JPH0652147B2 - Open showcase - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an air curtain blower for improving the outside air shut-off performance of an open chow case, in particular, the air curtain closing the opening thereof, and the cooling performance of a refrigerating compartment. It relates to the blowing velocity distribution at the outlet.

[Conventional technology]

FIG. 2 is a side cross-sectional view showing the most common open-chow case of the double air curtain system among open-chow cases. In the figure, (1) is an open chowcase container having an opening (2) for loading and unloading products on the front, (3) is a refrigerating chamber (4) for storing the product in the container (1) and a cold air circulation duct (6)
And (5) is a duct plate that divides the cool air circulation duct (6) and the guard air circulation duct (7), and (8) communicates with the duct (6), and the product loading / unloading opening (2 ) Is the first outlet provided at the upper opening edge, in this case, the cool air outlet,
(9) communicates with the duct (7) and has an opening for loading and unloading the product
The second outlet provided at the upper opening edge of (2), in this case, the guard air outlet, (10) is provided at the lower opening edge facing the cold air outlet (8), and is provided in the duct (6). In this case, the first suction port communicating with the cold air suction port, and (11) the second suction port communicating with the duct (7) provided at the lower opening edge facing the guard air outlet (9). Is a guard air inlet. (12) and (14) are cooling blowers provided in the duct (7), in this case, a blower and cooler, (13) a blower provided in the duct (7), and (15) is a product loading shelf Is.

FIG. 8 (a) is an enlarged cross-sectional view of the conventional air outlet portion (A) of the open canister shown in FIG. 2, and FIG. 8 (b) is described, for example, in Japanese Utility Model Publication No. 55-13372. It is a blowing wind speed distribution chart which shows the blowing velocity distribution when the blowing velocity distribution which is applied to a double air curtain is applied. In the figure, (1) to (9) are the same as in Fig. 2, (B) is the end position of the refrigerating chamber (4) of the first outlet (8), and (D)
Is the partition position of the first outlet (8) and the second outlet (9), (E) is the outermost position of the second outlet (9), and (C) is the velocity in the air curtain outlet velocity distribution. Indicates the maximum position.

Next, the operation will be described. In FIG. 2, by operating the blower (12) and the cooler (14), the first suction port
The air sucked in from (10) is cooled by the cooler (14), blown out as cold air from the first outlet (8) through the duct (6), and is sucked into the inlet (10) again, for product loading and unloading. Opening
An air curtain on the cooling side is formed in (2), which keeps the refrigerating chamber (4) at a desired temperature. Furthermore, blower (13)
By operating the, the mixed gas of the gas of the cooling side air curtain from the second suction port (11) and the outside air outside the open canister case (1), and the air at the intermediate temperature between the gas of the cooling side air curtain and the outside air The second outlet through the duct (7)
A guard side air curtain is blown from (9) as guard air, flows along the cooling side air curtain and is blown again into the second suction port (11). Furthermore, Fig. 8
In (b), the air curtain blowing velocity distribution shape is such that the wind velocity gradually decreases from (C) to (E). Therefore, in the air curtain flow, as a shear region,
It is formed by two parts, ▲ ▼ and ▲ ▼. Most of the cooling air curtain flow and the air curtain on the guard side are included in the same shear region ▲ ▼, so the mixing effect of both is great.

[Problems to be solved by the invention]

In the case where the air curtain is in contact with the outside air (E), the entrainment of the outside air due to the shearing force caused by the velocity gradient at the boundary is suppressed, but the mixture of the cooling air curtain and the guard side air curtain can be detected from the area near the outlet. As a result, the temperature of the cooling air curtain rises, and the air curtain's outside air blocking performance,
There were problems that the cold storage performance of the refrigerating room deteriorated and that the temperature inside the refrigerating room could not be made uniform.

The present invention has been made in order to solve the above problems, and provides an open canister case that suppresses the mixing of air in the air curtain, has a high outside air blocking performance of the air curtain, and a high cold storage performance of the refrigerating compartment. With the goal.

[Means for solving problems]

The open chow case according to the present invention has a plurality of subdivided parallel flow passages, and a straightening grid whose length in the flow passage direction becomes longer from the refrigerating compartment side to the outside air side is provided at the outlet of the air curtain. A plurality of wind velocity distributions having a velocity gradient in which the blowout speed at the outlet is reduced from the refrigerating chamber side of the blowout outlet to the outside air is formed, and at the boundary of each stage, the blowout of the refrigerating chamber side is blown. The speed is slower than the blowing speed of the stage on the outside air side.

