Ventilating System

Abstract

A ventilating system for an enclosed space having a plurality of air inlet ducts communicated therewith with each duct including a distributor defined by vertically spaced plates forming a peripheral discharge with the upper plate having a central aperture receiving a fan. Adjustable members are provided between the plates for varying the discharge characteristics of air and air inlet means is provided between the distributor and ceiling for inlet of air from the space into the distributor with the air inlet means having control flaps or baffles associated therewith for simultaneously controlling the air inlet from the space and the air inlet from the ducts for varying the ratio of recirculated air and fresh air being discharged from the distributor.

Parent Case Text

This is a continuation of application Ser. No. 826,176, filed May 20, 1969, now abandoned.

Description

The invention concerns a ventilating system, for instance for stables greenhouses, and large halls, where the intake of fresh air is done by mixing with return air before the air, through one or several distributorheads, is spread through the room. Where ventilation is required, the spent air is removed through one or several extractors.

The extraction system at the best known ventilating plants consists of a number of fans placed either in the wall or in the chimney(s). mainly the latter. Hereby is caused a partial vacuum in the room so that fresh air can be introduced from outside through a number of ventilators placed in the walls of the room. The ventilators are normally equipped with dampers for regulation of the airstream. Relatively small climatic alterations demand, however, immediately corresponding alterations of the damper position in all ventilators. Should the alteration take place during the night or during such times when the room is left unminded, it can result in catastrophic alterations in the climate, since for instance very few domestic animals can tolerate draught or too low air circulation. Furthermore, the force of the wind will result in a larger amount of air entering the building on the windy side as against the lee side.

It has therefore been attempted to inject air mechanically in order to avoid the above disadvantages. In newer systems of this type the extraction chimney has been surrounded with a pipe of a larger diameter so that a circular area is created around the extraction chimney. Hereby is made a double chimney. Down through this area, which is connected with the open air directly above the roof, fresh air is sucked in, whilst the spent air is pressed out through the middle, circular area and sent vertical up over the roof. The entire double chimney ends under the ceiling in the room, which is to be ventilated. The power for it is supplied by an axial fan with a special propeller, which inner circular part has a diameter corresponding to that of the extractor chimney and is placed directly under this. With this part the air is directed upwards. The outer part of the propeller corresponds to the circular area around the extractor chimney, and here the propeller blades are so shaped so that fresh air is sucked down through the circular area. As not the same amount of air is required at all times the system is equipped with mixing dampers placed part of the way up in the chimney so that all or a part of the spent air which is expelled through the centre extraction chimney can be returned down through the outer circular area whilst being mixed with the incoming fresh air. Thereafter, with the help of a number of injection ports the air is directed radially round the room parallel with the ceiling or slightly downward.

Admittedly with such a system one can avoid most of the disadvantages with having ventilators in the walls but it does entail other disadvantages. The special propeller is very expensive and complicated to produce, and the same goes for the double chimney pipe. The narrow outer circular area together with the sudden turning which the return air must make in order to get from the inner to the outer pipe means a quite considerable air resistance and thereby a heavy power demand. As especially stable air contains rather large quantities of dust and humidity, these will, among other places, settle in the outer circular area, which is difficult to clean just as condensation problems easily will arise in inaccessible places inside the chimney. The air injected into the room will be constant the whole year through, where one could wish for a stronger air injection during the summer and a weaker one during the winter. Finally, it will be necessary to discard the existing suction devices in rooms, where this system is now wanted.

The purpose of the invention is to surmount the disadvantages at known constructions where injection of air is used instead of wall-ventilators and furthermore to attain an improved distribution of the air in the room. According to the invention this is reached with a system with one or several centrally under the ceiling placed injection devices, each equipped with a distributorhead, which from its circle injects air into the room mainly parallel with the ceiling or sloping downwards thus forming a aircarpet of injection jets from the distributorhead. The injected air consists partly of fresh air from outside and partly of returned air from the room, the proportion of which can be regulated with mixing dampers. Devices for extraction of the spent air are placed separately from the injection.

