EP0003970A1 - Method for ventilating rooms and ventilating device for carrying out the method - Google Patents

Abstract

1. Process for ventilating rooms, in which the air flow is conveyed through a duct provided with opening cross-sections of varying sizes at both ends and having an expansion chamber in the area between its ends, characterized by the fact that the pressure level of the air flow is suddenly lowered (3, 7 or 7, 5) when it flows into the expansion chamber (5) and is then suddendly raised again (5, 7 or 5, 3) before emerging from this expansion chamber (5), and that the air flow is diverted or rerouted between the lowering of the pressure (3, 5 or 7, 5) and the rise in pressure (5, 7 or 5, 3).

Description

a) Title

Method for ventilation of rooms and ventilation device for carrying out the method

b) Technical field

The invention relates to a method for ventilation of rooms, in which. the air flow is guided in a channel provided with different passage cross sections at both ends. The invention also relates to a ventilation device for carrying out the method, in which the passage opening at one channel end has a substantially larger passage cross section than the passage opening at the other channel end and a chamber with an enlarged cross section is arranged in the channel, immediately after the larger passage opening . is trained.

Ventilation in particular supplies fresh air to human lounges in order to compensate for the changes in breathing air that are disadvantageous in such rooms at least to such an extent that they can no longer be annoying or even harmful.

Such changes in the air we breathe are caused by heat release, moisture release, carbon dioxide release and fragrance release by humans. However, changes in the air we breathe often result from other causes, such as tobacco smoke, dust, exhaust gases and odors during certain work processes in workshops, factories, etc.

The basic requirement for every ventilation is to ensure the necessary air exchange while avoiding drafts and sound transmission.

The number of air changes caused by ventilation per hour is essentially determined by the type of use. of the lounges. Depending on the type of use and size of the common rooms, the number of air changes per hour is between one and twenty, the air change must be such that an air exchange per head takes place between 20 and 30m ^g per hour.

The common rooms are ventilated in that the used room air is discharged to the outside as so-called exhaust air and is exchanged for a corresponding amount of drafts.

If only a small number of hourly air changes are necessary in the common rooms, these air changes can be effected regularly on the basis of the so-called free ventilation. The criterion of this free ventilation is that the air change is caused by the natural properties of the air when there are temperature and pressure differences (wind). This so-called free ventilation takes place as joint ventilation, as window ventilation as duct ventilation and as shaft ventilation.

In contrast, safe room ventilation, regardless of all temperature and wind conditions, is provided by so-called forced ventilation, i.e. ventilation with mechanical air delivery. The fan operation allows the necessary amount of air to be supplied to every room.

In the case of forced ventilation, the supply air can either be conveyed into the building from the outside - that is, it can be operated with outside air - or the room air can be conveyed from the inside to the outside - i.e. in exhaust air mode.

The main criterion in the supply air operation of the forced ventilation is that the room air has overpressure relative to the air outdoors, while on the other hand, when the forced ventilation is operated in the exhaust air mode, the room air is underpressure compared to the air outdoors.

The forced ventilation mainly takes place on the basis of duct ventilation because this is the best way to meet the requirement for optimal sound insulation.

As far as the forced ventilation of rooms is concerned, the present invention therefore also relates to duct ventilation.

c) State of the art

From DE-PS 23 08 479 a ventilation element for rooms has already become known, which contains a channel at each end having a passage opening, directed essentially transversely to these passage openings. The air passage cross section of both passage openings practically matches in shape and size and is in each case larger than the passage cross section of the actual duct.

Because of this configuration, on the basis of the so-called free ventilation, that is to say, by utilizing the natural properties of the air in the event of temperature and pressure differences (wind) after the air flow has entered the one passage opening within the duct, one results from the reduced duct cross section resulting increased flow rate, which, however, is reduced again at the end of the channel section, that is to say when the other passage opening is reached. Since the flow velocity of the air in the area of the two passage openings is practically the same, the higher, higher air flow velocity within the narrow duct section has no influence on the effectiveness of the duct ventilation. At best, the increased flow velocity of the air within the narrower cross-section of the duct can somewhat counteract the increased flow resistances caused by bending in the flow path.

US Pat. No. 1,236,157 already includes a ventilation device of the prior art, which has a channel running in the direction of the wall plane between an outer and a plurality of inner outlet openings, the outer outlet opening being arranged halfway along the length of one wall of the channel, while at least one inner passage opening is provided on both ends of the channel on the opposite wall. The air flow is thus divided into two substantially equal partial flows, each of which has the full cross section of the duct. This results in a significant reduction in flow resistance.

In this known ventilation device is built in at several points in the channel cross-section internals, for. B. by the individual passage openings surrounding frames, a multiple deflection of the two partial air streams by 90 ⁰ each and a total of 360 reached, whereby the flow resistance in the sub-channels increases again.

