EP0003970B1 - Method for ventilating rooms and ventilating device for carrying out the method - Google Patents

Description

The invention relates to a method for ventilating rooms, in which the air flow is conducted in a passage cross sections of different sizes at both ends, and in the region between its ends a duct having an expansion chamber. The invention also relates to a device for ventilating rooms with an air duct, in which the passage opening at one end of the duct has a substantially larger passage cross section than the passage opening at the other end of the duct and in the duct a chamber with an enlarged cross section is arranged or formed, the Wall openings are arranged at an angle to each other below.

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 common rooms. Depending on the type of use and size of the common rooms, the number of hourly air changes is between one and twenty, the air change must be such that an air exchange per head takes place between 20 and 30 m ³ 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.

State of the art

From DE-A-23 08 479 a ventilation element for rooms has already become known which contains a channel which has a passage opening at each end and is 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.

On the basis 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 channel, this results from the reduced channel cross section. increased flow rate, which is however 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-sectional duct section can somewhat counteract the increased flow resistances caused by bending in the flow path.

From US-A-1 236 157 a ventilation device belongs to the prior art, which is between one outer and several Ren passage openings has a channel extending in the direction of the wall plane, in this case the outer passage opening is arranged halfway along the one wall of the channel, while at least one inner passage opening is provided at 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. e.g. achieved by the frames surrounding the individual passage openings, a multiple deflection of the two partial air streams by 90 ° and a total of 360 °, 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-A-1 236 157 is distinguished according to US-A-1 375 378 in that internals are arranged in the subchannels of the housing which adjoin the central passage opening and which direct the air to the air block 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-A-23 31 841 discloses a ventilation device which has the same basic structure as that of US-A-12 36157. 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-A-1931 346, it is also already known to assign duct ventilators to a fan or a cross-flow fan in the region of one of the passage openings, in order to bring about forced ventilation which is independent of all temperature and wind conditions safe room ventilation. 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 velocity by the enlarged duct cross-section and at the same time the (slight) excess pressure generated by the fan or cross-flow blower is reduced. The extent of the pressure reduction is essentially dependent on three sizes, 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 are large relative to the delivery capacity of the fan or cross-flow fan, 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.

A ventilation device of the generic type is known from DE-A-2240937. Here, the chamber is formed in that the boundary wall for the channel, which is adjacent to the larger passage opening, has an end surface which is beveled in the direction of the desired flow pattern. However, this beveled end surface has the result that the cross section of the chamber there gradually increases on the one hand from the passage opening, while on the other hand it gradually decreases to a corresponding extent towards the chamber-side mouth of the channel. This results in a diffuser-like and a nozzle-like effect of the chamber.

In this ventilation device, the chamber also has a cross-sectional area in its plane directly adjoining the passage opening, which is practical in its size is equal to the cross-sectional area of the passage opening. From there, the chamber forms a funnel to the chamber-side mouth of the channel.

This known design of a ventilation device has proven to be disadvantageous in terms of its mode of operation, because here the chamber is not conducive to the air throughput through the duct, but rather rather impairs it, namely on the one hand relative to the passage opening as a type of diffuser and on the other hand with reference to the duct entrance düsenar- ti ^g acts. The resulting mutually opposing effects have a lasting effect on the flow behavior of the air in the duct and inevitably result in throughput losses. Since in the known ventilation device a similar chamber with an enlarged cross-section is arranged or formed between the smaller passage cross-section and the duct, the negative effects arise to an increased extent, so that the throughput losses only result from the additional installation of a blower in one of the chambers can be compensated.

Duct vents with mechanical air delivery have a similar mode of operation, in which the fan or fans are built directly into the flow cross-section of the duct section lying between the two openings, such as e.g. according to DE-B-1 199 956, 1 219 203, 1 222 642 and 1 239 832.

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 section connecting them. Basically, these known ventilation devices differ from the ventilation device according to DE-C-2308479 only by the additional installation of fans in order to achieve mechanical air delivery.

