HK1072288B - Air shutter and installation method thereof - Google Patents

Description

Air gate and installation method thereof

Technical Field

The present invention relates to an air shutter installed at an inlet where a temperature difference exists between the inside and the outside, for preventing an air flow from passing through the inlet, i.e., preventing external air from entering and internal air from flowing out.

Background

Japanese patent No. 37-12183 discloses an air curtain generating apparatus for use in a building for preventing the entry of outside air through a doorway of an insulated door.

The above invention proposes a device for producing an air curtain, the device being constructed so that air is ejected from both sides of the doorway in a horizontal or downwardly inclined direction to form two air streams of opposite flow directions, each air stream being parallel to each other in a direction perpendicular to the plane of the entrance, and a swirling air flow being produced between the two air streams.

However, the use of the above-described device involves a problem: the air curtain generating apparatus, which forms an air curtain by ejecting air from one side of a doorway, requires a large amount of air to form an air flow.

Among the solutions disclosed hereinafter, one is disclosed in japanese patent laid-open No. 51-118149, in which an air curtain generating apparatus is proposed which is constructed in the following manner (see fig. 9): the flow direction of the circulating air passing through the fan 110 disposed in the top of the portal duct 106 for forming the air curtain is changed by 180 degrees in the vertical section of the portal duct by using the guide member 108. In this way, the air is ejected in a downwardly inclined direction, particularly in the region near the top of the portal duct where the velocity of the ejected air is high. Therefore, there is a problem: it is difficult to form the air curtain in the upper region of the inlet, and thus the effect of preventing the entrance of the external air in the upper region of the inlet is poor.

In addition, according to the apparatus of this embodiment, since the return fan 110 is located at the upper portion of the door duct 106, it is difficult to perform maintenance of the heat insulating door, which is not shown in the drawings.

An example of another device for generating an air curtain which has been proposed in the past is shown in figures 10A and 10B. Fig. 10B shows a cross-sectional view along the line VI-VI in fig. 10A. According to this embodiment, a portal duct 53 is provided outside the heat insulating door 57, and an air return passage 55 and an air return fan 54 are formed in the portal duct. The door can be slid to be opened or closed while being in contact with a rubber or vinyl seal provided between the rear surface thereof and the outer surface 51 of the wall 50 of the building. An air curtain 56 is formed between the opposite vertical side surfaces 53a, 53a of the duct 53 in such a manner that air is blown out from the slits in the surface 53a of the vertical duct portion disposed on the left side of the duct 53 and is sucked in from the slits in the surface 53 of the vertical duct portion disposed on the right side of the duct 53, to prevent outside air from entering the building.

The gaps 53b, 53b between the rear side surfaces of each vertical portion of the duct 53 and each of the above-described heat-insulating doors are sealed with a rubber or vinyl seal.

As shown in fig. 10B, when the heat-insulating door is slid to the left and right to open the entrance, even if an air curtain is formed in front of a space 65a surrounded by a dotted line formed between the doors 57, the apparatus cannot prevent the outside air from entering from a gap formed at the top of the space 65a when the doors are opened. Therefore, a very good effect of intercepting the external air cannot be achieved.

Another proposal is disclosed in japanese utility model laid-open publication No. 5-73436. As shown in FIGS. 11A and 11B, FIG. 11B is a cross-sectional view taken along line VII-VII in FIG. 11A. In this embodiment, heat insulating doors 60 and 61 are provided so as to be slidable outside the building wall 50, these doors are covered with a heat insulating material 52, and a seal 51 is provided around the opening of the wall 50. Hot air fans 60a and 61a are provided at the left end of the heat insulation door 60 and the right end of the heat insulation door 61, respectively. The outside air taken in by the fan 61a passes through an air passage formed outside the right side door 61, is ejected therefrom toward an air passage formed outside the left side door 60 and is taken in by the fan 60a, so that an air curtain 62 is formed in front of a space 65b between both doorway side ends of the opened doors 60, 61. The air is discharged outward from the fan 60 a.

With this arrangement, although the air curtain 62 for intercepting the air flow between the inside and outside of the building is generated in front of the space 65b, there is still a problem: the inflow of the external air from the gap above the top of the space 65b cannot be prevented.

In addition, with this scheme, the temperature of the cutoff air flow is considerably higher than that of the cold air inside, and since the cutoff air flow is composed of the outside air sucked from the right side of the heat-insulating door 61, white mist is easily generated due to condensation of moisture in the air flow caused by contact or mixing of the air flow with the cold air inside. The white mist causes poor visibility when people look from the outside. This solution also creates a problem: there is ice formation on the floor and on the doorway side end faces of the doors 60 and 61 where the inside cool air mixes with the cutoff air flow formed only by the outside air of higher temperature.

As already mentioned above, a problem exists in prior art devices for generating an air curtain of the cross-flow type: when the door is opened, the external air flows in from the gap formed above the top of the open space of the doorway.

Fig. 10c shows a hitherto widely used downdraft type air curtain generating device.

