Tube metal temperatures reach combustion gas temperatures of 1600F (870C) or greater which lead to tube failure. Components typically affected : Furnace wall tubes, superheaters, reheaters. Solutions : Ensure that no blockages exist within the tubes and bends.
As in Step 2, record the stack gas temperature, CO concentration (for gaseous fuels) or smoke spot number (for liquid fuels), and observe flame conditions for these higher oxygen levels after boiler operation stabilizes. 4. Decrease combustion air flow until the
Water tube boilers represent one of a number of pressurized equipment options used to convert water into steam under controlled conditions. Water passes through boiler tubes while the combustion gases remain on the shell side, passing over the tube surfaces.
1/10/2017 · Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out.
In economizer tubes, sulfuric acid corrosion is an unlikely event because flue gas and tube temperatures are normally over the acid dewpoint. In this paper, the failure analysis of generator tubes (similar to the economizer of bigger boilers) of two small oil-fired subcritical boilers is reported.
Check out the efficiency of your old boiler with a simplestack analysis or preferably for a more accurate assessment, measure the gas input vs. steam or hot water output. The data will give you a general idea of the difference between the fuel cost of the
The data required for calculation of boiler efficiency using indirect method are: Ultimate analysis of fuel (H 2, O 2, S, C, moisture content, ash content) Percentage of Oxygen or CO 2 in the flue gas. Flue gas temperature in o C (T f ) Ambient temperature in o C (Ta) & humidity of air in kg/kg of dry air.
Low-water trips are generally installed approximately 6" lower, but the manufacturer's drawings usually indicate normal and minimum water levels which vary from unit to unit. The potential for damage is more critical with solid fuel-fired boilers. A gas/oil boiler has no inventory or bed of fuel.
gases which boil the water of boiler drum. Then flue gases passes through super heater, secondary super heater, re-heater, economizer, air pre-heater and tri-sector air heater after that its temperature is reduced. The flue gas mainly content fly ash
When water chemistry is suspected of influencing failures or boiler chemical cleaning may be required, furnace tube samples should be extracted for deposit analysis. Similarly, when a newly replaced component starts popping tubes, the cost associated with removing and sending samples for metallurgical analysis
The gross calorific value of the fuel includes the energy used in evaporating this water. Flue gases on steam boiler plant are not condensed, therefore the actual amount of heat available to the boiler plant is reduced. Accurate control of the amount of air is essential to boiler efficiency:
Failure analysis of the tube was accomplished by taking into account visual inspection, thickness measurement, and hardness testing as well as microstructural observations using scanning electron
boiler. Water tube boilers require less weight of metal for a given size, are less liable to explosion, produce higher pressure, are accessible and can response quickly to change in steam demand. Tubes and drums of water-tube boilers are smaller than that of fire
Water-tube boilers are used in power station applications that require: A high steam output (up to 500 kg/s). High pressure steam (up to 160 bar). Superheated steam (up to 550°C). However, water-tube boilers are also manufactured in sizes to compete with shell boilers.
In shell boilers with a working pressure of between 7 and 17 bar the temperature of the mass of water in the boiler is typically in the range of 170–210 C. Allowing for, say a temperature difference of 30–50°C between the exhaust gases and the water temperature, the boiler exit gas temperature cannot be economically reduced beneath about 200–260°C, dependent on the operating pressure.
Water Tube Industrial Boiler Market value crossed USD 7 billion in 2017 and annual installation is anticipated to exceed 60 thousand units by 2024 as rising demand for energy efficient heating units along with rapid industrialization across developing economies
External treatment: Treatment of water—makeup, condensate, or both, before it enters the boiler, to reduce or eliminate chemicals (such as hardness or silica), gases or solids. 2. Internal treatment: Treatment of the boiler feed water, boiler water, steam, or condensate with corrective chemicals. 3.
Fly ash erosion, is a significant boiler tube failure concern, occurs in the regions with high local flue gas velocities, with high ash loading, and with abrasive particles such as quartz Corrosion: Deterioration and loss of material due to chemical attack. There are