JPH07151108A - Piffuser - Google Patents

Abstract

PURPOSE: To assure a uniform spread of flow into a spread flow portion by avoiding separation of flow from a diffuser wall at slight expenses and slight pressure losses. CONSTITUTION: In this diffuser having a built-in element built into a conduit through which a fluid is passed and causing turbulence, at least one built-in surface 4 causing front-edge turbulence is provided as the built-in element in the range of the spread flow part 2 of the diffuser.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diff user, preferably for power plants, especially with heat exchangers, silencers, admixtures, etc., which have built-in elements which are incorporated into fluid-carrying conduits and produce turbulence.

[0002]

Diffusers which are incorporated in a conduit through which a fluid is passed are known, for example, from U.S. Pat. No. 4,971,768. Such a diff user has the purpose of reducing the flow rate of gas or liquid while recovering the pressure. Diff users are used before heat exchangers, silencers, reactors, admixers, burners, rectifiers, humidifiers and conduit branches, especially in power plants, ventilation technology and equipment operation. Since the recovery of the pressure due to the decrease in the flow velocity greatly depends on the pressure loss generated in the diff user, the structural configuration of the diff user is particularly important.

In the Diff user known from US Pat. No. 4,971,768, a turbulent built-in element is used to bring the flow into contact with a Diff user wall which extends in the flow direction. However, this becomes difficult as the opening angle of the Diff user increases.

In the Diff user known from US Pat. No. 4,971,768, the built-in element consists of a corrugated guide surface which is provided in front of the Diff user inlet, by means of which a turbulent swirling flow is generated. In practice, however, such guide surfaces do not produce relatively large pressures, but also have a slight turbulence effect, so that the advantages and advantages described here do not occur in practice.

[0005]

The problem underlying the present invention is to improve on the first type of diff user, avoiding flow separation from the diff user wall, low cost and low pressure. The loss is to ensure a uniform spread of the flow to the spreading flow cross section.

[0006]

In order to solve this problem, according to the invention, at least one built-in surface, which produces a leading-edge turbulence as built-in element, is provided in the area of the flow area where the Diff user spreads.

[0007]

Due to the steady vortex wake occurring at the leading edge of the known turbulent flow integration surface that forms an acute angle with the main flow direction, that is, the vortex wake whose position changes little or little, the loss is small. A turbulent flow is generated, and the turbulent flow causes the flow entering the differential user to be uniformly distributed in the flow cross section. The uniform flow distribution created by the leading edge turbulence provides a pressure recovery that at least compensates for the flow losses created by the built-in surface, resulting in a significant overall improvement in efficiency.

[0008]

DETAILED DESCRIPTION Depending on the dimensions of the diff user and the embedding element, according to the invention a plurality of embedding elements can be provided side by side or in front of each other in the spreading part of the diff user.

According to another feature of the invention, each embedding surface waits for an edge curve symmetrical with respect to a plane of symmetry extending in the main flow direction and has a basic shape of circle, ellipse, parabola, rhombus or triangle. Can be formed as.

Finally, it is proposed according to the invention that the cross-section of the mounting surface is V-shaped in the form of a groove or is provided with bendable edges, which enhances turbulence and increases the stability of the mounting surface. It

As a whole, the invention makes it possible to ensure that even a diff user with a strongly spreading flow section will have a good contact of the flow to the wall of the diff user by means of a built-in element which requires only a small outlay. Since the leading edge turbulence caused by the built-in elements causes only small flow losses, there is a significant improvement in Diffuser action as well as an increase in efficiency.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The drawing shows five embodiments of a Diff user according to the invention and four embodiments of the mounting surface used therein.

The diff-users shown in FIGS. 1 to 5 each include an inflow passage 1, which is followed by a widening flow section 2 which extends into the outflow passage 3. In the embodiment according to FIGS. 1, 2, 3 and 4, the central axis of the outflow passage 3 is on the extension of the central axis of the inflow passage 1, so that a symmetrically spreading flow section 2 occurs, but in the embodiment according to FIG. Since the central axis of the inflow passage 1 and the central axis of the outflow passage 3 are deviated from each other, a flow portion 2 that asymmetrically spreads occurs.