As shown in the drawing, the downdraft type air curtain generating device 63 is simple in structure. Which is disposed above the outer wall 50 of the building and generates a down-draft, cutoff air flow 63a within the top extent of the door 64. The device has been widely used because of its simple structure. However, the intercepting effect is reduced near the ground where the air flow velocity is lowest and white water mist is generated, which is formed by condensation of moisture in the air flow caused by mixing of the air flow with cold air leaking from the inside, resulting in poor visibility of people when seen from the outside and also ice on the ground.

With the downdraft type air curtain, since the angle of the air flow is constant, it is difficult to obtain a stable air curtain effect. If the air temperature differs between the interior and the exterior of the building, the effect of the cutoff near the bottom of the air curtain is reduced, particularly in the bottom region of the air curtain where the air velocity is low, and the air curtain is easily broken.

Since the downdraft type air curtain involves the problems as described above, it is difficult to sufficiently prevent the cool air from leaking out from the inside.

In order to solve the above-mentioned problems, the inventors of the present application proposed in japanese patent laid-open No. 2000-249382 an apparatus for producing an air curtain which solves the problem of the lowering of the intercepting effect in the vicinity of the end of the down stream as observed in the down type air curtain in the related art and the problem of the condensation due to the leakage of the cool air as observed in the above-mentioned cross-flow type air curtain, so that it is possible to produce an air curtain which is high in the intercepting efficiency and does not produce the condensation of moisture.

According to this solution, as shown in fig. 12, the device is composed as follows:

(a) each of the heat-insulating door leaves 71 and 72 of the double door is provided in its doorway side with air jets 76 and 73, air suction ports 74 and 77, and air circulation fans 83 and 84, respectively, to generate a circulating cutoff air flow including a lower cutoff air flow 78a and an upper cutoff air flow 78 b.

(b) That is, a cold air cutoff flow 78a is formed in a lower region of the doorway to prevent the cold air inside from leaking out, and a hot air cutoff flow 78b is formed in an upper region of the doorway to prevent the hot air (outside air) from entering the inside, the air of the cutoff flow being converted from one flow circulation to another flow.

(c) In addition, a descending air flow 79 is formed by a part of the circulating air flowing in the upper part of the doorway.

(d) The ejection angle of the air of the lower cutoff air flow, i.e., the cool air cutoff flow 78a, is inclined inward, and the inclination angle is changed depending on the conditions in order to achieve higher cutoff efficiency.

As described above, according to this scheme, the down stream 79 and the cross-flowing hot air cutoff stream 78b are formed to prevent the outside air from flowing to the inside, and the cross-flowing cold air cutoff stream 78a is also formed in order to prevent the cold air in the inside 80 from flowing out to the outside. The air of the down flow and the warm air cutoff flow 78b is introduced into the fan 83 to form the cool air cutoff flow 78 a.

According to this scheme, although it is possible to prevent the generation of white mist due to the condensation of moisture in the external hot air unlike the apparatus of the prior art that forms the circulation cutoff air stream including the hot air cutoff air stream and the cold air cutoff air stream, it does not sufficiently solve the problem regarding the effective cutoff air stream.

Disclosure of Invention

The object of the invention is to provide a low-cost, high-efficiency, easy-to-maintain air lock which effectively blocks the air flow, in particular through the doorway opening area of a cold storage, based on experimental data on the air flow through the doorway opening area of the cold storage.

According to a first aspect of the present invention, there is provided an air door installed in front of a doorway in which a temperature difference exists between the inside and the outside to intercept an air flow passing through the doorway, characterized in that: the upper and lower regions of the doorway opening region constitute a hot air cutoff region in which a hot air cutoff airflow is formed and a cold air cutoff region in which a cold air cutoff airflow is formed, respectively, with an airless boundary therebetween, and both airflows are formed by circulating air that circulates from one cutoff airflow to the other cutoff airflow.

The first aspect of the present invention described above is the basic structure of the air lock of the present invention, which can prevent outside air (hot air) from entering through the opening area and prevent cold air from flowing out to the outside of the opening area.

Fig. 4A and 4B show the effect of the airflow through the open area, which will be described in detail later. As shown, the velocity of the air flowing out through the open area is greatest near the ground, decreasing with increasing height relative to the ground, becoming zero at 0.8H (H being the height of the open area). In the upward region, the velocity increases in the opposite direction, i.e., outside air (hot air) enters the interior through the opening region. The most open area is the cold air outflow area, the upper small part is the hot air inflow area, and a windless boundary is arranged between the two areas.

In the present invention, in consideration of the test results, the upper region is defined as a hot air cutoff region where a fast cutoff air flow is formed by blowing air from a nozzle having a small opening, and the lower region is defined as a cold air cutoff region where a slow cutoff air flow is formed by blowing air from a nozzle having a large opening.

The air in the air stream may be circulated. The circulating air is lowered in temperature by mixing and contacting with the cold air flow inside the opening area, lower than the temperature of the outside air. The temperature difference between the cutoff air flow and the outside air decreases. Therefore, the formation of white mist due to the condensation of moisture in the outside air is prevented. That is, in the initial stage of the formation of the cutoff air flow, most of the air flow is composed of air having a temperature close to that of the outside air (hot air), and the moisture condensed in the hot air is heated during the circulation so that it is released from the condensate, while on the other hand, the temperature of the cutoff air flow is lowered.

