AU739008B2 - An improved refrigerating mechanism - Google Patents

Description

-1 I

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor: Address for Service: ORFORD PTY LTD 104 JOHN HENRY ORFORD CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

Invention Title: AN IMPROVED

MECHANISM

REFRIGERATING

Details of Associated Provisional Application: No. P05697 filed 19 March 1997 The following statement is a full description of this invention, including the best method of performing it known to us: AN IMPROVED REFRIGERATING MECHANISM THIS invention relates to an improved refrigerating mechanism. In particular, the invention relates to an improved arrangement of components in a refrigerating mechanism for a refrigerated cabinet, to permit the cabinet to be used in confined spaces and/or positioned close to a wall.

BACKGROUND ART A refrigerated cabinet typically comprises a refrigerated space which is closed by at least one door, and a refrigerating mechanism for cooling the refrigerated space. (The term "refrigerated cabinet" includes a domestic refrigerator).

The main components of the refrigerating mechanism are normally a pump, an evaporator, a condenser, and a condenser fan. A refrigerant is pumped through tubing in a closed circuit. Heat is absorbed, directly or indirectly, from the refrigerated space by the evaporating refrigerant in the evaporator. The heat is then dissipated by the refrigerant gas as it passes through the condenser which is positioned outside the refrigerated cabinet. The condenser fan draws or blows air through the condenser to S"cool it.

Conventionally, condensers are formed by winding the refrigerant tubing in a sinuous configuration in one or more parallel planes. The fans draws or blows air perpendicularly through the plane(s) of tubing. A conventional condenser normally has a wide or large face or sectional area in one plane, and is relatively thin in an orthogonal plane. The condenser is so configured to present a large area to the flow of air and thereby maximise heat exchange.

The condenser is normally located at the rear of the refrigerated cabinet, with its largest side parallel to the rear wall of the cabinet. As air is drawn in transversely to the large face of the condenser, the refrigerated cabinet must be spaced a minimum distance from a rear wall. (Otherwise air flow is reduced, resulting in overheating, loss of efficiency and/or reduced operating life). Stand-off bolts are normally provided at the rear of the refrigerated cabinet to ensure that the cabinet is not pushed too far back against a wall.

It is an object of the present invention to provide a refrigerating mechanism which permits a refrigerated cabinet to be used in a confined space or close to a wall.

SUMMARY OF THE INVENTION In one broad form, the present invention 1 provides a refrigerated cabinet having an interior space, 5 at least one door for accessing the interior space, and a refrigerating mechanism for cooling the interior space of the cabinet, the refrigerating mechanism including a generally planar condenser adjacent and parallel to an *.*exterior wall of the cabinet, and fan means for creating air flow from outside the cabinet, along the condenser in ooa direction generally parallel to the exterior wall and ee:thence to the door.

Typically, the condenser comprises tubing configured in a sinuous pattern in one or more parallel, 25 generally vertical, planes. The condenser is therefore relatively large in the vertical plane, but relatively thin in the horizontal plane. The air is drawn or blown along the condenser in a predominantly vertical direction.

Cooling fins may be provided in thermal contact with the tubing.

The condenser is normally located at the back of the refrigerated cabinet (or refrigerator) in an upright orientation. As the air flow is predominantly along, rather than horizontally through the condenser, the condenser can be placed close to a rear wall. This enables the refrigerated cabinet to be pushed back close to a rear Lwall, thereby minimising the floor space required. for the cabinet. A rear cover may also be placed on the refrigerated cabinet (or refrigerator) close to the condenser.

Although the condenser presents a narrower face to the air flow, and hence the rate of heat exchange is less, this can be compensated by increasing the air flow, e.g. by using a faster or larger fan.

The air may be drawn or blown unidirectionally along the condenser, or it may be drawn or blown first in one predominantly vertical direction and then diverted or turned in the opposite direction, e.g. in an up and down flow path.

The condenser is usually mounted in an upright orientation at the rear of the refrigerated cabinet. Since the refrigerant in the tubing of the condenser is cooled 15 gradually, the condenser tubing is normally hotter at the upper part of the condenser than the lower part.

Preferably, the air flow enters the condenser at its cooler end for greater thermal efficiency.

After the air has travelled along the condenser and has been warmed thereby, it is blown to the door where S"at least some' of the warmed air moves along the door to reduce condensation on the door.

In order that the invention may be more fully understood and put into practice, preferred embodiments 25 thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic sectional elevation of a refrigerated cabinet according to one embodiment; and Figs. 2 and 3 are schematic fragmentary elevations of modified versions of the refrigerated cabinet of Fig. 1.

DESCRIPTION OF PREFERRED EMBODIMENT As shown in Fig. 1, a refrigerated cabinet RA( has a refrigerated space 11 which is closed by at least one door 12, typically a glass door. The refrigerated space 11 is chilled by a refrigerating mechanism located at the bottom rear of the cabinet.