The invention is unique in that the mixing dampers in the injection device are placed between the ceiling and the distributor head and that the returned air is taken from the area between the ceiling above and the injection jets below.

With this construction a long line of advantages has been attained. One can mix fresh air and returned air without requiring a complicated double chimney and only a single channel to the open air is required which is cheaper to produce and easier to keep clean from dust. As no hot humid stable air will be sent up through the same chimney which transports cold air downwards, the problems of condensation will be minimum. It is not necessary, either, to use a propeller with a double function as all that is needed is a simple propeller or a radial fan-wheel. Furthermore, one rarely needs to discard already existing suction devices, which is of great importance, as these are available in nearly all newer rooms. As the ducting system is simple with no narrow ducts and the air does not have to make sharp turns, the power consumption is reduced in a plant (system) set up in accordance with the invention below, which is of great importance, as the system normally must be on 24 hours a day.

Of greatest importance for rooms with animals is finally the fact that with this invention the amount of air, which reaches the animals from the air injection, automatically will become less when more returned air is mixed in with the injected air, whilst the amount of air likewise automatically is increased as one approaches pure outside air injection without mixture of returned air. This is because the returned air is taken from the area between the ceiling and the injection jets, and it is therefore only possible to get returned air by taking from the injection jets with the result that the more returned air needed the more is taken from the injection jets before these reach the limits of the area an injection device covers. This is important because with such a system the dampers during the winter are adjusted so that the cold air is mixed with a great proportion of returned air by which the injected mixture reaches a temperature only a few degrees below the temperature in the stable, which for most types of animals ideally is about 15.degree.-18.degree. Celcius. A proportionally lesser movement of air is also required around the animals during the winter as against the summer, and this is also obtained by the automatic reduction of the amount of air after it has been despatched from the distributorhead. Reversedly; a greater movement of air is needed during the summer, where the temperature of the fresh air outside may be considerably higher than the temperature wanted in the stable, but where the increased amount of air then will assist the animals to get rid of the heat.

According to the invention the ventilating system can be arranged in such a way that the suction devices consist of a number of ventilators with regulating dampers which, electrically or mechanically, are joined to the dampers placed in the injection devices in such a way that the expelled air remains in direct proportion to the injected air and that this proportion is controllable. By letting the dampers follow each other in this way, constant pressure conditions are obtained in the stable as against the surroundings, and by regulating the proportion one can decide whether positive, negative or neutral pressure is required as against the surroundings. If, for instance, the regulating damper is coupled with the mixing damper in such a way that -- although the dampers otherwise follow each other -- there is all time a little more opening for the regulating damper than the mixing damper opens for the fresh air, a negative pressure will be created in the stable on account of the greater amount of air expelled. Again a positive pressure will be created if the damper are adjusted to each other in such a way that more fresh air is injected than is expelled. A positive pressure can have the advantage that no false air reaches the room through occasional leaks at doors etc. A positive pressure in a room can cause humid air to escape out into adjoining rooms, and where such are present it may be best to keep a constant small negative pressure in the room. Therefore, it is an advantage to be able to decide the pressure conditions in the room at will.

Furthermore there will, according to the invention, in certain forms of embodiment, be an advantage in letting the adjustment of the coupled dampers be done by one or several servo motors on a signal from a communal thermostat or hydrostat.

The mixing damper itself can consist of one or several dampers flexibly suspended so that they in one extreme position completely cut off the returned air and in the other extreme position cut off completely for the fresh air injection and in the intermediate stage control the proportion between returned air and fresh air.