[Action]

In the present invention, since a plurality of rectifying grids are provided at the outlet of the air curtain to form the wind speed distribution, the air curtain suppresses the mixing between adjacent air due to the speed difference at the boundary of each stage, and both potentiometers. The core is maintained far away from the outlet.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1A is an enlarged cross-sectional view showing a blowout port portion (A) of a double air curtain type open chow case according to an embodiment of the present invention. In the figure, (1) to (9) and (B) to (E) are exactly the same as the above conventional device, and (16) is provided at the first and second outlets (8) and (9). Rectification for forming a desired blowout velocity distribution shape, which has a plurality of parallel flow paths each having a finely divided and uniform cross-sectional area and whose length in the flow path direction becomes longer from the refrigerating chamber side toward the outside air side. It is a grid. Further, FIG. 1 (b) is a wind velocity distribution diagram showing a blowout velocity distribution shape of the double air curtain system open chow case of one embodiment of the present invention. Two stages of wind velocity distribution having a velocity gradient in which the blowing velocity at the outlet of the air curtain decreases from the refrigerating compartment side to the outside air side are provided. In the figure, (F) is the outer end of the second outlet
The speed difference in (E), (G) is the speed difference at the step portion in the speed distribution at the partition position (D) between the first outlet and the second outlet, and (θ) is the two layers of ▲ ▼ and ▲ ▼ Is the velocity gradient assuming that the velocity distributions of have the same gradient,
The counterclockwise direction is positive. For example, the flow rate of each layer is
It is the same as Fig. (B) and the velocity gradient (θ) is zero, that is, based on the flat velocity distribution diagram of Fig. 1 (c), the blowing flow rate and blowing width of each air curtain are constant (θ) Fig. 3 shows the characteristics of the effect on the amount of invasion of outside air when V is changed. The vertical axis represents the outside air penetration amount (h), and the horizontal axis represents the slope (θ) of the outlet velocity distribution. In this figure, the minus sign of (θ) indicates that the gradient is inverse. This figure shows that the cooling side air curtain flow rate is 9 × 10 ^-2 m ³ / s, the guard side air curtain flow rate is 4.2 × 10 ^-2 m ³ / s, the outlet width of the first outlet is 90 mm, the second
The outlet width of the outlet is 60 mm, and the outlet temperature of the cooling air curtain is
These are the results when the air curtain blowout temperature on the guard side is -5 ° C and 10 ° C. Position where the maximum outside air penetration amount is shown in the figure
In (H), when (G) is zero (for example, in Fig. 1 (b), θ is To the extent, this corresponds to the conventional one and is shown in FIG. 1 (d)), that is, when the velocity distribution of ▲ ▼ is aligned with the velocity distribution of ▲ ▼. Then, as the value of (θ) moves from point (H) to the left and right, (G) increases and the amount of outside air infiltration decreases. As a result, the larger (G), the smaller the amount of outside air entering. That is, it can be seen that the outside air blocking performance is increased. Also, (F) decreases as θ increases in the positive direction. That is, the smaller the speed difference between the air curtain and the outside air, the smaller the amount of outside air invading. That is, it can be seen that the outside air blocking performance is increased. The above is physically explained. FIG. 4 is a characteristic diagram of each factor affecting the outside air intrusion amount, where the vertical axis represents the outside air intrusion amount (h) and the horizontal axis represents the slope (θ) of the blowing velocity distribution.

In the figure, the curve M represents the effect of F (shearing force at the contact surface with the outside air), the curve N represents the effect of G (gap between velocity distributions), and the curve O represents the combined effect of F and G. This corresponds to the characteristic diagram shown in the figure. For example, in a two-layer air curtain, the mixing of the two layers is suppressed due to the velocity difference (G) at the boundary, that is, both potential cores are maintained far away from the air outlet. Further, the smaller the speed difference (F) at the contact point of the air curtain on the guard side with the outside air, the smaller the shearing force generated by the speed difference at the air curtain boundary, and the less the entrainment of the outside air. For the above reasons, Fig. 1 (b)
It can be seen that the velocity distribution shape shown in Fig. 2 has high outside air insulation performance and cold storage performance in the cold storage room. This velocity distribution shape can be easily formed as desired by changing the length in the flow passage direction of the rectifying grids (16) provided at the first and second outlets (8) and (9).

Furthermore, the velocity gradient of each layer in Fig. 1 (b) does not have to be the same, and in the velocity distribution in the layer of ▲ ▼, if (F) is zero, that is, triangular shape, An air curtain with less outside air entrapment, high outside air blocking performance, and high cooling performance in the refrigerating room can be obtained.

In the above-mentioned embodiment, in the case of the double air curtain, each air curtain has a one-to-one correspondence with the sawtooth-like wind velocity distribution having a velocity gradient in which the blowing velocity decreases from the refrigerating compartment side to the outside air side. However, if one air curtain has multiple stages of sawtooth-like wind velocity distribution, that is, in the case of FIG. 5 (a), if there is one stage of sawtooth-like wind velocity distribution across multiple air curtains, that is, It may be the case of FIG.

