ABSTRACT

A temperature control apparatus an “Armfield model was refurbished.  The methodology employed were to detect the pulty parts of the equipment especially in the sump where leakages were observed.  In the repair, the water in the sump was drained off, corrosion and rusting in the tank were scraped off, the sump was washed and allowed to dry.  A homogenous mixture of crown filler and hardener mixed in the ratio of 5.1 was used to coat the inner surface of the tank. 

Antirust protection was applied all over the inner surface of the tank in order to avoid further corrosion and rusting.   Metallic parts of the apparatus including the sump were painted with carlux 842 paint so as to avoid the development of pricklings, pittings, roughness or cracks which promote corrosion when in contact with air, water or chemical attack.  Pipes, air-hoses, dips, nuts and values of the temperature control apparatus were also serviced.

After refurbishment, the equipment functioned effectively when operated and it is recommended that it be used for further practical in the pilot plant laboratory.

CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY

Armfield temperature control appara [tus is a pilot plant scale apparatus for the study of heat transfer, process control fluid mechanism and thermodynamics by chemical Engineering students in various institutions of higher learning.

The apparatus consists of two heaters, with voltage between 220-240 and 6kw of power.  The heaters has thermostatic range from 380C-82C0, heat transfer area (A) of the heat exchanger is 0.64m2 (0.059fts2) ALFA-LAVAL. Four thermo walls, each fitted at the inlet and outlet points on the heat exchanger for insertion of thermometers for temperature measurement.  It has a sump tank of capacity of 70 litres, three flow meters (Rotameters), two of variable area type, a pump of power 0.23kw and capacity of 55litres/min at 1.5m and 9 litres/min at 6m. a control valve (air regulator) of ½ inch, PID (Honey well) controller, two pen chart recorder, temperature sensor, electronic controller etc.  as the name applies it is used to control or measure temperature.

In industries in order to avoid wastes during production of goods, even in pilot plant where production of good are in small scale, there is need for control system which gives more stable (Uniform) process and higher quality products.  Certain variables like temperature applied to fluid or rather dictated from body, fluid flow rate, pressure etc which causes loss of valuable materials during production.  Some of the above mentioned variable can be corrected using temperature control apparatus.

Heat exchange is one of the most frequent operations mainly in process industries.  A large number of processes proceed at a much faster rate as the temperature is raised and it is economically advantageous to use as high a temperature as possible.  Chemical reaction rates are approximately doubled for every 100 rise in temperature.

Chemical reactions are frequently exothermic, however, and it may well be necessary to remove heat through a heat exchanger rather than supply it inorder to avoid a catastrophic temperature rise.  Thus, to balance the requirements of maximum efficiency and complete control over the process may require the very close regulation of the temperature.

The pilot plant temperature control apparatus is designed to show the working of a heat exchanger and to permit a series of experiments to be performed with it.  Water is both the process fluid and the heating fluid, the rate of flow may be set up to show how flow control may be obtained in various ways.

1.2       AIMS OF THE STUDY

Refurbishment is to keep the apparatus in top operating condition through repairs, maintenance and  servicing of parts of the apparatus.  Through the refurbishment it increase the workability of the apparatus (equipment) the degree of accuracy and precision as well the sensitivity of the equipment.  It improves the performance of the equipment, maximize efficiency and bring error to minimum.

Through the maintenance or refurbishment of the equipment, quantity/quality control, cost effectiveness, strength of material and prolonged apparatus/plant life span can be obtained.

1.3      SCOPE OF THE STUDY

This involves detecting the faulty components of the temperature control apparatus and the repairing which includes general servicing, flushing of the sump tank.  To reduce fouling, scraping off the corroded parts, filling of the leaking parts with filler and painting of the sump tank.  Ensuring that there would be no leakage either by values or pipes when running the apparatus and the efficiency of the circulating pump.

At the end, it is expected that he pilot plant temperature control apparatus will be in top operating condition.