Both the passage openings and the substantially transverse sub-channels have a rectangular cross section in this ventilation device. In addition, both the flow paths located behind the central passage opening and the flow paths located behind the lateral passage openings each directly adjoin the relatively large channel cross section. As a result, the air flow velocity is considerably reduced within the duct cross section, which results in a reduction in the air throughput.

A ventilation device further developed from US Pat. No. 1,236,157 is distinguished according to US Pat. No. 1,375,378. that fittings are arranged in the subchannels of the housing adjoining the central passage opening, which block the straight path of the air to the passage openings adjoining the two channel ends. These internals extend essentially in the longitudinal direction of the two sub-channels and form guide walls inclined towards the plane of the passage openings. Here, too, the flow path located behind the central passage opening immediately adjoins a relatively large channel cross section, the depth of which, however, decreases steadily in the direction of the channel ends. This is intended to influence the air flow rate through the two subchannels in such a way that it remains as constant as possible, although the passage area of the passage openings adjoining the two channel ends is in each case dimensioned substantially larger than the passage area of the central passage opening.

DE-OS 23 31 841 discloses a ventilation device which corresponds in its basic structure to that according to US Pat. No. 12 36 157. In this case, an air duct also extends from a central passage opening in two opposite directions, so that the air flow is divided into two substantially equal partial flows, each of which has the full channel cross-section up to the further passage openings provided at the two channel ends is available.

As can be seen, for example, from DE-AS 19 31 346, it is also already known to assign duct ventilators to a fan or a cross-flow fan in the area of one of the passage openings. in order to achieve forced ventilation, which leads to safe room ventilation regardless of all temperature and wind conditions. In this case, however, the total flow cross section of the channel section is larger than the cross section of the two passage openings provided at the different channel ends. However, the cross-section of these two passage openings is again of different sizes, namely that it is chosen smaller for the passage opening to which the fan or the cross-flow fan is assigned than for the passage opening which is located away from the mechanical air conveying device.

In this duct ventilation, which works with mechanical air conveying, the air flow sucked in by the fan or the cross-flow blower is considerably reduced in its flow rate by the enlarged duct cross-section and at the same time the (slight) overpressure generated by the fan or cross-flow blower is reduced. The extent of the pressure reduction is essentially dependent on three variables, namely 1. on the delivery capacity of the fan or cross-flow fan, 2. on the total volume of the fan element between the two passage openings and 3. on the air passage cross section of the passage opening removed from the fan or cross-flow fan. If the total volume of the ventilation element and the air passage cross-section of the second passage opening is large relative to the delivery capacity of the fan or cross-flow blower, then a correspondingly large pressure reduction takes place and there is a considerable reduction in the air flow speed in the region of the second passage opening.

From DE-OS 22 40 9:37 a ventilation device is also known in which the passage opening at one channel end has a substantially larger passage cross-section than the passage opening at the other channel end and in which in the channel, directly after the larger passage opening, a chamber is arranged or formed. The chamber is formed by the fact that the boundary wall for the channel, which is adjacent to the larger passage opening, has a transverse surface that is beveled in the direction of the desired flow pattern. As a result of this beveled transverse surface, the cross section of the chamber gradually increases from the passage opening to a maximum value, and then gradually narrows again towards the mouth of the channel on the chamber side.

This structure of the known ventilation device has the result that an effective air flow is generated practically only in one direction, namely from the larger opening in cross section to the smaller opening in cross section and are still supported by a fan to achieve a sufficiently large air throughput must, which is arranged in a further chamber, which adjoins the passage opening with a smaller passage cross section.

A similar mode of operation also has duct ventilation with mechanical air delivery, in which the fan or fans are built directly into the flow cross-section of the duct section lying between the two passage openings, as is the case, for. B. according to DE-ASen 11 99 956, 12 19 203, 12 22 642 and 12 39 832 has become known.

In these known duct ventilation elements with mechanical air conveyance, the air passage cross section of both air passage openings provided at the different duct ends is large relative to the flow cross section of the duct connector connecting them. Basically, these known ventilation elements differ from the ventilation element according to DE-PS 23 08 479 only by the additional installation of fans in order to achieve mechanical air delivery.

d) Description of the invention

The purpose of the invention is to improve the mode of operation of the duct ventilation, regardless of whether it works according to the principle of so-called free ventilation or else according to the principle of forced ventilation. Accordingly, the invention has for its object to provide a ventilation method and a ventilation device of the generic type by or with the help of which human lounges can be ventilated in an optimal manner without annoying or even harmful drafts and sound transmissions can result.

