WO1982002934A1

WO1982002934A1 - Cold-storage building

Info

Publication number: WO1982002934A1
Application number: PCT/NL1981/000003
Authority: WO
Inventors: Ontwikkeling Koeltechniek Stichting
Original assignee: Vahl Laszlo; Van Male Johannes
Priority date: 1981-02-24
Filing date: 1981-02-24
Publication date: 1982-09-02

Abstract

Cold-storage building (101) having a cold space (102), a door opening (105) in at least one of the cold-store walls and means (107) for generating an air curtain intended for thermal separation at the area of the door opening (105) between the cold space (102) and the ambience, said cold-storage building (101) being characterized in accordance with the invention in that the door opening (105) is formed by a tunnel (106) extending over a predetermined distance, said means (107) being located in a zone between the ends of the tunnel.

Description

Short title: Cold-storage building - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

The invention relates to a cold-storage building comprising a cold space, a door opening in at least one of the cold-store walls and means for producing an air curtain for thermal separation in the area of the door opening between the cold space and the ambience. The term "cold space" is to be understood to mean herein a cold space, for example, for storing frozen nutrients. The results so far obtained by air curtains have almost invariably been found to be disappointing in practice despite optimistic prognostications on theoretic bases.

Several causes thereof may be put forward. It is, for example, difficult .to dispose the means for producing an air curtain in a correct manner with respect to the door opening, as a result of which conditions in practice do not correspond to a theoretical model. A further, very important cause of the defective results is the high sensitivity of the known air curtain to wind, which may blow leaks in the air curtain. This may result in serious deterioration of the heat insulating properties of the air curtain.

The invention has for its object to provide a cold storage building having an air curtain, the properties of which come up better to the theoretical prognostications so that in addition optimizing steps can be taken, for example, with regard to local conditions to be expected whilst the adverse effect of wind is strongly reduced. To this end the invention proposes a cold-storage building of the type set forth above in which the door opening is formed by a tunnel extending over a given distance and said means are located in a zone located between the ends of the tunnel. This tunnel operates as en enclosing or boundary corridor, which prevents the air from blowing out laterally.

Preferably said means are formed by at least one air blowing gap extending substantially transversely of said tunnel and at least substantially across the whole transverse dimension thereof.

Further features and particularities of the coldstorage building according to the invention will be mentioned and explained with reference to a drawing of a few embodiment to which the invention is, however, not limited. In the drawing show:

Fig. 1 a perspective view partly broken away of part of a cold-storage building according to the invention, in which the tunnel extends only inside the cold space;

Fig. 2 an elevational view corresponding with that of fig. 1 of a further embodiment of the invention;

Fig. 3 a perspective view of part of a further embodiment of a cold-storage building according to the invention, in which the tunnel extends only outside the cold space; Fig. 4 a perspective view, partly broken away, of a wall of a further variant of a cold-storage building according to the invention, in which the tunnel extends both inside and outside the cold space;

Fig. 5 a cross-sectional view of a suction/blowing unit, the angular position of which is adjustable;

Fig. 6 a variant of the disposition shown in fig. 5; Fig. 7 a horizontal cross-sectional view of a coldstore wall having a tunnel in a different embodiment of a cold-storage building in accordance with the invention;

Fig. 8 is a longitudinal sectional view of part of a sixth embodiment of the cold store in accordance with the invention;

Fig. 9 is a longitundinal sectional view of part of a seventh embodiment of the cold store in accordance with the invention; and Fig. 10 is a perspectivedview of part of the cold store with curtain strips joining the tunnel walls.

Fig. 1 shows a cold-storage building 101 according to the invention. The air in the cold space 102 bounded by the front wall 103 and the further walls is cooled by a cooling unit 104, which sucks in air, extracts heat therefrom and gives off the air thus cooled to the cold space. Arrows schematically indicate the way in which the air is sucked in and blown out.