The air lock preferably includes a pair of doorposts each of which is provided at one side of the doorway and forms the cold-air cutoff flow by ejecting air from a cold-air cutoff flow generating part including a nozzle and one or more fans provided in a lower portion of one of the doorposts. The hot-air cutoff flow is formed by ejecting air from a hot-air cutoff flow generating part including a nozzle and one or more fans provided in an upper portion of the other of the doorposts. The opening area of the nozzle forming the cool air cutoff flow is larger than the area of the nozzle forming the hot air cutoff flow.

Since the cold air cutoff air flow generating portion provided with the one nozzle and the one or more fans is integrally provided on one of the doorposts and the hot air cutoff air flow generating portion provided with the one nozzle and the one or more fans is integrally provided on the other doorpost, it is not necessary to provide the one or more fans to circulate the circulating air outside the doorposts, whereby it is possible to provide the air lock door having a simple structure, low cost, and easy maintenance.

In the air shutter according to the first aspect of the present invention, it is preferable that the hot-air cutoff airflow is formed so as to cover a region (H is a height of the doorway opening region) having a height ranging from 0.1H to 0.4H from a top end of the region. The cool air cutoff flow is formed to cover an area having a height ranging from 0.5H to 0.9H from the ground.

This was determined in view of the experimental data shown in fig. 4A and 4B.

Fig. 4A is an illustrative graph showing the velocity of air passing through a doorway and the velocity profile along a vertical centerline. Fig. 4B is an explanatory diagram showing a velocity distribution by a velocity vector.

As previously mentioned, the velocity of the outgoing air through the open area is greatest near the ground, decreasing with increasing height relative to the ground, becoming zero at 0.8H (H being the height of the open area). The velocity increases in the reverse direction in the upward region, i.e., the outside air (hot air) enters the inside through the opening region, which is defined in a small region in the upper part of the opening region.

Thereby defining the hot air intercepting region to be a region having a height ranging from 0.1H to 0.4H from the top of the opening region and the cold air intercepting region to be a region having a height ranging from 0.5H to 0.9H from the ground, the boundary region between the hot air intercepting region and the cold air intercepting region forming a windless boundary.

In the air shutter according to the first aspect of the present invention, the air forming the hot air cutoff flow is preferably ejected at an angle inclined inward by 0 to 20 degrees, and the air forming the cold air cutoff flow is preferably ejected at an angle inclined outward by 0 to 20 degrees.

In the air lock according to the first aspect of the present invention, the cold-air cutoff airflow generating portion and the hot-air cutoff airflow generating portion are suitably provided in the heat insulating door for opening or closing the doorway.

In the air lock according to the first aspect of the present invention, the door columns are preferably of a portal structure having an upper beam connecting the two door columns. By adopting this structure, it is avoided that a gap is formed above the top of the doorway opening space when the door is opened. Therefore, the inflow of the outside air into the top range of the hot air intercepting region can be prevented.

In the air lock according to the first aspect of the present invention, it is preferable that a short curtain member is provided in a hot air cutoff region at an upper portion of the doorway opening region to cut off a flow of hot air between the inside and the outside of the opening region.

With this arrangement, in addition to the temperature difference between the cutoff air flow and the cool air in the warehouse being reduced by the air circulation flow of the cutoff air flow, the effect of the hot air flow in the upper portion of the cutoff opening area can be enhanced by using the short curtain member.

Since the short curtain member is disposed only in the hot air intercepting region of the upper portion of the opening region, it does not shield the middle and lower portions of the opening region, so that it does not obstruct people from viewing the inside of the refrigerator, and at the same time, it does not obstruct the work vehicle, such as a forklift truck, from entering and exiting the refrigerator.

According to a second aspect of the present invention, there is provided an air lock door installed in front of a doorway having a temperature difference between inside and outside and provided with a door of a vertical sliding type for intercepting an air flow passing through the doorway, comprising: a door structure consisting of a pair of door columns and an upper beam connecting the two door columns; the upper area and the lower area of the doorway opening area respectively form a hot air cutoff area and a cold air cutoff area, and a windless boundary exists between the hot air cutoff area and the cold air cutoff area; the hot air cutoff flow is formed so as to cover a region having a height ranging from 0.1H to 0.4H from the top end of the region (H is the height of the doorway opening region). The cool air cutoff flow is formed to cover an area having a height ranging from 0.5H to 0.9H from the ground. The cold air cutoff flow is formed by ejecting air from a nozzle provided in a lower portion of one of the doorposts, and the hot air cutoff flow is formed by ejecting air from a nozzle provided in an upper portion of the other of the doorposts. The opening area of the nozzle forming the cold air cutoff flow is larger than that of the nozzle forming the hot air cutoff flow; the air forming the hot air cutoff flow is preferably ejected at an angle inclined inward by 0 to 20 degrees, and the air forming the cold air cutoff flow is preferably ejected at an angle inclined outward by 0 to 20 degrees.

