JPH11211326A - Anti-frosting unit for air curtain type refrigerating showcase - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for periodic defrosting by disposing a member for straightening circulation chill flow at an air outlet and forming a water repellent layer on the surface of the straightening member thereby protecting it against frosting with moisture contained in the conducting air and the outer air. SOLUTION: A straightening member 14 having honeycomb tubular chill passages 15 formed in same direction is fixed to an air outlet 11. The member 14 for delivering chill from an evaporator 2 while straightening has surface subjected to ultra water repellent electric plating and a water drop does not adhere easily thereto. A dew drop formed on the surface of the member 14 is scattered in the conducting direction of chill by the wind force thereof before being frozen. Since moisture contained in the conducting air and the outer air does not adhere easily thereto, cause of frosting is eliminated thus eliminating the need for periodic defrosting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frost prevention device for an air curtain refrigerated showcase.

[0002]

2. Description of the Related Art A liquefied refrigerant having a low boiling point is injected into a low-pressure evaporator from an expansion valve to evaporate the air, and the air is forcibly passed through the evaporator by a blower fan to be cooled. The air curtain is formed by circulating between the air outlet and the suction port provided on both sides of the case opening to cool the inside of the refrigerated showcase. In order to form well, a rectifying member in which a plurality of tubular bodies or the like for rectifying the cool air by restricting the flow direction of the cool air is generally provided at the outlet.

The temperature of these rectifying members is reduced because they are constantly exposed to the cooling air, and the moisture in the cooling air and the moisture in the outside air are easily frosted on the surfaces of the rectifying members. Since the passage of the cooling air is blocked by the frost and the flow rate of the cool air is reduced, or a predetermined rectification effect cannot be obtained, it is necessary to periodically perform defrosting.

[0004]

Conventionally, as a method of defrosting in such an air curtain type refrigerated showcase, the supply of the refrigerant is stopped, and the distribution air is heated using a heat source such as a defrost heater. By rotating the blower fan to melt frost and the like attached to the rectifying member and the like, defrosting is performed.

[0005] However, in the case of the above-mentioned conventional method,
High-temperature, high-humidity air associated with defrosting will also be supplied to the refrigerated showcase, and dew or frost will form on the surface of the products in the showcase, especially in low-temperature showcases. Remarkable.

Further, at the time of defrosting by this method, the supply of the cooling air into the refrigerated showcase is stopped at the same time, so that the temperature inside the case cannot be kept low, which leads to deterioration of the goods in the refrigerated showcase. However, the use of a heat source such as a defrost heater has a problem that the amount of electricity consumed increases.

[0007] In order to solve the above problems, the present invention has to prevent the moisture contained in the circulating air and the outside air from forming on the rectifying member and perform the above-mentioned periodic defrosting. The frost prevention device in the air curtain type refrigerated showcase which eliminates the quality deterioration of the product due to the temperature rise in the refrigerated showcase at the time of defrosting and can eliminate the electricity consumption due to the heating at the time of defrosting. It is intended to provide.

[0008]

In order to achieve the above object, an apparatus for preventing frost formation in an air curtain type refrigerated showcase according to the present invention comprises an air outlet and a suction port on both sides of an opening of a refrigerated showcase main body. In an air curtain refrigerated showcase in which an air curtain of circulating cool air is formed between the outlet and the inlet, a rectifying member for rectifying the flow of circulating cool air is provided at the outlet, and the rectifying member is provided. Is characterized in that a water-repellent layer having a water-repellent property is formed on the surface thereof. According to this feature, by providing the water repellent layer on the surface of the rectifying member, the adhesion of the condensed water droplets to the surface of the rectifying member is reduced, and before the water droplets condensed on the surface of the rectifying member freeze and form frost. Since the wind of the cool air scatters in the flow direction of the cool air, the moisture of the flowing air and the moisture of the outside air hardly adhere to the surface of the rectifying member, and the cause of frost formation is cut off. No frost is required. Furthermore, since the regular defrosting operation is not required, the quality of the product does not deteriorate due to the temperature rise in the refrigerated showcase at the time of defrosting, and electricity consumption due to heating at the time of defrosting can be eliminated.

