
3
5443 113 v1.9
Pyrotec Technical Data
 Boiler Description
Description
The PYROTEC Grate Firing System (patent no: EP 0 905 
442 B1) was developed for automatic combustion of all dry 
to moist wood fuels (remnant wood, pellets and forest wood 
chips to max. W50, (see section “Wood Fuel Requirements”) 
and combines the benefits of underfeed firing with the 
benefits of grate firing.
The PYROTEC Grate Firing System is characterized by 
highest efficiencies and perfect combustion in all load 
stages. The PYROTEC Boiler Plant has been built to 
ASME Sec. IV and has CRN for Canada. It is tested and 
approved to the applicable CSA / UL safety standards.
Function:
- The solid, powerful and heat-resistant in-feed auger 
 moves the fuel over the burner trough into the 
 descending and moving grate zone. An electrical 
 and mechanical temperature sensor to operate the 
 thermal extinguishing valve are located on the in-feed 
 auger. Above the auger is the metering container with 
 a light barrier for setting the level of the fuel insulating 
 layer.
- The fuel is either ignited manually or automatically with 
 an automatic ignition blower (optional). The boiler 
 features a reliable burner trough, a descending grate and 
 a moving burn-out grate made from highly-refractory 
 cast steel [approx. bin. (12 mm)]. These items allow 
 to achieve excellent performance control and highest 
 safety against back-burn in conjunction with an automatic 
 de-ashing system (optional) for the combustion chamber. 
 The solid, horizontally positioned and large-volume 
 fire box has been optimized in terms of combustion, 
 consists of a high-quality refractory brick lining and 
 has multiple layers of insulation for the lowest possible 
 surface temperatures. A variable speed primary air 
 blower provides preheated air to the combustion grates 
 in the fire box.
- In the upper part of the fire box, the secondary air is
 blown into the gas space of the firing system by 
 variable speed blower via an encircling ring with 
 individually adjustable nozzles to achieve high
 turbulence. This mixes the fuel gases with fresh 
 secondary air to achieve perfect combustion and very 
 low emissions.
 The fire box door is solidly constructed, air-cooled and
 very well insulated. The fire box door is equipped with
 solid double-jointed hinges for easy maintenance. 
 The heat is transferred to the water in the horizontal 
 tube heat exchanger. The boiler is well insulated and 
 highly accessible through the boiler door on the front. 
 A pneumatic cleaning system (optional) can be installed 
 at the insulated boiler door.
- The flue gas blower has been specially designed for 
 wood burning boilers and quiet operation. The spring- 
 suspended motor has a solid, heat-resistant design 
 with a heat dissipation hub. The blower housing on 
 the intake can be mounted radial by 360° and has a 
 variable rotation speed and a round blow-out nozzle.
 It is mounted directly on the boiler or on the flue gas 
 de-duster (optional).
General Information
Supplied with:
- Boiler with fire box and pressure vessel / tube heat 
 exchanger including supply and return temperature 
 sensors and over pressure monitor
- Fire box with burner trough, descending grate, moving 
 burn-out grate and light barriers for ember monitoring
- In-feed auger including insulating layer, safety end 
 switch for maintenance lid, back-burn temperature 
 sensor, extinguisher valve with strainer, extinguisher 
 water container with mounting bracket
- Flue gas blower including flue gas temperature sensor 
 and oxygen sensor
- Boiler cleaning tools for the fire box, combustion 
 chamber and tube heat exchanger
- Installation fittings including pressure relief valve, drain 
 valve, low water cut off, safety temperature limiter, 
 temperature and pressure gauges
- Control cabinet with integrated Pyrocontrol control 
 system
Customer supplied:
- Counter flanges for the boiler supply and return
- Piping to the mixing valve, boiler pump and hot water 
 storage tank
- Piping for the safety heat exchanger
- Wiring to the control panel
- Insulation for the flue gas re-circulation line, the flue 
 gas recirculation system is optional
Accessories for PYROTEC Grate Firing System:
- Flue gas de-duster 63 USG (240 L)
- Flue gas de-duster 211 USG (800 L)
- Automatic de-ashing system in bin, 63 USG (240 L)
- Automatic de-ashing system in bin, 211 USG (800 L)
- Pneumatic cleaning system
- Automatic ignition blower
- Set of displacement rods (for Pyrotec 720, 950 and 
 1250 only)
- Operating pressure 30 or 60 psi
- Two-stage in-feed auger
- Flue gas recirculation system
- Thermal safety flush valve
- Slide valve / Rotary valve
- Boiler pump and boiler mixing valve
- Pyrocontrol control system options: 
- 5 sensor hot water storage tank management system
- External control module for field supplied extraction 
 system
- Output module / Input module
- Input module 0-10V
- ModBus
- BacNet gateway
- Visualization