The front wall 103 has a hole 105 joining the ground, and communicating with a tunnel 106 of rectangular crosssection extending in the cold space 102. At a distance from the ends of the tunnel 106 a suction/blowing unit 107 is arranged on the top wall 109 of the tunnel so that air is sucked in from the cold space 102 and is caused to leave the unit 107 through a blowing-out gap (not shown) covering the whole width of the tunnel 106. In the embodiment shown in fig. 1 the blowing-out gap is slightly directed towards the cold space 102. The solid arrows 108 indicate the general shape of the "separating plane" of the air curtain thus formed. The separating plane is that plane which separates the quantities of air flowing in and out near the floor. Arrows 112 and 113 indicate the general form of the free boundary faces of the air curtain. It will be obvious that the larger the distance from the air inlet gap the greater will be the lateral spread or fanning of of the stream profile. A portion of the air of the air curtain moves near the tunnel floor 114 towards the cold space 102. A further portion moves to the outside so that in the cold space 102 the pressure is lower, which contributes to the shape of the air curtain shown schematically.

The side walls 110 and 111 of the tunnel form the lateral boundary of the air curtain so that the stream and velocity profile of the air curtain is at least substantially constant for any height throughout the width of the tunnel.

From the shape of the air curtain shown in fig. 1 and particularly from this form near the blowing gap it appears that this gap, whose direction of length is substantially horizontal, is at such an angular position that the air blown out has a velocity component in the direction towards the cold space 102. This angular position is preferably chosen so that the said separating plane of the air curtain indicated by the solid central arrows near the tunnel floor 114 is at least substantially perpendicular to said tunnel floor. The shape of the air curtain and hence the place where the centre of the air curtain strikes the tunnel floor 114 depend, however, on various factors. Parameters that are (substantially) constant are, for example, the height of the cold space, the temperature in the cold space. Variable parameters are inter alia the ambient temperature, the direction of the wind and the wind velocity. Therefore, the optimum angular position of the blowing gap depends upon local conditions and influences of the ambience. For this reason the angular position of the air inlet gap is preferably adjustable, whilst its direction of length is maintained. Hereinafter it will be explained how this can be achieved with reference to figures 5 and 6. With respect to the foregoing it is advantageous to use an embodiment which comprises means for adjusting said angular position of the air inlet gap, said means being controlled by detecting means responding to the air velocity, the direction of the wind and the ambient temperature. There may furthermore be provided means for controlling the initial velocity of the air of the air curtain, said means being controlled by detecting means responding to the velocity and the direction of the wind.

Owing to the screening effect of the tunnel the air curtain has a considerably higher immunity to the effect of the wind than the air curtains hitherto employed. A further improvement is obtained by the embodiment shown in fig. 2. In this figure elements corresponding with those of fig. 1 are designated by the same reference numerals. The difference from the cold store of fig. 1 consists in that the vertical tunnel walls 210 and 211 each have a profiled part 215 and 216 respectively between the blowing gap and the outer end of the tunnel. These profiled parts 215 and 216 are constructed in this embodiment in the form of concave, depressed parts covering the whole height of the tunnel 206. The top wall 209 of the tunnel has a corresponding shape.

Arrow 217 schematically indicates the direction of the wind. The curved end indicates that the incoming wind starts whirling so that its adverse effect is suppressed for the major part.

Fig. 3 shows a cold-storage building 301 according to the invention, in which the tunnel 306 only extends to the outer side. The top wall 309 of the tunnel is provided with four suction/blowing units 318, 319, 320 and 321. The units 319 and 321 together generate an outer air curtain. The units 318 and 320 together generate an inner air curtain.

The tunnel 306 is broader than the conventional door openings. The thermal insulation achieved by the invention is so high that this widening does not give rise to problems of thermal loss. In this case one can pass in two separate directions, which enhances safety. For this purpose a line of separation 322 is made on the floor 314. The units 319 and 321, 318 and 320 respectively may be integral with one another. In the embodiment shown in fig. 3, however, units are employed, which each have the same length as the unit 107 of figs. 1 and 2.