In a particularly advantageous form of distributorhead this will consist of two horizontal, preferably square follower plates held at a suitable distance by a number of gap-plates, consisting of a tubular part, which may be split, and two flaps. With the help of bolts, fitting into the tubular part and into holes along the cicumference of the follower plates these are fitted around the gap-plates so that a number of air-gaps is formed, corresponding to the number of gap-plates. The flaps in the gap-plates are made of flexible material and one can therefore after assembly adjust the flaps and thereby direct both direction and amount of air through the individual air-gaps. In one particular type of this one can furthermore distribute the gap-plates around the circumference of the distributorhead in such a way that proportionally more air is injected from the corners of the square follower plates. Finally one can according to the invention in a particularly easy way add heat to the room by just adding hot air to the space between the ceiling and the injection jets preferably near the mixing dampers, whereby the warm air will follow the returned air for mixing before the distributorhead, which will spread the heat in the room. One thereby avoids having to build heater into the injection device, as this placed here would become clogged with dust.

In the following the invention has been more explicitly explained through same versions under reference to the drawing, on which

FIG. 1 shows a version with two injection devices and one suction device in part of a room seen from the side.

FIG. 2 shows the same seen from above.

FIG. 3 shows a vertical section through an injection device by the air-gap.

FIG. 4 shows a horizontal section through the same by the air-gaps.

FIG. 5 shows a version of a gap-plate in perspective.

An injection device can consist of an inlet duct 1 over a box shaped mixing chamber 2 and underneath a distributorhead 3. The inlet duct is taken through the ceiling 4 down to the room 5, where ventilation is required, and stands in connection with the outside air in a manner not shown and from where fresh air is introduced in the direction as shown by the arrow 6. The mixing chamber has in this version two identical mixing dampers 7, suspended by their uppermost edges in journals 8 so that the mixing dampers in their one extreme position close for a returned air opening 9 in the two sides 10 of the mixing chamber, whilst they in their other extreme position close for fresh air by meeting an angled dividing plate 11. Normally the two mixing dampers will have the same setting but in order to illustrate further the working of the dampers, the left mixing damper in FIG. 3 is shown set so that both fresh and returned air is introduced, whilst the right mixing damper is shown open for full returned air 12, and it can be seen that the mixing damper in this position closes completely for the fresh air. The setting can be done manually but it is more advantageous to couple it together with the setting of the regulating dampers 13 in one or several suction chimneys with built in ventilators 14 with the help of a steel wire or bar 15. The regulation of the dampers coupled together in this way can then take place with a servomoter 16 in a signal from a thermostat or hygrostat, not shown, which opens more for the fresh air introduction and suction, when it becomes too hot or humid in the room.

The distributorhead 3 sucks air from the mixing chamber above and thereafter presses the air out between two horizontal follower plates 18 and 19, of which the top one has a circular opening in the middle for the ventilator, and the bottom one has from its centre a distributor ring coming up 20 which assist in turning the air from vertical to horizontal and gives an even airstream out towards the circumference, of the distributorhead. There is around the circumference, between the follower plates, fixed a number of gap-plates 21, which in a purposeful version is shown in FIG. 5. where the gap-plate is made of a relative thin, flexible sheet with a tubular part 22 which fits a bolt 23 and is split with two flaps 24. The gap-plates are held in their place by the bolts and can be turned on these until the flaps are set in the position for the airstream required direction, before the bolts which also go through suitable holes in the follower plates 18 and 19, tighten these around the gap-plates which thereby are held in the required positions. In this way is formed a number of air-gaps 25 corresponding to the number of gap-plates along the entire circumference of the distributorhead, from where the air will form a carpet of horizontal or downward sloping injection jets 26. As is apparent from FIG. 2 the corners in the room 5 are further away than the sides of the area an injection device must supply, and the area will nearly always be a rectangular one. It would therefore be useful to have a greater amount of air coming from the corners than from the sides of the distributorhead, and a method for doing this is explained in FIG. 4 which for clarification has been divided up into four parts according to the lines A-B and C-D With the help of these and four centre lines a each quarter is now divided into for instance five angles of equal size 27, and each angle will now represent the same amount of air, since the ventilator with the assistance of the distributor-ring 20 can be considered to distribute the air evenly all round. If the centre of the bolts 23 for the gap-plates are fixed parallel to the edge of the follower plates, four bolt centre lines b can be drawn, and where these cross the centre lines a will be points 28, as shown in the top left quarter of FIG. 4. This is where the bolts for the gap-plates are to be affixed, if the amount of air also after having left the distributorhead should be even in all directions. In the bottom left quarter of FIG. 4 the gap-plates are placed in this manner. Should more air be required from an air-gap in the corner, this can be obtained by shifting the bolts here away from points 28 so that the air-gap in the corner becomes larger at the expense of the adjoining gaps as shown in the top right quarter of the drawing. Finally, it is shown in the bottom right quarter that the gap plates can be turned on the bolts 23 and the flaps bent so that the air thereby partly can be in the required direction and also the air-gaps can be more or less closed, which might be preferred in rooms of irregular shape.

