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Title:
A METHOD FOR THE CULTIVATION OF CROPS OR PLANTS IN A SPACE AND AN IMPROVED CASING FOR ACCOMMODATING LAMPS
Document Type and Number:
WIPO Patent Application WO/2019/164393
Kind Code:
A1
Abstract:
A casing for accommodating a first lamp and a second lamp spaced apart from the first lamp, the first and the second lamp forming an array of lamps in a longitudinal direction of the casing comprising: - a basis extending parallel to the longitudinal direction, wherein the basis is equipped with a first mounting position for mounting the first lamp and with a second mounting position for mounting the the second lamp in such a way that the first lamp and the second lamp are capable of directing to a common target to be lit; - an inlet opening for receiving a flow of air to transport heat generated by the first lamp and the second lamp during operation; - an outlet opening for discharging the flow of air including the heat generated by the first lamp and the second lamp during operation; wherein the second mounting position is during operation downstream the first mounting position, wherein the inlet opening is formed by a plurality of apertures arranged at least at one side along the casing, the side of which is oriented transverse to the longitudinal direction of the casing, and wherein at least one of the plurality of apertures is located between the first and the second mounting position of the first and the second lamp respectively.

Inventors:
VAN STAALDUINEN GERRIT JOHANNES (NL)
Application Number:
PCT/NL2019/050112
Publication Date:
August 29, 2019
Filing Date:
February 20, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
LOGIQS B V (NL)
International Classes:
A01G7/04; F21V29/60; F24F13/078
Foreign References:
TWI589833B2017-07-01
US20080117617A12008-05-22
US8322011B22012-12-04
US20170359966A12017-12-21
EP3120692A12017-01-25
Other References:
None
Attorney, Agent or Firm:
ALTENBURG, Bernardus Stephanus Franciscus (NL)
Download PDF:
Claims:
C L A I M S

1. A method for the cultivation of crops or plants in a space, wherein the climate in said space is controlled;

wherein the space is provided with a duct provided with apertures and air from the space is extracted via apertures of the duct to a climate control unit, and air treated by the climate control unit is passed back into the space comprising crops or plants;

characterized in that the duct comprises a casing (100) for

accommodating a first lamp (201) and a second lamp (202) spaced apart from the first lamp (201), the first and the second lamp (201, 202) forming an array of lamps in a longitudinal direction (111) of the casing (100) comprising:

- a basis (152) extending parallel to the longitudinal direction (111), wherein the basis (152) is equipped with a first mounting position (501) for mounting the first lamp (201) and with a second mounting position (502) for mounting the the second lamp (202) in such a way that the first lamp (201) and the second lamp (202) are capable of directing to a common target to be lit;

- an inlet opening (600, 601, 602) for receiving a flow of air to transport heat generated by the first lamp (201) and the second lamp (202) during operation;

- an outlet opening (900) for discharging the flow of air including the heat generated by the first lamp (201) and the second lamp (202) during operation;

wherein the second mounting position (502) is during operation downstream the first mounting position (501) .

2. A casing (100) for accommodating a first lamp (201) and a second lamp (202) spaced apart from the first lamp (201) , the first and the second lamp (201, 202) forming an array of lamps in a longitudinal direction (111) of the casing (100) comprising:

- a basis (152) extending parallel to the longitudinal direction (111), wherein the basis (152) is equipped with a first mounting position (501) for mounting the first lamp (201) and with a second mounting position (502) for mounting the the second lamp (202) in such a way that the first lamp (201) and the second lamp (202) are capable of directing to a common target to be lit; - an inlet opening (600, 601, 602) for receiving a flow of air to transport heat generated by the first lamp (201) and the second lamp (202) during operation;

- an outlet opening (900) for discharging the flow of air including the heat generated by the first lamp (201) and the second lamp (202) during operation;

wherein the second mounting position (502) is during operation downstream the first mounting position (501) , characterized in that the inlet opening (600, 601, 602) is formed by a plurality of

apertures (601, 601', 601'', 602, 602', 602'') arranged at least at one side (153) along the casing (100), the side (153) of which is oriented transverse to the longitudinal direction (111) of the casing (100), and wherein at least one of the plurality of apertures (601, 601', 601'', 602, 602', 602'') is located between the first and the second mounting position (501, 502) of the first and the second lamp (201, 202) respectively.

