Cork Institute of Technology
Higher Certificate in Engineering in Mechanical Engineering – Stage 1
(NFQ – Level 6)
Autumn 2006
Machine Systems (Pneumatics & Hydraulics)
(Time: 2.5 Hours)
Instructions
Answer FOUR questions.
All questions carry equal marks.
Examiners: Mr. Sean Williams
Mr. Manfred Uhlemann
Mr. J. Connolly
Mr. R. Simpson
Q1. (a) State two applications which utilize pneumatics. In each case outline why pneumatics
was chosen as the control medium for the applications. (4 marks)
(b) Sketch and describe the operation of one compressor from those which appear below:
(i) Single-acting, single-stage, vertical, reciprocating compressor
(ii) Rotary vane compressor
(iii) Turbo compressor (6marks)
(c) List the functions undertaken by the receiver in an air generation system. (6 marks)
(d) Explain the term “automatic drain trap”. (3 marks)
(e) Describe with the aid of sketches the operation of a chemical absorption dryer. (6
marks)
Q2. (a) Using table 1 and table 2 provided calculate the pressure drop between the compressor and
point “A” on the pipeline.
Pipeline shown in figure 1.
Pressure at compressor = 6 bar
Nominal pipe diameter = 40 mm
Airflow, converted to free air = 100 litre per second. (8 marks)
(b) Explain the term “Air Service Unit”. (3 marks)
(c) Describe the primary function of each principal element in an air service unit. (3 marks)
(d) Show using diagrams the features incorporated in a pipe distribution system, which
facilitate the removal of condensate. (8 marks)
(e) Explain the term “dead end” used in relation to pipe distribution systems. (3 marks)
