(19)
(11) EP 1 074 798 A2

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
07.02.2001 Bulletin 2001/06

(21) Application number: 00306652.9

(22) Date of filing: 04.08.2000
(51) International Patent Classification (IPC)7F24F 13/06
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 06.08.1999 GB 9918637

(71) Applicant: ABB Building Technologies Limited Sandford House
Solihull, West Midlands B91 3QJ (GB)

(72) Inventor:
  • Duke, Neville Charles
    Pershore, Worcestershire WR10 3PX (GB)

(74) Representative: Johnson, Terence Leslie 
Edward Evans & Co., Clifford's Inn, Fetter Lane
London EC4A 1BX
London EC4A 1BX (GB)

   


(54) Conditioning apparatus


(57) The invention relates to apparatus for providing conditioning medium in a space having at least opposed boundary walls and a base, characterised by inlet means (5) positioned to direct conditioning medium into the space (2), and by the inlet means (5) comprising a plurality of elongate inlets (6, 7, 8) which are spaced apart vertically and extend over a desired length of a boundary wall (3).




Description


[0001] The invention relates to conditioning apparatus, and particularly apparatus which conditions a space by cooling it, usually by the introduction of cooling air.

[0002] The space is often a processing space separated from the surroundings by inter alia the cooling air so that there is a barrier of cooled air between a product in the space, and the surrounding air.

[0003] Air in particular industries often has particular requirements such as temperature. Thus in the food industry, a product often has to be handled at a temperature below 10°C to provide hygienic conditions, for example the reduction of bacteria, and for general preservation during processing. This is so when conveyor systems are used, say during packaging of a food product. However, to cool the product the required amount, high cooling power is required, if there is to be consistent cooling. Even with high cooling power, uneven cooling can occur, both in a conveyor system and in a room or cabinet, owing to the incursion of uncooled ambient air.

[0004] It is an object of the invention to seek to mitigate these disadvantages.

[0005] According to a first aspect of the invention there is provided apparatus for providing conditioning medium in a space having at least opposed boundary walls and a base, and inlet means positioned to direct conditioning medium into the space, the inlet means comprising a plurality of elongate inlets which are spaced apart vertically and extend over a desired length of a boundary wall.

[0006] There may be three rows of inlets. This provides a particularly simple, yet effective construction.

[0007] The middle row of inlets may be closer to the upper row of inlets than to the lower row of inlets. This provides for a particularly efficient conditioning of the space, particularly when cooling.

[0008] The upper row of inlets may be narrower, in a vertical sense, than the other two rows of inlets. This may provide a faster velocity jet at an upper level, so containing the conditioning medium in the space, particularly when the middle row of inlets may be wider as considered vertically than the lower row of inlets.

[0009] Each row of inlets may comprise a plurality of discrete slots.

[0010] At least two rows of inlets each may comprise a plurality of elongate blocks each of which may have a plurality of inlet nozzles.

[0011] Adjacent blocks may have a gap therebetween in the longitudinal direction, or, alternatively the lower two rows of inlets may comprise contiguous blocks.

[0012] The upper rows of inlets may be directed downwardly into the space at an angle of inclination of less than 90 °. This contains the jets from the lower inlets in the space, particularly when the angle of inclination may be about 45°.

[0013] The space may comprise a conveyor trough, and the base may include a conveyor belt of the trough and the boundary walls may define a path of the conveyor belt.

[0014] Thus the apparatus may comprise a conveyor system.

[0015] There may be a plurality of elongate inlets in each boundary wall, each of which walls may comprise a duct for supply of conditioning medium to the inlets.

[0016] There may be a source of cooled air as the conditioning medium. This provides for a cooling environment, say in food processing, and the source may comprise air at a temperature whereby to provide a temperature in the range 1.5°C to 3.75°C across the trough.

[0017] The source may provide about 20 litres per second per metre of inlet per trough boundary wall.

[0018] The inlets may be covered by a filter device, suitably a fabric covering.