3. The casing for accommodating lamps according to claim 2, wherein the inlet opening (600, 601, 602) formed by the plurality of apertures (601, 601', 601'', 602, 602', 602'') is arranged at both lateral sides

(151, 153) along the casing (100), the lateral sides (151, 153) of which are oriented transverse to the longitudinal direction (111) of the casing ( 100 ) .

4. The casing for accommodating lamps according to any of the claims 2 or 3, wherein a first partition wall (156) is arranged in the interior of the casing (100), the first partition wall (156) extending parallel to the longitudinal direction (111) of the casing (100), in such a way that a first channel portion (410) is formed by the one lateral side (153) along the casing (100) and the first partition wall (156), and that a second channel portion (490) is formed by the other lateral side (151) along the casing (100) and the first partition wall (156) so as to allow a flow of air from the inlet opening (602) through the first channel portion (410) via a bend to the second channel portion (490) towards the outlet opening (900) .

5. The casing for accommodating lamps according to any of the claims 2 or 3, wherein a first partition wall (156) is arranged in the interior of the casing (100), the first partition wall (156) extending parallel to the longitudinal direction (111) of the casing (100), in such a way that a first channel portion (410) is formed by the one lateral side (153) along the casing (100) and the first partition wall (156), a second partition wall (156') is arranged in the interior of the casing (100), the second partition wall (156') extending parallel to the longitudinal direction (111) of the casing (100), in such a way that a further first channel portion (420) is formed by the other lateral side (151) along the casing (100) and the further first partition wall (156'), and that

a second channel portion (490) is formed between the first partition wall (156) and the second partition wall (156') so as to allow a flow of air from the inlet opening (601, 602) through the first channel portion (410) and the further first channel portion (420) via a further bend to the second channel portion (490) towards the outlet opening (900) .

6. The casing for accommodating lamps according to any of the claims 2 to 5, wherein the inlet opening (600, 601, 602) formed by the

plurality of apertures (601, 601', 601'', 602, 602', 602'') arranged at least at the one side (153) along the casing (100), is arranged in a top portion of the casing when in operation.

7. The casing for accommodating lamps according to claim 6, wherein the inlet opening (601, 602) is arranged in a third channel portion extending parallel to the longitudinal direction (111) of the casing (100), the third channel portion extending over a fourth channel portion extending parallel to the longitudinal direction (111) of the casing (100) to allow an air stream (305) from the third channel portion via an elbow shaped duct downward to the fourth channel portion and towards the outlet opening (900) in a reversed direction (311) parallel to the longitudinal direction (111) of the casing (100), wherein the third and the fourth channel portion are separated by a partition element (159) .

8. The casing for accommodating lamps according to any of the claims 2 to 7, wherein the inlet opening (600, 601, 602) or at least one of the plurality of apertures is provided with a cap (651, 652) forming an elbow shaped duct extending, from the side (153) along the casing (100), into a space in which the casing (100) is located and which cap or duct (651, 652) is adapted for guiding an entering flow of air from the space into the casing (100) .

9. The casing for accommodating lamps according to any of the claims 2 to 8, wherein the plurality of apertures form a pattern of through holes arranged in the at least one side along the casing, the pattern forming a grid for filtering particles in the flow of air, a size of which is exceeding a predetermined maximum size so as to prevent too large particles to enter the casing.

10. A hall for cultivation of crops or plants, wherein the hall is provided with a series of casings (100) according to anyone of the previous claims, wherein the casings are arranged in the top of the hall.

11. The hall for cultivation of crops or plants according to claim 10, wherein the series of casings are arranged in a pattern above a target site of the hall on which cultivation of crops and plants is to be performed .

12. The hall for cultivation of crops or plants according to claim 11, wherein the pattern is formed by a series of lines, in each line of which a plurality of casings is arranged, and wherein each of the series of lines are spaced apart and extending parallel to each other.