Experiments have now shown that this complex problem can be solved surprisingly simply procedurally both for the so-called free ventilation and for the forced ventilation of rooms if, according to the invention, the pressure level within the guided air flow is initially reduced spontaneously, but then downstream or later in time, again spontaneously, and that the air flow is deflected or redirected between the pressure drop and the pressure increase.

This procedural measure surprisingly makes it possible to achieve an increased delivery rate, irrespective of whether operation is carried out in the ventilation or venting mode, and thus improve the air exchange.

According to the invention, it has proven to be advantageous for ventilating the room if the pressure level of the guided air flow is influenced near its upstream end.

On the other hand, it is favorable for venting the room if the pressure level of the guided air flow is influenced near its downstream end.

When the room is ventilated, the air flow can be split into several partial flows approximately simultaneously with the increase in its pressure level, while it can be combined with the lowering of the pressure level from several partial flows approximately simultaneously with the lowering of the pressure level.

The pumping effect brought about by the lowering and subsequent increase in the pressure level in the air stream can in turn be influenced according to the invention by regulating or changing the extent of the lowering and the subsequent increase in the pressure level volumetrically.

A ventilation device for practicing the ventilation method, in which the passage opening at one channel end has a substantially larger passage cross-section than the passage opening at the other channel end and in the channel, immediately following the larger passage opening, a chamber with a Larger cross section is arranged or formed according to the invention is essentially characterized in that the chamber adjoins a passage opening with a spontaneously enlarged cross section and the channel is in turn connected to the chamber with a spontaneously narrowed cross section and at an angle to the passage opening.

On the basis of these training features, the ventilation device works according to the pressure vessel principle, that is to say the pressure prevailing in the chamber is decisive for the pressure and thus also the flow conditions in the cross-sectionally narrow areas of the duct ventilation connected to this chamber.

According to the invention, it has proven to be worth copying to make the cross-sectional plane of the chamber parallel to the plane of the passage opening approximately several times larger than the cross section of this passage opening. The cross-section of the chamber parallel to the level of the channel cross-section should also be made several times larger than the overall channel cross-section.

Within the scope of the invention it can also prove important to give the passage opening a different geometric cross-sectional shape than the chamber and the channel.

The sound and ventilation effectiveness of such a ventilation device can also be influenced in that two duct sections are connected to opposite walls of the chamber and / or that the through opening has a neck-like extension protruding into the chamber.

A ventilation device of the type described can also be expanded in a particularly simple manner to a duct ventilation with forced air movement if an axial fan is installed as an air conveyor in the larger passage opening and the neck-like extension forms a jacket ring surrounding the axial fan. The axial fan can then be used to influence the pressure conditions within the chamber as a function of its delivery rate. Practical tests have shown that the cooperation of the axial fan with the chamber adjacent to the passage opening only results in gap losses which are of the order of 50%. In contrast, it has been shown that when the axial fan is installed directly in a ventilation duct of corresponding cross-section, gap losses occur which are approximately 90%. This clearly shows that the efficiency of a ventilation device according to the invention, which works according to the pressure vessel principle, increases practically by a considerable factor compared to the conventional design.

If, according to the invention, the axial fan is provided with blading which is symmetrical with respect to its plane of rotation and is driven by a reversible electric motor, then one and the same ventilation device can optionally be used for ventilation or for ventilation of the room.

Further features of the invention are that on the one hand the the chamber adjoining channel sections and the passage opening of smaller cross section are formed in molded parts made of soundproofing material, while on the other hand the wall of the chamber opposite the passage opening of the larger passage cross section of the chamber is designed to be removable or arranged. All parts of the ventilation device are therefore easily accessible at all times for cleaning purposes.

So that the extent of the lowering and the subsequent increase in the pressure level in the guided airflow can be influenced in a simple manner, the invention provides that at least one wall of the chamber by a drive device, for. B. an electric motor is adjustable. The drive device can via a reduction gear, for. B. attack a screw gear, or a slow-running crank on the adjustable wall.

So that the volume of the chamber depending on different pressure and / or flow conditions or other changing environmental conditions, such as. B. temperatures, gas concentrations or the like can be changed, different points of the flow path are assigned measuring points which are formed by flow probes, which can be compared with a comparison circuit, for. B. are connected to a control loop, which forms a control value transmitter for the drive device.

As flow probes, pressure-dependent capacitors or inductors, piezoelectric crystals or also by pressure - provide for length-dependent resistances (strain gauges).

Bending vibrators made of Seignette salt can also be used as flow probes if necessary.

