SE518776C2 - Throttle valve for regulating flow of e.g. air, comprises flexible sleeve with fixed end and rotatable end - Google Patents

Abstract

The valve comprises a sleeve (2) made from a flexible material and having a cross-section essentially the same as the flow channel (1). The sleeve has one end which is fixed in relation to the flow channel and one end which can rotate during a controlled displacement in the axial direction. During rotation the sleeve adopts a multi-pointed star cross-section. The valve is enclosed by noise insulating material and the tube around the sleeve is air permeable.

Description

25 so 11.1 »b 35 S18 m áL These mufflers are relatively space-consuming as they must cover a certain length of the duct in which it is installed, and have a larger outer diameter than the duct system in general.

An air handling installation should be made of such material and arranged so that it can operate for the estimated life of the installation. The control damper must therefore be made of material that resists gases and other substances in the air and the environment, it must also be able to withstand some mechanical impact. Adjustment must be possible at any time without the damper jamming or deforming. For hygienic and functional reasons, the damper should be able to be cleaned and designed in such a way that clogging of dirt, dust and grease can not permanently prevent the intended function. Unlike shut-off valves, the damper can allow a certain air flow even in its most closed position, in other embodiments it can also be used as a tightly closing shut-off damper.

The present invention relates to a damper with which the above-mentioned disadvantages of other damper types can be eliminated or significantly reduced. Because dampers according to the invention cause significantly less turbulence than previously known dampers and also include special means for sound attenuation, a reduction of disturbing noise and a saving of space are achieved at the same time. Throttles according to the invention have the features that appear from the patent claims.

The invention will be described in more detail below with reference to the exemplary embodiments shown in the accompanying drawings.

Figure 1 shows in principle the function of a damper according to the invention.

Figure 2 shows details of a practical embodiment.

Figure 3 shows a part of a sleeve in the damper.

Figure 4-6 shows the sleeve in different positions for the damper.

Figure 7 shows the propagation directions of the sound in a completely open damper.

Figure 8 shows the propagation directions of the sound in a partially throttled damper.

The principal function of the damper according to the invention is shown in Figure 1. The air 7 flows through a channel 1 in which a sleeve 2 of elastically slightly 10 is arranged. v u n. 518 776 3. air-permeable and extensible material. The sleeve, which in the initial position has the shape of a. - Q o o u.

In a straight, circular cylinder, it is arranged at one end to rotate in a controlled manner as shown by the arrow 3. In this case, one of the sleeve brackets is displaced inwards in the direction marked by the arrow 6 and a reduction of the diameter of the sleeve inwards towards center according to arrows 4 and 5. This results in a reduced fl fate through the channel by reducing the fl fate inside the sleeve.

Some essential parts of a practical embodiment of the invention are shown in Figure 2. In a circular channel 1, a sleeve of the above-mentioned type is fixed partly on a pipe socket 9 and partly at its other end on a slightly longer pipe socket which constitutes a running pipe 8. For sealing against the channel 1 and its extension in both directions, the pipe socket 9 and the opening pipe 8 have sealing rings 10-13. The pipe socket 9 is fixed in relation to the channel 1, while the pipe 8 is slidably arranged in the channel in its longitudinal direction. When the tube is rotated, in the manner described in more detail below, the sleeve 2 contracts during creasing and the sleeve assumes the appearance shown in Figures 3 and 4-6 in different positions. In other embodiments, the pipe socket 9 can be rotated but not displaced in the longitudinal direction of the channel, but all displacement takes place at the pipe 8.

The sleeve can be made of many different materials, with different textile materials being preferred, examples of materials that may be suitable are polyamide, polyester and other materials with limited elasticity and extensibility. In some applications, rubber or rubber-like materials may be conceivable. A sleeve in the form of a sock of textile material can be made by weaving or. Etching. Preferably, this is arranged with a wire direction parallel to the direction of the channel and a wire direction perpendicular thereto.

When rotating one of the brackets as shown in Figure 1, the sleeve assumes the appearance shown in Figure 3, which shows the sleeve cut off a distance from the opening tube 8 before the center of the sleeve.

During rotation, the sleeve 2 folds so as to form a number of ridges 14 and valleys 15 which in cross-section form a fl blurred star 20. This is also apparent from fi grooves 4A-6A, which show the sleeve in different rotational positions seen in the axial direction, and fi grooves 4B- 6B showing the sleeve seen in the radial direction in the same positions. Figure 6B also schematically shows the thread direction of a sleeve of textile material.

Figures 7 and 8 show in section a damper according to the invention with sleeve 2 in a duct pipe 22 which is surrounded by insulating, sound-absorbing material 23 which is enclosed by an outer casing 24. The damper is connected to an air duct with the pipe sockets 25 and 26. The sleeve is mounted in the duct 22 by means of a first fastening ring 18, which is displaceable in the longitudinal direction of the channel, and a second fastening ring 16 which is rotatable in the channel but not displaceable in the longitudinal direction of the channel. The rotation of the fastening ring 16 is effected with an operating device 21 which can be manual or actuated by, for example, a 518 776 H. servomotor. The operating device is of a per se known design and is not shown in detail in the clocks. The duct pipe 22 is perforated so that its surface is partially open against the insulation 23. Pressure pipes 17 and 19 can be mounted on the damper and inserted through the jacket pipe.