CH-A-384 173 discloses an air connector which is inserted into an air flow channel of relatively large cross-section and has two nozzle-like constrictions arranged one behind the other. By means of this exhaust air connection, additional air flows are to be fed into the air flow channel of large cross section in such a way that they accelerate the flow in the main channel.

The mode of operation of the known exhaust port is therefore different from that of the ventilation device according to DE-A-2 240 837.

US-A-3 800 685 deals with a ventilation system which works with a main flow duct and an auxiliary flow duct for the air, both flow ducts running parallel to one another and at a horizontal distance above one another and working together through a vertical connecting duct. The cooperation between the main flow channel and the auxiliary flow channel is such that part of the air entering the auxiliary flow channel is fed as additional air into the main flow channel via the connecting channel. If, in the known ventilation system, certain cross-sectional relationships are provided between the main flow channel and the auxiliary flow channel, it is necessary to form a pressure chamber between the auxiliary flow channel and the connecting channel, in order to ensure that a certain proportion of those flowing through the auxiliary flow channel Air is actually fed into the main flow duct as additional air. This is the case, for example, if the main flow channel and the auxiliary flow channel have matching cross sections, or also if the main flow channel has an acceleration section in the feed region of the additional air.

The construction effort for this known ventilation system is considerable.

The purpose of the invention is to improve the operation of the duct ventilation, regardless of whether it works on the principle of so-called free ventilation or else on the principle of forced ventilation. The invention is therefore based on the object of specifying a ventilation method and a ventilation device of the generic type, by means of which or with the aid of which human lounges can be optimally ventilated without the occurrence of annoying or even harmful drafts and sound transmissions.

Carried out 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 of the air flow suddenly drops when it flows into the expansion chamber and then before it Outflow from this in turn is suddenly increased and that the air flow between the pressure drop and the pressure increase is deflected or deflected.

This procedural measure surprisingly, regardless of whether ventilation or venting operation takes place, an increased delivery rate can be achieved because the chamber works on the pressure boiler principle and thus causes a pumping effect in the flow direction of the air.

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 increased approximately at the same time Split the pressure levels into several partial flows, while it can be combined with the lowering of the pressure level from several partial flows for the ventilation of rooms.

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 process with an air duct, in which the passage opening at one duct end has a substantially larger passage cross-section than the passage opening at the other duct end and a chamber with an enlarged cross section is arranged or formed in the duct, the wall openings of which lie at an angle to one another , is characterized according to the invention essentially by the fact that the chamber suddenly has a cross section that increases in relation to the one wall opening and the other wall opening is in turn connected to the chamber with a suddenly narrow cross section.

Due to these training features, the ventilation device works according to the pressure vessel principle already mentioned, i.e. The pressure prevailing in the chamber is decisive for the pressure and thus also for the flow conditions in the areas of the ventilation duct which are narrower in cross-section and adjoin this chamber.

It has also proven to be worth copying according to the invention 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 by connecting two duct sections to opposite walls of the chamber. For the same purpose it is also useful to provide the larger passage opening with a neck-like extension protruding into the chamber.

If, according to the invention, 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, then the ventilation duct can be easily removed for forced air movement. 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 can occur which are around 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 the axial fan is provided with blades that are symmetrical to its rotation plane and driven by a reversible electric motor, one and the same ventilation device can be used either for forced ventilation or for forced ventilation of a room.

Further features of the invention lie in the fact that, on the one hand, the channel sections adjoining the chamber and the passage opening with a 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 having a larger cross section 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 air flow can be influenced in a simple manner, the invention provides that at least one wall of the chamber is driven by a drive device, e.g. an electric motor that is adjustable. The drive device can engage the adjustable wall via a reduction gear, for example a screw gear or a slowly running crank.

So that the volume of the chamber can be changed as a function of different pressure and / or flow conditions or also of other changing environmental conditions, such as temperatures, gas concentrations or the like, various points of the flow path are assigned to measurement points which are formed by flow probes. which with a comparison circuit, e.g. a control circuit, which forms a control value transmitter for the drive device.

