Pressure equalizing device for refrigerators

A pressure equalizing device for refrigerators, having a chamber, a door on the front wall of the chamber, an evaporator, and an evaporator defrost heater, is provided. The pressure equalizing device includes a pressure relief valve, an installation hole, and a deicing device for the pressure relief valve. The pressure relief valve connects the inside and outside of the chamber, and includes an inner end and an outer end. The installation hole is perforated on one of the walls of the chamber. The pressure relief valve equalizes the pressure inside and outside of the chamber to facilitate the opening of the door. The pressure relief valve includes an operation switch, and the operation switch is activated by the opening of the door. The pressure relief valve is disposed over deicing device, and the deicing device melts ice formed on the inner end of the pressure relief valve.

BACKGROUND OF THE INVENTION

The present invention relates to a pressure equalizing device for refrigerators. More particularly, this invention relates to a pressure equalizing device for refrigerators, which facilitates the opening of the doors of refrigerators.

Definitely, a refrigerator is an unmistakable achievement of science and technology. It is a cool result of the intensive research in thermodynamics, electric engineering, and material engineering such as heat pump, thermal expansion, latent heat, and the like.

One of the most well-known physical phenomena in cooling is the thermal contraction. When cooled down, the objects contract. It holds true to everything existent; solid, liquid, and even gas.

Refrigerator is a device to cool down the inside of a chamber that is thermally insulated from the outside. That means that everything in the chamber experiences thermal contraction. The air trapped in the chamber cannot be exceptional. It contracts under the cooling condition of the refrigerator.

When the door is open, the chamber gets filled with air from the outside, that is, warm air. If the door is closed and remains closed, the trapped air cools down and contracts. The cooled down and contracted air inside the chamber with a fixed volume brings about lower air pressure compared to that outside.

Then, the air pressure difference between the inside and outside of the chamber expresses itself as a force holding the door from opening.

The situation gets worse with the volume of air trapped in the chamber. Even with a refrigerator having a small volume of chamber, it happens when the temperature difference between the inside and outside of the chamber is very large.

A walk-in refrigerator is not uncommon in many industries. Considering the vast volume of chamber, the holding force of the door must be very demanding.

Accordingly, a need for a pressure equalizing device for refrigerators has been present for a long time considering the tendency of growing in size of refrigerator. This invention is directed to solve these problems and satisfy the long-felt need.

SUMMARY OF THE INVENTION

The present invention contrives to solve the disadvantages of the prior art.

An object of the invention is to provide a pressure equalizing device for refrigerators.

Another object of the invention is to provide a pressure equalizing device that facilitates the opening of the refrigerators.

Still another object of the invention is to provide a pressure equalizing device for refrigerators, which removes ice formed at one end of the pressure relief valve.

Still another object of the invention is to provide a pressure equalizing device for refrigerators, which removes the melted water out to a drain pan.

A pressure equalizing device is installed on the top of the refrigerator. The refrigerator has 1) a chamber enclosed by front, rear, right, left, top, and bottom walls defining inside and outside; 2) a door on the front wall of the chamber; 3) an evaporator; and 4) an evaporator defrost heater, is provided.

The pressure equalizing device includes a pressure relief valve, an installation hole, and a deicing device for the pressure relief valve.

The pressure relief valve connects the inside and outside of the chamber, and includes an inner end and an outer end.

The installation hole is perforated on one of the walls of the chamber.

The pressure relief valve equalizes the pressure inside and outside of the chamber to facilitate the opening of the door.

The pressure relief valve includes an operation switch, and the operation switch is activated by the opening of the door.

The pressure relief valve is disposed over deicing device, and the deicing device melts ice formed on the inner end of the pressure relief valve. The deicing device operates periodically. For example, the deicing device operates in a predetermined period of time after closing the door of the chamber.

The pressure relief valve is disposed over the evaporator defrost heater. The pressure equalizing device further includes a drain pan, and the drain pan is disposed below the evaporator defrost heater. The melted water from the pressure relief valve drops into the drain pan.

The pressure relief valve is installed in the installation hole, and the installation hole is perforated at the door. The pressure relief valve is buried and installed in the door.

The pressure relief valve is installed in the installation hole, and the installation hole is perforated through the top wall of the chamber above the evaporator defrost heater.

The pressure relief valve is detachably fixed on the installation hole, and the pressure relief valve protrudes over the installation hole. The evaporator defrost heater is operated with a predetermined interval. The predetermined interval includes, for example, eight (8) hours.