An air lock according to a second aspect of the present invention relates to an air lock installed in front of a doorway with a temperature difference between inside and outside of the vertical sliding door to intercept an air flow passing through the doorway. A door structure including left and right door columns and an upper cross member connecting the two door columns is provided in the vicinity of the vertical sliding door. The hot air cutoff air flow generating part and the cold air cutoff air flow generating part according to the first aspect of the present invention are respectively provided in the respective doorposts. This forms a circulating cutoff air stream comprising a hot air cutoff air stream and a cold air cutoff air stream.

The angles of the areas covered by the warm air cutoff flows and the cool air cutoff flows with the air ejection direction are the same as those in the case of the first aspect of the present invention described above.

According to a third aspect of the present invention, there is provided an air door for intercepting an air flow passing through a doorway installed in front of the doorway where a temperature difference exists between the inside and the outside, the air door comprising: which is installed with a pair of doorposts each of which is disposed at one side of the doorway to face each other. A duct through which air passes is formed in each of the doorposts, and an air ejection port and an air suction port are provided in the height direction of each of the doorposts such that each ejection port of the doorpost face on one side is opposed to each air suction port of the doorpost face on the other side, respectively. A plurality of fans are arranged behind each air outlet; one of the door posts is provided with an air outlet, and the fans are arranged at the upper part and the lower part of the door post; the other door post is provided with an air jet, and the fan is arranged in the middle of the door post in the height direction; air is ejected from the air ejection ports toward the corresponding opposite air intake ports.

According to the present invention, the air ejection port and the fan of the one side door post are located at the upper and lower portions of the door post, the air is ejected from the air ejection port toward the air suction port provided in the other side door post, the air ejection port and the fan of the other side door post are located at the middle portion in the height direction of the door post, and the air is ejected from the air ejection port toward the air suction port provided in the door post on the above side. Thus, by dividing the fans provided in a pair of door posts into three groups having at least three suction passages: the group of fans and the other group of fans are respectively positioned at the upper part and the lower part of the door post at one side, and the group of fans is positioned at the middle part of the door post at the other side, so that the length of a fan suction channel can be reduced, the air flow can smoothly pass through, and the mutual interference of the suction air flow among the fans is eliminated.

This arrangement reduces the suction resistance of each fan, suppresses an increase in suction negative pressure due to a small width of the suction passage, and thus can prevent a decrease in speed, i.e., the flow velocity of the circulating air accompanying the increase in suction negative pressure.

Further, in the invention, the fans provided in the middle are preferably divided into two groups, and each group of fans sucks air through each of the two-divided suction passages divided by a partition member for partitioning the duct inside the other side doorpost.

With this arrangement, the fans located in the middle can be divided into two groups of fans having two passages, and therefore, all the fans can be divided into four groups having four suction passages, which can further enhance the effect of suppressing the increase in suction negative pressure.

Further, according to a fourth aspect of the present invention, there is provided a method of installing an air door, characterized in that: seals for air sealing are provided in the doorways and doorposts for opening and closing the first to third aspects of the present invention.

According to the invention, the sealing element is simply arranged on the doorpost, so that the door keeps in contact with the sealing element while sliding, and air sealing between the doorpost and the door can be realized.

Drawings

Fig. 1 is a perspective view schematically showing the structure of an air lock according to a first embodiment of the present invention.

Fig. 2A is a longitudinal sectional view showing an installed air lock door according to a second embodiment of the present invention when cargo is carried into or out of a warehouse or onto a truck in a case where a door of a warehouse room is a drop door (a vertical sliding door). FIG. 2B is a cross-sectional view taken along line C-C of FIG. 2A.

FIG. 3 is a graph showing the temperature change within the warehouse with and without the air curtain being formed.

Fig. 4A is an explanatory diagram showing the distribution of air velocity along the vertical center line passing through the doorway, and fig. 4B is an explanatory diagram showing the distribution of velocity with velocity vectors.

FIG. 5A is a front view of a third embodiment of an air lock door according to the present invention, schematically illustrating a fan unit; fig. 5B is a front view of an example for comparison, showing a fan apparatus.

Fig. 6 is a front view of an air shutter in a fourth embodiment of the present invention, showing the structure of a short curtain.

Fig. 7 is a perspective view of an air door according to a fifth embodiment of the present invention, showing a fixed seal member for sealing a gap between a double door and the air door.

Fig. 8 is a view in the direction indicated by the arrow Z in fig. 7.

FIG. 9 is a perspective view schematically showing the construction of one example of a door type air curtain producing apparatus in the prior art.

FIG. 10A is a front view schematically showing the construction of another example of a door type air curtain forming apparatus in the prior art. FIG. 10B is a sectional view taken along line VI-VI of FIG. 10A, and FIG. 10C is a side view showing the structure of an example of a downdraft type air curtain generating apparatus in the prior art.

