How our Biotech wood pellet boiler system works

Components & function

1. Daily pellet tank
2. Vacuum flap
3. Separator
4. Vacuum device
5. Worm screw unit
6. Worm screw
7. Lambda Probe
8. Burner
9. Automatic ignition
10. Air flow sensors
11. Self-cleaning heat exchanger

For further information, click here to view the Biotech Pellet Heating presentation..

The regulation of the combustion of our heating unit works exactly in the same way as that of a modern car. The air is sucked in, the combustion takes place and the exhaust gas is controlled by the lambda probe – level of residual oxygen – the fuel supply is regulated accordingly.

The air flow sensors are provided with 2 temperature sensors and 1 heating element.
The heating element will pre-heat (accordingly to pre-set values); the (cold) air which is supplied to the burner will cool the heating element: the quantity of air supplied is calculated depending on the temperature variation of the heating element. The combined action with Lambda Probe ensures the highest efficiency and self-regulation of fuel combustion.

The burner is made of heat resistant steel and is composed of extendable upper and lower parts. It has the additional advantage that the scales which form during the combustion will break and fall into the ashes drawer during the automatic cleaning cycle.

The heat exchanger exchanges the heat with the water. Flue gas passes through the tube. The middle tube is closed and blocks the stream of the gas. The spiral springs inside the heat exchanger (part of self-cleaning device) also force the gas to run upwards in a circle generating a vortex thus ensuring a better heat exchange.

Automatic cleaning system - In order to maintain a high heat exchange, thus keeping high efficiency of the system, it is important to keep the heat exchanger clear of ashes.

The heat exchanger is cleaned by means of spiral springs which rise and fall down the inside of the tubes, thus removing deposit of ashes from the surface.

This cycle starts with pellet feeding system and last approx. 10 minutes; at the same time, the grate of the burner opens and the ashes fall directly in to the lower ash drawer.

Burner Grate - The grate is cleaned after every burning process.

The grate automatically opens under the burner passing under a blade which remove ashes from the surface of the grate and which fall into the ashes drawer. Ashes are leveled on the ashes drawer thus maxmising its content capacity.

The ash drawer, depending on the models, needs to be emptied approx. every 2000 up to 4000 Kgs. of burned pellet.

Continuous modulation - Our pellet heating systems have a huge power range and enable a continuously variable modulation. In the heating season, the outside temperatures can fluctuate between plus 15 degrees celsius to minus 5 degrees celsius and sometimes colder.

Whilst the traditional heating systems adjust to the outside temperature with frequent switching on and off or with few fixed power levels, our pellet units adjust their power fully stepless thus reducing the starting cycles, increasing the efficiency, reducing electric consumption and prolonging the life of mechanical / electrical components of the system.

An LCD display provides an easy to understand graphic menu with simple menu description, facilitates use, first start-up, maintenance and failures research. Boiler and buffer management is integrated in the software of the pellets heating system and up to 4 heating circuits can be integrated. When using a room thermostat, it is enough to set the desired room temperature as all parameter adjustments will be automatically carried out by the software of the heating appliance.

Automatic pellet tank refilling can be programmed at desired hour times and a worm screw revolution counter avoids the tank running out of pellets, starting if necessary, the re-filling cycles out of pre-set times.

The capacity of the pellets intermediary tank varies depending on the heating system model; its average capacity is for 12 hours of operation. The vacuum system 'Vacu Trans' enables the pellets to be fed without being damaged.

The Vacu-Trans system can be combined at choice with the various feeding systems, which bring the pellet to the suction zone, depending on the individual requirements.

There are various automatic feeding systems available including worm feed, suction probe, rotating worm screw, silo bag and underground pellet tank.