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Long Life-Span Comes As Standard

Clare Hollister

Chris Franklin MD at Ranheat Engineering Ltd.  a leading UK manufacturer of wood combustion equipment-continues his series of articles for Panel and Joinery Production. This issue he looks at the long lifespan of Ranheat warm air heaters.

The renawable heat Incentive, (RHI) was a Government scheme that paid money to the operator of a Biomass burning plant for 20 years to encourage the use of renewable energy.

However it was only applicable to boilers and not to warm air heaters. As with many Government schemes this skewed the market with people choosing a more expensive water based heating system over a simple warm air system.

Ranheat WA 150 industrial wood-waste heater, 150 kW output with Bag Loader, after 17 years of operation.

Now the RHI has stopped for new applicants, more and more users are again choosing a warm air system. The government argued that a warm air system would not last the 20 years that the scheme was set to run.  This is not the case. The design life of a boiler or heater is the same. What does affect the lifespan is what is used as a fuel.

Natural timber contains no ”nasties” however some wood based products once processed can contain compounds that can be corrosive to boilers and heaters. The main culpret is PVC. Some people still use PVC in their manufacturing process mainly in the form of PVC edgebanding. When PVC is burnt it combines with the water in the boards and produces hydrochloric acid,  HCl.

So what about other conventional fuels? Coal was widly used but contained large amounts of Sulphur. Heating oil also cointains sulphur. Natural gas is less polluting but is a finite resource.

But what about Greenhouse gasses? By using wood as a fuel when trees grow they absorb Carbon Dioxide conventional fossil fuels do not have this ability.

Ranheat “Bag-loader for feeding warm air heaters.

Ranheats range of warm air heaters make an affordable soloution to even the smallest of joinery companies. To be able to control emmissions the plant needs to be automatically controlled. Hand loading of offcuts is time consuming and labour intensive far better to use a small granulator to process the offcuts and then mix with other extracted material fom woodworking machinery.

Most small sites have a bag based extraction system this can be a small 2 , 3, 4, 5or 6 bag unit. To safely use this extracted material Ranheat invented the “bag-loader”

The Bag-loader consists of a central auger and two agitator arms driven by a simple low kW electric motor. The bag-loader is for use with warm air heaters only and is not suitable for boilers. The reason is the Ranheat Warm Air heaters are fitted with a continuously running Induced Draught Fan or chimney fan. There are also two combustion air fans one for primary air and one for secondary air. The I/D fan and the secondary air fan run continuously with the primary air fan switching on and off with flue temperature.

This control over the combustion process gives the smaller Ranheat Warm air heaters a high degree of control when compared to a hand loaded heater which is more dependent on the operator and the frequency of loading. A lot of other makes of warm air heater do not have an I/D fan as they run at high flue temperatures (400oC) where a Ranheat Warm air heater has a multi-tube heat exchanger which ensures low flue temperatures Typically 160-180oC. This means more heat into the workspace and less heat up the chimney.

Ranheat also make spares and service and repair other makes of woodburning boilers and heaters.

T: 01604 750005 

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