WO2006088352A1

WO2006088352A1 - Ventilating apparatus with pressure-dependently regulating valve

Info

Publication number: WO2006088352A1
Application number: PCT/NL2005/000142
Authority: WO
Inventors: Andreas Wilhelmus Jozef Meester; Adrianus Jacobus Zwaan
Original assignee: Alusta Natuurlijke Ventilatietechniek B.V.
Priority date: 2005-02-18
Filing date: 2005-02-18
Publication date: 2006-08-24
Also published as: EP1848929A1; NL1031172C2; BE1016994A3

Abstract

A ventilating apparatus provided with a substantially block-shaped housing (1) with a ventilating channel (2) extending in it, while at least one valve body is present for pressure-dependently regulating the free passage of the ventilating channel, for which purpose the valve body is designed as a body arranged to be substantially freely rotatable about a pivot (9) and provided with at least two closing legs (12, 13) and an initiating leg (14), while one of the closing legs in the initial position extends in and opposite to the flow direction of the ventilating air through the ventilating channel, with respect to which leg a further closing leg and an initiating leg are arranged so as to diverge in a V-shape. The pivot for the valve body, viewed in the flow direction of the air in the ventilating channel, is preferably placed in the outflow mouth area or just behind it.

Description

Title: Ventilating apparatus with pressure -dependently regulating valve

This invention relates to a ventilating apparatus provided with a substantially block-shaped housing with a first wall break and a second wall break, between which extends a ventilating channel, while at least one valve body is present for pressure-dependently regulating the free passage of the ventilating channel, for which purpose the valve body is designed as a body arranged to be substantially freely rotatable about a pivot and provided with legs which are so arranged with respect to the pivot that, at least in an initial position, a leg extends in the flow direction of the ventilating air through the ventilating channel. In such a ventilating apparatus, for instance known from

NL-A-9102132, the valve body is designed as a substantially L-shaped body, of which, in the initial position, one leg extends from the pivot in the air flow direction and the other leg extends more or less perpendicular thereto. An increase of the pressure in the external environment of a space to be ventilated will result in an increase of the speed of the air flowing through the ventilating channel and result in the transverse leg initiating a pivotal movement of the valve body as a result of which, partly due to a pivotal movement of the longitudinal leg, the free passage of the ventilating channel is reduced, to thereby keep the total amount of ventilating air allowed to pass constant as much as possible. In the initial position, one of the legs extends more or less transversely in the ventilating channel, which means that the true passage, also in that position of the valve body, is considerably smaller than the possible passage of that ventilating channel, that is, this always involves a considerable loss of ventilation capacity. Further, in the case of low pressure differences, the self -regulating power of such a valve body is to be qualified as unsatisfactory.

The object of the invention is for a ventilating apparatus of the type described in the opening paragraph hereof to be designed so as to have a quickly responsive self -regulating power for the purpose of keeping the ventilation capacity equal as much as possible, and also at low pressures, while a further aim is to keep the loss of ventilation capacity as small as possible. This is achieved, according to the invention, if the valve body is provided with at least two closing legs and an initiating leg, while one of the closing legs in the initial position extends in and opposite to the flow direction of the ventilating air through the ventilating channel, with respect to which leg a further closing leg and an initiating leg are arranged so as to diverge in a V-shape. Through these measures, the air flow in the ventilating channel is split into two by the closing leg extending in and opposite to the flow direction of the ventilating air. Thereupon, the other closing leg and the initiating leg provide for the deflection of a respective partial flow in a manner raising only minor resistances and thus leading to just minor losses of ventilation capacity. If the pressure difference between the outside and inside augments, the initiating leg will cause the valve body to rotate, with the result that also the closing leg pointing into the ventilating channel against the flow, pivots, so that the passing air will act on that closing leg, more specifically with a component acting in the closing direction. Experiments have shown that in this way a valve body is obtained which, also at low pressure differences, is quickly responsive and optimally self-regulating, while the loss of ventilation capacity remains relatively low.

