JPH11211327A - Anti-frosting fan in freezing/refrigerating showcase - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for periodic defrosting by forming a water repellent layer on the surface of a fan thereby protecting the fan against frosting with moisture contained in the conducting air. SOLUTION: A fan 6 for feeding the air to an evaporator 2 has surface subjected to ultra water repellent electric plating and a water drop does not adhere easily thereto. The material for ultra water repellent electric plating is TFE(tetrafluoroethylene) oligomer obtained by cutting the molecular chain of PTFE(polytetrafluoroethylene), i.e., a straight-chain polymer where hydrogen atoms of polyethylene are entirely substituted by fluorine atoms, and then adding a fluorine atom to the cut part. A good water repellence can not be attained if the plating layer is too thin and the cost increases if it is too thick.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan for preventing frost from forming in a refrigerated display case.

[0002]

2. Description of the Related Art A liquefied refrigerant having a low boiling point is injected from an expansion valve into a low-pressure evaporator to evaporate it, and air is forcibly passed through the evaporator by a blower fan to be cooled. In the refrigerated display case that supplies air to the case and cools the inside of the case, the moisture in the circulating air forms frost on the surface of the blower fan, reducing the blower capacity or causing vibration due to eccentricity of the fan due to frosting. Therefore, it is necessary to periodically perform defrosting.

[0003]

Conventionally, as a method of defrosting in such a refrigerated display case, the supply of the refrigerant is stopped, the flowing air is heated using a heat source such as an electric heater, and the air is blown. Defrosting is performed by rotating the fan to melt frost and the like attached to the fan and the like.

[0004] However, in the case of the above-mentioned conventional method,
Since high-temperature, high-humidity air accompanying the defrosting is supplied into the freezing and refrigerated display case, dew condensation or frost occurs on the surface of the product in the display case, and this phenomenon is remarkable especially in a low-temperature display case.

[0005] In addition, when defrosting by this method, the supply of cooling air into the case is stopped at the same time, so that the temperature in the case cannot be kept low, which leads to deterioration of the commodities in the display case. However, there is a problem in that the use of such a heat source increases the amount of electricity consumed.

[0006] In order to solve such problems, the present invention prevents the moisture contained in the circulating air from frosting on the blower fan, thereby making it necessary to perform the above-described periodic defrosting. To provide a fan for preventing frost formation in a refrigerated display case, which can eliminate the quality deterioration of a product due to a rise in temperature inside the case during defrosting and eliminate electricity consumption due to heating during defrosting. It is intended to be.

[0007]

In order to achieve the above object, a frost prevention blower fan in a refrigerated display case according to the present invention cools air supplied into an evaporator by a blower fan with a refrigerant, and performs the cooling. In a refrigerated display case in which air is supplied into the case to cool the inside of the case,
A water repellent layer is formed on the surface of the blower fan. According to this feature, by providing a water-repellent layer on the surface of the blower fan, the adhesive force of the water droplets condensed on the fan surface is reduced, and before the water droplets condensed on the blower fan surface freeze and frost, Due to the centrifugal force caused by the rotation of the blower fan, it is scattered in the outer circumferential direction of the blower fan, so that the moisture of the circulating air hardly adheres to the blower fan surface, and the cause of frost formation is cut off. No need for defrosting. Furthermore, regular defrosting operation is not required,
There is no quality deterioration of the product due to the temperature rise in the case at the time of defrosting, and it is also possible to eliminate electricity consumption due to heating at the time of defrosting.

[0008] In the fan for preventing frost formation in the refrigerated display case of the present invention, the water-repellent layer is preferably 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 blower fan having a complicated shape, but the contact angle of the water droplets is almost 180 degrees due to the high fluorine density on the surface of the water-repellent layer. , And the adhesive force of water droplets is significantly reduced, so that a blower fan to which water droplets are less likely to adhere can be provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings. A refrigerator / refrigerated display case 1 (hereinafter referred to as a display case) has an upper opening and an inner surface covered with a heat insulating material 9. This box has a cool air passage between the heat insulating material 9 and the product storage space while leaving the internal product storage space.

