EP0329498B1 - Device for moving air in a duct - Google Patents

Abstract

Method brought about by a weak flow of air or of fluid blown or pulsed at high speed through a nozzle (3) at the centre of the duct (1) in the desired direction of circulation. Application examples are: - method for extraction of air by blowing in the centre of the duct (1), which is open on the outside, and close to the outlet, of a weak flow of air at high speed in the direction of extraction; - regulating blowing method for conditioned air by virtue of a weak flow of air blown at high speed in the centre of the duct (1); - method for moving delicate fluids, for example for the extraction of exhaust vapours in condensation boilers. <IMAGE>

Description

The present invention relates to the setting in motion of air or more generally of fluid in relatively tight ducts, by a low flow of air or of fluid blown or pulsed at high speed in the center of the duct in the desired direction of circulation. .

There are already traditional ventilations in which the movement of the air is done by motorized fans placed in the air stream, that is to say that all the moving air passes through the ventilator. These fans are helical or centrifugal.

• la ventilation mécanique contrôlées (VMC), qui permet l'extraction mécanique de l'air vicié dans les salles humides (toilettes, salles de bains, cuisines) des logements ou des bâtiments tertiaires ou industriels,
• la climatisation qui permet de souffler de l'air chaud ou froid, suivant les besoins climatiques, dans des locaux.

It is on this principle that are carried out:

• controlled mechanical ventilation (VMC), which allows the mechanical extraction of stale air in humid rooms (toilets, bathrooms, kitchens) of housing or tertiary or industrial buildings,
• air conditioning, which blows hot or cold air, depending on climatic needs, into rooms.

• dans les éjecto-convecteurs, où de l'air soufflé à grande vitesse, après une batterie de climatisation d'un convecteur, permet à un débit nettement plus important d'air recyclé dans le local de traverser la batterie, grâce à la dépression créée derrière les buses d'air soufflé à grande vitesse,
• dans le brassage de l'air ambiant dans les grands locaux, par des jets d'air climatisé et à grande vitesse.

Similarly, there is already the use of high speed air jets:

• in ejector convectors, where air blown at high speed, after an air conditioning coil from a convector, allows a significantly greater flow of air recycled in the room to pass through the battery, thanks to the vacuum created behind the high speed blown air nozzles,
• in the circulation of ambient air in large premises, by air jets of high-speed air conditioning.

Patent DE-C-9 630 describes a device for activating the ventilation of a duct using high-speed air jets.

The device described in DE-C-9 630 is composed of a collective air extraction duct made up of collective extract air ducts open to the outside, and a medium pressure air network comprising a fan, a network of horizontal and vertical ducts of small sections. The medium pressure air is blown in the center of the collective duct of extracted air in the direction of extraction, by an activation tube bolted to the circuit.

The invention relates to the movement of air or more generally of a fluid, in relatively tight sheaths, by a low flow of air or of fluid blown or pulsed at high speed, in the center of the sheath, in the desired direction of movement. The present application proposes a device for activating the ventilation of an air extraction duct according to claim 1.

It is thus possible to control the speed of the air or the fluid in the sheath at any location, thus disseminating the driving force as required, better controlling the pressure drops, the head heights and the acoustic levels.

• dans la construction neuve et ancienne :
  • . l'extraction de l'air, le plus souvent pollué,
  • . le soufflage de l'air, le plus souvent climatisé.
• dans l'industrie :
  • . l'aspiration ou le refoulement de fluides dangereux ou corrosifs ou à haute température, acceptant le mélange d'un fluide neutre en faible proportion mais qui le met en mouvement car il est éjecté à grande vitesse.

The invention relates, when the fluid is air:

• in new and old construction:
  • . air extraction, most often polluted,
  • . blowing air, most often air conditioned.
• in industry :
  • . suction or discharge of dangerous or corrosive fluids or at high temperature, accepting the mixture of a neutral fluid in small proportion but which sets it in motion because it is ejected at high speed.