The pressure pipes are connected to the air flowing in the duct through gaps next to the fastening rings of the sleeve. This advantageous mounting with a small distance between the measuring points and installation in the damper unit is possible due to the properties that are achieved with a damper according to the invention. The folds formed in the sleeve material act as guide rails for the air and force it to a rotating movement through the sleeve. The more you choke on the damper, the more marked the guide rails become and thus their effect on the air. The rotation is significant because it forces the air to follow the shell surface of the sleeve, which causes less turbulence, pressure drop and sound stringing. Less turbulence also provides the opportunity for safer pressure and flow measurement, which is important in modern ventilation systems where great demands are placed on low energy consumption. In the lures, the directions of the sound waves are marked with dashed arrows 27. It appears from the lures that there is always a sound deserted in the surrounding insulating material 23.

Because the sleeve 2 and the duct 22 are both designed so that they are air-permeable, a sound-absorbing function is achieved even with a fully open damper according to Figure 7, the unit then functions as an absorption sound-absorber of the traditional type. The more the damper is throttled, the more the fastening 18 is displaced inwards towards the center of the damper and consequently more of the sound-absorbing material is exposed for direct contact with the air without this first having to pass through the sleeve 2. The device thus functions as a combination of damper and muffler thereby significantly shorter construction length than a conventional combination of silencers and dampers arranged next to each other. The sound-insulating material also means that the unit meets the requirements for fire insulation.

Another important property achieved by reduced turbulence is that the damper becomes less dependent on how it is mounted in the duct system and it can therefore be mounted in ao direct connection to, for example, a duct bend without this affecting the pressure and fate measurement, which is of great practical importance when there is almost always a lack of space in a ventilation system. '35 Damper according to the invention can of course be manufactured with different diameters and lengths. An example of suitable dimensions for many applications is a sleeve with a diameter of 160 mm and a length of 180 mm. At a rotation of 120 degrees, which may be a suitable maximum angle of rotation, the reduction in length is about 60 mm, the free area in the center being reduced by 75-80% in relation to the initial position. 10 15 20 25 i 518 776 = ". = _'_ '= f.¿ 5 Due to the controlled creasing, it is achieved that flow around sharp edges is completely avoided, which in turn leads to a significantly reduced turbulence compared to, for example, an iris damper with the same area reduction. The folding means, as mentioned above, that a form of guide rails is formed which controls the air flow and gives a smooth transition between the inlet and outlet of the damper. thereby the generation of disturbing noise is significantly less than with other types of dampers.

The duct and sleeve shall be of air-permeable material which allows the sound waves to pass out to the surrounding sound-insulating material fi this means that the air-permeable material shall allow air molecules to pass through the material;

For this purpose, the duct pipe can, for example, be made of perforated sheet metal.

As mentioned, the sleeve can be made of different materials, however, textile materials are preferred for your reasons. Textile materials usually have a certain limited extensibility or elasticity, which can give a smoother and smoother surface of the sleeve in different vfld fl i fl gs fi ge fl- EL * .vëvte fl ec fl aïai material. This low capacity can affect the flow conditions in a beneficial manner and further reduce the sound generation and eliminate any disturbances in the pressure measurement. The sound attenuation is achieved mainly by the damper being surrounded by an outer casing of sound-insulating material in which passage openings for the control device and the pressure measuring tubes can be found.

Within the framework of the invention tank, other embodiments in addition to those described above are possible. The control device can be designed in many different ways as well as the mounting of the sleeve in the surrounding jacket pipe. The material of the sleeve can be varied and its properties affected by impregnation, material mixing and other similar measures.

Claims (2)

10 15 sis 776 | o Q c of u CLAIMS. A damper for regulating air fl desolation or other flowing medium comprising a sleeve (2) of fl exhibible material whose cross-section substantially corresponds to the channel (1, 22) in which the flow takes place, one end of the sleeve being fixed relative to the channel and the the other end can be rotated during a displacement controlled in axial direction in relation to the rotation so that the sleeve (2) in the fully open position has the shape of a straight circular cylinder and upon rotation assumes a cross section in the form of a ud eroded stem (13) characterized by the duct (1, 22) is surrounded by sound-absorbing material (23) and that the duct (1, 22) and the sleeve (2) through openings obtained by perforation or otherwise have a certain permeability to the flowing air and a small part of the air flow can take place between the outside of the sleeve and the surrounding jacket pipe. Damper according to claim 1, characterized in that the sleeve has a fixed and a movable end, the movable end being displaced inside the surrounding channel (1, 22) when the setting of the damper changes so that the more the damper is throttled, the more surface of the channel (1 , 22) for direct transmission of sound waves to the insulating material (23).