Finally, sensors can be assigned to the control loop as additional measuring points, which respond, for example, to temperature changes, changes in the gas concentration or the like.

e) Description of the drawing figures

• Fig. 1 shows a schematic simplified schematic diagram of a horizontal section through the basic structure of a ventilation device, in
• 2 shows the ventilation device according to FIG. 1 schematically in a view from the front,
• 3 shows in a basic spatial representation a modified embodiment of the ventilation device according to FIGS. 1 and 2,
• Fig. 4 shows a horizontal longitudinal section and detailed representation of the ventilation device according to Fig. 3 in a sound-absorbing version and installed in a prism-shaped housing, the
• Fig. 5 show different cross-sections through the Ventilationsbis 7 device according to Fig. 4, namely according to lines V -V, VI-VI and VII-VII.
• FIG. 8 shows a schematically simplified sectional illustration of a ventilation device with a flow path that is adjustable in terms of its volume, in
• 9 is a corresponding representation of a modified embodiment of a ventilation device with a flow path that is adjustable in terms of volume, while
• 10 shows a control circuit in a purely schematic manner, in which the controlled system is formed by the flow path of the ventilation device, which can be changed in volume, and the controller is formed by the actuator causing the change in volume.

f) ways of carrying out the invention

When it comes to ventilating human lounges, it is important to achieve a sufficient number of air changes while at the same time preventing drafts and sound transmission. Depending on the type of use of the rooms, the number of air changes required every hour is between 2 and 15, which means that the room air must be replaced between 2 and 15 times every hour. According to the VDI ventilation rules, the minimum amount of the outside air flow to the room every hour - that is the outside air rate - applies to rooms with a smoking ban 3 3 20 m, for rooms in which smoking is 30 m ³ .

In order to optimally meet these requirements on the basis of a so-called duct ventilation, in which the Air is conveyed through a channel having at least one passage opening at each end, in particular directed transversely to these passage openings, a method has been developed in which the air flow in one passage opening passes through a substantially larger cross section than in the other passage opening and thereby in the channel is passed spontaneously in front of or behind the larger cross section through a section with an even larger cross section.

This ventilation method is only applicable to the so-called free ventilation, in which the air change in the room in question is caused solely by utilizing the natural properties of the air in the event of temperature and pressure differences (wind); rather, it can be used for so-called forced ventilation, which achieves safe room ventilation through mechanical air conveyance regardless of all temperature and wind conditions. It is also essential that this ventilation method is equally well suited for ventilation as well as for the ventilation of the common rooms.

It is particularly important that the same basic structure for the ventilation device can be used to carry out the ventilation process.

The basic structure for such a ventilation device 1 is shown in FIGS. 1 and 2 of the drawing.

1 and 2, the ventilation device 1 has a channel 2, which has a passage opening 3 and 4 at each of its two ends. Channel 2 extends in the substantially transversely to the plane of the two passage openings 3 and 4. The passage openings 3 and 4 are assigned to different channel sides and are, based on the installation level of the ventilation device 1, preferably on opposite channel sides.

An essential feature of the ventilation device 1 is that the two passage openings 3 and 4 have completely different air passage cross-sections in terms of size, and for example the passage opening 3 is dimensioned substantially larger than the passage opening 4.

It is equally important, however, that a chamber 5 is arranged or formed in the channel 2, directly after the larger passage opening 3, which in turn has a larger cross section than the larger passage opening, which spontaneously increases in size.

This larger cross section of the chamber 5 passes, again with spontaneous narrowing, into the channel section 6, the flow cross section of which is not only smaller than the passage cross section of the passage opening 3 and the chamber 5, but also smaller than the passage cross section of the passage opening 4.

It has also proven to be important that the channel section 6 connects to the chamber 5 relative to the passage opening 3 at an acute, for example a right angle, in such a way that the chamber-side mouth 7 of the channel section 6 from both the front wall 8 and the Rear wall 9 and from the bottom wall 10 and the ceiling turn 11 is at a distance.

It has proven to be useful if the edges of the mouth 7 of the channel section 6 from the front wall 8, the bottom wall 10 and the top wall 11 of the chamber 5 have approximately the same distance, while they have a larger, and have at least twice the distance.

From Fig. 1 it follows that the passage opening 3 is delimited by a jacket ring 12 protruding into the chamber 5, the length of which is approximately equal to the distance between the front wall 8 of the chamber 5 and the adjacent mouth edge of the channel section 6.

Fig. 2 shows that both passage openings 3 and 4 are circular, while the chamber 5 has the shape of a rectangular box. The passage section 6 is also approximately rectangular in its flow cross-section.

Because of the design described for the ventilation device 1, it works according to the pressure vessel principle, that is to say the flow behavior of the air through the entire ventilation device 1 is determined by the volume of the chamber 5 and the pressure differences present at the different large passage openings 3 and 4.

While channel ventilation usually places value on the ventilation channels having the lowest possible flow resistance, in the construction of a ventilation device described, locally restricted flow resistances are built in in a certain way. As a result, chamber 5 to some extent caused a pumping effect, which increases the air throughput through the ventilation device. This pumping effect of the chamber 5 occurs regardless of whether there is a pressure drop from the passage opening 3 to the passage opening 4 or from the passage opening 4 to the passage opening 3.