The refrigerating mechanism includes a condenser 13 shown schematically in the drawing. The condenser 13 is typically a tube condenser formed by configuring refrigerant tubing in a sinuous pattern in one or more parallel vertical planes. Cooling fins may be placed in thermal contact with the condenser tubing.

Condensers normally have a large face or cross sectional area in one plane, and a comparatively small face or sectional area in the two orthogonal planes. The condenser 13 shown in Fig. 1 has a relatively large face or sectional area A in a vertical plane parallel to the rear wall of the cabinet 10, but a relatively narrow face 15 or sectional area in the horizontal planes at the top and *.bottom of the condenser, and the vertical planes at the sides of the condenser.

The refrigerating mechanism also includes a condenser fan 14 which draws or blows air along the condenser 13. Heat extracted from the refrigerated space S"11 by the refrigerant flowing in the tubing is dissipated to the exterior through the condenser. The condenser is therefore a warm element which is cooled by the air drawn e or blown along it. Since the refrigerant is cooled 25 gradually along the length of the tubing in the condenser, the temperature of the condenser varies along the length of its tubing. In a conventional upright condenser, the coolest part of a functioning condenser is at its lower end.

In known refrigerating mechanisms, the cooling air is drawn or blown by the condenser fan in a direction generally perpendicular to the broad face A of the condenser (to maximise thermal exchange between the condenser tubing and the air). In this invention however, the air is drawn or blown by the condenser fan through a narrow face or section of the condenser.

As shown in the embodiment of Fig. 1, the condenser fan 14 draws air up through the bottom face C of the condenser 13. The air passes upwardly along the condenser, and is then drawn down between the cabinet and the condenser, and into the fan. The warmed air is blown by the fan 14 along the bottom of the refrigerated cabinet 10, and rises upwardly along the glass door 12. The movement of the (warmed) air along the door 12 prevents or removes condensation on the door 12.

Since the air is drawn in mostly from under the condenser 13, rather than from directly rearwardly of the condenser, the refrigerated cabinet 10 may be placed close against a rear wall, thereby minimising the floor space required for the refrigerated cabinet. Furthermore, as the cooling ambient air first comes in contact with the coolest part of the condenser, more efficient cooling of 15 the condenser is obtained.

The foregoing describes only one embodiment of the invention, and modifications which are obvious to S: those skilled in the art may be made thereto without departing from the scope of the invention.

For example, in the embodiment of Fig. 2, the S"air is drawn mostly from above a condenser 13A, and flows *go9 along the condenser 13A from top to bottom in the direction shown in Fig. 2. Air may also be drawn in o• horizontally at the sides B of the condenser.

9*oo In another embodiment, shown in Fig. 3, sheeting is provided around the condenser to define a U-shaped duct. Air is drawn upwardly along one plane of condenser tubing in the outer duct, and then down along a second parallel plane of condenser tubing in the inner duct.

In these embodiments, the condenser can be placed close to a wall at the rear of the refrigerated cabinet.

The upright planar condenser need not be perfectly vertical; it may be slightly inclined.

Claims (8)

1. A refrigerated cabinet having an internal space closed by at least one door at the front of the cabinet, and a refrigerating mechanism for cooling the space within the cabinet, the refrigerating mechanism including an upright, generally planar condenser which is located at the rear of the cabinet, and a fan for creating a flow of air along and generally parallel to the condenser so that the air is warmed by the condenser in use, the warmed air then being directed towards the door.

2. A refrigerated cabinet as claimed in claim 1, wherein in use, the air flows generally vertically from a cooler part of the condenser to a warmer portion. 15

3. A refrigerated cabinet as claimed in claim 1 or 2 wherein, in use, the fan draws air from the rear of the cabinet and blows it to the front of the cabinet.

S4. A refrigerated cabinet as claimed in claim 3 wherein at least some of the warmed air blown to the front of the cabinet rises upwardly along the door to S"thereby reduce or prevent condensation on the door. *o

5. A refrigerated cabinet as claimed in any preceding claim, wherein the condenser comprises tubing o: wound in a sinuous pattern, in one or more generally 25 vertical planes.

6. A refrigerated cabinet as claimed in claim wherein the tubing is wound in at least two generally vertical planes, further comprising ducting around the condenser to channel the air upwardly along one plane of tubing and then downwardly along another plane of tubing.

7. A refrigerated cabinet having an interior space, at least one door for accessing the interior space, and a refrigerating mechanism for cooling the interior space of the cabinet, the refrigerating mechanism including a generally planar condenser adjacent and parallel to an exterior wall of the cabinet, and fan means for creating air flow from outside the cabinet, along the condenser in a direction generally parallel to 8 the exterior wall and thence to the door.

8. A refrigerated cabinet substantially as hereinbefore described with reference to the accompanying drawings. DATED this third day of August 2001 ORFORD REFRIGERATION PTY LTD By their Patent Attorneys Cullen Co. *o