FIG. 11A is a front view schematically showing the structure of another example of an air curtain generating apparatus in the prior art. FIG. 11B is a cross-sectional view taken along line VII-VII in FIG. 11A.

Fig. 12 is a perspective view schematically showing the structure of another example of a prior art air curtain generating apparatus in which a cut-off flow of hot air flowing in a horizontal direction, a cut-off flow of cold air flowing in a horizontal direction, and a cut-off flow of hot air flowing in a vertical direction are formed.

Detailed Description

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, unless otherwise specified, the dimensions, materials, and relative positions of constituent elements in the embodiments and the like should be construed merely as illustrative of the present invention and not as a limitation on the scope of the invention.

Fig. 1 is a perspective view schematically showing the structure of an air lock according to a first embodiment of the present invention. Fig. 2A is a longitudinal sectional view showing an installed air lock door according to a second embodiment of the present invention when cargo is carried into or out of a warehouse or onto a truck in a case where a door of a warehouse room is a drop door (a vertical sliding door). FIG. 2B is a cross-sectional view taken along line C-C of FIG. 2A. FIG. 3 is a graph showing the temperature change within the warehouse with and without the air curtain being formed. Figure 4A is a graphical illustration showing the air velocity profile along a vertical centerline through the doorway and figure 4B is a graphical illustration showing the velocity profile with velocity vectors. FIG. 5A is a front view of a third embodiment of an air lock door according to the present invention, schematically illustrating a fan unit; fig. 5B is a front view of an example for comparison, showing a fan apparatus. Fig. 6 is a front view of an air shutter in a fourth embodiment of the present invention, showing the structure of a short curtain. Fig. 7 is a perspective view of an air door according to a fifth embodiment of the present invention, showing a fixed seal member for sealing a gap between a double door and the air door. Fig. 8 is a view in the direction indicated by the arrow Z in fig. 7.

Referring to fig. 1, a first embodiment of the air lock of the present invention is comprised of a door type structure including a door post 12 for generating a cutoff flow of cool air, a door post 13 for generating a cutoff flow of hot air, and an upper beam 16 for connecting the two door posts. The door type structure is arranged in front of the door way of the refrigeration house. A lower slit-shaped nozzle 12a is provided in a lower portion of the doorway side surface of the gate post 12, and a lower end of the lower slit-shaped nozzle 12a extends to the floor 14. An inlet port 12b extending upward to the upper beam 16 is provided on the upper surface of the lower slit nozzle 12 a. Inside door post 12, lower fan 12c and intake duct 12d are provided, and intake duct 12d guides circulating air 11 taken in through intake port 12b to the intake side of lower fan 12 c.

On the other hand, an upper slit nozzle 13a is provided in an upper portion of the doorway side surface of the gate post 13, and an upper end of the upper slit nozzle 13a extends to the upper beam 16. An air inlet 13b extending downward to the floor 14 is provided below the upper slit nozzle 13 a. An upper fan 13c and an intake duct 13d are provided in the door post 13, and the intake duct 13d guides the circulating air 11 sucked through the intake port 13b to the intake side of the upper fan 13 c.

The upper beam 16 connecting the doorposts 12 and 13 constitutes an upper end of the opening region 010 of the door type structure, so that the air lock door of the door type structure can be installed in front of the doorway, so that there is no gap above the cut-off air stream of the hot air flowing in the lateral direction, thereby completely preventing the inflow of the external air.

The height of the lower slit nozzle 12a with respect to the ground is about 0.5H (H is the height of the opening area 010). The air ejected from the lower slit-shaped nozzle 12a forms a cool air cutoff airflow 10 a. The vertical length of the upper slit nozzle 13a with respect to the upper beam is approximately 0.1H, and the air ejected from the upper slit nozzle 13a forms the hot air cutoff flow 10 b.

The opening area of the lower slit-shaped nozzle 12a is larger than that of the upper slit-shaped nozzle 13a, and therefore, the velocity of the cool air cutoff airflow 10a is smaller than that of the hot air cutoff airflow 10 b. The air inlet 13b provided in the door post 13 extends from the floor 14 to a height of about 0.9H, so that when the slow air flow 10a ejected from the lower slit-shaped nozzle 12a of the door post 12 reaches the air inlet 13b of the door post 13, it expands to a height of about 0.9H with respect to the floor 14, and the air flow is sucked at the air inlet. When the relatively fast air flow 10b ejected from the upper slit-shaped nozzle 13a reaches the air inlet 12b of the door post 12, it expands to a height of about 0.4H with respect to the upper beam 16, and the air flow is sucked at the air inlet.

With the above-described structure, the relatively fast air flow from the upper slit-shaped nozzle 13a forms the hot air cutoff air flow 10b in the hot air cutoff region.

The above-mentioned relatively fast airflow 10b is sucked from the suction port 12b of the doorpost 12, and the airflow passes through the suction duct 12d and is ejected from the lower slit-shaped nozzle by the lower fan 12c to form the relatively slow cool air cutoff airflow 10a in the cool air cutoff region.

