A DEVICE IN HOT-AIR UNITS

Abstract: A device in hot-air units for emitting an air curtain along particularly such smaller openings, as kiosk and ticket office windows and the like, inside which at least one person is staying rather frequently, and which device is of the type, which within a common casing (11) incorporates a blower (27), at least one electric infra-red heater (37) and an air director (29) provided in the air flow from the blower. The air director (29) of the blower (27) is directed towards and is provided adjacent to the opening (47), and at least one heater (30) is positioned in the flow of air emitted by the blower (27). The infra-red heater (37) and the heater (30) are located behind a common screen (17) adapted to direct the air jets of the heater and the heat rays of the infra-red heater mainly in parallel to each other.

Description: A DEVICE IN HOT-AIR UNITS The present invention refers to a device in hot-air units for emitting an air curtain along particularly such smaller openings, as kiosk and ticket office windows and the like, inside which at least one person is staying rather frequently, and which device is of the type, which within a common casing incorporates a blower, at least one electric infra-red heater and an air director provided in the air flow from the blower. Background of the invention In premises which via an opening adjoins to open air and which for different reasons must be kept open, it may be difficult to create an atmosphere which is not experienced as draughty and associated with big temperature variations for the person sitting in front of said opening. Examples of said premises are kiosks, street kitchens, sentry-boxes, entrances, office caretaker's windows, but it also may be appropriate for big premises, where the ambient temperature is low and where a spot heating is desired, e.g. over a cash counter. The problem hitherto has been solved by means of hot-air units, which emit a hot air curtain, but this requires big volumes of air for conveying the desired heat quantity and it has hitherto substantially been used in doorways, where people normally only passes through and not stays for longer time. These hot-air units efficiently prevent cold air from penetrating into the premises through the hot-air curtain, but they generally are not suffi- cient for heating the premises. The strong flows of air further¬ more give rise to draught and make it almost impossible to work with papers of different types, as those will be blown away by the air flows. The hot-air unit emitting the air curtain is provided inside and above the opening to be screened off and at such a low level as possible, which means that the unit will shade away the light from the light fittings which commonly is positioned in the ceiling above the opening. The purpose and most essential features of the invention The purpose of the present invention is to provide a hot-air uni having an air curtain effect preventing the cold air from pene- trating in, but still having so low velocity that it will no whirl around pieces of paper inside the action area of the ho air flow, which emits so much heat, that the temperatur differences are eliminated and the stay adjacent the open windo is experienced as comfortable. Another purpose of the new hot-ai unit is to obtain better light conditions inside the opening an a practically noiseless device. These tasks have been solved i that the air director of the blower is directed towards and is provided ad acent to the opening, that at least one heater is positioned in the flow of air emitted by the blower and that th infra-red heater and the heater are located behind a commo screen adapted to direct the air jets of the heater and the hea rays of the infra-red heater mainly in parallel to each other. Description of the drawings The invention hereinafter will be further described wit reference to the drawings, which show an embodiment. Fig. 1 shows the hot-air unit according to the invention in front view. Fig. 2 shows the unit according to Fig. 1 in a view from below. Fig. 3 is a section along line III-III in Fig. 1. Fig. 4 is a section along line IV-IV in Fig. 4 Fig. 5 shows in a view analogous with Fig. 1, the hot-air unit, but with the front panel and the side panels removed. Description of embodiment The hot-air unit according to the invention consists of rectangular housing 11, incorporating a front side 12 with a inlet opening 13, a rear side 14, an upper side 15 and a lowe side 16, which substantially is constituted by a screen 17. Th open ends of the housing are closable by means of end panels 18, which are preferably snapped into the housing structure. In the lower side there is also provided a panel 19 provided with switches etcetera, which will be described later on in the text. The housing 11 is built around the rear side 14 and the upper side 15, which form a continuous unit 20. In order to obtain sufficient rigidity, the rear side is reinforced with a mounting plate 21, which in cross-section is U-shaped, thus that it together with the rear side 14 forms a duct 22 for wiring. At each one of the two end portions of the housing 11 there is fitted to the mounting plate 21 one bracket 23 and 24, between which is fixedly provided a U-shaped sheet metal profile 25, which is open at its lower side and designed as a part of the light armature 26 of the hot-air unit. Two blowers 27 of cross-flow type are arranged axially after each other in such a manner, that the inlet opening 28 of the blowers is facing the admission opening 13 of the housing, whereas the discharge socket 29 of the blowers is directed towards the screen 17 at the lower side 16 of the housing. In the space, to which the blowers 27 emit the flow of air, is provided an electric heater 30, e.g. a finned heater, said space on one side being limited by the mounting plate 21 and on the opposite side of an intermediate wall 31, which mainly forms an extension of one side wall 32 of the discharge socket 29. The lower end edge of the discharge socket is positioned at some distance above the upper end edge of the intermediate wall 31, thus that a slot 33 is formed, through which slot air can be ejected by the flow of air from the blowers, which air has flown around the light fittings 26 and an infra-red heater 37 provided in the space 34 between said intermediate wall 31 and one shank 35 of the U-shaped sheet metal profile 25. The reflector of the infra-red heater is designated 38. The three units, i.e. the heater 30, the infra-red heater 37 and the light fittings 26 are positioned mainly in parallel beside each other and mainly in a common plane, thus that the screen 17 provided on the lower side 16 of the housing is a common director for these three units. The screen 17 directs the air jets from the heater, the heat rays from the infra-red heater and the light beams from the light fittings mainly in parallel to each other. The mutual sequence of the three units 30, 37, 26 is also important for obtaining the function aimed at, whereby the heater 30 is located outmost, closest to the wall 46 where the opening 47 is situated, thus that the air curtain sweeps along it. Thereupon comes the infra-red heater and farthest in the light fittings 26. As hot-air units of this type are arranged above the window or opening 47 to be swept by the hot air curtain, the unit will be positioned just a little above the person staying adjacent the window. It is therefore very important that the unit has a very low noise level. In order to achieve this the blower is mounted thus in the housing that no vibrations can be transferred to it. As a combined fitting and dampening member it has according to the invention been used double VELCRO tapes 39, one being glued to the mounting plate 21 and the other to the rear side of the housing, such as shown in Fig. 3. Practical tests have shown that with the device according to the invention is obtained: I. Lower installed effect is consumed with radiation heat than with convection heat if the same operational temperature shall be produced in the stay zone below the unit. II. As the radiation heat in the infra-red range (3 μm) in- fluences the air jet only to a neglibile extent from heat transfer aspects it is possible to keep the air jet colder as compared to convection heat. This means that the power content of the air jet automatically will become higher. III. An air jet always suffers from a certain turbulency in its bordering layer against ambient air, which results in a admixture of ambient air in the air jet. This admixture is however lower the lower the temperature of the air jet is as compared to the ambient air, which means that the throw of the jet increases. For control of the hot air unit there is at the lower side provided a panel 19, having an overall switch by which the entire hot-air unit can be turned on or off without changing earlier chosen settings. The flow of hot air can be adjusted regarding air quantity, i.e. whole and half by means of the switch 41. The heater 30 is connected to the switch 42, the infra-red heater to the switch 43 and the light to the switch 44. The amount of heat is adjusted with an electronic, proportional thermostat, which senses the temperature of the incoming air. The temperature range of the thermostat can be adjusted with a hand wheel 45.