Pressure-dependent capacitors or inductors, piezoelectric crystals or resistors (strain gauges) variable in length due to the influence of pressure can be provided as flow probes. Bending vibrators made of Seignette salt can also be used as flow probes. Finally, sensors can also be assigned to the control loop as additional measuring points, for example respond to changes in temperature, changes in gas concentration or the like.

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
• 5 to 7 show different cross-sections through the ventilation 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 control 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 which changes the vote.

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 Regulations, the minimum amount of outside air supplied to the room per person per hour - that is the outside air rate - applies to rooms with a smoking ban of 20 m ³ , 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 duct 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 is guided through a substantially larger cross section than in the other passage opening and is spontaneously conducted in the duct immediately before or after the larger cross section through a section with an even larger cross section.

This ventilation method is not 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. The channel 2 extends essentially 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 cross section which is spontaneously enlarged relative to the larger passage opening.

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 adjoins the chamber 5 relative to the passage opening 3 at an acute or, for example, a right angle, in such a way that the chamber-side mouth 7 of the channel section 6 extends from both the front wall 8 and the rear wall 9 as well as 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 Bo denwand 10 and the top wall 11 of the chamber 5 have approximately the same distance, while they have a larger, at least twice the distance from the rear wall 9 of the chamber 5.

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 channel 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, a pump effect is produced via the chamber 5, 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.

4 of the drawing, a ventilation device 1 is shown, which is identical in its basic structure with 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 casing 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 ² ) can produce.

By the interaction of such an axial fan 13 with the. between the passage opening 3 and the channel section 6 or the channel sections 6 'and 6 "arranged chamber 5, a static pressure of about 2 942 Pa = N / m ² can then be generated 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 show that the entire ventilation device 1 is installed in a prismatic housing 14 of, for example, a 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 and the top wall of the chamber are also formed by 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 inserted into the housing 14, with which an end plate 21 can be detached, e.g. 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 moldings 24 and 25 made of soundproofing material, for example foam. The molded part 24 has an essentially U-shaped cross section, the legs and the web of the U-profile being of the same thickness exhibit. The molded part 25, on the other hand, is formed by a block of material which is rectangular in cross-section, in particular a foam block, the cross-sectional thickness of which is at least twice as large as 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 "with a smaller cross section. The passage openings 4' and 4" face the longitudinal wall 26 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 openings face the interior of the room. Within the housing 14, an end plate 27 is also 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 closed 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 effective 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 overall Cross section of the channel section 6 or 6 ', 6 "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 "approximately 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 it is also recommended to adjust the volume of the chamber 5 in such a way that 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 automatically to the adjustment of the transverse walls 19 and 20.

In many cases it may prove to be expedient to adjust the transverse walls 19 and 20 continuously in order to change the volume of the chamber 5 by means of a power drive, e.g. an electric motor, via appropriate transmission links, for example screw 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 'or 4 "at each of its two ends. The channel 2 extends essentially transversely to the axis of the two passage openings 3 and 4'. or 4 ". These passage openings 3 and 4 'or 4 "are assigned to different channel sides and are, based on the installation level of the ventilation device 1, preferably on opposite channel sides.

The two passage openings 3 and 4 '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 4' or 4".

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 'or 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' or 4 ".

The channel section 6 'or 6 "adjoins the chamber 5, viewed in the axial direction of the passage opening 3, at an acute, for example a right angle, in such a way that its chamber-side mouth 7 from both the front wall 8 and the rear wall 9 as well as a certain distance from the floor and ceiling walls.

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 'or 6 "and the chamber 5 preferably have a rectangular flow cross section, while the passage cross sections of the passage openings 3 and 4' or 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 is determined by the volume of the chamber 5 and the pressure differences present at the two different large passage openings 3 and 4 'or 4 ".

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.

9, on the other hand, 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.

To adjust the side walls 19 and 20 or the rear wall 9, an electric motor 30 is used which, in the case of FIG. 8, moves, for example, two screw spindle transmissions 31 ′, 31 ″, with the aid of which the two side walls 19 and 20 are each displaced simultaneously and in opposite directions can.

