CONSTRUCTION OF A VERTICAL FIRE TUBE BOILER

CONSTRUCTION OF A VERTICAL FIRE TUBE BOILER
 
ABSTRACT
The construction of this vertical fire tube boiler was carried out both at the industrial center and Mechanical Engineering workshop of the Institute of Management and Technology (IMT), Enugu. The boiler contains 2 steam  tubes at triangular pitch which are enclosed in a shell.  Water is introduced through the shell.  When the burner is put on, the products of combustion – excess oxygen, nitrogen and carbondioxide pass through the tubes at a high temperature and then heats the surrounding water, as a result, steam is generated. It has a capacity of 20,000cm3 of water and can produce 0.05kg of steam per hour.  It can be used widely for the generation of stem for laboratory uses and by small scale industries. The materials used were mainly mild steel.  About 10 electrodes were used for the welding and care was taken to ensure strong welding, although it is a low pressure boiler. The top sheet plato is 0.0125cm thick.  The tube bundles are galvanized tubes.  Details of the engineering and working drawings are shown.  The construction of this boiler did not follow any code.
 
CHAPTER ONE
INTRODUCTION
The term “boiler” applies to a device for generating: Steam for power, processing or heating purposes; Hot water for heating purposes or hot water supply. Boilers are designed to transmit heat from an external combustion source (usually full combustion) to a fluid contained within the boiler itself. Boilers can be broadly grouped into lower pressure type and high pressure boiler.  The constructed vertical fire tube boiler is a low pressure boiler. The boiler is constructed so as to generate steam for chemical engineering processes, heating drying, sterilizing, etc.
Holes at triangular pitch were drilled at the bottom and top sheet plates of the boiler.  Steam tubes were passed through these holes and then welded strongly.  Other holes were drilled only on the top plate, so that steam will pass through them.  This was pushed in to a shell and welded together.  A mild steel plate was used to prevent the products of combustion passing from the steam tubes to come into contact with the generated steam.  A stack was provided for the flue gases to escape.