Construction of a Model Shell and Tube Heat Exchanger
The precise content of this project was to construct a model shell and tube heat exchanger.
The material for construction of this project (equipment) and their dimensions are as follows:
500mm length of a tube bundle
20mm diameter of the tube bundle
650mm length of the shell
120mm diameter of the shell
70mm length of the inlet and outlet
20.5mm diameter of the inlet and outlet
160mm diameter of the flanges
8mm diameter of the holes on the flanges.
The construction of this equipment involves a series of processes which includes:
i. Marking out which was done using metre rule, pair of compasses, scribers and punch.
ii. Cutting of the marked materials to shape
iii. Folding to shape where necessary
iv. Rolling and boring holes as appropriate
v. Welding together by electric welding
vi. Filling for good finish
vii. Assembling together of the individual component.
The carefulness with which the marking out, welding and final assemble of the work was done made it possible for us to obtain an equipment suitable for use as a model shell and tube heat exchanger.
It is established that a horizontal heat exchanger with cold water at the shell side and the treated steam at the tube side is adequate for this operation, with the aim of cooling the steam from the distillation column.
The introduction of vapour (or any hot fluid) and removal of condensate (or a cooler fluid) is near perfection (100%) while the equipment being a heat exchanger is used to recover vapourised liquid in its former form (liquid) or removed heat from a very hot processed fluid. Significantly, this equipment is of great need when vapourised liquid must be recovered back as liquid at specified conditions.
TABLE OF CONTENTS
1.1 Background of the Study
1.2 Statement of the Problem
1.3 Purpose/Aims/Objectives of the Study
1.4 Scope and limitation of the study
1.5 Method of Research
1.6 Significance of the study
A – Total surface area of the exchanger (m2)
as – Goss Sectional Area for flow (m2)
Cp – Specific Heat Capacity of fluid (j/kg.k)
Di – Shell Internal Diameter (m)
De – Equivalent mean diameter (m)
Gs – Fluid Mass Velocity kg/m2s
Gt,Mn- Mass flow rate of fluid in the tube kg/s
g – Groove depth
hi – Heat transfer co-efficient of the tube w/m2.k
hio – Film heat transfer co-efficient in the tube w/m2.k
ho – Film heat co-efficient in the shell w/m2.k
di – Internal diameter of the tube m
k – Thermal conductivity w/mk
c – Length of Tube
LMTD – Log mean of temperature difference 0C or k
Mc – Mass flow rate of cold water in the shell (kg/s)
Do – Outer diameter of tubes m
T1 – T2 – Inlet and outlet temperature of steam 0C or k.
t – shall thickness m
u – Overall heat transfer co-efficient w/m2. K
v – Volumetric flow rate m3/s
Pa – Density of water kg/m3
U – Viscosity of water MS/m2
Dt – Temperature different 0C or k
1.1 BACKGROUND OF THE STUDY
The title of this project is construction of a model shell and tube heat exchanger.
Heat exchanger is a device in which heat is transferred from one fluid stream to another normally by the combined process of conduction and convection. Heat exchangers are the most important item in many thermal systems (Abalu 2006).
According to Jaeger 1995, heat exchangers are devices used to transfer heat. On the basis of numerous application in the industry for which they are designed and manufactured, heat exchangers are often given various names such as boilers, steam generator, automobile radiators, evaporators, condensers, heaters, coolers generators etc.
It is used to transfer heat from one fluid steam to another. it is also used to predict the amount of energy required to change a system from one equilibrium state to another (Abalu 2006).
There are various types of heat exchanger equipment generally defined by the function it performs in a chemical industry, they are; regenerator, open-type heat exchanger and closed-type heat exchanger or recuperated (Dickinson 1970).
Since our major concern is construction of model shell and tube heat exchanger, which is a type of recuperates or closed-type heat exchanger.
Model shell and tube heat exchangers constitute the bulk of unfired heat transfer equipment used in chemical process plants. They are found in different forms as fixed – tube-sheet heat exchanger, u-tube heat exchanger, floating heat exchanger, and internal floating heat exchanger. They can be inform of; double-pipe heat exchangers. Plate-type heat exchangers, air-cooled heat exchangers and graphite block heat exchangers (Harriot 1985).
FIGURE. 1.1 SHELL AND TUBE HEAT EXCHANGER
1.2 STATEMENT OF THE PROBLEM
There are some problems associated with the study of heat exchanger:
Time: Due to lectures and other school activities like practical’s and assignments we do not normally have enough time to visit the library and cyber café for the study of modern shell and tube heat exchanger.
Browsing problem: When browsing, sometimes there is network problem in the sense that the result will not come out easily, sometimes it will not be easy to fishout the main thought in the outcome.
Cost: There is high cost of construction of a modern shell and tube heat exchanger and browsing for the study.
1.3 AIMS OF THE STUDY
The study is being carried out in order to:
i. Make appropriate thermal control in the chemical industries since the most important aim in the chemical engineering sector of any plant is to control the flow of thermal energy between two thermal.
ii. Enable us to predict the amount of energy required to change a system from one equilibrium state to another
iii. Examine some of the techniques through which heat is transferred from one fluid stream to another.
iv. Know the rate at which the exchange of heat take place.
1.5 METHODS OF RESEARCH
Since the major concern is the construction of model shell and tube heat exchanger, the research method used was mainly constructional method of model shell and tube heat exchanger.
1.6 SIGNIFICANT OF THE STUDY
The future developments in the aerospace industries will hinge mainly upon the case with which structures and engines can be cooled; modern electrical and electronic plants require efficient dissipation of losses converted to thermal energy; the design of chemical engineering plant is usually governed by heat transfer and the analogues mass transfer processes and even civil engineers must take account of thermal effects in buildings and structures.
Process fluids from a chemical reactor are brought to reasonable temperature by transferring heat from this fluid (Kern 1950). Heat exchange or transfers is a major principle of industrial operation.