The invention relates to a wall fan construction including an entrance opening, a pipe piece, an exit opening, a motor suspension for a motor fitted with wing blades, a diffuser and a damper. The ventilator constructions are useful for ventilation of stables.

Introduction.

An animal herd must, in order to thrive optimally, have fresh air with the right temperature.

A well-known principle for such ventilation of keeping of animals is low pressure ventilation (Low Pressure Ventilation, LPV). The system works by the air being pulled in through passive fresh air valves placed for example as wall valves in the side of the stable. The air is pulled out of the stable by use of active exhaust ventilators placed distributed in the stable room.

Another technique is tunnel ventilation, where the air is pulled in through large openings in the walls in the one end of the stable and is pulled out through large active exhaust units placed in the opposite gable. The system is expensive in both acquisition and operation. Known technique in the area for ventilation of large buildings such as stable buildings is described in for example EP2427954B1 .

It is known from EP2427954B1 that the suspension for a ventilator's motor can be placed such that the motor is placed centrally behind the wing blades' mounting on a center axis, which is rotatably mounted on a main support on the motor. It is hereby achieved that the motor causes less resistance towards the air, which is sucked through by the motor's wing blades, than if the motor was placed away from the center. It is also known to use a conically shaped exit for the air from an exhaust wall fan such as for example as stated in Fig. 1 in WO 9641520A1 .

WO 96/41520A1 describes a wall fan construction in the ceiling on an animal stable. The object of the invention is to create a not too warm ventilation, which also does not cause draught on the animals in the stable. A wall fan in the ceiling sucks air out in the free, while diffusers a distance from the wall fan, also in the ceiling, draw new air into a stable. The diffusers are special holes in the ceiling, where air diffuses through, hence the term diffusers. There is also valves in the sides of the stable, through which additional air intake can occur. A control system regulates the wall fan blower's rotational speed and whether the valves must be open or closed, so the resulting air mixture from sucked in new air and rising up hot air from the animals' bodies do not cause draught and has a suiting temperature.

Fig. 1 shows an exit opening from the wall fan, which is shaped as a cone stump, and which can be understood as a simple actual diffuser. A motor drives the wall fan, but is not additionally described. The wall fan and its motor sit a place in or by the intake in the ceiling.

Additionally, it is known from WO2005061078 A1 for a diffuser in the exit opening to use a double curved curvature radius, which increases out towards the free, in order to prevent run-back of for example water on the outer side of the ventilation channel.

The drawback of the known technique is that it has not been studied if there can be won additional performance of a wall fan, if a wall fan construction has another design instead of the known. It is therefore two objects of the invention, namely to show a wall fan construction, which causes that the wall fan becomes more economical in operation, than if the wall fan sat in a construction, which is usually used for wall fans and to show a wall fan construction, which is more stable in operation. The object of the invention is achieved by using a wall fan construction according to claim 1 .

A hydrodynamic optimally shaped and thus more operationally economic wall fan construction has an exit opening consisting of a diffuser in order to create low speeds by the exit to the open. Hereby, the air pressure is lowered on the wall fan wing's blades as a result of lower air speed back in the system. It can also be seen as a relative suck in direction out towards the open.

It is best that the diffuser has a double curved design, which causes that the exhaust becomes a relatively linear air current, such that turbulence is minimal, whereby energy loss hereto is minimized. Curvature radius is increasing, meaning the farther away from the wall fan wing in direction towards the open the larger curvature. The wall fan's diffuser is different from the curvature of diffusers according to known technique, since the internal surface does not curve outwards, but inwards. Hereby is achieved an even more relative laminar flow of, and simultaneously suck from the air out towards the open. It provides the highest effect of the wall fan.

Another preferred embodiment for a wall fan construction, which in claim 2 additionally includes a special motor suspension. By use of the motor suspension, one can place a motor centrally behind the wing blades, which are mounted on a center axis rotatably mounted on a main support for the motor. Hereby, the air resistance is reduced in relation to if the motor was placed decentralized in the air stream. The main support for the motor suspension has a design, where the number of arms in for example a cross is different from the number of blades on the wing on the wall fan and that they are never parallel. By this is avoided resonance, which could otherwise occur, and which would cause an energy loss for the suspension of the motor. It also means that the suspension becomes more stable.

The wall fan construction with the special motor suspension, according to claim 2, is especially suited for gable wall fans, which are used for exhaust, especially in warm countries in stables where there is used tunnel ventilation. Another preferred embodiment, which in claim 3 is where wall fan construction has a motor mounted in the motor suspension and on which motor the mentioned wing blades are attached.

Moreover, it is preferred that the diffuser has a curved notch, which a butterfly valve with a curved, aerodynamic edge can abut closely to, when the wall fan is stopped.

The open / closing mechanism for the butterfly valve can be a spring clutch or a simple rope drive. The materials must simply be weather-resistant and solid. The chosen solution must also be easy to mount and not require much maintenance.