Description:
A method for the cultivation of crops or plants in a space and an improved casing for accommodating lamps

The present invention relates to a method for the cultivation of crops or plants in a space, wherein the climate in said space is controlled;

wherein the space is provided with a duct provided with apertures and air from the space is extracted via apertures of the duct to a climate control unit, and air treated by the climate control unit is passed back into the space comprising crops or plants.

Such a method is generally known in the art for greenhouses and also for a recent development where cultivation takes place in closed chambers, e.g. in the form of containers, where light is provided by lamps .

A problem with the duct is that condensation of water from the space may occur, resulting in an increased risk of contamination by micro-organisms .

The object of the present invention is to alleviate or reduce said risk.

To this end, a method according to the preamble is characterized in that the duct comprises a casing for accommodating a first lamp and a second lamp spaced apart from the first lamp, the first and the second lamp forming an array of lamps in a longitudinal direction of the casing comprising:

- a basis extending parallel to the longitudinal direction, wherein the basis is equipped with a first mounting position for mounting the first lamp and with a second mounting position for mounting the the second lamp in such a way that the first lamp and the second lamp are capable of directing to a common target to be lit;

- an inlet opening for receiving a flow of air to transport heat generated by the first lamp and the second lamp during operation;

- an outlet opening for discharging the flow of air including the heat generated by the first lamp and the second lamp during operation;

wherein the second mounting position is during operation downstream the first mounting position.

Thus the air extracted from the space is heated by the heat generated by the LEDs, reducing the risk of condensation and hence of growth of micro-organisms in the duct . Hereinafter the casing and various embodiments thereof are discussed, and the method also relates to their use in any

combination, repetition being omitted for the sake of brevity only.

In the present invention, the duct and preferably the casing may comprise a fan for extracting air from the outside into the casing.

The fan may be centrally located, e.g. as part of a climate control system, or individual ducts and/or casing may contain fans.

The present invention also relates to a casing for accommodating a first lamp and a second lamp spaced apart from the first lamp, the first and the second lamp forming an array of lamps in a longitudinal direction of the casing comprising:

- a basis extending parallel to the longitudinal direction, wherein the basis is equipped with a first mounting position for mounting the first lamp and with a second mounting position for mounting the the second lamp in such a way that the first lamp and the second lamp are capable of directing to a common target to be lit;

- an inlet opening for receiving a flow of air to transport heat generated by the first lamp and the second lamp during operation;

- an outlet opening for discharging the flow of air including the heat generated by the first lamp and the second lamp during operation;

wherein the second mounting position is during operation downstream the first mounting position.

Such casings are well known in the art, wherein at a side of the outlet opening, an suction device is arranged for causing an

underpressure in the casing to suck through the flow of air from a space in which the casing is located via the inlet opening to the outlet opening along the first and the second lamp.

To this end, the casing for accommodating lamps according to the preamble is characterized in that the inlet opening is formed by a plurality of apertures arranged at least at one side along the casing, the side of which is oriented transverse to the longitudinal direction of the casing, and wherein at least one of the plurality of apertures is located between the first and the second mounting position of the first and the second lamp respectively.

In this way, the flow of air drawn from the space in which the casing is located, arrives in the casing at several places or spots along the casing so the air extracted from the space is raised in temperature immediately so as to transport air with a temperature raised by heat generated by the first lamp and the second lamp during operation, thus reducing the risk of condensation.

Air passed downstream located lamps is composed of a first flow of air which has passed along at least one upstream located lamp and of a second flow of air which has not passed along at least one upstream located lamp but which entered the casing directly via the at least one of the plurality of apertures which is located between the first and the second mounting position of the first and the second lamp respectively.

In halls (spaces) , according to one embodiment the casings are mounted preferably just below the ceiling of the hall. In such halls, it is important, for the purpose of batch cultivation of the crops and the plants, to maintain a constant air flow from the cultivation in upward direction towards the ceiling. This allows for a more

homogeneous climate in the space to be achieved with an

alleviated/ reduced risk of infection by stagnant water in the duct used to extract air from the space.

According to another embodiment, the inlet opening formed by the plurality of apertures is arranged at both lateral sides along the casing, the lateral sides of which are oriented transverse to the longitudinal direction of the casing.