Further, in the above-mentioned embodiment, the double air curtain type open can case is described, but the present invention can also be applied to the single air curtain type open can case. FIG. 6 is a side cross-sectional view showing a general single air curtain system open chow case. In the figure, (1) to (14) are exactly the same as the above conventional device. FIG. 7 (a) is an enlarged cross-sectional view of the air outlet portion (I) of the open cowboy case in FIG. 6 showing another embodiment of the present invention, and FIG. 7 (b) is a wind velocity distribution showing the air outlet velocity distribution. It is a figure. In the figure, (J) shows the position of the air curtain outlet (8) on the side of the refrigerating chamber (4), and (K) shows the position of the air curtain outlet (8) on the outside air side. Also,
(L) shows the boundary position of the step of the wind velocity distribution provided in the blowout velocity distribution provided in the single air curtain. In this way, in the air curtain with a single blowout velocity distribution shape, it consists of multiple trapezoidal or triangular stages with a velocity distribution in which the wind velocity gradually decreases from (J) to (K). Even if the velocity at the boundary of is changed into a stepped shape, the mixing of each step is suppressed, and the same effect is obtained. In addition, in the above-mentioned embodiment, the case of the single and double air curtain type open showcases has been described, but it goes without saying that the present invention can also be applied to other multiple air curtain type open showcases. Further, in the above-mentioned embodiment, the air curtain of the open case is described, but it is needless to say that it can be applied to the air curtain of other uses.

〔The invention's effect〕

As described above, the present invention has a plurality of subdivided parallel flow passages, and a plurality of rectifying grids whose lengths in the flow passage direction become longer from the refrigerating compartment side to the outside air side at the outlet of the air curtain. Provide a plurality of stages of wind speed distribution having a velocity gradient in which the blowout speed at the blowout port decreases from the refrigerating chamber side of the blowout port to the outside air side, and at the boundary of each stage, the blowout speed of the refrigerating chamber side stage Is slower than the blowing speed of the stage on the outside air side, thereby suppressing the mixing of air in the air curtain, the outside air blocking performance of the air curtain, the cold storage performance of the refrigerating room are high, and the refrigerator load is reduced. There is an effect that an open chow case can be obtained.

[Brief description of drawings]

FIG. 1 (a) is an enlarged cross-sectional view of an air outlet portion of a double air curtain type open-shoulder case of an embodiment of the present invention, and FIG. 1 (b) is a first embodiment of the present invention. Fig. 1 (c) is a flat wind velocity distribution map when the velocity gradient is 0, and Fig. 1 (d) is a blowout velocity at the air outlet in a special case. Fig. 2 is a side cross-sectional view showing a general double air curtain type open chow case, Fig. 3 is a characteristic diagram showing the outside air intrusion amount according to the present invention, and Fig. 4 is an outside air intrusion amount. 5 (a) and 5 (b) are characteristics diagrams of each factor affecting the above, respectively, and FIG. 5 (a) and FIG. 5 (b) are blown air velocity distribution charts at the air outlet of the double air curtain type open chow case of another embodiment of the present invention, and FIG. FIG. 7 (a) is a side cross-sectional view of a typical single air curtain type open chow case, which is another embodiment of the present invention. An enlarged cross-sectional view of the air outlet portion of FIG. 6 of the embodiment, FIG. 7 (b) is FIG. 7 (a) of the present invention.
Fig. 8 (a) is an enlarged cross-sectional view of the outlet part of a conventional double air curtain system open chow case, and Fig. 8 (b) is the conventional Fig. 8 (a). FIG. 7B is a wind velocity distribution diagram showing the blowout velocity at the blowout port shown in FIG. In the figure, (1) is a container, (2) is an opening, (4) is a refrigerator, (8)
Is the first (cold air) outlet, (9) is the second (guard air) outlet, (16) is the rectifying grid, (B) is the refrigerating chamber end of the first outlet, (C)
Is the maximum velocity position in the air curtain blowing velocity distribution,
(D) is the partition position of the first outlet and the second outlet, (E) is the outermost end position of the second outlet, (J) is the refrigerating chamber side end of the outlet, (K) is the outlet The outer edge, (L), is the boundary of each step. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A container provided with a refrigerating chamber having an opening, and a cooling blower for cooling and blowing gas, wherein the cool air blown by the cooling blower is blown out from an outlet provided at one end of the opening. A suction port provided at the other end, is circulated so as to be cooled and blown again, and is provided with a means for forming an air curtain in the opening, having a plurality of subdivided parallel flow paths, A plurality of rectifying grids whose length in the flow path direction is longer from the refrigerating compartment side toward the outside air side are provided at the air outlet of the air curtain, and the blowing speed at the outlet is from the refrigerating compartment side of the outlet toward the outside air side. An open showcase characterized by forming multiple wind speed distributions with decreasing velocity gradients, and making the blowing speed of the refrigerating room side slower than the outside air side blowing speed at the boundary of each stage. . 2. The open showcase according to claim 1, wherein the wind speed distribution has two stages. 3. The outside air side wind speed at the outside air side final stage of the wind speed distribution is 0.
Claim 1 or 2 characterized in that
Open showcase described in section.