SA213T22 Alloy Steel H fin tubes boiler parts economiser for hot water boiler China manufacturer
H fin tubes Economizer Inspection
1. The major problem at the economizer section is low temperature corrosion and problems from gas side deposits.
2. Sliding and leaky expansion joints at the casing may allow accumulation of soot with severe acid attack.
3. Inspection of tubes bends by opening the inspection covers needs to be carried out to check these.
4. Uptake area may show cracked expansion bellows sign of acid corrosion.
5. General cleanliness of these areas indicates the combustion performance in boiler.
Boiler Economizer Introduction
1. To obtain an acceptable degree of efficiency and reduce fuel consumption as much as possible by introducing further heat recovery surface so that the gas temperature at the funnel may be as low as practicable, the gas temperature leaving a boiler cannot be reduced much below 30oC above the saturation temperature.
2. In radiant types a much higher exit gas temperature is usually found. To carry out this further heat exchange, surfaces such as economizers and air heaters are commonly used.
3. In many radiant boiler types, economizers are also found arranged integrally within the boiler unit. In this location they consist of a number of multi-loop elements of plain tubes connected at their ends to inlet and outlet headers.
4. Since are situated in a hot gas temperature zone and are required to perform a considerable heat exchange duty, a portion of the water pumped through them may be converted into steam. These steaming economizers are arranged so that water enters the lower header and the steam and water mixture leaves from the top header to the steam drum where the steam and water separate.
Economizers are used externally to boilers for further heat recovery. Economizers are found in the cooler gas zone and are fed with water temperatures around 116oC or 185oC depending upon whether the feed cycle includes high pressure feed heaters after the de-aerator.
The function of Boiler Economiser
1. The Economizer in Boiler works on the principle of Heat Transfer. Heat transfer usually takes place from high temperature to low temperature.
In the case of Boilers, flue gases or exhaust from the boiler outlet are at high temperature and water that needs to be preheated is at low temperature.
2. So, this temperature difference between water and flue gases helps to increase the feed water temperature.
3. Depending on the type of operations, design of Economisers can be smoke tube type or water tube type.
4. In smoke tube type flue gases are inside the tubes and water is on the shell side while in the water tube type, water is in the tube and flue gases are on the shell side.