Please enable JavaScript.
Coggle requires JavaScript to display documents.
CHAPTER 2: BOILER AND THERMIC FLUID HEATER - Coggle Diagram
CHAPTER 2: BOILER AND THERMIC FLUID HEATER
INTRODUCTION : BOILER
FUNCTION
Vessel that heats water to become hot water or steam
BASIC OPERATION
Density differences , pressure, temperature and water level are all factors that affect the efficiency of a boiler.
It is made up of a water-containing drum, a water inlet, and a steam output.
As heat is supplied to the drum , the temperature rises until the water boils.
ASSESSMENT OF BOILERS
BOILER PERFORMANCE
example of the causes of poor boiler performance
poor combustion
heat transfer surface fouling
deposition of unwanted material
BOILER BLOW DOWN
necessary to protect the surfaces of the heat exchanger in the boiler.
INTERMITTENT BLOW DOWN
The process involves cleaning the internal surface of the boilers after they have gone out of solution.
CONTINUOUS BLOW DOWN
Continuous and consistent delivery of a tiny stream of concentrated boiler water, followed by a steady and constant supply of feed water.
Benefits
Lower pretreatment costs
Increase boiler life
BOILER FEED WATER TREATMENT
EXTERNAL WATER TREATMENT
REVERSE OSMOSIS
Suitable for water with very high total dissolved solid
DE-AERATION
expelled dissolved gases such as O2 & CO2
ION EXCHANGE
softening
Demineralization
INTERNAL WATER TREATMENT
Chemicals added to boiler to prevent the formation of scale.
THERMIC FLUID HEATER
Advantages
operational flexibility
Non-Pressurized system operation
Good thermal efficiencies
Thermic fluid is heat transfer medium
TYPE OF BOILER
FLUIDIZED BED COMBUSTION BOILER
compactness, fuel flexibility, higher combustion efficiency, reduced SOx & NOx
THERMIC FLUID HEATER
Wide application for indirect process heating
WASTE HEAT BOILER
Used when waste heat available at medium or high temperature
STOKER FIRED BOILER
Spreader stokers
Chain-grate or traveling-grate stoker
PACKAGED BOILER
High heat transfer, faster evaporation, good convective heat transfer, good combustion efficiency, high thermal efficiency
WATER TUBE BOILER
Used for high steam demand and pressure requirements
most common type of large boiler is a water tube boiler.
FIRE TUBE BOILER
A more complicated boiler is the fire tube boiler, which resembles a modified shell and tube heat exchanger.