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 is automatically and continuously adjusted by adjusting the side walls 19, 20 or the rear wall 9 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 41 is formed by the ventilation device 1, as shown in FIGS. 8 and 9. The actuator for the controller 45, 49 or 45, 59, 60 consisting of the chamber 5 or its adjustable walls 9 or 19, 20 is formed by the electric motor 30 shown only in FIGS. 8 and 9.

A management group can Be W can be stored, which determines the values of a controlled variable X. The disturbance variables Z, on the other hand, are determined by the respective environmental influences (air pressure, flow velocity, temperature, gas concentrations) and can, for example, in the ventilation device according to FIGS. 8 and 9 on the one hand at a measuring point 32 in the area of the passage opening 3 and at measuring points 33 or 33 ', 33 "in the area of the passage openings 4 and 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 Z, which can be tapped, for example, using flow probes. Pressure-dependent capacitors and inductors, piezoelectric crystals or length-dependent resistors (strain gauges) can also be used as flow probes. It is therefore possible to provide bending transducers made of Seignette salt as flow probes because they respond to very small pressure fluctuations. It would also be possible to use Pitot tubes or Prandtl tubes as flow probes if these act on the control loop with suitable connecting elements. The disturbance variables Z determined by the flow probes at the various measuring points 32 and 33 are introduced into the control loop according to FIG. 10 and act on it together with the reference variable W in such a way that the electric motor 30 serving as the actuator controls the chamber 5 acting as the regulator by displacement of the walls 9 or 19, 20 varies in volume, in order to influence the ventilation device 1 forming the controlled system in the sense of achieving an optimal ventilation effect.

In the ventilation device according to FIG. 9, by shifting the wall 9 in the chamber 5, the area ratio between the chamber-side mouth 7 of the channel 6 is changed and thus the efficiency for the pressure conversion in the chamber in the region of the discontinuous cross-sectional expansion or the loss coefficient in the region of discontinuous cross-sectional narrowing.

8, however, the cross-sectional ratio between the passage opening 3 and the parallel cross-sectional area of the chamber is changed by the displacement of the walls 19 and 20 in the chamber, likewise for the purpose of increasing the efficiency for the pressure conversion or the loss coefficient influence.

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 example are used, in addition to the disturbance variables Z determined by the environmental influences, to enter correction variables into the control loop, which in turn then influence the reference variable W of the control loop. As a result, a controlled system with compensation can then be created.

10 is constructed as a so-called continuous control, in which the controlled variable X is continuously measured. Here, the controlled system 41 is subject to the disturbance variables Z. The controlled variable X is compared with the setpoint value X _K , which is either a constant or preferably a time-variable reference variable W. The control deviation XW enters into the controller 45, 49 or 59, 60, so that a control value Y comes out of the controller. After the closing condition of the control loop, this manipulated variable Y _R acts with a negative sign as manipulated variable -Ys on the controlled system 41, in such a way that a difference is formed between the disturbance variable Z and the negative manipulated value -Y _s , which then affects the controlled system 41 acts in the sense of eliminating the control deviation XW.

If the ventilation device 1, as shown in FIGS. 4, 5 and 8 and 9, is assigned an axial fan 13 in the area of the passage opening 3, this can of course be functionally included in the control circuit according to FIG. 10, in this way that it is dependent on the environmental conditions present at measuring points 32 and 33 or 33 ', 33 "and possibly also on the pressure and flow conditions prevailing in chamber 5 at measuring points 34 or 34', 34" is switched on and off automatically.

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 according to FIG. 10 as disturbance variables. Thus, at the additional measuring points, suitable sensors can be used not only to determine temperatures, but also, for example, gas concentrations which influence the control circuit according to FIG. 10 and use it to determine the respective operating state of ventilation device 1.

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 optimally ventilate human lounges.

Claims (16)

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, characterised by the fact that the pressure level of the air flow is suddenly lowered (3, 5 or 7, 5) when it flows into the expansion chamber (5) and is then suddenly raised again (5, 7 or 5, 3) before emerging from this expansion chamer (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).