The pressure equalization device further includes a lid, an outer protection cover, and an inner protection cover. The lid fits in the installation hole, and covers the installation hole with the pressure relief valve detached for storing or carrying of the refrigerator. The outer protection cover is for protecting the outer end of the pressure relief valve, and the inner protection cover is for protecting the inner end of the pressure relief valve. The lid includes a rubber cover.

The pressure equalization device further includes a seal between the inner side of the pressure relief valve and the outer surface of the chamber. The seal has a thickness from about eight (8) millimeters to about twelve (12) millimeters.

The deicing device is adapted to keep the inner end of the pressure relief valve over zero (0) degree in Celsius.

The advantages of the present invention are: (1) the pressure equalization device is very useful to facilitate to open doors for refrigerator; (2) the pressure equalization device is especially effective in the large scale refrigerators such as a walk-in refrigerator; and (3) the pressure equalization device works properly even in an atmosphere of high humidity.

DETAILED DESCRIPTION OF THE INVENTION

The pressure equalizing device10is installed on the top of the refrigerators100. The refrigerator100has 1) a chamber90enclosed by front, rear, right, left, top, and bottom walls91,92,93,94,95,96respectively defining inside and outside; 2) a door97on the front wall91of the chamber90; 3) an evaporator98; and 4) an evaporator defrost heater99, is provided.

The pressure equalizing device10includes a pressure relief valve12, an installation hole14, and a deicing device16for the pressure relief valve12.

The pressure relief valve12connects the inside and outside of the chamber90, and includes an inner end11and an outer end13as shown inFIG. 3.

The installation hole14is perforated on one of the walls91through96of the chamber90.

The pressure relief valve12equalizes the pressure inside and outside of the chamber90to facilitate the opening of the door97.

The pressure relief valve12includes an operation switch (not shown), and the operation switch is activated by the opening of the door97. The operation switch can be disposed in the door handle, and the operation pressure relief valve12is able to be operated by sensing the squeeze of the door handle, for instance.

The pressure relief valve12is disposed over deicing device16, and the deicing device16melts ice formed on the inner end11of the pressure relief valve12. The deicing device16operates periodically. For example, the deicing device16operates in a predetermined period of time after closing the door of the chamber90.

The pressure relief valve12is disposed over the evaporator defrost heater99. The pressure equalizing device10further includes a drain pan18, and the drain pan18is disposed below the evaporator defrost heater99. The melted water from the pressure relief valve12drops into the drain pan18.

In an embodiment of the invention (not shown), the pressure relief valve12is installed in the installation hole14, and the installation hole14is perforated at the door97. The pressure relief valve12is buried and installed in the door97.

In another embodiment of the invention (refer toFIG. 1,FIG. 2, andFIG. 5, the pressure relief valve12is installed in the installation hole14, and the installation hole14is perforated through the top wall95of the chamber90above the evaporator defrost heater99.

The pressure relief valve12is detachably fixed on the installation hole14, and the pressure relief valve12protrudes over the installation hole14. The evaporator defrost heater99is operated with a predetermined interval. The predetermined interval includes, for example, eight (8) hours.

With the pressure installation device10on the top of the refrigerator100as shown inFIG. 1andFIG. 2, it is not going to possible to stack the refrigerators100in warehouse. For the purpose, the pressure relief device12should be able to be detached from the refrigerator100as shown inFIG. 5. Therefore, the pressure equalization device10further includes a lid22(refer toFIG. 4), an outer protection cover24, and an inner protection cover (not shown) as shown inFIG. 5. The outer protection cover24and an inner protection cover are for protecting the pressure relief valve12. The lid22fits in the installation hole14as shown inFIG. 5, and covers the installation hole14with the pressure relief valve12detached for storing or carrying of the refrigerator100. The outer protection cover24is for protecting the outer end13of the pressure relief valve12, and the inner protection cover (not shown) is for protecting the inner end11of the pressure relief valve12. The lid24includes a rubber cover.

The pressure equalization device10further includes a seal26between the inner side11of the pressure relief valve12and the outer surface of the chamber90. The seal26has a thickness from about eight (8) millimeters to about twelve (12) millimeters.

The deicing device16is adapted to keep the inner end11of the pressure relief valve12over zero (0) degree in Celsius. The evaporator defrost heater99can be adapted to work as a deicing device16.