To further optimize the effect of the reduction of loss of ventilation capacity, it is preferred, according to a further embodiment of the invention, that the pivot for the valve body, viewed in the flow direction of the air in the ventilating channel, is placed in the outflow mouth area or just behind it. Conventionally, in that area, the ventilating channel is of widening design. By presently having the first closing leg extend as a partition plate into the ventilating channel and placing the further legs, diverging relative to each other in a V-shape, in the widening area, at least in the initial position a free passage of the ventilating channel can be realized that is equal to the possible passage without valve body. The free passage is not reduced until such is required from a viewpoint of control, so that, in addition to an optimization of the shape of the flow paths, also a maximization of the passage is obtained, resulting in a minimization of the loss of ventilation capacity compared with the situation without self- regulating valve body.

If there is no or a very small pressure difference, for instance 1 Pascal, the valve body hangs from its pivot in balance, with the first closing leg in a generally horizontal position resulting from a correspondingly chosen weight distribution of the valve body. By its self -regulating operation, upon increase of the pressure difference the valve body is forced from its initial position by the air flow. When the pressure subsequently decreases again, the valve body is to move back in the direction of its initial position again by action of gravity. This return effect can be promoted in a simple but effective manner if, according to a further embodiment of the invention, the valve body comprises a hollow tube which carries the legs and is arranged to be eccentrically rotatable relative to the centerline of the pivot. In the balanced initial position, the eccentric rotation point of the hollow tube is in the upper area thereof. As a result, the greater part of the hollow tube will hang under and laterally of the pivot, which affords excellent possibilities of setting the return pressure force. Further, according as the valve body pivots further out of the initial position, the hollow tube will be situated more and more laterally of the pivot, so that the resetting couple resulting from action of gravity is augmented.

The eccentric arrangement of the hollow tube can be realized in a simple but effective manner if the hollow tube is provided with end caps in which eccentrically with respect to the centerline of the hollow tube, bores are provided for accommodating a journal. This embodiment has the additional advantage that the hinge areas, which are fairly short with respect to the length of the valve body, raise minor friction, which promotes quick response of the regulation at low pressure differences.

According as the pressure difference between the outside and inside increases, the valve body will be rotated further and further towards a closing position. At the end of that rotation, the initially horizontal leg will butt against a stop. To promote a complete closure at the leg upon its being stopped, it may be provided, according to a further embodiment of the invention, that at least that closing leg is provided with at least one elastic part arranged locally and, viewed in the direction of the pivot, over the full width of the leg. Thus, even when the rest of that leg is made of relatively stiff design, a complete and effective closure can be realized. It is to be noted that at the other closing leg, always a residual slit will remain present so as to maintain a certain ventilation also in the case of large pressure differences. An elastic part in the leg coming to a stop further has the particular additional effect that this leg, upon the pressure difference rising still further, can bend in the elastic area, as a result of which the valve body rotates a bit further still and the residual slit diminishes, so that an additional control range for regulating a constant flow of ventilating air can be obtained. A same effect can be achieved if, according to a further embodiment of the invention, the closing leg comes to a stop against an elastically designed wall part of the ventilating channel. Naturally, a combination of elastic part and elastic stop is also possible. Further, the ventilating apparatus may be further provided with a conventional closing valve operable by hand or a motor, allowing the ventilating apparatus to be regulated and closed independently of the pressure difference between the outside and inside.

In general, given normal operation and assembly of the valve body, this valve body in its initial position will hang balanced in the proper position and pivot to the closing position upon increasing pressure difference. However, to allow, for instance, for inaccuracies involved in building in, it may further be preferred that it has been provided through stop means that the valve body can pivot from its initial position in one direction only. Thus, it can always be ensured that the valve body can pivot from the initial position only in the direction determined by the initiating leg.

As mentioned, it is preferred that the valve body, viewed in the flow direction of the air in the ventilating channel, is placed in the outflow mouth area or just behind it. This arrangement makes it optimally possible to situate the valve body in a unit which can be detachably connected with the housing using fastening means. This creates optimal circumstances for any service, inspection or repair, not only of the valve body, but also of the parts placed behind it. Conventionally, in that area, a ventilating apparatus is provided with a detachable attachment piece, provided with insect gauze and/or a closing valve operable by hand or motor. Presently, this makes it possible for a self-regulating valve body as discussed and elucidated above to be fitted afterwards to ventilating apparatuses already mounted.