• un ventilateur à moyenne et haute pression, le plus souvent 1OO à 3OO mm de colonne d'eau suffisent, est placé soit en terrasse mais le plus souvent en sous-sol, de préférence en chaufferie ou en sous-station, ce qui en facilite l'entretien.
• un réseau constitué de gaine ou tuyau de faible diamètre (∅ 1OO à 2OO mm environ) en PVC, polyéthylène ou autre matériau, va du ventilateur à chaque bâtiment en sous-sol ou en galerie.
• à chaque bâtiment une gaine verticale, peu utilisée,permet de faire monter le réseau jusque sur la terrasse.
• sur la terrasse, le réseau est posé sur l'étanchéité, accroché éventuellement au pied de quelques souches.
• par groupement de souche de ventilation un "barillet" réalisé sur un branchement de gaine ou éventuellement directement sur la gaine principale, permet d'alimenter les canalisations de faible section, ∅ 2O à 5O mm, souples ou rigides allant à chaque souche.
• au bout de chacune des canalisations est fixée une crosse rigide (en métal ou en plastique de 1 à 2 m de long environ) qui est glissée dans le conduit de ventilation par le sommet de la souche, le plus souvent sans avoir à démonter le chapeau de celle-ci.
• au bout de la crosse se trouve une buse réglable permettant d'équilibrer le réseau. L'air est soufflé, par exemple à une vitesse de 2O à 3O m/seconde ; au centre du conduit (2O x 2O cm par exemple) le jet d'air a tendance à se coller rapidement vers les parois du conduit et donc à très bien balayer la surface de celui-ci. Il se crée une dépression en amont du jet d'air qui augmente d'autant le débit d'air extrait naturellement par tirage thermique. De plus, les buses seront telles qu'à faible débit d'air soufflé, cet air soit soufflé latéralement, ralentissant ainsi le débit de la ventilation naturelle par tirage thermique. En effet, dans les ventilations naturelles par conduits collectifs le débit d'air extrait est d'autant plus important qu'il fait plus froid dehors. D'où un débit trop fort par grand froid, d'autant plus que l'air neuf est très peu chargé de vapeur d'eau. Il est donc souhaitable de pouvoir ralentir le débit de ventilation naturelle par grand froid et de pouvoir l'activer pendant les autres saisons.

Ces buses souffleraient latéralement :

• soit parce qu'à faible débit, la réaction du jet sur les parois latérales du conduit sera plus faible et que la buse articulée à sa base aura tendance à s'incliner par son propre poids.
• soit par action sur un petit clapet ou volet intérieur à la buse et commandée électriquement ou par air sous pression. Par régulation et programmation la ventilation serait activée quelques heures par jour suivant les besoins et les saisons, en fonction de la température extérieure, de la vitesse du vent, de l'ensoleillement, du degré d'humidité...

Most often, depending on the shape and pressure drop of the network, the air flow or fluid entrained in the sheath is 5 to 10 times that of air or fluid blown or pulsed at high speed. We say that the multiplier effect is 5 to 10.
* For example, in old housing with collective ducts as high ventilation, it is possible to carry out ventilation called "activated natural ventilation" composed of:

• a medium and high pressure fan, usually 1OO to 3OO mm of water column is sufficient, is placed either on the terrace but most often in the basement, preferably in the boiler room or in a substation, which facilitates maintenance.
• a network made up of sheath or pipe of small diameter (∅ 1OO to 2OO mm approximately) in PVC, polyethylene or other material, goes from the fan to each building in the basement or gallery.
• each building has a vertical duct, little used, which allows the network to be mounted up to the terrace.
• on the terrace, the network is placed on the waterproofing, possibly hung at the foot of some stumps.
• by grouping of ventilation stumps a "barrel" produced on a duct connection or possibly directly on the main duct, makes it possible to supply the pipes of small section, ∅ 2O to 5O mm, flexible or rigid going to each strain.
• at the end of each of the pipes is fixed a rigid stick (made of metal or plastic, about 1 to 2 m long) which is slid into the ventilation duct by the top of the stump, most often without having to dismantle the cap of it.
• at the end of the stock is an adjustable nozzle to balance the network. The air is blown, for example at a speed of 20 to 30 m / second; in the center of the duct (2O x 2O cm for example) the air jet tends to stick quickly to the walls of the duct and therefore to very well sweep the surface of the latter. A vacuum is created upstream of the air jet, which increases the air flow extracted naturally by thermal draft. In addition, the nozzles will be such that at low flow of blown air, this air is blown laterally, thus slowing the flow of natural ventilation by thermal draft. In fact, in natural ventilation through collective ducts, the flow of extracted air is all the more important the colder it is outside. Hence a too strong flow in cold weather, especially since the fresh air is very little loaded with water vapor. It is therefore desirable to be able to slow the rate of natural ventilation in very cold weather and to be able to activate it during other seasons.

