01Wood chips · up to
Spring agitator
The spring arms rotate across the floor and sweep the wood chips in towards the screw. The standard solution for Multiauto.
180m³
View the spring agitatorFuel stores for wood chips and pellets
Fuel stores
11–500m³Store volume, from silo to scraper floor
A fuel store is built to suit the site, the fuel and how you want to fill it. Besides PelleTech's solutions, we also manufacture a range of different stores in-house.
01The stores
Five ways tostore the fuel.
From a pellet silo to a scraper-floor store for 500 m³ of wood chips. We choose the store together with you, based on your conditions on site.
The store is planned together with the boiler. Wood chip boilers from 20 kW to 4.6 MW
02Wood chips · up to
Scraper-floor store
Hydraulic scrapers push the wood chips forward to a cross screw – for the large volumes.
500m³
View the scraper-floor store03Built-in store
Heating plant
Boiler room and fuel store in the same building, manufactured in-house.
200 kW–2 MW
View the heating plantsAs required
View the carport11–185m³
View the silo02Why a store
Why havea fuel store?
The store is what makes the heating fully automatic. The fuel stays dry and goes into the boiler by itself.
The boiler feeds itself
A screw carries the fuel from the store, through a tight rotary valve and into the burner – fully automatically.
Refill rarely
A 500 m³ scraper-floor store holds roughly a year's wood chips for a 250 kW boiler.
Dry fuel gives more heat
Wetter chips mean lower output and higher consumption. In the store the fuel stays dry, under a roof.
Burn what is cheapest
With your own store you choose the fuel yourselves – and wood chips are one of the cheapest ways to heat.
03Guidance
Which storeshould you choose?
Answer three questions and we'll show you where to start. The store is always decided together with you, based on conditions on site.
Not sure? We calculate the store and the rest of the plant – the heat-load calculation is free of charge.
Our suggestion
Spring agitator
up to180m³
The spring arms rotate over the floor of the store and bring the chips to the screw. Standard with Multiauto.
- Diameter
- Up to 6 m
- Support floor
- Not needed
Our suggestion
Scraper-floor store
up to500m³
Wedge-shaped scrapers driven back and forth by hydraulics bring the chips to a cross screw.
- Drive
- Hydraulic
- Fuel
- Wood chips
Our suggestion
Carport
tosuit
A store with a steel frame and roof, where the chips stay dry.
- Frame
- Steel, with roof
- Fuel
- Wood chips
Our suggestion
Silo
11–185m³
Galvanised steel. Filled straight from the bulk truck – the pellets are blown up to the cyclone on the roof.
- Bottom
- Conical
- Filling
- From the bulk truck
Our suggestion
Heating plant
storebuilt-in
Boiler room and fuel store in the same building – for wood chips or pellets.
- Output
- 200 kW–2 MW
- Store
- Under the same roof
04Feed system
From the storeinto the burner.
A screw carries the fuel from the store, through a tight rotary valve, and the stoker screw feeds it into the burner.
- 01
The feed screw
The spring arms bring the chips to the screw, which carries them on from the store towards the boiler.
Screws up to 180 mm in industrial boilers
- 02
The rotary valve
The fuel drops through the tight rotary valve – fully sealed and safe against burn-back.
With a sprinkler, required in Sweden
- 03
The stoker screw
The stoker screw feeds the fuel into the burner, evenly and in step with the heat demand.
Wood chips of size G50+
Larger chip sizes call for larger screws – industrial boilers have feed screws of up to 180 mm. Burn-back protection comes from the tight rotary valve together with a sprinkler, which is required in Sweden. Pellets can also be drawn by a vacuum system from a store some distance away – up to 20 m for Multiauto.
- Filling
- From above, from the side or via a pipe
- Feed system
- By screw or vacuum to the boiler
- Wood chips
- G50+, larger chip sizes with larger screws
05Sizing
How much fueldo you need?
The rule of thumb: wood chips in cubic metres per year come to roughly twice the boiler output in kilowatts, and up to three times with poorer chips. For pellets, divide the chip volume by 3.9.
Enter the output, 10–2,000 kW, or choose a row in the table.
| Boiler output | Chips per year, approx. | Pellets per year, approx. |
|---|---|---|
| 100 m³ | 26 m³ | |
| 200 m³ | 51 m³ | |
| 400 m³ | 103 m³ | |
| 1,000 m³ | 256 m³ |
200m³of wood chips a year
With poorer chips, up to 300 m³Pellets 51 m³ a year
Annual demand against store sizes
Chips
Pellets
Spring agitator 180
Scraper floor 500
Silo 11–185
0600 m³
Example: a 500 m³ scraper-floor store holds roughly one year's wood chips for a 250 kW boiler. A worked example based on the rule of thumb – actual consumption depends on the quality and moisture content of the fuel and on how the plant is used. We calculate the figures for your plant in the needs analysis.
The brochure
All our fuel stores in one brochure.
PDF · 12 pages · 2.0 MB
Free heat-load calculation
Let's calculate your heating.
Tell us about the site, the fuel and how you want to fill the store, and we will calculate the store and the rest of the plant – the heat-load calculation is free of charge.
info@biothermheat.comVästerås · Luleå