Claims: CLAIMS 1. A device in hot-air units for emitting an air curtain along particularly such smaller openings, as kiosk and ticket office windows and the like, inside which at least one person is staying rather frequently, and which device is of the type, which within a common casing (11) incorporates a blower (27), at least one electric infra-red heater (37) and an air director (29) provided in the air flow from the blower, c h a r a c t e r i z e d t h e r e i n, that the air director (29) of the blower (27) is directed towards and is provided adjacent to the opening (47), that at least one heater (30) is positioned in the flow of air emitted by the blower (27) and that the infra-red heater (37) and the heater (30) are located behind a common screen (17) adapted to direct the air jets of the heater and the heat rays of the infra-red heater mainly in parallel to each other. 2. A device as claimed in claim 1, c h a r a c t e r i z e d t h e r e i n, that the infra-red heater (37), the heater (30) and a light fittings (20) are arranged in a row beside each other and that a common screen (17) is provided for them all. 3. A device as claimed in claim 1, c h a r a c t e r i z e d t h e r e i n, that the blower (27) is constituted by at least one cross-flow blower adapted to extend over a substantial part of the length of the unit above the heat and light sources (30, 37, 26) positioned in parallel beside each other. 4. A device as claimed in claim 1, c h a r a c t e r i z e d t h e r e i n, that the housing (11) consists of a unit (20) forming its rear side (14) and its upper side (15), which at its end panels is equipped with two brackets (23, 24) attached to the rear side, and between which is provided a U-shaped sheet metal panel (25) attached along the front side (12) of the housing and being open at its lower side, the inner side of said panel being designed as a light reflector. 5. A device as claimed in claim 4, c h a r a c t e r i z e d t h e r e i n, that the infra-red heater (37) is separated from the heater (30) by means of an intermediate wall (31), which is mainly an extension of one side wall (32) of the discharge socket (29) of the blower (27), and that between the end edge of the discharge socket (29) and the upper edge of the intermediate wall (31) is formed a slot (33) for ejection of the air around the light fittings (26) and the infra-red heater (37). 6. A device as claimed in claim 4, c h a r a c t e r i z e d t h e r e i n, that at the inner rear side (14) of the housing (11) is attached a mounting plate (21) forming together with said rear side a through duct (22), to which mounting plate the blower (27) is fixed by means of double VELCRO tapes.

Inventors: JOENSSON JERRY, MAGNEHAG ARNE, MARKUSSON PER, JOENSSON, JERRY, MAGNEHAG, ARNE, MARKUSSON, PER
Applicants: FRICO AB
Application year: 1988
Main classification: F24F9
IPC codes: F24F9, F24H3