What is Steam Boilers

What is Steam Boilers

A steam boiler is a device used to create steam by applying heat energy to water. Although the definitions are somewhat flexible, it can be said that older steam generators were commonly termed steam boiler and worked at low to medium pressure (1–300 psi or 6.895–2,068.427 kPa) but, at pressures above this, it is more usual to speak of a steam generator.

A steam boiler is a closed vessel that uses heat from a fuel source to convert water into steam, which is used in various industrial and commercial applications such as heating and power generation. The basic working principle involves the combustion of fuel inside the boiler’s combustion chamber, which produces high-temperature gases that transfer heat energy to the water surrounding the chamber, causing it to boil. Steam boilers come in different types, such as fire-tube and water-tube boilers, and have essential roles in providing heat and steam for various applications. Proper maintenance and adherence to safety protocols are crucial for their efficient and safe operation.

Purpose of Steam Boiler

• For generating power in steam engines or steam turbines
• In process industries for various processes.
• For heating the buildings in cold weather and for producing hot water for hot water supply
  

Primary Requirements of a Steam Boiler

• The water must be contained safely
• The steam must be safely delivered in the desired condition (as regards its pressure, temperature, quality and a required rate

Type & Function of Boiler

• Fire-tube boilers: These boilers have a firebox where the fuel is burned. The hot gases from the firebox pass through tubes that are surrounded by water.
• Water-tube boilers: These boilers have water tubes that are surrounded by hot gases. The water tubes are arranged in a variety of ways, depending on the specific boiler design.
• Packaged boilers: These boilers are pre-assembled and skid-mounted. They are typically used in commercial and industrial applications.
• Condensing boilers: These boilers recover heat from the steam that condenses back to water. This can improve the efficiency of the boiler.

The size and capacity of a boiler depends on its application. For example, a small hot water boiler for a home might have a capacity of 100 gallons, while a large steam boiler for a power plant might have a capacity of millions of gallons.

The efficiency of a boiler is measured by the amount of energy it uses to produce a unit of heat. The efficiency of a boiler can be affected by a number of factors, such as the type of boiler, the fuel used, and the maintenance of the boiler.

Boiler safety is important to prevent accidents and injuries. Boilers should be regularly inspected and maintained by qualified personnel. Boilers should also be equipped with safety devices, such as pressure relief valves and flame detectors.

Function of Boiler

A boiler is a closed vessel that heats water or other fluids to produce steam or hot water. The steam or hot water can then be used for a variety of purposes, such as:

• Generating electricity
• Cooking food
• Sterilizing medical equipment
• Drying clothes
• Powering industrial machinery

The function of a boiler depends on its type and application. For example, a hot water boiler is used to heat water for domestic or commercial use, while a steam boiler is used to generate steam for power generation or industrial applications.

The basic principle of a boiler is to heat a fluid by transferring heat from a combustion process. The combustion process can be fueled by a variety of materials, such as coal, oil, natural gas, or biomass. The heated fluid then flows through a heat exchanger, where it transfers its heat to a secondary fluid, such as air or water.

Boilers are an essential part of many heating and power generation systems. They are also used in a variety of industrial processes. Boilers can be a complex and dangerous piece of equipment, so they should only be operated by qualified personnel.

Terms Of Boiler

• Shell: Consists of one or more steel plates bent into a cylindrical form and welded together. The shell ends are closed with end plates

• Grate/ Bed: it is a platform in the furnace upon which fuel is burnt. It can be a Simple Grate for combustion of solid Fuel or a Nozzle Bed for Fluidized Bed Combustion.

• Furnace: it is the chamber formed by the space above the grate and below the boiler shell, in which combustion takes place.

• Water space and steam space: the volume of the shell that is occupied by the water is termed as water space while the entire shell volume less the water and tubes is called steam space

• Mountings: The items which are used for the safety of the boiler are called mountings

• Accessories: The items which are used for increasing the boiler efficiency are called accessories

• Water level: The level at which water stands in the boiler is called water level

• Refractory: insulation material used for lining combustion chamber

• Foaming: Formation of steam bubbles on the surface of boiler water due to the high surface tension of water

• Scale: A deposit of medium due to extreme hardness occurring on the water heating surfaces of the boiler because of an undesirable condition in the boiler water

• Blowing off: The removal of mud and other impurities of water from the lowest part of the boiler. Accomplished with the help of blow-off cock or valve

• Lagging: Insulation wrapped on the outside of the boiler shell or steam piping