These nozzles would blow laterally:

• either because at low flow, the jet reaction on the side walls of the duct will be weaker and the nozzle articulated at its base will tend to tilt by its own weight.
• either by action on a small valve or flap inside the nozzle and controlled electrically or by pressurized air. By regulation and programming the ventilation would be activated a few hours a day depending on needs and seasons, depending on the outside temperature, wind speed, sunshine, humidity ...

Thus, the flow of fresh air in old buildings can be controlled and greatly reduced compared to that which currently exists, which will allow significant energy savings. In addition, comfort can be increased and the risk of condensation, especially in mid-season, will disappear.

Finally, the type of natural ventilation activated has the great advantage of no longer being dangerous when individual gas boilers are connected to the ventilation duct: if the fan stops, there is always the thermal draft, while with the VMC there is no technically reliable solution found to date, despite the fatal accidents that have occurred.

• la gaine d'extraction peut être comme actuellement, réalisée par une seule gaine principale, la perte de charge des bouches étant assez importante pour équilibrer les débits. Cette conception est meilleure que celle avec une VMC actuelle car la perte de charge du ventilateur est enlevée. Cependant, il n'est pas totalement sûr, dans ce cas, que le tirage thermique soit toujours suffisant pour empêcher le refoulement des fumées de chaudières à gaz.
• la gaine d'extraction est réalisée en béton, terre cuite ou en métal sous le principe d'un réseau de conduits collectifs (primaire) : chaque bouche donne sur une gaine verticale d'un étage débouchant sur une gaine secondaire de quatre étages, par exemple, cette dernière pouvant déboucher sur une gaine tertiaire, pouvant aller jusqu'à seize étages, par exemple, et recevant tous les quatre étages l'extrémité d'une gaine secondaire et ainsi de suite.
• les gaines primaires peuvent être les unes sur les autres formant qu'une seule gaine ayant des coupures par étage.
• les gaines secondaires peuvent être les une sur les autres, formant qu'une seule gaine ayant des coupures tous les quatre étages, etc...
• ces coupures peuvent être fixes comme actuellement. Mais pour des raisons de facilité de fabrication et de nettoyage, les coupures pourraient être mobiles autour d'un point ou d'un axe, s'ouvrant toutes ensemble ou séparément grâce à des tiges, câbles faisant toute la longueur de la gaine ou par commande électrique ou pneumatique.
  Chaque coupure serait réalisée par une plaque, qui fermée permet une assez bonne étanchéité à l'air entre deux gaines verticales.

L'air extrait serait activé en partie haute de la gaine terminale par jet d'air soufflé à grande vitesse vers l'extérieur à partir :

• d'une crosse glissée comme dans la construction ancienne à partir du sommet de la gaine.
• de tube d'activation, traversant la gaine terminale à partir de boulonnage prévu à cet effet, et courbé vers la sortie. L'air peut être activé à différents niveaux dans les gaines primaires, secondaires, et terminales par des jets d'air soufflé à grande vitesse à partir de tubes traversant la paroi de la gaine par boulonnage, et courbés vers la sortie, le réseau d'air à haute pression étant le plus souvent à l'extérieur des gaines. Ainsi il est possible d'obtenir les pressions statiques et dynamiques désirés le long des gaines et d'avoir ainsi des gaines plus légères qu'actuellement.