In the frost prevention apparatus for an air curtain refrigerated showcase of the present invention, it is preferable that the water-repellent layer is a dispersed metal plating layer containing a tetrafluoroethylene oligomer. In this way, not only can the water-repellent layer be formed uniformly and easily on the surface of the rectifying member having a complicated shape such as a tubular shape or a slit shape, but also because the fluorine density of the water-repellent layer surface is high. Since the contact angle of the water droplet is nearly 180 degrees and the adhesion of the water droplet is significantly reduced, a rectifying member to which the water droplet is less likely to adhere can be provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings.
As shown in FIG. 1, the display case (hereinafter, referred to as a display case) is formed of a box body which is open at the top and whose inner surface is covered with a heat insulating material 9, and this box body retains the internal product storage space. And a cooling air flow passage between the heat insulating material 9 and the product storage space.

The structure will be described in more detail. A suction port 5 is formed near the front upper end of the display case 1, a flow passage 7 extends downward from the suction port 5, and a cooling fin is provided downstream of the blower fan 6. An evaporator (fan coil) 2 comprising a refrigerant pipe 3 and a refrigerant pipe 4 is installed, and then a flow path 8 extending upward,
Further, an air outlet 11 is formed at an upper portion thereof, and an air curtain by cold air is formed between the inlet 5 and the air outlet 11 as shown by an arrow 12. Reference numeral 13 denotes a drain port for discharging water accumulated inside to the outside.

When the display case 1 is cooled, a cooling cycle (not shown) is operated to flow a low-temperature refrigerant through the above-described refrigerant pipe 4, to draw air from the suction port 5 by blowing air from the blowing fan 6, As shown in FIG. 10, the intake air is applied to the evaporator 2, and the air cooled by the cooling fins 3 and the refrigerant pipe 4 of the evaporator 2 is passed through the flow passage 8 from the rectifying member 14 provided at the outlet 11 through the arrows. Discharge as in 12.

As shown in FIG. 2, the rectifying member 14 has a shape in which a honeycomb air-cooled passage 15 is formed in the same direction. In the present embodiment, the rectifying member 14 is formed of aluminum, and Mounted on

A part of the cool air discharged from the rectifying member 14 as shown by the arrow 12 is guided to the product storage space, and cools the product in the display case 1 to a set temperature. The cooling operation is appropriately controlled by a temperature detector provided at a predetermined position.

In such a display case 1, the surface of the rectifying member 14 for rectifying and discharging the cool air from the evaporator 2 is super-water-repellent electroplated as shown in FIG. Water droplets are less likely to adhere.

The material for this super-water-repellent electroplating is PTFE (polytetrafluoroethylene) which is a linear polymer in which all hydrogen atoms of polyethylene are replaced by fluorine atoms.
Is a TFE (tetrafluoroethylene) oligomer obtained by cleaving the molecular chain of PTFE and adding a fluorine atom also to the cut portion. Its molecular weight is about several thousand,
It is 1/50 to 1/50.

The method of plating this TFE oligomer on the surface of the metal flow straightening member 14 in this embodiment is as follows.
A metal material in which a TFE oligomer having an average particle size of about 4 μm is dispersed in a sulfamic acid solution using a fluorine-based surfactant and plated as an anode in the sulfamic acid solution;
For example, nickel or the like and a metal rectifying member 14 as a cathode
Are immersed in the rectifying member 1
4 can be easily plated electrically or chemically on the metal surface.

If the thickness of the plating layer is too small, good water repellency cannot be obtained, and if the thickness is too large, the cost becomes high.
Preferably, it is -20 microns, but the invention is not so limited.

It should be noted that the TFE oligomer can be plated not only on a metal but also on various materials such as ceramics, resins and other materials. Even if the rectifying member 14 is made of a material other than metals, it can be used.

The plating on the underlayer other than these metals cannot be performed by the above-described plating by energization because the underlayer does not have conductivity. It can be dispersed in an electroless nickel plating solution to which an agent has been added, and can be formed as a metal thin film using a dispersion plating method.

As shown in FIG. 2, the surface of the plating layer formed on the surface of the rectifying member 14 has a high fluorine density on the surface, and therefore has a low adhesive force with water molecules and a cohesion of water itself. Since the force is larger than the adhesive force, the water droplet A has a spherical shape. That is, since the contact surface between the water droplet A and the plating layer surface is almost 180 degrees, the water droplet A moves on the plating layer surface even with a very small force or own weight.
As shown in FIG. 4, the rectifying member 14 is easily moved by the wind power of the cool air passing through the rectifying member 14.
A state can be created in which water droplets do not or do not always adhere to the surface of the substrate.