The above-mentioned relatively slow air flow is sucked in from the air inlet 13b of the door post 13, passes through the air intake duct 13d, and is then ejected again from the upper slit-shaped nozzle 13a by means of the upper fan 13 c. Thus, an airflow circulation path is formed.

Referring to fig. 2A and 2B, a hanger door 21 (vertical sliding door) separates a cold storage room 30a from a room 31 for disposing of goods located at an outside 30B. A gate structure including an air gate of the present invention, which includes a gate post 12 generating a cutoff flow of cold air, a gate post 13 generating a cutoff flow of hot air, and an upper beam 16, is installed in front of a doorway of the drop door 21.

The figure shows a state in which the truck 26 enters a room 31 for disposing of goods. The room for disposing of the goods is provided with a single-inclined ceiling 32, a curtain 22 and a shield cover 24, and a double-leaf hinged door 26a of a truck 26 is opened, and a drop door 21 is slid upward to open a doorway between a cold store 30a and a room 31 for disposing of the goods located outside the cold store 30 a.

After the truck enters the room for disposal (cargo), the drop door 21 is opened, and the air lock door is operated to form the cold air cutoff air flow 10a and the hot air cutoff air flow 10 b.

In this case, as shown in the drawing, the panel 23 surrounds the door post 12, the door post 13, and the upper beam 16, so that the outside of the door structure is sealed with respect to the refrigerated warehouse 30 a.

With the air lock door of the present invention, the door structure can be installed in front of the doorway of the cold storage room with its outer portion sealed with respect to the cold storage room 30a, so that the door can be applied to the case of using any type of door, and an air lock door with low cost and improved maintainability can be provided.

Fig. 3 is a graph showing the change in temperature in the refrigerated warehouse with and without the air curtain formed in the case where the air shutter shown in fig. 1 is provided. It can be seen from the graph that the temperature in the cold store-24 degrees celsius changes after 4 minutes as follows:

when the air curtain is formed, the temperature rises by approximately 2 degrees celsius.

When no air curtain is formed, the temperature rises by about 22 degrees celsius.

Thus, the air gate of the present invention achieves a significant effect of intercepting the air flow.

Referring to fig. 5, the arrangement of the fan in the air brake according to the third embodiment of the present invention is shown. Reference numeral 40 denotes a fan having a similar structure to the fans 12c, 13c in the first and second embodiments. The first fan group 40a includes three fans 40 which are vertically and mutually parallel arranged in an upper portion of an air suction duct 13d formed inside the door post 13 so as to blow out air through an upper slit-shaped nozzle 13a provided in the upper portion of the air suction duct 13d₁Into the opening area 010.

The second fan group 40b includes three fans 40 disposed vertically and in parallel with each other in the lower portion of the air suction duct 13d so as to eject air through the lower slit-shaped nozzles 13a disposed in the lower portion of the air suction duct 13d₂Into the opening area 010.

An upper suction duct 12d is formed in the doorpost 12₁And a lower suction duct 12d₂The partition member 41 separates the two pipes.

The third fan group 40c includes two fans 40 disposed vertically and parallel to each other in the upper suction duct 12d₁So that air is ejected through the air intake duct 12d₁Middle slit-like nozzle 12a in the lower part₁Into the opening area 010.

The fourth fan group 40d comprises two fans 40 arranged vertically and parallel to each other in the lower suction duct 12d₂So that air is ejected through the air intake duct 12d₂Middle slit-like nozzle 12a in the upper part₂Into the opening area 010.

By a first fan group 40a arranged in the upper part of the air suction duct 13d in the door post 13The blown air passes through the opening region 010 from the air inlet 12b₁An air suction pipe 12d flowing into the upper part of the doorpost 12₁. The air continues to flow through the air intake passage 42c of the third fan group 40c for each fan 40 of the third fan group 40c to draw.

The air blown by the second fan group 40b provided in the lower portion of the air suction duct 13d in the doorpost 13 passes through the opening region 010 from the air suction port 12b₂Lower air suction duct 12d flowing into doorpost 12₂. The air continues to flow through the air intake passage 42d of the fourth fan group 40d for each fan 40 of the fourth fan group 40d to draw.

By an upper suction duct 12d provided in the doorpost 12₁The air blown by the third fan group 40c in the lower portion passes through the opening region 010 from the air inlet 13b₁Flows into the suction duct 13d in the doorpost 13. The air continues to flow through the air intake passage 42a of the first fan group 40a for each fan 40 of the first fan group 40a to draw.

By a lower suction duct 12d provided in the doorpost 12₂The air blown by the fourth fan group 40d in the upper part passes through the opening region 010 from the air inlet 13b₂Flows into the suction duct 13d in the doorpost 13. The air continues to flow through the air intake passage 42b of the second fan group 40b to be drawn by each fan 40 of the second fan group 40 b.