3 has basically the same structure as the ventilation device according to FIGS. 1 and 2. It differs from this only in that channel sections 6 'and 6 "directed towards the opposite sides of the chamber 2 equipped with the larger passage opening 3" are connected, each of which has its own passage opening 4 'or 4 "with a smaller passage cross section at its other end.

Both the ventilation device according to FIGS. 1 and 2 and that of FIG. 3, the passage openings 4 and 4 ', 4 ", which have the smaller passage cross section, with the interior of the room, while the passage opening 3 larger passage cross section Outside air is turned.

FIG. 4 of the drawing shows a ventilation device 1 which is identical in its basic structure to the ventilation device according to FIG. 3. However, it differs from this in that it can also work on the principle of forced ventilation. For this purpose, an axial fan 13 is installed in the passage opening 3 with a larger passage cross section, and this sits concentrically within the jacket ring 12, which protrudes from the passage opening 3 into the chamber 5. The axial fan 13 can be designed so that it has a delivery rate of 260 m ³ / h and in operation at a delivery rate 0 a static pressure of about 9 806, 65 Pa (Pascal) = N / m 2 (Newton each m) able to produce.

The interaction of such an axial fan 13 with that between the passage opening 3 and the channel section 6 or the channel sections 6 '. and 6 "chamber 5 can then generate a static pressure of approximately 2 942 Pa = N / m ² in the chamber 5 and an air delivery rate of 130 m ³ / h can be achieved by the ventilation device 1.

The interaction of the axial fan 13 with the chamber 5 therefore only results in gap losses of 50% for the latter.

In comparison, however, with an appropriately designed axial fan, if this is installed in a duct section having the same cross-section over the entire length between the two through openings, only an effective delivery rate of approximately 26 m ³ / h is achieved because a static pressure is present in this duct section not build up. Compared to the gap losses of 50% in the construction of a ventilation device described here, gap losses of approximately 90% arise here, that is to say the effective air delivery capacities of the two different ventilation systems behave approximately as 5: 1.

4 to 7 that the entire Ventilvorvor direction 1 is installed in a prismatic housing 14 of, for example, square cross section, the ends of which are closed by end plates 15.

A portion of a longitudinal wall 16 of the housing 14 forms the front wall 8 for the chamber 5 and is provided for this purpose with the passage opening 3 which is larger in the passage cross section and to which the casing ring 12 connects.

The bottom wall 10 and the top wall 11 of the chamber are also formed by partial sections of longitudinal walls 17 and 18 of the housing.

To form the transverse walls for the chamber 5, two partition plates 19 and 20 are used in the housing 14, with which an end plate 21 can be detached to form the rear wall 9 for the chamber 5, for. B. is connected by screws.

In each of the separating plates 19 and 20 there is an opening 22 and 23, respectively, with these openings 22 and 23 being followed by the duct sections 6 'and 6 "of the ventilation device 1. The duct sections 6' and 6" each extend over the between the partition plates 19 and 20 and the end plates 15 limited length range of the housing 14 and are limited overall by molded parts 24 and 25 made of soundproofing material, for example foam. The shaped part 24 has an essentially U-shaped cross section, the legs and the web of the U-profile having the same thickness. The molded part 25, on the other hand, is formed by a block of material with a rectangular cross section, in particular a foam block, with its cross section thickness is at least twice the thickness of the legs and web of the U-profile. The two molded parts 24 and 25 are each inserted into the housing 14 relative to one another such that they enclose the channel section 6 'or 6 "of rectangular cross section between them.

The molded parts 25 each have an opening which forms the passage opening 4 'or 4 ^{H of} smaller cross section. The passage openings 4 'and 4 "face that longitudinal wall 2G of the housing 14 which lies opposite the longitudinal wall 16. The longitudinal wall 26 has slot-like or lattice-like openings over its entire length and over part of its width which face the interior of the room of the housing 14 is also an end plate 27 slidably guided transversely to its plane, which in its one sliding position releases the slot-like or lattice-like openings of the longitudinal wall 26 for air passage while closing it in its other sliding position. The passage openings 4 'and 4 " are arranged relative to the end plate 27 so that the end plate 27 can form an effective guide surface for the air flow within the housing 14.

The molded parts 24 and 25 made of soundproofing material are simply inserted loosely into the housing 14 and can therefore, if necessary, be easily removed from the housing 14 after removal of the longitudinal wall 26 and the end plate 27. Likewise, after removing the longitudinal wall 26 and the end plate 27, the rear wall 21 of the chamber 5 can be easily removed, so that the interior of the chamber 5 is made easily accessible for the purpose of cleaning or for installing and removing the axial fan 13 can.

