 16, 1962

Opening day: February 10, 1966

The invention relates to a flow diffuser whose diverging boundary wall consists of a there is auxiliary fluid introduced under pressure through an annular nozzle and the one upstream the annular nozzle arranged converging solid wall part. Such diffusers are for example in German patent specification 1,028,889 and in British patent specification 847,500.

Diffusers of the type indicated are supported by the use of a fluid curtain Instead of a fixed diffuser wall, a considerable increase in efficiency is achieved. It is known, that the remaining losses depend significantly on the speed difference between depend on the auxiliary fluid introduced and the fluid passed through the diffuser. Trying to reduce losses by removing the fluid curtain Introducing auxiliary constituent fluids at a slower rate may not be successful lead because for the correct formation of the fluid curtain the auxiliary fluid must be introduced with a certain pressure and with a certain amount or veil strength.

The invention has set itself the task of reducing the losses in a diffuser despite these difficulties of the type specified at the beginning.

According to the invention, the object is achieved in that the outer wall of the to form of the fluid curtain serving annular nozzle into an arched, downstream over the Terminating edge of the inner ring nozzle wall also expires collar, which is initially narrows radially inward and then merges into an outwardly diverging end part, of which Length is not greater than about 15% of the smallest inner diameter of the collar.

In view of the fact that diffusers which work with fluid curtains generally have a better efficiency than diffusers with solid walls, it is surprising that a further increase in efficiency is achieved in the diffuser according to the invention by introducing a solid diverging wall part. This can be explained by the fact that the jet of the auxiliary fluid reduces its speed after exiting the ring nozzle, but is guided further by the collar-like end of the outer nozzle wall and is deflected in the desired diverging direction. In this area, the speed difference between the flow diffuser is one of a kind
Auxiliary fluid curtain existing
Boundary wall

Applicant:

Societe Bertin & Cie., Paris

Representative:

Dr.-Ing. H. Negendank, patent attorney,

Hamburg 36, Neuer Wall 41

Named as inventor:

Marcel Pierre Le Nabour, Montreuil-sous-Bois

(France)

Claimed priority:

France of July 28, 1961 (869 390)

see the fluid curtain and the main fluid flowing through the nozzle everywhere

«5 Mine than with a nozzle in which the guide of the auxiliary fluid takes place in an annular channel delimited by two solid walls. To achieve This effect, it is useful that the end edge of the inner ring nozzle wall approximately in a level with the narrowest point of the collar or upstream of this point.

Two embodiments of the invention are shown in the drawings.

The F i g. 1 and 2 each show an axial section through a diffuser according to the invention.

The diffusers shown contain an annular nozzle 3 and one arranged upstream thereof fixed converging wall part 1. The outer wall of the fluid curtain 6 serving ring nozzle 3 runs in a curved, downstream over the end edge 10 of the inner Ring nozzle wall 7 also extending collar 8. This collar initially narrows radially inward and then merges into an outwardly diverging end portion 8 α, the Length is no greater than about 15% of the smallest inner diameter of the collar 8. The inner end the ring nozzle can be at the level of the narrowest point of the collar8 (FIG. 1) or upstream of this point (Fig. 2) lie.

The divergence of the fluid curtain emerging from the ring nozzle is caused by adhesion

609 507/174

causes the diverging end part 8 a. The efficiency of the diffuser is reduced by both Friction in the ring nozzle as well as the better mixing between the inducing flow and the induced flux increased. The increase in efficiency can be 10 to 20%. Further the construction of the diffuser described here significantly simplifies its practical implementation. The diffuser can be made of two concentric parts, which, as in the two to Figures shown are assembled in a connecting plane 9.

The diffuser according to the invention can, for. B. as simple or used as an ejector jet pump or as a lifting or buoyancy device for missiles will.

Claims (3)

Patent claims: 1. Flow diffuser, the diverging boundary wall of which consists of a ring ao There is auxiliary fluid introduced under pressure and the one upstream of the Having an annular nozzle arranged converging solid wall part, characterized in that that the outer wall of the ring nozzle used to form the fluid veil (6) (3) in a curved, downstream over the end edge (10) of the inner ring nozzle wall (7) also extending collar (8) expires, which: initially narrows radially inward and then merges into an outwardly diverging end part (8 a), of which Length is not greater than about 15% of the smallest inner diameter of the collar. 2. Flow diffuser according to claim 1, characterized in that the end edge (10) of the inner annular nozzle wall (7) ^u approximately in a plane with the narrowest point of the collar - ■ (8) is (Fig. 1). 3. flow diffuser according to claim 1, characterized in that the terminating edge (10). the inner ring nozzle wall (7) is upstream of the narrowest point of the .. collar. (8) (Fig. 2). Considered publications:
German Patent Nos. 973164, 1028 889, '607; . .. German Auslegeschrift No. 1057461;
British Patent No. 847 500. 1 sheet of drawings 609 507/174 2.66 © Bundesdruckerei Berlin