2. Process in accordance with claim 1 for ventilating the room, characterised by the fact that, the pressure level of the air flow conveyed (2, 3, 5, 6, 4) influenced near its upstream end.

3. Process in accordance with claim 1 for extracting air from the room, characterised by the fact that the pressure level of the air flow conveyed (2, 3, 5, 6, 4) is influenced near its downstream end.

4. Process in accordance with claims 1 and 2, characterised by the fact that the air flow is divided into several partial flows (6' and 6") roughly simultaneously with the rise (5, 7) in its pressure level.

5. Process in accordance with claims 1 and 3, characterised by the fact that several partial flows (6' and 6") are combined roughly simultaneously with the lowering of the pressure level (7, 5).

6. Process in accordance with one or more of the claims 1 to 5, characterised by the fact that the extent of the lowering (3, 5 or 7, 5) and the subsequent rise (5, 7 or 5, 3) in the pressure level are controlled or modified (30, 31, 30, 31', 31") volumetrically (5, 19, 20 or 5, 9).

7. Device for ventilating rooms with an air duct . in which the opening at one end of the duct has a far greater passage cross-section than the opening at the other end of the duct and, in the duct, a chamber with an expanded cross-section is arranged or formed, whose wall apertures are at an angle to each other, characterised by the fact that the chamber (5) has a cross-section which expands suddenly in comparison with the opening (3) and the duct (6 or 6', 6") is connected to the chamber (5) again with a suddenly reduced cross-section (7).

8. Ventilation device in accordance with claim 7, characterised by the fact that the cross- sectional plane of the chamber (5) parallel with the plane of the opening (3) is larger than the cross-section of this opening (3) by approximately a multiple.

9. Ventilation device in accordance with one of the claims 7 or 8, characterised by the fact that the cross-section of the chamber (5) parallel with the plane of the duct cross-section (6) is larger than the overall cross-section of the duct (6) by a multiple.

10. Ventilation device in accordance with one of the claims 7 to 9, characterised by the fact that the opening (3) has a cross-section of geometrical form different from that of the chamber (5) and the duct (6 or 6', 6").

11. Ventilation device in accordance with one of the claims 7 to 10, characterised by the fact that two duct sections (6' and 6") are connected (22 or 23) to opposite walls (19 and 20) of the chamber (5).

12. Ventilation device in accordance with one of the claims 7 to 11, characterised by the fact that the larger opening (3) has a neck-shaped extension (12) projecting into the chamber (5).

13. Ventilation device in accordance with one of the claims 7 to 12, characterised by the fact that an axial-flow fan (13) is installed in the larger opening (3) as an air feed device and, as a result, the neck-shaped extension (12) forms a jacket ring surrounding the axial flow fan (13).

14. Ventilation device in accordance with one or more of the claims 7 to 13, characterised by the fact that the duct sections (6', 6") connected to the chamber (5) and the opening (4', 4") are designed as formed parts (24 and 25) in sound- absorbing material.

15. Ventilation device in accordance with one or more of the claims 7 to 14, characterised by the fact that the wall (9 or 21) of the chamber (5) opposite the opening (3) is designed or arranged to be removable.

16. Ventilation device in accordance with one or more of the claims 7 to 15, characterised by the fact that at least one wall (9 or 19, 20) of the chamber (5) is adjustable by means of a drive mechanism, e.g. an electric motor (30), that the drive mechanism (30) engages with the adjustable wall (9 or 19, 20) via reduction gearing, for example helical gearing (31 or 31', 31") or a slowly moving crank, that measuring points (32, 33 or 33', 33", 34 or 34', 34") are provided and formed by flow probes which are connected to a comparing circuit, e.g. a control circuit (figure 10), which forms a control value generator for the drive mechanism (30), that pressure-dependent capacitors or inductors, piezoelectric crystals, particularly flexible resonators of Seignette salt, or else length-dependent resistors affected by pressure (strain gauges) are provided as flow probes, and that the control circuit (figure 10) is provided with sensors as additional measuring points which, for example, respond to changes in temperature, variations in gas concentration etc.

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