FORM 2
THE PATENTS ACT - 1970
(39 OF 1970)
&
THE PATENT RULES, 2003
PROVISIONAL SPECIFICATION [SECTION 10; RULE 13]
IMPROVED REFRIGERATION APPLIANCE'


VOLTAS LIMITED, AN INDIAN LIMITED LIABILTTY COMPANY INCORPORATED UNDER THE INDIAN COMOPANIES ACT, 1913, HAVING OUR REGISTERED OFFICE AT VOLTAS HOUSE W, DR. BABASAHEB AMBEDKAR ROAD, CHINCHPOKLI, MUMBAI 400033

THE FOLLOWING SPECIFICATION DESCRIBES THE INVENTION:


Introduction
This invention relates to a refrigeration system with improved serviceability, which can be easily detached from the refrigeration appliance in which it is used, by pulling the tray housing it, thus making the appliance very easy to service. This is achieved without sacrificing the uniformity of cooling found in existing non-detachable refrigeration systems.
Prior Art
A typical refrigeration appliance (Fig. No. 1) comprises of a refrigeration system, an
insulated cabinet (6) having insulation (7) that encloses the space to be refrigerated,
and accessories. The refrigeration system is normally based on compression
refrigeration cycle, and comprises of the following components brazed together in an
airtight hermetically sealed system:
Compressor (3)
Condenser(5)
Expansion Device (not shown in the figure)
Evaporator (2)
Interconnecting piping between the above components
Refrigeration effect (cooling) is produced in the Evaporator (2), and distributed by circulation of refrigerated air in the cabinet (6) either through forced convection by means of Evaporator Fan (1), as shown in Fig. No. 1, or through natural convection. In either case the evaporator has to be located at the top of the cabinet to ensure uniform cooling throughout the cabinet, since cold air being heavier goes down. Therefore the evaporator cannot be housed in the same enclosure as other components of the refrigeration system, which are located at the bottom. The heat
2

removed by the refrigeration system is rejected into the atmosphere with the help of the condenser fan (4) run by a motor.
If any component of the refrigeration system listed above malfunctions or fails, refrigeration effect (cooling) is reduced or ceases. In such an event, the service technician diagnoses the refrigeration system to identify the malfunctioning/ failed component, removes it from the hermetically sealed refrigeration system by debrazing it, replaces it with a functionally equivalent component, brazes the refrigeration system again to make it hermetically sealed, vacuumises the refrigeration system, charges it with fresh refrigerant, and tests it. This procedure necessitates taking the entire refrigeration appliance to a properly equipped workshop, and bringing it back after repairing and testing it. In the meanwhile, as the customer is deprived of the refrigeration appliance for a few days, there is a possibility of perishable goods stored in the refrigeration appliance getting spoilt, and the customer may lose business and goodwill.
In prior art, an attempt was been made to locate the evaporator at the bottom of the refrigerator, in the same housing that contains other components of the refrigeration system, and blowing cool air into the cabinet through a fan. However, this suffers from the disadvantage that the evaporator fan is cut off when the compressor is cut off, since they are both in the same electrical circuit, leading to cool air settling at the bottom and not reaching the upper parts of the cabinet when the compressor is cut off. Therefore such appliances have not been commercially successful.
3

Disadvantages of Prior Art
a) In the event of malfunctioning/ failure of any component of the refrigeration system, refrigeration appliance downtime is high (a few days), causing inconvenience and loss to the customer.
b) The refrigeration appliance needs to be transported from the customer's premises to the workshop, and again back to the customer's premises after the repairs. This may lead to transportation cost and handling related damages to the refrigeration appliance.
c) In prior art, an attempt has been made to overcome the disadvantages a) and b) above by locating the evaporator at the bottom, i.e. in the same enclosure that houses the other components of the refrigeration system. The evaporator fan is used to blow cool air into the cabinet. This fan is in the same electrical circuit as the compressor. Therefore this fan does not operate when the compressor is cut off. Hence this solution solves the problem of serviceability, BUT at the cost of uniform cooling. Such appliances have not been commercially successful.
The following invention is therefore proposed.
Summary of Invention
The invention will now be described with reference to Fig. No. 2. This figure shows a Visicooler, which is a typical refrigeration appliance used for storing soft drink bottles. The entire refrigeration system is housed in a Deck (11) kept below the Cabinet (6) having insulation (7). The refrigeration effect (cooling) is produced in the Evaporator (2) and the refrigerated air is forced in the cabinet by means of Evaporator Fan (1). The space between the Partition wall (12) and insulation (7) acts as duct and allows refrigerated air to travel till top. The said refrigerated air enters the inside of the
4

cabinet through holes (8) provided in the partition wall and from the top with the help of another fan (10). This ensures uniform distribution of cooling in the cabinet. FAN (10) IS INDEPENDENT of the compressor (3) circuit, therefore it does not cut off when the compressor is cut off. This ensures uniform cooling throughout the cabinet at all times.
The heat removed by the refrigeration system is rejected into the atmosphere with the help of the condenser (5) through the condenser fan (4). In the event of malfunctioning/ failure of any component of the hermetically sealed refrigeration system leading to reduced or ceased cooling, the sen/ice technician can bring a replacement refrigeration system from his workshop, pull out the defective refrigeration system with the help of castor wheels (9), replace it with the replacement brought by him, and take away the defective refrigeration system to his workshop for diagnosis and repair later at his convenience. Thus the defective refrigeration appliance can be set right in a few minutes.
Advantages of Invention vis-a-vis Prior Art

5
a) Reduced down time of refrigeration appliance.
b) Avoidance of loss of perishable goods stored in the refrigeration appliance.
c) Avoidance of loss of customer's business caused by high downtime of refrigeration appliance.
d) Uniform cooling in the refrigeration appliance despite a detachable refrigeration system.