Fire tube biomass boilers
HoSt supplies cylindrical fire-tube biomass boilers. In this type of biomass boiler, the shell is filled with water (the tubes are surrounded by water) and the flue gasses flow through (inside) the fire tubes. In the HoSt water tube steam boiler it is exactly the other way around.
For improved cleaning, the first part of the fire tube biomass boiler is equipped with a radiation section where the flue gasses are being cooled before they flow though the tubes. The cooling in the radiation section prevents harsh and hard to remove ash depositions in the fire tubes. In addition, for regular cleaning the cylindrical boilers can be equipped with compressed air soot blowers to minimise the number of production stops.
Advantages of the HoSt Fire Tube Biomass Boiler
MINIMISED PRODUCTION STOPS
DESIGNED TO PREVENT FOULING
EASY TO CLEAN
Horizontal cylindrical hot water boilers
Horizontal cylindrical boilers are cheaper. However, their disadvantage is that more production time is lost for the stops required for cleaning.
Vertical cylindrical hot water boilers
In the vertical hot water boilers the flue gasses initially flow downwards through a radiation section. The flue gasses are reversed into vertical pipes when they reach the bottom of the boiler. Due to the vertical orientation the soot blowers clean the pipes more efficiently. In this configuration the soot always falls vertically, in the flow direction or the opposite direction, and is unable to deposit again which is a frequent issue with horizontal flame tube boilers.
Cylindrical steam boilers
Horizontal cylindrical boilers are often used for steam production up to 32 bar as a cost saving measure. The flue gasses are first cooled in the radiation cooler before they enter the flame tubes. At pressures up to 20 bar the radiation cooler is integrated in the boiler, however for pressures in excess of 20 bar another radiation cooler, a larger room of membrane walls, is installed before the boiler inlet.