Feeding screws

The feeding screws used in the Ariterm bio burning systems are made of steel and designed to endure the strain caused by different fuels. The right choice of screws is a critical factor when deciding the faultless functionality of the bio heating system.

In a dual screw system there is more leeway in positioning the boiler and the storage in relation to each other. The free fall funnel can also be ordered with special measurements, so that the devices can be positioned to fit the operating space.

Dual screw feeding system

The dual screw system is recommended because it has a better burnback protection. The free fall funnel between the screws forms a flame-retardant, fuel-free space between the storage and the burner. The funnel, along with the rising burner screw, enables the formation of a water lock in a case of a burnback.

The transmission of the feeding screws is dimensioned according to the size of the screws and the chosen fuel. The motors and gears are maintenance-free worm gears and conical cylinder gears.

Pellet feeders

Pellet feeder PS10 (40 – 400 kW)

In pellet use the pellet screw can be replaced with a PS10 pellet feeder. PS10 is composed of a dosing screw, a rotary feeder and a burner screw which are chain steered by one motor. The system makes the fuel feeding process more balanced and provides one additional backfire protection. PS10 is also equipped with a powder extinguishing system.

PS10 can be combined with BioJet, HakeJet and MultiJet burners within the power range of 40-400 kW. In Arimatic 500 pellet control center the PS10 is operated by a frequency controller.

Pellet feeder PS13 (500 – 1 500 kW)

PS13 is composed of a separate rotary feeder and a burner screw each of which is steered by a separate motor. PS13 can be combined with BioJet and MultiJet burners within the power range of 500-1500 kW. In Arimatic 500/AM1001 pellet control centers the PS13 is operated by a frequency controller.





SSP (motor 0,37 kW)


SSH (motor 2,2 kW)

Rotary feeders

It is possible to install a rotary feeder above the dropping funnel between the storage screw and the burner screw, the use of which is justified when:

  1. the fuel used is extremely dry
  2. the installation space restricts the feeding screw length to be too short
  3. the fuel used has sticks or a large lump size

Ariterm manufactures two types of rotary feeders: the SSP model is designed for pellets and the SSH model for fuels types that are harder to feed, such as woodchips.


Ariterm manufactures SSP rotary feeders for pellets in order to increase the backfire protection of the system when installing in limited operating space.


SSH rotary feeder consists of a cast iron frame, a steel rotor and a gear motor. The cutting blades of the rotor and the powerful operating unit ensure the suitability of the device for handling challenging fuel types. The gap between the rotor blades and the frame is small making the equipment hermetically sealed.

Note! Dimensioning of the larger objects should be done on a case-by-case basis. Ash screws are dimensioned according to the type of boiler.

The firebox portion of the ash screws is manufactured from special fireproof steel.

Measurement of the burner screws, bio burners between 40 and 3000 kW (woodchips)

Bio burner type

Screw pipe diameter x wall thickness (mm) Screw diameter (mm) Margin (mm)
Burners 40 kW 139x4,51152x7,5
Burners 400 - 500 kW 193,71652x7,5
Burners 60 - 300 kW 159x51352x7,5
Burners MJ1000 - 1500 and step grates 1000 - 3000 kW 2x(193,7x5)1652x7,5
Burners MJ700 and step grates 700 kW 2x(159x5)1352x7,5