The reasons for using steam as a heat transfer media in industry are its property to be a good heat carrier, high heat transfer property and easiness to physical movement. Steam is also used as humidifier in some processes.
You will find some useful information about chosing of steam boiler and some tips about boilers below.”
1- Heating Surface :
Heating surface is the main unit for the boilers or any kind heat exchanger. Especially when buying a boiler it is a big advantage for the customer to be familiar with this description. Heating surface description is used to describe the capacity and size of the boiler. The heating surface of a boiler means the total area of the boiler parts that are in contact with water and the hot gases and flame. the bigger the heating surface of a boiler bigger is the capacity of boiler.
2- Steam Quality :
This description is used to give idea about the quantity of the condensate that coexists with the saturated steam.The value of steam quality is in between 0 and 1. The formula is ; steam quality = Saturated Steam (kg) / [ Saturated Steam + Condensate ] (kg). For dry steam required processes this value is expected to be close to 1.
3- F&A 100 C and Actual Steam Value :
Steam Capacity can be from and at 100 degC or it can be actual. Steam capacity at F&A 100 degC is an industry standard which means equivalent steam generated when operating conditions are reduced to 100 degC and 1bar. For example, equivalent steam generated at F&A 100 degC from a Boiler, which generates 5000 kg/hr of actual steam at 10.5 Kg/cm2, is about 5870 Kg/hr
4- Tips about the steam boilers :
Here we want to share some tips especially about smoke tube boilers.
- In solid fired boilers the heat release rate of a 1 m2 grate area for dumping and stationary grates gives 1.500 kW to 2.000 kW. Moving grates and water cooled grates gives up to 3000 kW / 1m2 grate area
- Solid fired boilers requires bigger furnace volumes.
- Liquid and gas fired boilers gives approximately 35-40 kg steam for 1 m2 heating surface
- As as design parameter 12000 kW is taken for each furnace (17000 kg/h steam). For bigger capacities more than one furnace should be used.
- the thcikness / diameter limit for combustions chamber is 22/1800 mm
- It is safe and adviced to chose design pressure 15% higher than operating pressure and to chose safety valves set value 10% higher than the operating pressure of the boiler.
- Hydrostatic test pressure must not be less than 1,5 times of the operating pressure
- The most suitable solution to overcome heat expansion problems in combustion chamber is to use corrugated type furnace.
- It is a must to use good quality materials according to the norms. The tubes and the sheet metal materials must have valid certificates.