In this way, the flow of air is further divided over a larger area of the inlet opening so as to allow the same amount of air entering the casing via the larger area of the inlet opening, causing less eddies and as such less noise.

According to another embodiment, a first partition wall is arranged in the interior of the casing, the first partition wall extending parallel to the longitudinal direction of the casing, in such a way that a first channel portion is formed by the one lateral side along the casing and the first partition wall, and that a second channel portion is formed by the other lateral side along the casing and the first partition wall so as to allow a flow of air from the inlet opening through the first channel portion via a bend to the second channel portion towards the outlet opening.

In this way, the flow of air is firstly directed along the first and the second lamp via the first channel portion of the casing, and secondly direction along the second and the first lamp respectively via the second channel portion of the casing. I.e. the flow of air is passing the lamps twice.

According to a favourable embodiment, a first partition wall is arranged in the interior of the casing, the first partition wall extending parallel to the longitudinal direction of the casing, in such a way that a first channel portion is formed by the one lateral side along the casing and the first partition wall,

a second partition wall is arranged in the interior of the casing, the second partition wall extending parallel to the longitudinal direction of the casing, in such a way that a further first channel portion is formed by the other lateral side along the casing and the further first partition wall , and that

a second channel portion is formed between the first partition wall and the second partition wall so as to allow a flow of air from the inlet opening through the first channel portion and the further first channel portion via a further bend to the second channel portion towards the outlet opening.

In this way, the flow of air is firstly directed along the first and the second lamp via the first channel portion of the casing, and secondly direction along the second and the first lamp respectively via the second channel portion of the casing. I.e. the flow of air is passing the lamps twice.

According to a favourable embodiment, the inlet opening formed by the plurality of apertures arranged at least at the one side along the casing, is arranged in a top portion of the casing when in operation.

In this way, a corresponding top portion of air located at the exterior side of the casing may be sucked in the casing to achieve a substantially unaffected condition of the flow of air in the hall arriving the casing with a constant speed spread over a target area such as a working frame or table on which for example the cultivation of crops or plants takes place.

According to a favourable embodiment, the inlet opening is arranged in a third channel portion extending parallel to the

longitudinal direction of the casing, the third channel portion extending over a fourth channel portion extending parallel to the longitudinal direction of the casing to allow an air stream from the third channel portion via an elbow shaped duct downward to the fourth channel portion and towards the outlet opening in a reversed direction parallel to the longitudinal direction of the casing, wherein the third and the fourth channel portion are separated by a partition element .

In this way, a structure of the casing allows the inlet openings to be arranged in top position while the first and the second lamps may be installed in the casing having sufficiently space around to exchange the lamp in case it needs to be replaced for maintenance purposes .

According to another embodiment, the inlet opening or at least one of the plurality of apertures is provided with a cap forming an elbow shaped duct extending, from the side along the casing, into a space in which the casing is located and which cap or duct is adapted for guiding an entering flow of air from the space into the casing.

In this way, the flow of entering air being guided via such cap or duct causes a lower level of noise since the amount of eddies occurring during entrance of air at the inlet opening or the at least one of the plurality of apertures, is reduced.

According to another embodiment, the plurality of apertures form a pattern of through holes arranged in the at least one side along the casing, the pattern forming a grid for filtering particles in the flow of air, a size of which is exceeding a predetermined maximum size so as to prevent too large particles to enter the casing.

In this way, a lifetime is enlarged of the suction device present to operate at the outlet opening of the casing to cause an

underpressure in the casing so as to draw the flow of air through the casing .

Finally, the present invention relates to a hall for cultivation of crops or plants, wherein the hall is provided with a series of casings according to anyone of the previous claims, wherein the casings are arranged in the top of the hall.

In this way, a hall (space) is provided in which, for the purpose of batch cultivation of the crops and the plants, light from the first and the second lamps may be used for thriving the crops and the plants, while a constant air flow may be maintained from the

cultivation in upward direction towards the hall ceiling. By using the casing in the hall according to the invention the problem of an increased risk of contamination by micro-organisms due to stagnant water in the ducts comprising the casings is alleviated/reduced.