[0019] According to a second aspect of the invention, there is provided a method of conditioning a space, comprising a space having at least opposed boundary walls, a base, and inlet means positioned to direct conditioning medium into the space, providing that the inlet means comprises a plurality of elongate inlets which are spaced apart vertically and extend over a desired length of boundary wall, and by passing a conditioning medium into the space across the base from one boundary wall towards the other whereby to condition the space between the boundary walls as desired.

[0020] The method may comprise the step of passing cooled air into the space to cool the space to a desired temperature range.

[0021] An apparatus and method embodying the invention are hereinafter described, by way of example, with reference to the accompanying drawings.

Fig. 1 is a perspective schematic view of a conveyor trough system according to the invention;

Fig. 2 is a perspective view of part of a boundary wall of the system of Fig. 1, to an enlarged scale, and showing part of a series of inlets;

Fig. 3 shows a similar view to that of Fig. 2, showing more of the inlets in elevation;

Figs. 4 and 5 show respectively in elevation two further embodiments of inlets;

Fig. 6 is a graph showing temperature along a three metre length of conveyor at the centre line thereof, using the apparatus of Fig. 1; and

Fig. 7 shows air jet speeds along a three metre length of the apparatus of Fig. 1.



[0022] Referring to the drawings there is shown apparatus 1 for providing conditioning medium in a space 2 having at least opposed boundary walls 3 and a base 4, and inlet means 5 positioned to direct conditioning medium into the space 2, the inlet means 5 comprising a plurality of elongate inlets 6, 7, 8 which are spaced apart vertically and extend over a desired length of boundary wall 3.

[0023] In the embodiment shown, the space 2 is a space defined between opposed boundary walls 3 of a conveyor system, the base 4 including a conveyor device in the form of a belt on which product such as a food product to be conditioned as by being cooled is conveyed.

[0024] There are two opposed boundary walls with the conveyor belt, which forms a base of the space therebetween for conveying a product through the space. A trough conveyor is thus provided. In the embodiment there are inlet means 5 in the form of three vertically arranged rows of elongate inlets 6, 7, 8, each row being fed with conditioning medium in the form of cold air from a duct 9 which is part of, or contiguous with, a boundary wall 3 on the side of that wall remote from the conveyor 4. The duct 9 is fed with conditioning medium in the form of cooled air from a source (not shown) of that air. Each inlet 6, 7, 8 is a row of discrete slots in Figs. 1 - 3, the upper row 6 as viewed being of a depth or narrower, (i.e. as considered vertically) which is of less depth than the respective slots 7, 8, the middle row of slots 7 being closer vertically to the uppermost row of slots 6 than it is to the lowest row 8.

[0025] The middle row of slots 7 is wider (as considered vertically) than the lowest row 8 and thus is the widest (vertically) of the three rows.

[0026] There may be inlets in only one boundary wall 3, or in both boundary walls, in which latter case the inlets are directed towards each other into the space between the boundary walls, and above the conveyor 4.

[0027] In either case, when there is a flow of cooled air of 20 litres per second per meter of inlets per side, the temperature at the centre line of the conveyor ranges from about 1.5°C (at a position about 1.3m along the 3m length) to 3.6°C at or adjacent the start of that length (Fig. 6). Thus using the invention, the space is conditioned by being cooled well below ambient temperature throughout the length of the conveyor 4, thereby enhancing the processing of product such as food conveyed through the space 2 on the conveyor.

[0028] Using the invention, microbial tests show that using three slots vertically arranged in rows of inlets fed from ducts, fewer than 10 counts of microbes per test plate were found on plates in the trough.

[0029] In a modification using a filter device such as a fabric over the inlets, microbial counts were between 5 and 24. This is in contrast to a count of between 400 and 600 outside the trough formed by the boundary walls and the conveyor. The speed of air jets along a 3 metre length of duct shows a variation of between 2.6 m/s and 0.3 m/s, depending on the position along the three metre length.

[0030] In a modification, the inlets may comprise blocks 10 having inlet nozzles 10'. Thus in Fig .4, the blocks 10 in a row of inlets 7, 8 are contiguous; in Fig. 5 they are spaced apart longitudinally by spaces 11.