Finally, it should also be pointed out that it is expedient to provide the axial fan 13 with blading which is symmetrical with respect to its plane of rotation and to drive it by means of a reversible electric motor. In this case, the ventilation device 1 can be used as an axial fan 13 either for ventilation or for ventilation of the room, by simply reversing the direction of rotation. When the axial fan 13 is at a standstill, however, the ventilation device 1 can also be operated by opening the end plate 27 according to the principle of free ventilation. Whether ventilation or ventilation of the room will take place depends only on whether there is a pressure drop from outside to inside or from inside to outside.

In the practical configuration of the ventilation device 1, it has proven useful to set the ratio of the passage cross section of the larger passage opening 3 to the cross section of the chamber 5 in the axial direction of the passage opening 3 to approximately 1: 2 to 1: 3, the ratio of the chamber cross section to the total cross section of the Channel section 6 or 6 ', 6 ⁿ in the axial direction of the channel section approximately between 3: 1 and 4: 1 and the ratio of the cross section of the channel section 6 or 6', 6 'to the cross section of the smaller passage opening 4 or 4', 4 "between 2: 1 and 3: 1.

If, as shown in FIGS. 4 and 5, an axial fan 13 is installed in the larger passage opening 3, then the volume of the chamber 5 should also be recommended to be adjusted so that it corresponds to the effective delivery rate (m 3 / s) of the Axial fan 13 - that is its delivery volume minus the gap loss occurring during operation - is in a ratio between 1: 8 and 1:10.

So that the volume of the chamber 5 can be easily adjusted to the respective needs, it is possible in the ventilation device 1 according to FIGS. 4 to 7 to arrange the transverse walls 19 and 20 in the longitudinal direction of the housing 14 so as to be displaceable and lockable as well as the end plate 21 in their Form length dimension so that ^- it can bridge the entire displacement range of the transverse walls 19 and 20.

Since the duct sections 6 ′ and 6 ″ are formed in molded parts 24 and 25 from elastically deformable soundproofing material, their length dimensions adapt completely automatically to the adjustment of the transverse walls 19 and 20.

In many cases it can prove to be expedient to adjust the transverse walls 19 and 20 continuously for the purpose of changing the volume of the chamber 5 by means of a power drive, e.g. B. an electric motor, via appropriate gear members, for example screwdriver drives. The operation of the electric motor can be regulated and / or controlled by remote action, for example depending on the differential pressure between the interior of the room and the outside air. Flow probes, for example Pitot tubes, Prandtl tubes or the like, can be used as measuring, regulating and / or control elements, which are mounted at suitable points in the flow path of the ventilation device 1.

The working features of the ventilation device can be further optimized by the design features described last.

The ventilation device 1 shown in FIG. 8 has a channel 2 which has a passage opening 3 and 4 at each of its two ends. The channel 2 extends essentially transversely to the axis of the two passage openings 3 and 4. These passage openings 3 and 4 are assigned to different channel sides and are preferably located on opposite channel sides with respect to the installation level of the ventilation device 1.

The two passage openings 3 and 4 are designed with completely different dimensions in terms of their air passage cross section, namely in the example shown the passage opening 3 is dimensioned much larger than the passage opening 4th

Immediately after the larger passage opening 3, a chamber 5 is arranged or formed in the channel 2, which in turn has a spontaneously enlarged cross section relative to the larger passage opening 3. This larger cross section of the chamber 5 merges, again with spontaneous narrowing, into the channel section 6, the flow cross section of which is not only smaller than the through cross section of the through opening 3 and the chamber 5, but also smaller than the through cross section of the through opening 4.

The channel section 6 connects to the chamber 5, seen in the axial direction of the Durch opening 3, at an acute, for example a right angle, in such a way that its chamber-side mouth 7 both from the front wall 8 and the rear wall 9 and from the bottom wall and the ceiling wall has a certain distance.

The passage opening 3 is delimited by a jacket ring 12 which projects into the chamber 5 and which, if necessary, can accommodate an axial fan 13.

The channel section 6 and the chamber 5 preferably have a rectangular flow cross section, while the passage cross section c of the through openings 3 and 4 are preferably circular.

Because of the design described for the ventilation device 1, it works according to the pressure vessel principle and is subject to the various resistance laws of the so-called pipe flow. The flow behavior of the air through the entire ventilation device from the volume of the chamber 5 and. at the two different large passage openings 3 and 4 respectively pending pressure differences determined.

While the pressure differences are dependent on the prevailing environmental conditions, the volume of the chamber 5, which essentially determines the mode of operation of the ventilation device 1, must be determined in terms of construction.

Experimental investigations have shown that, under different environmental conditions (pressure and flow conditions), 5 different degrees of efficiency of the ventilation device 1 occur for a certain, structurally determined volume of the chamber 5. It could also be demonstrated that the efficiency of the ventilation device 1 can be influenced in a lasting manner by changing the volume of the chamber 5 under different environmental conditions.