In this embodiment, the refrigerated showcase 1
This is an expression meaning each or both of a frozen showcase and a refrigerated showcase. Further, in the present embodiment, the description is made based on the display case of the upper opening type, but the same applies to the display case of the front opening type.

Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and even if there are changes and additions without departing from the gist of the present invention. Included in the invention.

In the present embodiment, the rectifying member is formed by the honeycomb tubular cold air passage 15 as described above, but the present invention is not limited to this.
Other shapes, such as a slit shape or a normal cylindrical shape, may be selected as appropriate from the strength and the like required for the rectifying member, as in the present embodiment. This is preferable because a rectifying member having high strength can be formed by using a thin material, and a large cold air passage area can be obtained.

[0025]

According to the present invention, the following effects can be obtained.

(A) According to the first aspect of the present invention, by providing the water repellent layer on the surface of the rectifying member, the adhesion of the condensed water droplet to the surface of the rectifying member is reduced, and the water droplet condensed on the surface of the rectifying member is reduced. Before being frozen and frosted, the wind of cold air is scattered in the flow direction of the cold air, so that the moisture of the circulating air and the moisture of the outside air hardly adhere to the surface of the rectifying member, and the cause of the frost is cut off. The need for periodic defrosting. Furthermore, since the regular defrosting operation is not required, there is no deterioration in the quality of the product due to the temperature rise in the case during defrosting, and it is also possible to eliminate electricity consumption due to heating during defrosting.

(B) According to the second aspect of the present invention, not only can the water-repellent layer be formed uniformly and easily on the surface of the rectifying member having a complicated shape such as a tube or a slit, but also the water-repellent layer can be formed. Since the fluorine concentration on the layer surface is high, the contact angle of the water droplet is close to 180 degrees, and the adhesive force of the water droplet is remarkably reduced.

[0028]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an air curtain refrigerated showcase as an embodiment of the present invention.

FIG. 2 is a perspective view showing an appearance of a rectifying member as an embodiment of the present invention.

FIG. 3 is a local sectional view of only a surface portion of a rectifying member, and is a diagram illustrating a relationship with a water droplet.

FIG. 3 is a cross-sectional view illustrating a relationship between a rectifying member and water droplets.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Display case (air curtain type refrigerated showcase) 2 Evaporator 3 Cooling fin 4 Refrigerant pipe 5 Suction port 6 Ventilation fan 7 Flow path 8 Flow path 9 Insulation material 10 Arrow 11 Outlet 12 Arrow 13 Drain port 14 Straightening member 15 Cold air aisle

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[Procedure amendment]

[Submission date] March 30, 1998

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2 ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 30, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an air curtain refrigerated showcase as an embodiment of the present invention.

FIG. 2 is a perspective view showing an appearance of a rectifying member as an embodiment of the present invention.

FIG. 3 is a local sectional view of only a surface portion of a rectifying member, and is a diagram illustrating a relationship with a water droplet.

FIG. 4 is a cross-sectional view illustrating a relationship between a rectifying member and water droplets.

[Explanation of Signs] 1 Display case (air curtain type refrigerated showcase) 2 Evaporator 3 Cooling fin 4 Refrigerant pipe 5 Suction port 6 Blower fan 7 Flow path 8 Flow path 9 Insulation material 10 Arrow 11 Outlet 12 Arrow 13 Drain port 14 Rectifying member 15 Cold air passage

Claims (2)

[Claims] 1. An air curtain type refrigerated showcase in which an air outlet and an air inlet are provided on both sides of an opening of a refrigerated showcase main body, and a circulating cool air curtain is formed between the air outlet and the air inlet. Wherein a rectifying member for rectifying the flow of circulating cold air is provided at the outlet, and a water-repellent layer having water repellency is formed on the surface of the rectifying member, thereby preventing frost formation in an air curtain refrigerated showcase. apparatus. 2. The water-repellent layer is a dispersed metal plating layer containing a tetrafluoroethylene oligomer.
The frost formation preventing device in the air curtain type refrigerated showcase described in 1 above.