According to the invention there is no reason why the follower plates cannot be oval, circular or rectangular, since the gap-plates also then can be shaped and affixed as above.

There is according to the invention no reason either for the distributorhead and mixing chamber having other shapes than those indicated in FIG. 1-4, as long as they fulfill the characteristics of the invention.

Claims

What I claim is:

1. A ventilating system for a space having a ceiling and an air inlet duct, a distributor disposed below the ceiling and communicated with said duct, adjustable air inlet means communicated with the space below the ceiling and above the distributor, said air inlet means being in communication with said distributor, said air inlet means including an adjustable baffle member simultaneously controlling the flow rate of air from the air inlet duct and from the space thereby varying the ratio of air from the inlet duct and from the space being discharged from the distributor, said distributor including upper and lower plates spaced from each other and defining a peripheral outlet, and adjustable means interposed between the plates peripherally thereof to vary the discharge characteristics of the air being discharged peripherally of the distributor to facilitate dispersal of air throughout the space.

2. The structure as defined in claim 1 wherein the upper plate of said distributor has a central opening therein communicating with the air inlet duct and the air inlet means, a fan disposed in operative association with the opening for conveying air downwardly into the space between the upper and lower plates of the distributor.

3. The structure as defined in claim 2 wherein said adjustable baffle member in the air inlet means in one position will close off the air inlet means and in another position will close off communication with the air inlet duct whereby adjustment of the baffle member will vary the ratio of air taken from the space and the air inlet duct.

4. The structure as defined in claim 3 wherein said adjustable means between the upper and lower plates forming the distributor include generally U-shaped gap plates having adjustable diverging legs extending toward the peripheral edges of the plates, and means adjustably interconnecting the plates for clamping the legs of the gap plates in adjustable position thereby enabling variation in the space between the adjacent free edges of the gap plates for varying the air discharged between the gap plates.

5. A ventilating system for a space having a ceiling and an air inlet duct, a distributor disposed below the ceiling and communicated with said duct, adjustable air inlet means communicated with the space below the ceiling and above the distributor, said air inlet means being in communication with said distributor, said distributor including plate means generally parallel with the ceiling and defining a peripheral outlet for horizontally discharging air while substantially preventing axial downward air flow, and adjustable means mounted in said outlet for varying the outflow characteristics of air from the distributor, said air inlet means including adjustable baffle means simultaneously controlling the flow rate of air from the air inlet duct and from the space thereby varying the ratio of air from the inlet duct and from the space being discharged from the distributor, said plate means including upper and lower plates spaced from each other and defining the peripheral outlet, said upper plate having an opening communicating with the space below the ceiling and above the distributor.

6. The structure as defined in claim 5 together with fan means disposed in operative association with the opening in the upper plate for conveying air downwardly into the space between the upper and lower plates of the distributor, said adjustable means between the upper and lower plates forming the distributor including generally vertically disposed plates extending generally radially thereof, and means adjustably mounting the plates in adjustable position between the plates thereby enabling variation in the spacing between the adjacent free edges of the vertical plates for varying the air discharge between the vertical plates.