Whole Bale Gasification Boiler

We recommend the well-engineered HERLT whole bale boiler, which provides hot water for a wide range of applications such as piggeries, greenhouses, and hotels. It also generate vapour and super heated steam and hot air for grain driers. Easy to operate, the HERLT boiler is not just a tin box . The complex boiler systems consists of an extensive gasification and two-stage combustion chamber/furnace, followed by a vortex after-burner, dust collection chamber and heat exchanger. Finally the expansion vessels adjust according to the buffer tank volume. 

The gasification and combustion technology in this boiler has been patented world-wide. It guarantees the inner part of the boiler is always free of precipitations. Herlt Boilers are the only boilers showing excellent reduced emission values and high efficiencies. The well-engineered gasification has a two stage furnace and the flue gas system is patented world-wide.

German made rugged and indestructible boiler Easy operation ? Good combustion behavior even with wet material Special designed gasification chamber ? Two stage circulation combustion chamber No clinkering no soot precipitation ? Excellent emission values Hot Water ? Vapour ? Overheated Steam ? Hot Air 85 - 2,000 kW 5 YEARS WARRANTY 

The boilers range from 85 kW up to 5 MW using straw and miscanthus bales and also baled brush wood and timber logs. They are designed and made by the North East German manufactu-r­er HERLT in the state of Mecklenburg Vorpommern . Herlt’s bale boiler systems need no extra debaling and bale chippers. This reduces investment and running costs and needs no additional safety installations such as fire protection equipment (spark detector) of the straw chipper. 

Basic principle of the Herlt gasification and combustion process.

The Herlt firing plant always exists of  3 main groups

  1. The gasification chamber where the whole bale is brought in by a tractor fork or by an automatic bale feed in systems. After the ignition of the bale the gasification process starts and continues permanently at low temperatures of about 700°C. The low temperature avoids melting of the fuel and no slagging or clinkering emerges.
  2. The main furnace chamber beneath the gasification the gases burn at temperatures around 1,000° C to 1,200 °C.
  3. The separate after burner system exists of one or two upright standing after burner designed as cyclone burner and an induced draft fan (suction fan). Depending on the design then there are also warm water heat exchangers, hot gas cyclons, dust precipitation and collection chambers and spark protection screens.

The system guarantees flue gases free of furan, dioxin, NOx and CO (carbon Monoxid).

Other features

  1. The burning chamber and the gasification chamber are fully lined with ceramics (no single bricks) containing a catalyst to improve a proper and good and efficient burn-out.
  2. Herlt offers client tailored solutions including a bespoken turnkey plant until the manifold incl. installation, flue system and the lay out and connection to the buffer tank.
  3. Their boilers take round bales with a diameter of up to 180 cm or rectangular bales with 240 x 120 x 120 cm. The large boilers take 4 bales at a time
  4. Herlt boiler produces warm water, hot water, vapor, super-heated steam, hot air direct heated or hot air via an air to air heat exchanger.
  5. Herlt gives a warranty of five years on the boiler. On the ceramic, the electric and all moving parts they give two years warranty

Depending on the design the boilers use round bales and squared bales up to 2.5 x1.2 x 1.2 m.

feeding a large bale into a hot air generator

Feeding a large bale into a hot air generator

  1. A non gasification boiler starts burning at a low flue temperature. It rises then up to its "peak stage temperature" and drops down again . That means there are only a few minutes were the boiler runs under optimal conditions. The rest of the time it is always unstable under non optimal conditions.
  2. Our gasification boiler starts up in a beginning heating period until achieved its running temperature.  It remains in this position until the bale or logs are almost gone. Coming to its "final stage" (The bale is almost gone), the boiler will give a signal on a mobile asking for more bales or it will feed them in automatically.  If the boiler is not getting bales (or logs) it shuts down itself and changes from the gasification phase into a glowing phase. That means in the gasification chamber is a small rest of fuel glowing only without heat output. This also means there are almost no flue gases coming out. This avoids bad flue values and unnecessary heat losses. This glowing phase stays to its final end. The long glowing phase also enables the boiler to catch easily fire again if a bale comes with a delay. 

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