Even with this widened tunnel 306 it is sufficient to use a single air curtain. The thermal losses, though already low as compared with the conventional air curtains, may even be further reduced by using the second curtain. Arrows indicate in fig. 3 the two air curtains. Fig. 4 shows a front wall 403, broken away, of a cold-storage building (not shown in detail). A tunnel 406 extends towards both sides of the wall 403. One side wall 423 is provided with a suction/blowing unit 426 disposed in off-set manner in the direction of length of the tunnel for sucking in air from the ambience. With this disposition two relatively off-set air curtains directed in opposite senses can be generated in the tunnel 406. Figures.3 and 4 show to variants of the cold-storage building according to the invention, which have in common that two air inlet gaps relatively off-set in the direction of length of the tunnel and covering each the whole transverse dimension of the tunnel are provided on the tunnel wall. In the embodiment of fig. 3 the gaps are provided in the same wall i.e. the ceiling 309. In the embodiment of fig. 4 the gaps are provided in opposite walls, in this case the side walls 423 and 425.

Fig. 5 is a cross-sectional view of a suction/blowing unit 527, the angular position of which is adjustable about a longitudinal axis. The unit 527 is supported by a tunnel wall 528 having an open gap formed by two walls formed by parts of accylindrical surface. The blowing gap 531 is provided in a cylinder 533 which is held via longitudinal sealing elements 534 by the gap walls 529, 530. The gap 531 extends substantially diametrically through the cylinder 532 and communicates by the opening remote from its free side with the blowing-out opening of an axial fan 535, which is hermetically connected with the cylinder 532 in the manner shown in fig. 5. The air is sucked in through an inlet opening 536. From the configuration shown it will be apparent that the angular position of the gap 531 is adjustable within given limits. Means for fixing the suction/blowing unit 527 in the selected angular position are not shown. The direction of the air stream is indicated by a few arrows. A further variant is shown in fig. 6. The top wall

609 of a tunnel 606 has a transverse gap 637. The side walls 610, 611 have, at the area of the gap 637, two cylindrically recessed parts 638 and 639 in a manner such that a cylinder 632 having annular recesses 640, 641 corresponding to the parts 638, 639 is held in sealing relationship by the edges of the gap 637 and the parts 638, 639. The cylinder 632 can be guarded against translation by brackets 642,

643 corresponding to the recesses 640, 641 and being fastened in line with the side walls above the top wall 609. The cylinder 632 is hollow and has a blowing-out gap

644 covering the whole length thereof. The cavity 645 of the cylinder 632 is closed on the sideof the side wall 611 and coupled on the other side with a flexible hose 646, which is connected with the blowing-out part of a suction/ blowing unit 647.

The disposition shown in fig. 6 has the advantage that with a change of the angular position of the gap 644 the mass centre of the cylinder 632 does not change in place, which is the case in the disposition of fig. 5. The aforesaid means for automatic adjustment of the angular position of the gaps 531, 644 are not shown. They may be formed by an electric motor, for example, a step motor, controlled by the above-mentioned detecting means. Fig. 7 shows a variant of the invention having two air inlet gaps extending at least substantially in the transverse direction of the tunnel and covering each sub stantially the hoi transverse dimension thereof, said gaps 748, 749 having the same axial positions in the tunnel on opposite walls. The air is blown through the gaps 748, 74 by two suction/blowing units 750 and 751 respectively. In this arrangement two opposite air streams together form an air curtain as is schematically indicated by arrows.

The invention is not limited to the embodiments described and illustrated. For example , combinations of the various aspects of the invention discussed above are possible.

Fig. 8 shows a variant in which the top wall 1 of the tunnel 8 has superimposed on it a chamber 2 having thermally insulating walls 3. The chamber 2 comprises two blowers 4, 5, which suck in air from the ambiance through the chamber 2 and an air suction gap 6 in the top wall 1 of the tunnel 8 and which dispense the air 12 through blowing gaps 9, 10 to form air curtains 11, 12. Such a configuration has proved to be highly effective.

Fig. 9 shows a further variant in which a chamber 7 having heat-insulating walls 13 is disposed on the top wall 1 of the tunnel 8. A blower 14 is arranged inside the chamber 7 and sucks in ambient air 16 to form an air curtain 17. A blower 15 sucks air from the cold space to form an air curtain 18. This embodiment also proves to yield excellent results.