In the first embodiment according to FIG. 1, the spreading flow section 2 is provided with an oblong or circular mounting surface 4 at an acute angle to the main flow direction, so that its symmetrical leading edge is Each has one vortex wake. The vortices shown in the figure form so-called leading edge turbulence and spread at right angles to the main flow direction, resulting in a lossless spread of the flow. Touch the wall. In this way, the flow is uniformly distributed in the flow cross section with a small loss, and since the built-in surface 4 is incorporated, pressure recovery that at least compensates for the flow loss is performed despite the unavoidable flow loss.

In the second embodiment according to FIG. 2, two spreading surfaces 4 are provided symmetrically with respect to the central axis of the Diff user in the diverging flow section 2, each producing a steady leading edge turbulence.

In the third embodiment according to FIG. 3, the inflow passage 1
An extension surface 4 is provided in the extension of the flow of the flow path and another extension surface 4 is provided in the area of the widening wall of the widening flow section 2. In this case, the position and size of both mounting surfaces 4 are adapted to the asymmetry of the spreading flow section 2 of the Diff user,
Even with this special configuration of the Diff user, the flow is in good contact with the Diff user wall with a wide cross section.

In a fourth embodiment according to FIG. 4, two mounting surfaces 4 are provided side by side in the spreading flow section 2, respectively, and two subsequent mounting surfaces 4 are also provided side by side, and the flow The embedding surface 4 in the front in the direction has a circular or elliptical basic shape, and the embedding surface 4 in the rear has a triangular basic shape. Also in this embodiment, each embedding surface 4 produces a steady leading edge turbulence with the properties and advantages described above.

In the embodiment according to FIGS. 5 and 6, in the inlet region of the spreading flow section 2 an oval or circular basic shape 4 is provided.
One built-in surface 4 is provided and this inlet area of the spreading flow section 2 is divided by a partition wall 5 into four passage sections. These partitions 5 prevent the mutual influence of the leading edge turbulence in the inlet region of the flow section 2 which is spread by the respective mounting surface 4.

FIGS. 7 to 10 show four embodiments of the construction of the mounting surface 4. The mounting surface 4 shown in FIG. 7 has a basic triangular shape, and the mounting surface 4 according to FIG. 8 is formed in a rhombus. 9 and 10 show an elliptical and circular mounting surface 4, respectively.

[Brief description of drawings]

1 is a sectional view along the central axis of a first embodiment of a Diff user having one mounting surface.

FIG. 2 is a sectional view along the central axis of a second embodiment of a Diff user having two mounting surfaces.

FIG. 3 is a sectional view along the central axis of a third embodiment of an asymmetric Diff user.

FIG. 4 is a sectional view along the central axis of a fourth embodiment of a Diff user having four mounting surfaces.

FIG. 5 is a sectional view along the central axis of a fifth embodiment of a Diff user having four built-in surfaces provided in the isolated passage portion.

6 is a cross-sectional view of the differential user taken along line VI-VI of FIG.

FIG. 7 is a front view of a first embodiment of a mounting surface having a triangular basic shape.

FIG. 8 is a front view of a second embodiment of a diamond-shaped mounting surface.

FIG. 9 is a front view of a third embodiment of a mounting surface having an oval basic shape.

FIG. 10 is a front view of a circular mounting surface as a fourth embodiment.

[Explanation of symbols]

 2 Expanding flow part 4 Assembly surface

Claims (5)

[Claims] 1. In a diff user incorporated in a conduit through which a fluid is passed and having a turbulent built-in element, at least one built-in surface (4) producing a leading edge turbulent flow as a built-in element is a spreading part of the diff user. Diff user characterized in that it is provided in the range of (2). 2. Diff user according to claim 1, characterized in that a plurality of built-in elements (4) are provided in the flow section (2) in which the Diff user spreads side-by-side or side by side. 3. Diffuser according to claim 1 or 2, characterized in that each mounting surface (4) has an edge curve which is symmetrical with respect to a plane of symmetry extending in the main flow direction. 4. The method according to claim 1, wherein each mounting surface (4) is formed to have a basic shape of a circle, an ellipse, an oval, a parabola, a rhombus or a triangle. Diff user described in one. 5. Diffuser according to claim 1, characterized in that the mounting surface (4) has a V-shaped groove in cross section or has a bent edge. .