Therefore, in order to obtain a constant efficiency of the ventilation device 1 in adaptation to the changing environmental conditions, precautions are taken by means of which the effective volume of the chamber 5 can be changed.

8 of the drawing, the two side walls 19 and 20 of the chamber are arranged to be adjustable for this purpose. Namely, the two side walls 19 and 20 are slidably guided between the front wall 8, the rear wall 9, the bottom wall and the top wall. Both side walls 19 and 20 are provided with the orifices 7 for the channel sections 6 'and 6 ", connecting pieces 7' and 7" adjoining these orifices, the cross-sectional shape of which is adapted to the cross-sectional shape of the channel sections 6 'and 6 ", whereby the nozzles 7 'and 7' are permanently in engagement with the adjacent channel sections 6 'and 6.

By moving the two side walls 19 and 20 accordingly, the volume of the chamber 5 can be changed practically infinitely between a maximum value and a minimum value.

In contrast, in the ventilation device 1 according to FIG. 9, the side walls 19 and 20 of the chamber 5 are rigid, while the rear wall 9 of the chamber 5 opposite the passage opening 3 having a larger passage cross section is designed to be infinitely adjustable. So here the volume of the chamber 5 can be changed continuously by appropriate displacement of the rear wall 9.

An electric motor 30 is used to adjust the side walls 19 and 20 or the rear wall 9, which, in the case of FIG. 8, moves two screw spindle transmissions 31 ′, 31 ″, for example, with the latter Help the two side walls 19 and 20 can be locked simultaneously and in opposite directions.

In the case of FIG. 9, on the other hand, this electric motor 30 works on only one screw spindle gear 31, which can continuously adjust the rear wall 9.

So that the volume of the chamber 5 by adjusting the side walls 19, 20 or the rear wall 9 is automatically and continuously adjusted depending on the respective environmental influences so that the ventilation device 1 achieves the best efficiency, the electric motor 30 is a comparison circuit in the form of a closed control loop actuated, as shown as a block diagram in Fig. 10.

In this closed control loop, the controlled system is formed by the ventilation device 1, while the actuator for the controller consisting of the chamber 5 or its adjustable walls 9 or 19, 20 is the electric motor 30.

The reference variable, which determines the values of the controlled variable, can be stored in the control loop.

The disturbance variables, on the other hand, are determined by the respective environmental influences and can be tapped, for example, at a measuring point 32 in the area of the passage opening 3 and at measuring points 33 in the area of the passage openings 4 or 4 ′, 4 ″.

The pressure and flow conditions in the open air and in the interior of the room can be used as such disturbance variables, which can be tapped, for example, using flow probes. As such flow probes, pressure-dependent capacitors and inductors, piezoelectric crystals or length-dependent resistors (strain gauges) can be provided. For example, it is possible to provide bending transducers made of Seignette salt as flow probes because they already respond to very small pressure fluctuations. It would also be possible to use Pitot tubes or Prandl tubes as flow probes if these act on the control loop with suitable connecting elements.

The disturbance variables determined by the flow probes at the various measuring points 32 and 33 are introduced into the control circuit according to FIG. 10 and act on this together with the reference variable in such a way that the electric motor 30 serving as an actuator acts as a controller chamber 5 in its volume varies in order to thereby influence the ventilation device 1 forming the controlled system in the sense of achieving an optimal ventilation effect.

In some cases it can also be advantageous if additional measuring points 34 or 34 '34 "in the form of suitable flow probes are provided within the chamber 5. These measuring points 34 or 34', 34" or flow probes can be used for this purpose, for example are to enter correction values into the control loop in addition to the disturbance variables determined by the environmental influences. This correction Sizes can then influence the filling size of the control loop in such a way that a controlled system with compensation is created.

The control circuit according to FIG. 10 is constructed as a so-called continuous control, in which the controlled variable is measured continuously. Here, the controlled system is subject to 1 disturbance variables Z. The controlled variable X is compared with the setpoint value X _K , which is either constant or preferably is a time-dependent reference variable W. In the controller 5 or 9; 19, 20 the control deviation X - W comes in, so that the control value Y _R comes out of the controller. After the closing condition of the control loop, the manipulated variable Y _R acts on control section 1 with a negative sign (Y _R = - Y _S ), so that the difference - Y _S + Z goes into control section 1.

If the ventilation device 1 is assigned an axial fan 13 in the area of the passage opening 3, this can of course be functionally included in the control loop, in such a way that it depends on the environmental conditions present at the measuring points 32 and 33 and possibly also depending is automatically switched on and off by the pressure and flow conditions prevailing at the measuring points 34 and 34 ', 34 "in the chamber 5.