Fig. 10 illustrates a tunnel 19 of a cold store according to the invention comprising curtains 22, 23 suspended to rails 20, 21 formed by overlapping, flexible strips. The rails can be turned aside around a vertical pivotal shaft 24, 25.

The lower edges 26, 27 of the curtains 22, 23 are located at a given distance from the tunnel floor 28. It is thus ensured that an effective operation of the air curtain is not hindered. The curtains ensure a substantially clear view and a free passage, whilst the influence of wind is reduced.

Claims

1. A cold-storage building having a cold space, a door opening in at least one of the cold-store walls and means for generating an air curtain intended for thermal separation at the area of the door opening between the cold space and the ambience characterized in that the door opening is formed by a tunnel extending over a predetermined distance, said means being located in a zone between the ends of the tunnel.

2. A cold-storage building as claimed in claim 1, characterized in that said means comprise at least one air inlet gap extending substantially in the transverse direction of the tunnel and substantially covering the whole transverse dimension thereof.

3. A cold-storage building as claimed in claim 1, characterized in that said means comprise two air blowing gaps extending at least substantially in the transverse direction of the tunnel and each substantially covering the whole transverse dimension concerned thereof, said gaps being relatively off-set in the direction of length of the tunnel.

4 A cold-storage building as claimed in claim 1, characterized in that said means comprise two air blowing gaps extending substantially in the transverse direction of the tunnel and each substantially covering the whole transverse dimension concerned thereof, said gaps being disposed in the same axial position of the tunnel on opposite walls thereof.

5. A cold-storage building as claimed in anyone of the preceding claims, characterized in that said tunnel extends in the cold space.

6. A cold-storage building as claimed in anyone of the preceding claims characterized in that said tunnel extends to the outer side.

7. A cold-storage building as claimed in anyone of the preceding claims, characterized by means for sucking i n air from the cold space for obtaining the air curtain.

8. A cold-storage building as claimed in anyone of claims 1 to 6, characterized by means for sucking in air from the ambience for obtaining the air curtain.

9. A cold-storage building as claimed in anyone of claims 2 to 8, characterized in that the angular position of the or each air blowing gap is adjustable whilst maintaining its longitudinal direction.

10. A cold-storage building as claimed in claim 9, characterized by means for adjusting the angular position of said air blowing gap, said adjusting means being controlled by detecting means responding to the velocity and direction of the wind and to the ambient temperature.

11. A cold-storage building as claimed in anyone of the preceding claims, characterized by means for controlling the initial velocity of the air of the air curtain, said means being controlled by detecting means responding to the velocity and direction of the wind.

12. A cold-storage building as claimed in claim 1, characterized in that betweeen at least one air blowing gap and the outer end of the tunnel the side walls of the tunnel have a concave, cylindrical part extending substantially to the outer end of the tunnel and at least subtantially along their entire height.

13. A cold-storage building as claimed in claims 2 and 8, characterized in that the means for sucking in air are formed by an air suction opening located in a zone located between the air blowing gap(s) and the outer end of the tunnel and in that a chamber is provided for establishing a communication between the air suction opening and the air blowing gap(s).

14. A cold-storage building as claimed in claims 5 and 13, characterized in that said chamber is thermally insulated.

15. A cold-storage building as claimed in claim 13 or 14, characterized in that the air-suction opening is formed by an air suction gap extending subtantially in the transverse direction of the tunnel and substantially along the whole transverse direction thereof.

16. A cold-storage building as claimed in claims 1 to 15, characterized in that near the outer end of the tunnel curtains formed by suspended strips having a small width as compared with the width of the tunnel join the two side walls of the tunnel in a substantially transverse direction thereto.

17. A cold-storage building as claimed in claim 16, characterized in that said strips are flexible.

18. A cold-storage building as claimed in claims 16 and/or 17, characterized in that the strips can be pivotally turned aside.

19. A cold-storage building as claimed in claims 16 to 18, characterized in that the lower edges of the curtains are located at a given distance from the tunnel floor.