According to the third embodiment, the above-described fans and slit-shaped nozzles of the door post 13 are provided at the upper and lower portions of the door post 13, and the air blown by the first fan group 40a provided at the upper portion is directed toward the air inlet 12b of the door post 12 opposed to the door post 13₁While flowing, the air is directed toward the air inlet 12b by the second fan group 40b provided at the lower portion₂Blowing, on the other hand, the suction duct inside the doorpost 12 is divided at its middle into an upper suction duct 12d₁And a lower suction pipe 12d₂The fan and the slit-like nozzle on the door post 12 side are respectively located in the air intake duct 12d₁And 12d₂Upper and lower portions. The air is directed toward inlet 13b of door post 13 facing door post 12 by third fan group 40c₁And (4) blowing. At the same timeThe air is directed from the fourth fan set toward the air inlet 13b of the door post 13₂Blowing so that each of the fan groups made up of a plurality of fans provided in the doorpost 12 and the doorpost 13 opposed thereto can be separately provided: the first fan group 40a is arranged at the upper part of the door post 13 and is provided with an air suction channel 42 a; the second fan group 40b is arranged at the lower part of the door post 13 and is provided with a suction channel 42 b; a third fan group 40c provided on the upper surface of the middle portion of the doorpost 12 and having an air intake passage 42 c; fourth fan group 40d is disposed below the middle portion of door post 12 and is provided with an air intake passage 42 d.

Therefore, compared with the comparative embodiment shown in fig. 5B, the fan groups 40f and 40e are provided in the doorposts 12 and 13 in this example, respectively, and therefore, the respective suction passages 42f and 42e of the respective groups of fans are inevitably long, which results in the difference in suction pressure between the respective fans and the large variation in the air flow velocity v. The length of the suction passage of each of the four fan sets in the third embodiment shown in fig. 5A can be reduced to smooth the air flow and eliminate the mutual interference between the suction air flows between the fans.

With this embodiment, the width B is reduced₁、B₂The generally smaller suction resistance in each of the suction passages 42a, 42b, 42c, 42d also prevents a decrease in the airflow rate, i.e., the airflow rate, due to an increase in suction negative pressure, and reduces a variation in the airflow rate.

In addition, the increase of the suction negative pressure of the fans arranged at the corners can be reduced by providing smoothly curved corner portions 44, 45 at the ends of the fan suction passages of each group.

In a fourth embodiment of the invention shown in fig. 6, a short curtain 46 of a plurality of curtains of different lengths depends from the head rail 16 mounted on the door posts 12 and 13 for intercepting the hot air flow between the inside and outside of the upper part of the opening area 010. To form the region 46a beneath the curtain 46 for convenient passage of a cart, the length H1 of the short curtain 46 is about one-half the height H of the open area 010 or less.

In the fourth embodiment, in addition to reducing the temperature difference between the cutoff air flow and the cool air in the warehouse by using the air circulation forming the cutoff air flow, the cutoff effect of the hot air flow above the opening area 010 can be enhanced by using the short curtain 46.

Since the short curtain 46 is disposed only in the hot air intercepting region located in the upper portion of the opening region, it does not shield the middle and lower portions of the opening region, so that the short curtain 46 does not obstruct people from viewing the interior of the refrigerator, and at the same time, it does not interfere with the entry and exit of work vehicles, such as forklift trucks, into and out of the refrigerator.

A fifth embodiment shown in fig. 7 and 8 relates to a method of installing an air lock according to the present invention, in which each of the columns 12, 13 of the air lock is provided with a seal 35 extending in the height direction thereof, and the seal 35 is always in contact with a door 36 slidable along a thermal insulation wall 37 of a warehouse to seal air between the columns and the door. In this embodiment, the air-tight seal between the doorposts 12, 13 and the opening area W of the door 36 can be properly achieved by simply disposing the seal 35 on the doorpost and sliding the door 36 while keeping contact with the seal 35.

The present invention is made in consideration of test data of air flow through an opening area of a doorway of a refrigerator, and provides a low-cost, high-efficiency air shutter which can form an effective circulation cutoff air flow in the opening area of the doorway, is easy to maintain, and is easily applied to various types of doors.

According to the present invention, by devising the fans to be divided into four groups each having the suction passage, the suction resistance of the fans of each group is reduced, so that it is possible to suppress an increase in suction negative pressure caused by a small width of the suction passage and to prevent a decrease in speed, i.e., a flow rate of the circulation cutoff airflow, caused by the increase in suction negative pressure.

In addition, according to the present invention, since the short curtain is disposed only in the hot air intercepting region located in the upper portion of the opening region, which does not shield the middle and lower portions of the opening region, the short curtain does not obstruct people from viewing the inside of the refrigerator. At the same time, it does not interfere with the movement of work vehicles, such as fork lift trucks, into and out of the cold storage.

Further, according to the present invention, by simply providing the sealing member on the doorpost, the door is slid while being kept in contact with the sealing member, and the air-tight seal between the doorpost and the door can be properly achieved.