According to another embodiment, the series of casings are arranged in a pattern above a target site of the hall on which cultivation of crops and plants is to be performed.

In this way, an efficient distribution of light generation at one hand and allowing a discharge of a constant upward air stream from the cultivation at the other hand, is achieved so as to cause an optimal environment for the cultivation of crops and plants, with a reduced risk of contamination due to stagnant water in the duct used to extract air from the hall and transport thereof to a climate control unit .

According to another embodiment, the pattern is formed by a series of lines, in each line of which a plurality of casings is arranged, and wherein each of the series of lines are spaced apart and extending parallel to each other.

In this way, several lines of casings may be reached easy for maintenance purposes while the pattern allows an efficient

distribution of light generation at one hand and allowing a discharge of a constant upward air stream from the cultivation at the other hand, is achieved so as to cause an optimal environment for the cultivation of crops and plants.

The present invention will now be illustrated with reference to the drawing where

Fig. la is a cross sectional view of the casing according to the invention along line IA-IA depicted in Fig. IB;

Fig. lb is a side view of the casing according to the invention according to line IB-IB depicted in Fig. 1A;

Fig. 2 is a cross sectional view of the casing according to the invention;

Fig. 3a is a cross sectional view of the casing according to a another embodiment of the invention along line IIIA-IIIA depicted in Fig. 3B;

Fig. 3b is a top view of the casing according to a another embodiment of the invention according to line IIIB-IIIB depicted in

Fig. 3A;

Fig. 4a is a cross sectional view of the casing according to a another embodiment of the invention along line IVA-IVA depicted in Fig. 4B;

Fig. 4b is a top view of the casing according to a another embodiment of the invention according to line IVB-IVB depicted in Fig. 4A;

Fig. 5a is a cross sectional view of the casing according to a another embodiment of the invention along line VA-VA depicted in Fig. 5B; and

Fig. 5b is a top view of the casing according to a another embodiment of the invention according to line VB-VB depicted in Fig. 5A.

It should be noted that items which have the same reference numbers in different figures, have the same structural features and the same functions, or are the same signals. Where the function and/or structure of such item has been explained, there is no necessity for repeated explanation thereof in the detailed description.

Fig. 1A shows a casing 100 for accommodating lamps 200, in this example indicated by a first lamp 201 and a second lamp 202. The first and the second lamp 201, 202 are described as a lamp in general, however, it should be understood that the lamp may be a LED lamp, and in many applications, such LED lamp will be used. For the purpose of simplicity, the feature lamp will be used in the description of the present invention.

According to Fig. 1, the casing 100 is constituted by a tube 150 or pipe 150. In this example the tube 150 is having a rectangular cross section. The shape of the tube 150 may of course be circular so as to form a circular tube, although a rectangular tube shape is preferred. The tube 150 having circumferential walls 151, 152, 153,

154 is constructed so as to suspend both the first lamp 201 as well as the second lamp 202 at the wall 152 forming a basis for the first and the second lamp 201, 202 facing an object to be lit by the lamp 201, 202. The wall 154 is, in this example, arranged to be fixed to a construction element 50 (frame member of a space 199 for growing plants) located in a place in which the casing 100 according to the invention needs to be mounted. The place may be any place in which a lamp installed in the casing 100 according to the invention needs to be mounted. According to the invention, the place is preferably a hall in which a regulated air condition is to be generated. An example of such regulated air condition may be a hall in which a cultivation of crops or potted plants is to be thrived or flourished. For some reasons, it is advantageous to generate and maintain an upward air stream 300 from a surface extending substantially in a horizontal direction, such as a working frame or table on which the object is located. The objects may be crops or plants that are staying in the place or, in this example, a hall in which the crops or plants need to grow until the crops or plants arrive in a next phase in which these need to be transported to another location.

Said upward air stream 300 is for many reasons required to follow an upward direction, or, generally, to be directed or aligned

according to a first direction 301. It is advantageous that, at substantially all sites over the surface, both the direction as well as the speed of the air stream 300 is having the same direction and the same speed respectively. In other words, both the place vector and the speed vector must be substantially the same at all locations spread over the surface. In this way, turbulences in the air stream 300 is prevented. Since most of the relevant applications are located under a roof separating the hall from the outside, the air stream 300 is blocked by a ceiling 50. The air stream 300 arriving at the top of the hall, needs to be discharged.

