Observation

The questions required the ability of the candidates to identify the component of a refrigeration equipment and the application of the component. Majority of the candidates attempted these questions and correctly identified the parts and stated the application.

(a)(i) The type of evaporator shown in Fig. 1
                    Flooded evaporator
             (ii) Identification of each of the labelled parts
            J – Stopper
            K – Pivot
            L – Float
            M – Liquid refrigerant
            N – Liquid
                                                                       
            (iii) Applications of the evaporator shown in Fig. 1

• The evaporator is used in dairy industries.
• The evaporator is used in brewery industries.
• The evaporator is used in beverage industries.
• The evaporator is used in pharmaceutical industries.
• The evaporator is used in chillers.

  (b) (i) Types of water-cooled condenser

• Shell and tube condenser
• Shell and coil condenser
• Concentric condenser
• Tube-in-tube or pipe-in-pipe condenser or double tube

             (ii)Merits of a dry expansion evaporator
                       

• Little refrigerant can be used by the evaporator.
• It is mostly used in domestic refrigeration.
• It is relatively not expensive.
• Refrigerants are completely vapourized in the coil of the dry expansion evaporator.
• It does not waste refrigerant
• It is easily constructed