Claims (10)

1. An air door for installation in front of a doorway having a temperature differential between the inside and outside thereof to intercept an air flow passing through the doorway, comprising:

the air shutter includes a pair of doorposts each disposed at one side of a doorway, the cold-air cutoff airflow being formed by air ejected from a cold-air cutoff airflow generating part including a nozzle and one or more fans disposed in a lower portion of one of the doorposts, the hot-air cutoff airflow being formed by air ejected from a hot-air cutoff airflow generating part including a nozzle and one or more fans disposed in a lower portion of the other doorpost, an opening area of the nozzle forming the cold-air cutoff airflow being larger than an area of the nozzle forming the hot-air cutoff airflow, so that upper and lower regions of an opening area of the doorway constitute a hot-air cutoff region and a cold-air cutoff region, respectively, with a windless boundary therebetween, and a hot-air cutoff airflow being formed within the hot-air cutoff region, in the region of the cold air cutoff region, a cold air cutoff flow is formed, which is formed by circulating air from one cutoff flow to the other cutoff flow.

2. The air door of claim 1, wherein:

the hot air cutoff airflow is formed such that it covers an area within a height range of 0.1H to 0.4H from the top of the area (H is the height of the doorway opening area), and the cold air cutoff airflow is formed such that it covers an area within a height range of 0.5H to 0.9H from the ground.

3. The air door of claim 1, wherein:

the air forming the hot air cutoff flow is ejected at an angle of 0 to 20 degrees inclined inward, and the air forming the cold air cutoff flow is ejected at an angle of 0 to 20 degrees inclined outward.

4. The air door of claim 1, wherein:

the cold air cutoff air flow generating part and the hot air cutoff air flow generating part are provided in the heat insulating door to open or close the doorway.

5. The air door of claim 1, wherein:

the doorpost is of a portal structure and is provided with an upper cross beam for connecting the two doorposts, and the upper cross beam can prevent a gap which enables the inner side of the doorway to be communicated with the outside from being formed at the top of the doorway space when the doorway is opened.

6. The air door of claim 1, wherein:

a short curtain member is provided in a hot air intercepting region in an upper portion of the doorway opening region to intercept a hot air flow between an inside of the opening region and the outside.

7. An air door for installation in front of a doorway having a temperature difference between the inside and the outside and provided with a vertical sliding type door to intercept an air flow passing through the doorway, comprising: :

the door structure consists of a pair of door columns and an upper beam connected with the door columns; the upper area and the lower area of the doorway opening area respectively form a hot air cutoff area and a cold air cutoff area, and a windless boundary is formed between the hot air cutoff area and the cold air cutoff area; the hot air cutoff airflow is formed to cover a region (H is the height of the doorway opening region) within a height range of 0.1H to 0.4H from the top end of the region, the cold air cutoff airflow is formed to cover a region within a height range of 0.5H to 0.9H from the ground, the cold air cutoff airflow is formed by ejecting air from a nozzle provided in the lower portion of one of the doorposts, the hot air cutoff airflow is formed by ejecting air from a nozzle provided in the other upper portion of the doorposts, and the opening area of the nozzle forming the cold air cutoff airflow is larger than the area of the nozzle forming the hot air cutoff airflow; the air forming the hot air cutoff flow is ejected at an angle of 0 to 20 degrees inclined inward, and the air forming the cold air cutoff flow is ejected at an angle of 0 to 20 degrees inclined outward.

8. An air door for installation in front of a doorway having a temperature differential between inside and outside thereof to intercept an air flow passing through the doorway, wherein:

a pair of doorposts each of which is provided on one side of the doorway so as to be opposed to each other, each of the doorposts having formed therein a duct through which air passes, each of the doorposts being provided in a height direction thereof with an air ejection port and an air suction port so that the air ejection port of each of the doorposts is opposed to each of the air suction ports of the doorposts on the other side, respectively, a plurality of fans being provided behind each of the air ejection ports; one of the door posts is provided with an air nozzle and a fan which are positioned in the upper part and the lower part of the door post; the other door post is provided with an air nozzle and a fan which are positioned in the middle of the height direction of the door post; air is ejected from the air jets toward the corresponding opposing air intake.

9. The air door of claim 8, wherein:

the fans arranged in the middle are divided into two groups, each group of fans sucking air through a respective passage divided into two parts by a partition for partitioning the duct in the door post on the other side.

10. An installation method of an air door installed in front of a doorway where a pressure difference exists between the inside and the outside to intercept an air flow passing through the doorway, wherein:

the truncation function is implemented as follows: the upper and lower regions of the doorway opening area constitute a hot air cutoff region and a cold air cutoff region, respectively, with a windless boundary therebetween, a hot air cutoff flow is formed in the hot air cutoff region, a cold air cutoff flow is formed in the cold air cutoff region, the two air streams are formed by circulating air from one cutoff air stream to the other cutoff air stream, the air lock has door columns, each of which is provided with a duct and one or more fans, which is installed at each side of the doorway to form a cutoff flow of cool air by spraying air from a nozzle provided at a lower portion of one of the doorposts, forming a hot air cutoff flow by ejecting air from a nozzle provided at another upper portion of the doorpost, an opening area of the nozzle forming the cold air cutoff flow being larger than an area of the nozzle forming the hot air cutoff flow; wherein the air lock door is provided with a sealing member to prevent air leakage between the doorpost and the door.