The casing according to the invention is, therefore, provided with an inlet opening 600. The wall portion or basis 152 for mounting the lamps 201, 202 is in connection with the wall portion 154 to be fixed to the ceiling 50, via two opposing side wall portions 151, 153. Fig. 1A shows the inlet opening 600 arranged at both sides 151, 153 of the casing 100 according to the invention. Specifically, a first inlet opening 601 is arranged in wall portion 151 and a second inlet opening 602 opposing the first inlet opening 601 is arranged in wall portion 153.

Fig. IB shows the casing 100 according to the invention

comprising a set of first apertures 601, 601', 601'' distributed over the length of the casing 100 at the lateral side formed by wall portion 151 of it. In this example, the first apertures 601, 601'' are formed by circular openings, and the second aperture 601' is formed by a rectangular opening, the shape of which to indicate that for a skilled man alternative shapes for the apertures 601, 601', 601'' are allowable to consider.

In the longitudinal direction indicated by arrow 111 in Fig. IB, at an upstream side of the casing 100, an enclosing element 155 is arranged, in this example, to allow an inlet of air into the casing, from the space in which the casing 100 is located, the inlet of air directed transverse to the longitudinal direction of the casing 100.

Fig. IB shows the basis 152 extending parallel to the

longitudinal direction 111 of the casing 100, wherein the basis 152 is equipped with a first mounting position 501 for mounting the first lamp 201 and with a second mounting position 502 for mounting the the second lamp 202 in such a way that the first lamp 201 and the second lamp 202 direct to a common target to be lit, wherein the target is, for example the cultivation of crops or plants.

Fig. IB shows a plurality of apertures 601, 601', 602' ' arranged at least at one side 151 along the casing 100, the side 151 of which is oriented transverse to the longitudinal direction 111 of the casing 100, wherein at least one of the plurality of apertures 601, 601',

602' ' is located between the first and the second mounting position of the first and the second lamp respectively.

Fig. 2 shows the casing according to Fig. 1A and IB, wherein both the first and the second inlet openings 601, 602 are equipped with a cap or a bend 651, 652, which is formed by an elbow shaped duct so as to guide the upward air stream 300 towards and into the casing 100 along a curve, in this example of 90 degrees. In this way, the flow of air entering the casing 100 is straight directed to the lamp to warm the air from the space.

Fig. 3A shows an other embodiment of the casing 100 according to the present invention, wherein an partition element 156 is arranged along the longitudinal direction of the casing 100. At the side wall 153 of the casing 100, the inlet opening 602 allows the flow of air passing along the first and the second lamp 201, 202. Even though Fig. 3A, and also Fig. 3B, does not, for drawing simplicity purposes, depict the inlet opening 601 at the side wall 151 of the casing 100, the presence of said inlet opening 602 is deemed present in the casing 100.

As shown in Fig. 3B, the partition element 156 extends from the enclosing element 155 downstream to near a further enclosing element 155' opposing the enclosing element 155, to form a passageway 410, 490 along the first and the second mounting position 501, 502 ending up in a bend of 180 degrees so as to guide the flow of air in a reversed direction along the casing 100 to pass along the second and the first mounting position 502, 501 respectively. The passageway 410, 490 is in this example formed by a first channel portion 410 extending from the enclosing element 155 towards the further enclosing element 155' at the bend side, and by a second channel portion 490 extending from the further enclosing element 155' or from the bend to the outlet opening 900.

In case the first and the second lamps 201, 202 are mounted and in operation, the flow of air entering the casing 100 is indicated by arrow 305. The flow/ of air is deflected on the end of the casing 100 and enforced to flow according to arrow 311 so as to leave the casing via the outlet opening 900.

