Bulk Pellet Storage
A bulk pellet store installed outdoors
There are many issues that have to be dealt with when using bulk pellet storage: Condensation, the strength of the store, earthing the store and much more.
Some of the basic considerations are as follows:
The store must:
- Be waterproof
- Be strong enough to hold 3-4 tonnes of pellets
- Contain the correct fittings for the delivery lorry
- Contain a breaker mat to prevent pellet damage during filling
- Be Earthed
Store components and features
Every pellet store must have some essential features. These are described as follows:
A camlock fitting is an essential component for a self built pellet store. The fitting is required for the delivery of wood pellets and is designed to be compatible with the hoses used by Irish pellet delivery companies.
A vent pipe is essential to reduce dust build up inside the pellet store on delivery. It must be used in conjunction with a filter sock and an earthing clip to ensure the safety of a self built pellet store.
A rubber breaker mat is essential to ensure that pellets are not damaged on delivery and remain intact while the store is filled.
A filter sock is used during pellet filling to minimise dust transfer into the wood pellet store.
An earth clip is designed to fit the pellet inlet pipe. It is an essential safety component of any self-built pellet store. It prevents the buildup of static electricity during filling and MUST be used in conjunction with dust filters and a vent pipe to ensure there is no possibility of a dust explosion.
The cone is the most essential part of a pellet store. It is needed to ensure that pellets fall down a slope to the point they are extracted from the store. This is essential if you are using an auger to feed your boiler from the bulk store as it ensures that every pellet in the store will drop into the auger.
Pellet access gate (Optional)
A pellet access gate can be a useful part of a pellet store as you can remove pellets in small quantities manually. This is useful where the user wants to feed the boiler manually or where a pellet stove has also been installed.
Self build store or ready made?
It is possible to either build a store yourself or purchase a ready made one. The advantages of building your own store is that it generally costs less and can be better customised to fit the space you have available. However, a ready made store is a great time saver and can also be very cost effective.
Option A: Self build storage
We offer a range of fittings, filling pipes, vent pipes, breaker mats and pellet cones that allow you to build your own storage.
However, there are also several other important considerations when building your own store.
Points to consider when building your storage unit are:
- The storage unit needs to be of sufficient strength to hold 4 tonnes of pellets as the minimum delivery is normally 3 tonnes.
- The storage unit needs to be accessible for filling and should be with 20m of where the delivery truck can park. The delivery pipe cannot be taken through a domestic household for Health and Safety reasons.
- It must be built specifically for the storage of wood pellets with suitable materials and insulated to prevent condensation. It must be sufficiently vented and waterproofed.
- There must be an appropriate air outlet (unless made from cloth) and have suitable fittings for connection of the delivery hose.
- The end of the camlock fitting must be within the drivers reach. The actual point where pellets enter the storage unit must be high enough to enable the pellets to fill evenly within the store.
- If there is a bend in the inlet pipe, it is recommended that this is a soft bend, not a 90 degree angle which will cause damage to pellets during delivery. The delivery pipe on the storage unit must be made from metal and must be earthed. Static electricity can build up on plastic piping and is a fire hazard.
- It is recommended that the storage unit has a flexible rubber sheet hanging opposite the inlet pipe. This will stop pellet damage during delivery. It is essential that pellets are not blown against a wall or hard floor.
- The inside of the storage unit needs to be free from electrical sockets, electrical switches, lights and electrical fittings. This is to prevent a dust explosion.
- The storage Unit should not be positioned where it would result in a fire risk. It is recommended that storage unit has a sight glass/inspection hatch to monitor volume and to indicate to customer when to re-order.
- The floors of the storage unit should have a slope of at least 40° going towards the feed mechanism.
- The storage should be lined with a suitable material (e.g. wood)
As 1m3 of storage space will hold about 600kg of pellets, the store needs to have a minimum usable volume of about 6.5m3. A rectangular shaped space is best for the store. About 2/3 of the space will be usable volume – This means the space needs to have an overall volume of about 10m3 minimum.
- Use a Rectangular Shape
- Minimum space needed is about 10m3
- 6.5m3 is usable when the volume of the sloped floor is subtracted
- This gives enough space for 4 tonnes
- Place Filling and Ventilation connectors on the narrow side walls
- The internal surfaces must be smooth to allow free flow of the pellets
Examples of self build storage
Above: Example 1 using 2.5m auger. 3000mm x 1500mm. Volume approx 7.2m3
Above: Example 2 using 2.5m auger. 1600mm x 2400mm. Volume approx 6.6m3
Above: Example 3 using 1.5m auger. 2000mm x 2000mm. Volume approx 6.6m3
Further information on self build components
For full details of the components we sell for building your own store (including lower cost kits) please visit the Self Build Pellet Storage product group here: http://www.rvr.ie/default.aspx?subj=catalog/ProductsList&catIdPath=0_186_204_211
Option B: Ready Made Storage
We offer a range of ready made stores designed specifically for pellet storage. These stores contain all the components required and need only be assembled.
Biobin outdoor stores
These stores are made from fibreglass and come with free assembly on site. They are also available as a very attractive wood cladded version. Augers are not included in the price of these stores but may be purchased seperately.
Metal outdoor store
An aluzinc metal store is quickly assembled and comes complete with a 6 metre flexible auger.
Cloth indoor store
A cloth indoor store offers a very low cost bulk storage method. It simply needs a frame to be assembled and then a large "Bag" is hung which stores the pellets. This type of store comes with a 3 metre auger included.
Further information on ready made storage
For full details of the ready made stores we sell please visit the Ready made storage product group here: http://www.rvr.ie/default.aspx?subj=catalog/ProductsList&catIdPath=0_186_204_202
Augers and transfer methods
Above: The main method used to transfer pellets is a mechanical auger. This takes the form of a large screw inside a plastic tube. As the screw turns, it conveys the pellets up the screw to the top of the tube.
Above is an image of a 100 litre store attached to a pellet boiler. The 100 litre store contains an auger (which is marked with the red dots) which reaches down to the bottom of the store.
When the boiler needs more pellets, it turns the auger.
- The screw raises the pellets up to the top of the auger
- The pellets drop into the burner
In the situation where a bulk store is beside the boiler, the uger simply draws from the bottom of the bulk store instead.