* Par exemple dans un réseau de soufflage d'air climatisé :
L'air pourrait être mis en mouvement, en amont ou en aval, de chaque élément du réseau principal provoquant des pertes de charges importantes, par un jet d'air soufflé à grande vitesse dans le sens de circulation désirée. Ce jet proviendrait d'un tube d'activation traversant la gaine, courbé dans le sens de la circulation de l'air, et relié à un tuyau d'air à haute ou moyenne pression suivant la gaine principale. Ainsi la pression statique + dynamique dans la gaine principale pourrait être contrôlée en tout point, et par exemple, être faible. Il est ainsi possible de régler à volonté dans chaque partie du réseau d'air climatisé, le sens de l'air, et son débit, en jouant sur le débit d'air du seul réseau moyenne pression, à travers des tubes d'activation de faible section traversant la gaine du réseau d'air principal, et bien placés, grâce à des vannes petites, nettement plus étanches, fiables et moins chères que les volets d'air classiques, d'un type se rapprochant des vannes hydrauliques.
* Par exemple dans les chaudières à condensation où les fumées saturées d'eau seraient refoulées dehors par soufflage à grande vitesse d'air après l'échangeur, ce qui permettrait de vaincre les pertes de charge de l'échangeur, de diminuer le taux d'humidité des fumées, sans risque de corrosion comme actuellement avec les ventilateurs tournants dans les fumées.In addition, maintenance conditions should be significantly less expensive than with a CMV.
* For example in extractions in the context of new construction or new extraction:

• the extraction sheath can be as at present, produced by a single main sheath, the pressure drop of the outlets being large enough to balance the flow rates. This design is better than that with a current VMC because the pressure drop of the fan is removed. However, it is not entirely certain, in this case, that the thermal draft is always sufficient to prevent the backflow of fumes from gas boilers.
• the extraction duct is made of concrete, terracotta or metal under the principle of a network of collective conduits (primary): each mouth gives onto a vertical duct of one floor leading to a secondary duct of four floors, by example, the latter can lead to a tertiary sheath, up to sixteen stages, for example, and receiving every four stages the end of a secondary sheath and so on.
• the primary sheaths can be on top of each other forming a single sheath having cuts per stage.
• the secondary sheaths can be one on top of the other, forming a single sheath having cuts every four stages, etc.
• these cuts can be fixed as currently. But for reasons of ease of manufacture and cleaning, the cuts could be movable around a point or an axis, opening all together or separately by means of rods, cables running the entire length of the sheath or by electric or pneumatic control.
  Each cut would be made by a plate, which closed allows a fairly good air tightness between two vertical ducts.

The extracted air would be activated in the upper part of the terminal duct by a jet of air blown at high speed outwards from:

• of a slide stock as in the old construction from the top of the sheath.
• of activation tube, passing through the terminal sheath from the bolt provided for this purpose, and bent towards the outlet. Air can be activated at different levels in the primary, secondary, and terminal ducts by blowing air jets at high speed from tubes passing through the wall of the sheath by bolting, and bent towards the outlet, the high-pressure air network being most often outside the sheaths. Thus it is possible to obtain the desired static and dynamic pressures along the sheaths and thus to have lighter sheaths than at present.

* For example in a supply air conditioning network:
The air could be set in motion, upstream or downstream, of each element of the main network causing significant pressure drops, by a jet of air blown at high speed in the desired direction of circulation. This jet would come from an activation tube passing through the sheath, curved in the direction of air circulation, and connected to a high or medium pressure air hose following the main sheath. Thus the static + dynamic pressure in the main sheath could be controlled at any point, and for example, be low. It is thus possible to adjust at will in each part of the air conditioning network, the direction of the air, and its flow, by playing on the air flow of the only medium pressure network, through activation tubes of small section crossing the sheath of the main air network, and well placed, thanks to small valves, clearly more tight, reliable and less expensive than the traditional air shutters, of a type approaching the hydraulic valves.
* For example in condensing boilers where the water-saturated fumes would be expelled outside by blowing at high speed of air after the exchanger, which would overcome the pressure losses of the exchanger, reduce the rate of humidity of the smoke, without risk of corrosion as currently with rotating fans in the smoke.

