Design And Fabrication Of Domestic Deep Freezer

4.5 STRAINER/DRIER
4.5.1 Strainer
    A strainer is a very fine filter and metal chips from the refrigerants since they can cause clog on the c6mpressor valve and controlling device in the refrigeration system [Gunther, C. R (1973)]
4.5.2 Drier
Drier are used for removing moisture from the refrigerant. It consist of a shell containing a desiccant which is a material that has the ability to absorb any acid already formed into sludge. [Gunther, C.R (1 973)].
These desiccant are made in such a way that they do not react with, nor dissolve in refrigerant oil, they are insoluble in moisture and do not combine chemically with refrigerant to form acids.
The combinations of strainer/drier are usually located ahead of the capillary tube to prevent the tube froth being plugged by ice or any foreign material circulating through the system. [Raymond, C. G.(1973)].
4.6     THE CAPILLARY TUBE
The capillary tube is a bore tube which aids to meter the flow of liquid refrigerant from the condenser to the evaporator. It is connected from condenser outlet to the evaporator inlet.
Hence, if condensed refrigerant vapor enters the capillary tube, the mass flow will be reduced, then the refrigerant increase in mass flow.
Under this extreme conditions, the capillary is either passed as considerable uncondensed gas or passed as liquid refrigerant up to the condenser. But the normal operating conditions, a capillary tube givens good performance and efficiency. [Ogundijo, J .A 19 88)].
4.7    IMPORTANT OF REFRIGERATOR 
1.    DOMESTIC: Refrigerators are commonly used in the house for domestic purpose. They are usually in all sizes having a compressor rating between (1/2) half and (1) one-horse power and are hermetically sealed type. They are commonly employed for cooling drinks and as food preservation [Andrew, D.& Alfred, F. B, (1970)].

2.     COMMERCIAL: Commercial refrigerators is concerned with designing, installation and maintenance of refrigeration fixture of the type used in retail store, restaurant, hotels and institution for storing, processing and dispensing of perishable goods [Andrew & Alfred, F. B. (1970)].
3.     INDUSTRIAL: Industrial refrigerator are larger in size than commercial application and have the distinguishable features requiring an attendant on duty, usually of licensed operating engineer Example are ice plant, large food packaging plant, breweries, ceramics and in industrial plant such as oil refineries, chemical plant and rubber plant [Andrew, D. & Alfred, F. B. (1970)].
4.     MARINE AND TRANSPORTATION: Refrigeration are needed for fishing boats and for marine vessels transporting perishable goods This is also applied in modern passenger train and trunks for carrying chilled fish, meat and other refrigerated fixture through a long distance [Raymond, C. 0.(1973)].
5.     AIR CONDITION: It deals with the control of temperatures and humidity of the air, moisture filtering and cleaning of air within some designated areaor space. They are of two types, the comfort air application or industrial air- conditioning, it could be formed in the control of moisture content of hygroscopic material governing the rate of chemical and biochemical reaction, limiting variation in the size of precision and manufactures articles due to thermal expansion and contraction, filtered is often essential to trouble free the operation and to give production of good product. [Raymond. C. O. (1973)].
6.     HOSPITAL: Refrigerators are used in hospital for preservation of bones, blood tissue and some drugs that are kept under a particular temperature; it also play an important role in the act of keeping dead Bodies in mortuaries from being decayed [Raymond, C. G. 1973)].