The calcium and magnesium (hardness) form scale on heat transfer surfaces if the groundwater is not treated before use in industrial cooling and boiler systems. In boiler feedwater applications, the thermal breakdown of the bicarbonate in the boiler leads to high levels of carbon dioxide in condensate return systems.Get Price
also lead to scale formation inside the boiler, resulting in localized overheating and finally causing boiler tube failure. Energy Conservation Opportunities in Boilers 27 1. Reduce Stack Temperature Stack temperatures greater than 200 C indicates potential It also Get Price
2013/9/9 · Let's have look at the properties of boiler water. 1. Ph --- For an ideal boiler water, PH is maintained between 10.5-11.5 ie alkaline. >> Controlling the PH of water is one of the important treatment in boiler water treatment. >>PH is below 7 the solution is acidic and above 7 it's alkaline. >>If either of the values increases, water will Get Price
Scaling in boilers - LenntechGet Price
Boiler scale is caused by impurities being precipitated out of the water directly on heat transfer surfaces or by suspended matter in water settling out on the metal and becoming hard and adherent. Evaporation in a boiler causes impurities to concentrate. This Get Price
Causes, and prevention of foaming and priming in boilers, prevention Boiler water carry-over is the contamination of the steam with boiler-water solids. Bubbles or froth actually build up on the surface of the boiler water and pass out with the steam. This is called foaming and it is caused by high concentration of any solids in the boiler water.Get Price
2020/9/3 · This can result in the formation of Magnesium Hydroxide precipitates which form insulating scale on the boiler tube surfaces. If Chloride ions are also available, they react with the Hydrogen ions previously associated with the precipitated Hydroxyl ions, to form Hydrochloric acid, thereby lowering the alkalinity of the water.Get Price
boiler. 1. Generation of steam is much quicker due to small. ratio of water content to steam content. This also helps. in reaching the steaming temperature in short time. 2. Its evaporative Get Price
Scale formation due to CaSO4 in low pressure boilers can be avoided by adding Na2CO3 to the boilers. CaSO4 + Na2 CO3 → CaCO3 + Na2SO4 The forward reaction is favored by increasing the concentration of CO3 2- .CaCO3 formed can be removed easily.Get Price
Scale formation can be avoided by adding sodium phosphate. It is used high pressure boilers.The phosphate react with Ca2+ and Mg2+ salts to give soft sludges Ca and Mg phosphates. 3CaSO4 +2Na3PO4 Ca3 (PO4)2 +3Na2SO4 5. What are boilerGet Price
Boilers MCQ Question 11. Download Solution PDF. In a power plant, the efficiencies of the electric generator, turbine, boiler, thermodynamic cycle and the overall plant are 0.97, 0.95, 0.92, 0.42 and 0.33 respectively. The total electricity generated …Get Price
Water is fed to a boiler at 50 C, the enthalpy of vaporization at atmospheric pressure in the boiler is 2400 kJ/kg, steam coming out from the boiler is 0.7 dry, the net heat supplied in …Get Price
MCQs: The formation of scale boiler leads to - Mechanical Engineering Questions - Thermodynamics Test Questions When the heat transfer into a system is more than the work transfer out of the system, then A. the internal energy of the system remains constantGet Price
boiler. 1. Generation of steam is much quicker due to small. ratio of water content to steam content. This also helps. in reaching the steaming temperature in short time. 2. Its evaporative Get Price
The formation of scale boiler leads to. The term which can differentiate thermodynamics from other sciences is ____. The thermodynamic work done by the system on the surrounding is considered as ____. When the heat transfer into a system is more than the work transfer out of the system, then.Get Price
Boilers MCQ Question 11. Download Solution PDF. In a power plant, the efficiencies of the electric generator, turbine, boiler, thermodynamic cycle and the overall plant are 0.97, 0.95, 0.92, 0.42 and 0.33 respectively. The total electricity generated …Get Price
Grain Boundaries David N. French, Sc.D. President of David N. French, Inc., Metallurgists, Northborough, MA October 1991 Category: Design/Fabrication Summary: The following article is a part of National Board Classic Series and it was published in the National Board BULLETIN..Get Price
2013/9/9 · Let's have look at the properties of boiler water. 1. Ph --- For an ideal boiler water, PH is maintained between 10.5-11.5 ie alkaline. >> Controlling the PH of water is one of the important treatment in boiler water treatment. >>PH is below 7 the solution is acidic and above 7 it's alkaline. >>If either of the values increases, water will Get Price
Hard scale formation takes place in high pressure boilers Soft scale formation due to hydrolysis of Mg salts in high pressure boiler. MgCl 2 + 2H 2 O Mg (OH) 2↓ + 2HCl iv) Presence of silica: Even very small amounts of silica leads to 3 3 inner boiler walls. It is Get Price
Scale – Scale is the formation of deposits that act as an insulator between the fire side and the water side. The creation of scale or other deposition can drastically decrease efficiency within the boiler. 1/32" of scale can translate to anywhere from 2-5% decrease inGet Price
Formation of deposits: Scale and sludge formation. Scale: If the precipitate forms hard and adherent coating on the inner walls of the boiler is known as scale. It is formed by the substances like CaSO4, Mg(OH)2 and Ca(HCO3)2. Scales are difficult to remove evenGet Price
Ultrasonic testing provides a quick and nondestructive method for measuring scale. Handheld, portable instruments, such as the 38DL PLUS ® thickness gage or the EPOCH ® series flaw detectors, can measure internal oxide layers down to a minimum thickness of approximately 0.2 mm or 0.008 in. using the commonly recommended M2017 transducer (20 Get Price
Steam Generators - Mechanical Engineering (MCQ) questions and answers. 1) What is the disadvantage of natural draught? No explanation is available for this question! No explanation is available for this question! 3) What is the pH value of water permissible for boiler?Get Price
2018/10/4 · Boiling can lead to sever scale formation Indirect Water Heating In this system the water cylinder is replaced by a direct heat exchanger called the calorifier where hot water or steam from the boiler enters the calorifier through a coil of tubes and heats the cold water passing through the calorifier.Get Price
2012/11/11 · Disadvantages of scale formation 1. Fuel wastage – scales have low thermal conductivity 2. Degradation of boiler material and increases of risk of accident 3. Reduces the efficiency of the boiler and- deposit on the valves and condensers 4.Get Price