The flow of air 300 streaming through the casing 100, covers a distance along the first channel portion 410 and, in reversed

direction, along the second channel portion 490 towards the outlet opening 900 of the casing 100. The flow of air streaming through the casing 100 may, during operation, subsequently have increasing temperatures Tl, T2, T3, T4 at the first mounting position 501, the second mounting position 502 and, at the reversed side of the casing 100, at the second mounting position 502 and the first mounting position 501 respectively. In such arrangement of the lamps 201, 202 at their mounting positions, the average temperture of the first lamp 201 is defined by temperatures Tl and T4, while the average temperture of the second lamp 202 is defined by temperatures T2 and T3. Based on the assumption that the average temperature of Tl and T4 is very similar to the average temperature of T2 and T3, the method does not substantially affect the lifetime of all the lamps to a different extent. This is advanteously for maintenance purposes so that all lamps can be replaced in one step at the same time.

Fig. 4A shows an other embodiment of the casing 100 according to the present invention, wherein the casing 100 comprises the partition element 156 arranged along the longitudinal direction of the casing 100 and a further partition element 156' arranged along the

longitudinal direction of the casing 100.

As shown in Fig. 4B, the partition element 156 and the further partition element 156' extends from the enclosing element 155

downstream to near a further enclosing element 155' opposing the enclosing element 155, to form a passageway 410, 490 along the first and the second mounting position 501, 502 ending up in a bend of 180 degrees so as to guide the flow of air in a reversed direction along the casing 100 to pass along the second and the first mounting position 502, 501 respectively. The passageway 410, 490 is in this example formed by a first channel portion 410 extending from the enclosing element 155 towards the further enclosing element 155' at the bend side, and by a second channel portion 490 extending from the further enclosing element 155' or from the bend to the outlet opening 900.

The casing 100 according to Fig. 4A and 4B differs from the casing 100 according to Fig. 3A and 3B in that a further passageway 420 is formed by a further first channel portion 420 extending from the enclosing element 155 towards the further enclosing element 155' at the bend side. The further first channel portion 420 ends up in the second channel portion 490 extending from the further enclosing element 155' or from the bend to the outlet opening 900.

The flow of air 300 streaming through the casing 100, covers a distance along the first or further first channel portion 410, 420 and, in reversed direction, along the second channel portion 490 towards the outlet opening 900 of the casing 100. The flow of air streaming through the casing 100 may, during operation, subsequently have increasing temperatures Tl, T2, T3, T4 at the first mounting position 501, the second mounting position 502 and, at the reversed side of the casing 100, at the second mounting position 502 and the first mounting position 501 respectively. In such arrangement of the lamps 201, 202 at their mounting positions, the average temperture of the first lamp 201 is defined by temperatures Tl and T4, while the average temperture of the second lamp 202 is defined by temperatures T2 and T3. Based on the assumption that the average temperature of Tl and T4 is very similar to the average temperature of T2 and T3, a lifetime of all the lamps is averaged as well. This is advangeously for maintenance purposes so that all lamps can be replaced in one step at the same time.

Fig. 5A and 5B show an other embodiment of the casing 100 according to the present invention, wherein the casing 100 comprises a partition element 159 arranged along the longitudinal direction of the casing 100 in such a way that the passageway extends over two

different stages or levels. Heat from the lamps is transferred via the partition element 159 to the air extracted from the space. So, the flow of air 300 enters the casing 100 via the inlet openings 601,

601', 602, 602' to flow according to the arrow indicated by reference number 305 towards the further enclosing element 155' enforcing the flow of air 305 downwards and in reversed direction along the first and the second lamp 201, 202 in the longitudinal direction 111 of the casing 100 towards the outlet opening 900. In this example, the plurality of apertures 601, 601', 602, 602' are arranged at the top side of the casing 100 to allow air 300 present in the top portion of the hall in which the casing is located to flow into the casing 100 without adversely affecting the air flow 300 having a constant direction and speed spread over a target area present in the hall.

It should be noted that the above-mentioned embodiments

illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments.

Such as described herein, the inlet opening is formed by the plurality of apertures arranged at least at one side along the longitudinal direction of the casing. A casing according to the invention may however extend along a centerline following a path which may have at least one bend or corner as long as the casing extends along its centerline. In other words, the casing may be part of a casing system comprising a plurality of concatenated casings according to the invention.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb

"comprise" and its conjugates does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a

combination of these measures cannot be used to advantage.