Solid propellant boilers — kind of the heating equipment using as fuel coal, coke, firewood, spill, peat, the pressed fuel briquettes, pellets and also waste of processing of products of crop production and carpentry.
Solid propellant boilers are classified by the following parameters: 1. Heat exchanger material: steel or cast iron. 2. Type of the consumed fuel: firewood, coal, pellets, spill. Also boilers are universal.
3. Way of loading of fuel: manual or automatic loading, frontal or horizontal. 4. Type of the built-in automatic equipment: non-volatile boiler (with thermosiphon) and volatile (air flow is regulated by the forcing fan).
5. Way of combustion of fuel: normal, pyrolysis (dry distillation of fuel) or with gasification. The boiler can be single-circuit or double-circuit. The first type is used for heating. The second type is intended for heating and heating of water.
Advantages and shortcomings
Non-volatile solid propellant boilers are good the fact that for work they do not need connection to the power supply network. Therefore they can be established in country houses where there are no communications. However solid propellant boilers, unlike gas, are not calculated on completely independent operation. They periodically need cleaning of ashpit. And even if boiler with the system of automatic loading of fuel, all the same fuel it is necessary to load manually as the sizes of the fuel tank are limited.
At wood boiler burning duration on one loading of fuel does not exceed 10 hours therefore even if it is equipped with the system of automatic fuel supply, at least every two days it is necessary to load new consignment of firewood into it manually. Pelletny boilers — rather new invention. They work at granules from the pressed woodworking waste. Boilers of this type have efficiency about 90% and can independently work up to 10 days. Lack of pelletny boilers is high cost. As for ways of combustion of fuel, at pyrolysis boilers efficiency is higher, than normal models for 10-20%. Pyrolysis boilers are more expensive, but the difference in cost pays off at the expense of higher efficiency. And boilers with gasification of fuel are calculated on more long continuous burning. The installed gas fuel burns through better, leaving less waste. Heat exchanger material influences the cost and features of operation of the boiler too. For example, steel heat exchangers are cheaper pig-iron, thanks to flap lid from above it is simpler to load fuel into them, but their working resource is less. In the boilers having pig-iron heat exchangers, loading of fuel is carried out through front door that it is not so convenient as flap lid from above.
Power of solid propellant boiler
Power of standard solid propellant boilers fluctuates ranging from 15 up to 40 kW, it is enough for heating of premises. There are 100 kW models and more, but the sphere of their application is limited. Approximately to calculate the power which is necessary on heating of country house, it is necessary to be guided by the following ratio: on warming up of 10 m² of the room 1 kW of power is required.