The ventilating apparatus according to the invention will presently be elucidated in more detail with reference to an embodiment which is represented, though exclusively by way of non -limiting example, in the single figure of the drawing. The single figure shows the ventilating apparatus in transverse cross section.

The ventilating apparatus is provided with an elongated, block-shaped housing 1, in which, by means of housing parts and sound-damping material, a ventilating channel 2 is defined, extending from an outer mouth 3 to an inner mouth 4. The housing 1 is provided with partly shown conventional provisions for mounting the ventilating apparatus in for instance a window frame or a wall. Further, a broken line schematically indicates a closing valve 5 which in a well known manner can be set by hand or a motor between a fully open position and, as indicated with the broken line, a fully closed position. Further, on the side of the inner mouth 4, the housing 1 is provided with an attachment unit 6, which is detachably mounted by means of well known connections, as by snap-fitting or with screws. The unit 6 is provided with an upper outflow opening 7 and a lower outflow opening 8, in which, typically, provisions such as insect gauze are provided. There, possibly, valves with the function of the schematically indicated closing valve 5 could be arranged. Mounted in the unit 6 is a pivot 9, on which a valve body 10 can rotate freely. The valve body 10 is made up of a hollow tube 11 which carries three legs: a first closing leg 12, a second closing leg 13 and an initiating leg 14. The rotary construction of the valve body 10 can be realized in a simple manner by closing the hollow tube 11 at its two ends with an end cap in which a bore is provided eccentrically for receiving a journal mounted in the housing 1 or a stationary part connected thereto. Compared with a continuous pivot 9, this design has the advantage of a lower friction resistance. The closing leg 12 is composed of two plate parts, and an elastic part 15 connecting these. By means of blocking or stop provisions (not shown), the closing leg 12 can be prevented from pivoting upwards from the initial position shown in the figure.

Shape, dimensions and material of the constituent parts of the valve body 10 are chosen such that in the case of no or only a very low pressure difference, for instance up to 1 Pascal, between the outer mouth 3 and the inner mouth 4, the valve body 10 is going to hang in the initial position designated with solid lines in the figure. Air flowing through the ventilating channel 2 will not or hardly experience any resistance from the closing leg 12 extending straight against it, but will be divided into two partial flows which are thereupon deflected by the closing leg 13 and the initiating leg 14, respectively, in the direction of the upper outflow opening 7 and the lower outflow opening 8, respectively.

When the pressure difference between the outer mouth 3 and the inner mouth 4 augments, so that also the air speed and amount of air increase, then the pressure on the closing leg 13 and on the initiating leg 14, as well as on the part of the hollow tube 11 that connects that leg with the closing leg 12, will augment likewise. The surface dimensions are then chosen such that the pressure on inter alia the initiating leg 14 prevails, so that the valve body 10 pivots about the pivot 9 anticlockwise. As a result of the attendant pivotal movement of the closing legs 12 and 13, the free passages to the outflow openings 7 and 8 are reduced, so that the amount of ventilating air being supplied is regulated to the desired, constant value. Upon rotation of the valve body 10 from its initial position, the closing leg 12 will also proceed to make its contribution to further rotation upon augmentation of the pressure difference between the outer mouth 3 and the inner mouth 4.

Eventually, at a sufficiently large pressure difference between the outer mouth 3 and the inner mouth 4, the valve body 10 will have rotated so far that the closing leg 12 comes into contact with the wall of the ventilating channel 2, which position of the valve body is indicated with a partly broken single line. As indicated, in that position, at the end of the closing leg 13 a slit will be left, so that the supply of fresh ventilating air is always ensured. If for some reason it is desired for the air supply to be closed off completely, this can be realized by means of the closing valve 5.