Since the environmental conditions are not only determined by pressure and flow conditions, but are also subject to other influences, the ventilation device 1 can also be assigned other measuring points which influence the control circuit as disturbance variables. So let's look at the additional Measuring points using suitable sensors not only determine temperatures but, for example, also gas concentrations which influence the control loop and thereby also determine the respective operating state of the ventilation device 1.

g) The commercial area of use

The claimed and described method of ventilation for rooms and the ventilation device provided for their implementation can be used wherever it is important to ventilate human lounges in an optimal manner.

Claims (11)

1. A method for ventilating rooms, in which the air flow is guided in a duct provided with different passage cross sections at both ends,
characterized,
that the pressure level within the guided (2; 3, 5, 6, 4) air flow is first spontaneously reduced (3, 5 or 7, 5), but then downstream or later, again spontaneously, increased (5, 7 or 5, 3) and that the air flow is deflected or deflected between the pressure drop (3, 5 or 7, 5) and the pressure increase (5, 7 or 5, 3). 2. The method according to claim 1 for ventilating the room,
characterized,
that the pressure level of the guided (2; 3, 5, 6, 4) air flow is influenced near its upstream end. _3rd Method according to claim 1 for venting the room,
characterized,
that the pressure level of the guided (2; 3, 5, 6, 4) air flow is influenced near its downstream end. 4. The method according to claims 1 and 2,
characterized,
that the air flow is split approximately simultaneously with the increase (5, 7) of its pressure level into several partial flows (6 'and 6 "). 5. The method according to claims 1 and 3,
characterized,
that several partial streams (6 'and 6 ") are combined approximately simultaneously with the lowering of the pressure level (7, 5). 6. The method according to one or more of claims 1 to 5.
characterized,
that the extent of the reduction (3, 5 or 7, 5) and the subsequent increase (5, 7 or 5, 3) of the pressure level is regulated or changed volumetrically (5; 19, 20 or 5; 9) ( 30, 31; 30, 31 ', 31 "). 7. Ventilation device for carrying out the method according to one or more of claims 1 to 6, in which the passage opening at one channel end has a substantially larger passage cross-section than the passage opening at the other channel end and in the channel, immediately following the larger passage opening, a chamber with a enlarged cross section is arranged or formed.
characterized,
that the chamber (5) adjoins a passage opening (3) with a spontaneously enlarged cross section and the channel (6 or 6 ', 6 ") in turn connects to the chamber (5) with a spontaneously narrowed cross section (7) and at an angle is connected to the passage opening (3). 8. Ventilation device according to claim 7,
characterized,
that two channel sections (6 'and 6 ") are connected to opposing walls (19 and 20) of the chamber (5) and are directed towards opposite sides (22 and 23). 9. Ventilation device according to claims 7 and 8,
characterized by
that the cross-sectional plane of the chamber (5) parallel to the plane of the passage opening (3) is approximately several times larger than the cross-section of this passage opening (3), that the cross-section of the chamber (5) parallel to the plane of the channel cross-section (6 or 6 '"6") is several times larger than the overall channel cross-section (6 or 6 'and 6 ") that the passage opening (3) has a different geometric cross-sectional shape than the chamber (5) and the channel (6 or 6 ', 6 "that the passage opening (3) has a neck-like extension (12) projecting into the chamber (5), that the channel sections (6', 6") adjoining the chamber (5) and the passage opening (4 ', 4 ") are formed in molded parts (24 and 25) made of soundproofing material and that the wall (9 or 21) of the chamber (5) opposite the passage opening (3) is designed or arranged to be removable. 10. Ventilation device according to claims 7 to 9,
characterized,
that an axial fan (13), preferably reversible in the direction of rotation, is installed as an air conveyor in the passage opening (3) and the neck-like extension (12) forms a jacket ring surrounding the axial fan (13). 11. Ventilation device according to one or more of claims 7 to 10,
characterized,
that at least one wall (9 or 19, 20) of the chamber (5) by a drive device, for. B. an electric motor (30) is adjustable that the drive device (30) via a reduction gear, for. B. a screw gear (31 or 31 ', 31 ") or a slow-running crank on the adjustable wall (9 or 19, 20) attacks that measuring points (32, 33 or 33';33", 34 or 34 ', 34 ") and are formed by flow probes which are connected to a comparison circuit, for example a control circuit (Fig. 10), which forms a control value transmitter for the drive device (30) that as flow probes, pressure-dependent capacitances or inductors, piezoelectric crystals, in particular bending vibrators made of Seignette salt, or length-dependent resistors (strain gauges) due to the influence of pressure are provided, and sensors are assigned to the control circuit (FIG. 10) as additional measuring points, for example to detect temperature changes or changes in the gas concentration or the like.

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