• La figure 1 est un exemple de "ventilation naturelle activée" dans une construction ancienne ayant une ventilation haute d'extraction par conduits collectifs.
• La figure 2 est un exemple de "ventilation naturelle activée" dans une construction neuve avec des gaines d'extraction shunt superposées.
• La figure 3 est un exemple de soufflage d'air climatisé.

The invention will be explained in a purely indicative manner during the description which follows, with reference to the appended drawings:

• Figure 1 is an example of "activated natural ventilation" in an old building having a high exhaust ventilation by collective ducts.
• Figure 2 is an example of "activated natural ventilation" in a new construction with superimposed shunt extraction ducts.
• Figure 3 is an example of air conditioning blowing.

FIG. 4 is an example of a corrosive fluid delivery, here in the case of a condensing boiler.

In Figure 1, the air is extracted by traditional extraction ducts by collective ducts (1). At the top of the sheath is slipped a stick (2) having at its end a nozzle (3) which is thus placed in the center of the sheath. This stick is connected to a small diameter pipe (4) which is pricked, by set of stumps, on the roof pipe (5) by a barrel (6). The roof pipe is connected to a vertical sheath (7) passing through an empty duct. This vertical pipe is connected to a horizontal pipe (8) in the basement, the latter going to the medium pressure fan (9) placed in the substation or in the boiler room. This fan is controlled by a regulator (1O) acting according to the hours and atmospheric conditions.

In FIG. 2, the superimposed collective conduits are made of rolled metal (1). On each floor, the primary duct is cut by a metal shutter (11), movable around an off-center horizontal axis (12). In the horizontal position, the flap is applied hermetically to a metal crown (13). The displacement of the superimposed flaps is achieved by a metal rod (14) connected to each flap near the end opposite to the axis, and thus making the entire height of the duct, that is to say as many floors as building. This rod is operated from the roof or the basement. The cleaning of the duct is thus carried out over the entire height, all at once, for example using a special vacuum cleaner. The extraction is activated by a tube (15) screwed onto the wall of the last duct, curved towards the outlet.

In FIG. 3, the air-conditioning supply network (16) is accelerated in places by activation tubes (15) passing through and bolted to the network (16), having as always nozzles (3) at their ends. , and connected to the medium pressure air pipe (5) and controlled by valves (17). These activation tubes can be placed either a little far before an obstacle (exchanger, ...) creating high pressure drops, or after. On bypass ducts, an activation tube can be placed to accelerate the flow in this duct, if it is in the direction of the network (18) or to stop the air flow, and even reverse the flow direction of air, if he is placed in the opposite direction (19). Optionally, to increase the authority of an activation tube, a "venturi" (2O) can be placed in front of the nozzle.

In FIG. 4, on the smoke duct (21) of a condensing boiler (22) is placed an activation tube (3) connected to a medium pressure fan (9) taking the air outside or in the boiler room.

Claims (4)

1. Device for activating the ventilation of an air extraction duct, comprising extracted air collection conduits (1, 1′) open to the outside, and a medium pressure air network comprising a fan (9) and a network of horizontal and vertical ducts (5,7,8) of small section, the medium pressure air being blown at the centre of the extracted air collection conduit (1,16), through a nozzle (3), characterised in that the nozzle for air blown at medium pressure is such that it can blow the air either in the axis of the conduit (1,16) to increase the amount of air extracted or laterally to slow it down, control means effecting the change from axial blowing to lateral blowing.
2. Device according to Claim 1, characterised in that the control means are electrical or pneumatic means acting on an internal flap of the nozzle.
3. Device according to Claim 1, characterised in that the nozzle is mounted so as to be articulated at its base, the control means being means for reducing the amount of air blown bringing about the inclination of the nozzle about its articulation under the effect of its weight.
4. Device according to any one of the preceding Claims, characterised in that the medium pressure air network (4,5,6,7,8) is made from polyvinyl chloride, polyethylene or other products of synthesis.

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