Upon a still further increase of the pressure difference, it will be possible for the closing leg 12, due to the presence of the elastic part 15, to proceed to bend to some extent, whereby the residual slit adjacent the closing leg 13 diminishes, which promotes the regulation of a constant amount of supplied ventilating air. A same effect could be achieved by making the wall of the ventilating channel 2 of elastic design at the point where the closing leg 12 strikes it. Depending on the effect contemplated, the elastic part 15 in the closing leg 12 can then be omitted or not.

Upon decrease of the pressure difference between the outer mouth 3 and the inner mouth 4, the valve body 10 will have to rotate back again in the direction of the initial position. The resetting force is then generated by gravity, to which end it has been provided that the weight of the parts of the valve body 10 on the right side of the pivot 9 is greater than the weight thereof on the left side. This effect has been promoted by the use of the eccentrically suspended hollow tube 11 as part of the valve body 10. Upon rotation, the greater part of the hollow tube 11 will be on the right side of the pivot 9 and thus generate a relatively large resetting couple, which couple augments according as the valve body 10 rotates further out of its initial position. It will be evident that within the framework of the invention as laid down in the appended claims, many modifications and variants are possible. The positive influence of the hollow tube on the resetting couple has been discussed. It is also possible, however, to use a more common hinge construction and, for instance, to fit a counterweight to the initiating leg. The hollow tube 11 represented has a circular cross section. It will be clear that this can also be any other desired and suitable shape, such as an oval or a triangle. In the drawing, the pivot 9 is situated somewhat upstream of the inner mouth 4. That pivot can also, if necessary with modification of the design of the legs 13 and 14, be situated in the ventilating channel 2. Also, for regulating the air flow, the direction of rotation of the valve body can be reversed by corresponding design and dimensioning. In the embodiment shown, the valve body is accommodated in a separate unit to be coupled-on. This provides the advantage of simple assembly, check, service and replacement, or fitting to older, already mounted ventilating apparatuses, which, for that matter, do not need to be of the sound-damping type as shown in the drawing. It will be clear that the valve body can also be accommodated in the housing without separate unit. Further, in the exemplary embodiment, upper and lower outflow openings are shown. Of course, these can also be replaced or combined with outflow openings in the end face.

Claims

1. A ventilating apparatus provided with a substantially block -shaped housing with a first wall break and a second wall break, between which extends a ventilating channel, while at least one valve body is present for pressure-dependently regulating the free passage of the ventilating channel, for which purpose the valve body is designed as a body arranged to be substantially freely rotatable about a pivot and provided with legs which are so arranged with respect to the pivot that, at least in an initial position, a leg extends in the flow direction of the ventilating air through the ventilating channel, characterized in that the valve body is provided with at least two closing legs and an initiating leg, while one of the closing legs in the initial position extends in and opposite to the flow direction of the ventilating air through the ventilating channel, with respect to which leg a further closing leg and an initiating leg are arranged so as to diverge in a V-shape.

2. A ventilating apparatus according to claim 1, characterized in that the pivot for the valve body, viewed in the flow direction of the air in the ventilating channel, is placed in the outflow mouth area or just behind it.

3. A ventilating apparatus according to claim 1 or 2, characterized in that the valve body comprises a hollow tube which carries the legs and is arranged to be eccentrically rotatable relative to the centerline of the pivot.

4. A ventilating apparatus according to claim 3, characterized in that the hollow tube is provided with end caps, in which, eccentrically with respect to the centerline of the hollow tube, bores are provided for receiving a journal.

5. A ventilating apparatus according to any one of the preceding claims, characterized in that at least one closing leg is provided with at least one elastic part arranged locally and, viewed in the direction of the pivot, over the full width of the leg.

6. A ventilating apparatus according to any one of the preceding claims, characterized in that at least one closing leg, upon rotating from the initial position, comes to a stop against an elastically designed wall part of the ventilating channel.

7. A ventilating apparatus according to any one of the preceding claims, characterized in that by means of stop means it has been accomplished that the valve body can pivot from the initial position in one direction only.

8. A unit provided with fastening means for connection to the housing and with a valve body as referred to in any one of the preceding claims, mounted in the unit.