[0031] In all embodiments, the upper, vertically narrowest, row of inlets may be angled into the space, in the embodiment at an angle of 45° to the vertical. This provides a relatively fast flow of cold air downwardly into the space, which impinges on the generally horizontal flows from the middle and lowermost inlets, whereby to protect that flow from the (lower) inlets from contamination by entrained ambient air, and thus to maintain a desired cold environment in the trough.

[0032] In a modification, not shown, the inlets may be covered with a filter device such as a fabric.

[0033] It will be understood that other modifications are possible, for example the space may be a cabinet or chamber rather than a conveyor trough kind of apparatus as shown.

[0034] Using the invention, the air temperature and integrity of the space is maintained at a desired, cooled, level, with respect to ambient conditions outside the space.


Claims

1. Apparatus for providing conditioning medium in a space having at least opposed boundary walls and a base, characterised by inlet means (5) positioned to direct conditioning medium into the space (2), and by the inlet means (5) comprising a plurality of elongate inlets (6, 7, 8) which are spaced apart vertically and extend over a desired length of a boundary wall (3).
 
2. Apparatus according to Claim 1, characterised by three rows of inlets (6, 7, 8).
 
3. Apparatus according to Claim 2, characterised by the middle row of inlets (7) being closer to the upper row of inlets (6) than to the lower row of inlets (8).
 
4. Apparatus according to Claim 2 or 3, characterised by the upper row of inlets (6) being narrower, in a vertical sense, than the other two rows of inlets (7, 8).
 
5. Apparatus according to Claim 4, characterised by the middle row of inlets (7) being wider than the lower row of inlets (6, 8).
 
6. Apparatus according to any preceding claim, characterised by each row of inlets (6, 7, 8) comprising a plurality of discrete slots.
 
7. Apparatus according to Claims 6, characterised by at least two rows of inlets (7, 8) each comprising a plurality of elongate blocks (10) each of which has a plurality of inlet nozzles.
 
8. Apparatus according to Claim 7, characterised by adjacent blocks (10) having a gap (11) therebetween.
 
9. Apparatus according to Claim 7, characterised by the lower two rows of inlets (7, 8) comprising contiguous blocks (10).
 
10. Apparatus according to any of Claims 2 to 9, characterised by the upper row of inlets (6) being directed downwardly into the space (2) at an angle of inclination of less than 90°.
 
11. Apparatus according to Claim 10, characterised by the angle of inclination being about 45°.
 
12. Apparatus according to any preceding claim, characterised by the space (2) comprising a conveyor trough, and by the base including a conveyor belt (4) of the trough and the boundary walls (3) defining a path of the conveyor belt (4).
 
13. Apparatus according to Claim 12, characterised by there being a plurality of elongate inlets (6, 7, 8) in each boundary wall (3).
 
14. Apparatus according to Claim 13, characterised by each boundary wall (3) comprising a duct (9) for supply of conditioning medium to the inlets.
 
15. Apparatus according to Claim 14, characterised by comprising a source of cooled air as the conditioning medium.
 
16. Apparatus according to Claim 15, characterised by the source comprising air at a temperature whereby to provide a temperature in the range 1.5°C to 3.75°C across the trough.
 
17. Apparatus according to Claim 16, characterised by the source providing about 20 litres per second per metre of inlet per trough boundary wall.
 
18. Apparatus according to Claim 16 or Claim 17, characterised by the inlets (6, 7, 8) being covered by a filter device.
 
19. Apparatus according to Claim 18, characterised by the filter device comprising a fabric covering.
 
20. A method of conditioning a space, characterised by providing a space (2) having at least opposed boundary walls (3), a base (4), and inlet means (5) positioned to direct conditioning medium into the space (2), by providing that the inlet means (5) comprises a plurality of elongate inlets (6, 7, 8) which are spaced apart vertically and extend over a desired length of boundary wall (3), and by passing a conditioning medium into the space (2) across the base (4) from one boundary wall (3) towards the other whereby to condition the space between the boundary walls as desired.
 
21. A method according to Claim 20, characterised by comprising the step of passing cooled air into the space (2) to cool that space to a desired temperature range.
 
23. A method according to Claim 21, substantially as hereinbefore defined.
 




Drawing