The structure will be described in more detail. A suction port 5 is formed in the vicinity of the front upper end of the display case 1, and a flow passage 7 extends downward from the suction port 5, and is blown by a fan motor 6 '. An evaporator (fan coil) 2 including a cooling fin 3 and a refrigerant pipe 4 is provided downstream of the fan 6, and a flow passage 8 extending upward and a discharge port 11 are formed above the flow passage 8. 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 allow a low-temperature refrigerant to flow through the above-described refrigerant pipe 4, to draw air from the suction port 5 by blowing air from the blowing fan 6, and As shown in FIG. 3, 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.
Through the discharge port 11 as shown by the arrow 12.

The cool air discharged as shown by the arrow 12 is guided to the product storage space, and cools the products 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, the surface of the blower fan 6 for sending air to the evaporator 2 is super-water-repellent electroplated as shown in FIG. It has become difficult.

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 TFE oligomer is plated on the metal blower fan of the present embodiment by dispersing the TFE oligomer having an average particle size of about 4 μm in a sulfamic acid solution using a fluorine-containing surfactant, A metal material, such as nickel, to be plated as an anode in an acid solution, and the metal blower fan as a cathode are immersed and arranged, and the metal surface of the blower fan 6 is easily electrically or chemically immersed by energizing. Can be plated.

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.

The TFE oligomer can be plated not only on a metal but also on various materials such as ceramics, resins and other materials, and can be used even if the blower fan 6 is made of a material other than metals.

[0018] The plating of the substrate other than these metals can not be carried out by the above-mentioned plating by energization, but the plating method for these is as follows. It can be dispersed therein and 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 blower fan 6 has a high fluorine density as shown in FIG. 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. 3, the blower fan 6 easily moves due to the centrifugal force caused by rotation, and a state can be created in which water droplets do not always adhere to the surface of the blower fan 6 or hardly adhere thereto. .

In the present embodiment, the expression “refrigerated display case 1” is used, but this expression means either the frozen display case or the refrigerated display case, or both. Further, in the embodiment, the description is made based on the display case having the upper opening, but the same applies to the display case having the front opening.

Further, in this embodiment, the super-water-repellent electroplating is applied to the blower fan 6, but the super-water-repellent electroplating is applied to the fan motor 6 'so as to be attached to the fan motor 6'. Frost may be similarly prevented to prevent the flow path of the circulation air from narrowing due to frost formation.

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.

[0023]

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

(A) According to the first aspect of the present invention, by providing a water-repellent layer on the surface of the blower fan, the adhesion of dewdrops on the fan surface is reduced, and the waterdrops condensed on the blower fan surface Before freezing and frost formation, the centrifugal force accompanying the rotation of the blower fan causes it to be scattered in the outer circumferential direction of the blower fan. It will be cut off, eliminating the need for regular 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 blower fan having a complicated shape, but the fluorine density on the surface of the water-repellent layer is high. In addition, since the contact angle of the water droplets is nearly 180 degrees and the adhesion of the water droplets is significantly reduced, it is possible to provide a blower fan to which the water droplets are less likely to adhere.

[0026]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a refrigerated display case as an embodiment of the present invention.

FIG. 2 is a local sectional view of only the surface portion of the blower fan,
It is a figure which shows the relationship with a water drop.

FIG. 3 is a top view showing a relationship between a blower fan and water droplets.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 display case (refrigerated display case) 2 evaporator 3 cooling fin 4 refrigerant pipe 5 suction port 6 blower fan 6 ′ fan motor 7 flow path 8 flow path 9 heat insulating material 10 arrow 11 discharge port 12 arrow 13 drain port

Claims (2)

[Claims] 1. A refrigerated display case in which air supplied into an evaporator is cooled by a refrigerant by a blowing fan and the cooling air is supplied into the case to cool the inside of the case. And a water repellent layer formed on the refrigerated display case. 2. The water-repellent layer is a dispersed metal plating layer containing a tetrafluoroethylene oligomer.
A frost prevention fan for a refrigerated display case as described in 1 above.