Other preferred embodiments are, according to claim 4, where a wall fan construction additionally includes a butterfly damper and a joint mechanism, where the ends can rotate freely in relation to each other, for opening and closing of the damper and according to claim 5, where the wall fan construction's joint mechanism includes a fork joint. Claim 6 relates to the use of a wall fan construction according to the invention.

The large items, entrance opening, pipe piece, exit opening and diffuser, can be manufactured in four parts. The smaller items can be advantageous with regard to the logistics by transport. Figures.

The invention will now be explained more fully with reference to the drawings, where Fig. 1 shows a wall fan construction with mounted wall fan according to the invention.

Fig. 2 shows a vertical cut through a part of the wall fan construction. Fig. 3 shows a damper motor with a joint mechanism anchored to a butterfly damper.

Figure 1 shows a 3D visualization of the principle setup of a wall fan construction (1 ) according to the invention. It, generally seen, consists of an inlet flange (2), a pipe piece (3), a butterfly damper (4) and a diffuser (5), which has an internal surface, which curves inwards. On the figure, there is also shown a motor (6), which is mounted in the wall fan construction's motor suspension (7), and a wall fan wing (8), which has 3 blades.

The inlet flange (2) is, as shown, divided into four parts with regard to logistics and transport to end user. The same goes for the pipe piece (3) and the diffuser (5).

The inlet flange (2) and the pipe piece (3) are designed for being able to be assembled and mounted in a suiting hole in a wall / gable. This hole can be round or rectangular depending on the building construction. The hole must fit the pipe piece, which must be in the hole. The flange is designed for abutting towards the wall / the gable and for fixation in the wall / the gable. The motor (6) is placed centralized and is directly connected to the wall fan wing (8). The motor (6) thus provides least possible resistance in relation to the air. Hereby is achieved a more energy efficient solution, since there is neither loss for, for example belt drive or similar, and the product also becomes more durable with less need for maintenance. The motor suspension (7) is made from plastic and the profile of the four legs is designed aerodynamic in order to provide a good flow with minimal turbulence. Also, the four legs are angled such that they will never be parallel to the wall fan wings.

Hereby, noise and the risk of natural vibrations are reduced. The latter is also sought to be avoided by the number of wings and legs being different.

Fig. 2 shows, in 3D, a vertical cut through the wall fan construction. The diffuser (5) is designed with a double curved surface (9) internally, meaning the inner surface curves inwards, and such that the spread angle in the start is low and slowly increases more and more. Hereby is achieved a larger effect of the diffuser (5), than if it was designed as a traditional cone stub shaped diffuser.

The diffuser (5) has the purpose of increasing the output by there being generated a controlled pressure loss, since the air is expanded on the way through the diffuser (5), where the diameter slowly becomes larger.

Thereby, there occurs a suction effect, which entails that there is pulled more air through the wall fan.

In the middle, the butterfly damper (4) is shown in open position. The damper (4) serves to close and seal, such that there is not pulled air into the stable, when an installed wall fan is not in use. The damper (4) abuts to an edge (10) round in the wall fan pipe (3) and against a vertical center pole (11 ), which is placed opposite the connection between the two halves of the butterfly damper. The center post (11 ) has the purpose of providing stability to the damper (4), since it is strengthened, when the negative pressure in the stable sucks the damper (4) inwards. Also, there is on the middle of the post mounted a rotatable hinging (12) of the damper, which causes that the damper (4) besides being hinged in top and bottom, is also hinged on the middle. Hereby, the damper (4) can neither move itself outwards because of wind impacts and pressure effects.

The damper (4) is operated by a damper motor (13), which is mounted on the center post (11 ). Hereby, it lies placed behind the hub on the wing (8), and thereby interrupts minimally in the air stream, while it is also placed such that it is accessible from the stable side. Other gable wall fans with forced motion damper (4) have the damper motor (13) placed externally, such that one in service situations must out and in of the stable.

Fig. 3 shows the damper motor (13) itself in 3D. It is driven by a gear motor. This can turn a quarter rotation, and the movement is transmitted to the damper (4) by use of a joint mechanism. The damper motor (13) turns an angle shaped shaft, such that an arm (14) is moved. This respectively pushes and pulls by opening and closing of the damper (4). The arm (14) is connected to the damper (4) by a middle piece (15), which has an eye (16) in each end, which can rotate freely in relation to each other. The

connection between this middle piece (15) and the arm (14) and between the middle piece (15) and the damper (4) occurs by use of a fork joint (17) connected to an eye on the middle piece by use of a pawl, while basis of each fork joint is rotatably connected to respectively the arm (14) and the damper (4). The joint mechanism thus has freedom degrees in all directions, which is essential in relation to being able to transfer the forces to the damper (4).

The gearing in the joint mechanism is made such that the gear motor's stroke both creates a distortion on the damper (4) in closed and in open position. The distortion causes that wind and pressure effects can not immediately move the damper position. The joint mechanism is symmetrical around the vertical symmetry plane in the wall fan, such that the damper halves (4) will open synchronized and without distortion. The damper halves have recesses in the material, so the halves fit into each other in assembled state by fully open damper. Hereby, the folded up damper halves will be assembled almost as stiffly and fill as little in the air stream as an undivided damper of the same size.