As the demand for an efficient form of renewable energy increases due to the ever decreasing volume of fossil fuels available, Biomass is now in the spotlight. Axair Fans Technical Product Engineer Andrew Ward explains the importance of industrial fan selection.
Biomass energy is produced using the matter contained in plants, typically including wood chips, trees, manure, sewage and mulch. Due to the nature of the matter harnessed, the energy is classed as renewable as it can be regrown and used again.
Biomass energy sources do not emit Co2 which means they limit the greenhouse effect by not polluting the atmosphere and rely on the lifecycle of nature to produce the matter needed to provide new fuels so it is a truly renewable energy resource. The method can by some, be seen as expensive due to the costs involved in growing living things. However, a huge advantage of using biomass energy is that it reduces the growing problem of landfill waste. By using waste products and turning them into energy the process reduces the dependency on fossil fuels and instead encourages using waste that would otherwise be added to landfills only adding to the problem. Therefore Biomass is a favourable energy production method in an energy conscious industry.
New technology to increase the efficiency of this plentiful resource is under constant development, clearly highlighting that Biomass plays an increasingly important role in a world that is running scarce of fossil fuels. Renewable energy sources, in particular Biomass, currently equate to around 10% of the world’s total energy requirement. So with a focus on green credentials and renewables, this figure can only look to increase. It’s definitely an area that should be concentrated on and in terms of environmental responsibility, a huge plus in any business’s future green strategy.
Axair are familiar with supplying industrial fans for use within renewable energy generation and offer a range of fans specially designed for use in Biomass fuel applications. These fans range from low to high pressure including those for materials handling and high temperatures. The simplest Biomass heaters burn chipped or palletised materials such as wood, straw and elephant grass and use low to medium pressure blowers to provide combustion air. The energy produced can be used to heat water or air and in the latter case, Axair can offer quiet, low pressure centrifugal fans for space heating in the BD range.
Biomass technology is safe, clean, reliable and sustainable, and as an example, a company spending £15,000 on heating can save up to 70% on heating and 50% on fuel costs. With such significant savings and energy reduction it’s clear why the spotlight is on renewable sources.
Many biofuel materials include logs, woodchip and wood pallets which utilise a state of the art drying process to enable them to increase the yield produced. The process begins when logs are sourced from regulated and well managed woodland areas across the UK, again ensuring the source is reliable and sustainable. These logs are chipped to enable them to be the required size. However, at this point they contain 60% moisture content. Drying happens by loading this woodchip into an air vented drying bin that has hot air blown on to it to force the woodchip to dry. This drying bin has a walking floor which moves the woodchip through the bin and onto the conveyor carrying the then 30% moist woodchip into a dry building. To achieve the drying of the sheer amount of woodchip is no easy task, but one that a heavy duty single inlet centrifugal fan with high performance, all steel backward curved impellers can achieve. The specific fans required must have IP55 environmental protection against dust and liquid ingress ensuring the fan is capable of handling small amounts of particles in the airstream given the nature of the application.
The moisture content of the biofuel woodchip is a crucial part of the energy generation and in ensuring that the biomass boiler runs efficiently and reliably. If the woodchip is too low in moisture it will burn too quickly while too much moisture will encourage the burner to cut out.
When handling materials, having a constant production and the focus on yield with zero downtimes in many Biofuel applications, there are a few things to consider when selecting industrial fans for use within biomass and biofuel generation.
Pressure:
If using an industrial fan for use in a heavy application, the fan selector must ensure that there is enough pressure generated by the fan to achieve the desired results. For example in wood chip applications, we must consider how much there is and how thick it may be. With the correct pressure, in this example, the woodchip can be dried effectively to pass on to the end user.
Type of Install:
When selecting the fan suitable, it is important to recognise the type of installation. Is the industrial fan to be installed directly into the equipment to produce or extract air? Using the example of a wood chip burner, an industrial fan may be attached to the machine to pump air and therefore increase the temperature. The right industrial fan will need to be chosen for the project.
Maintenance Programme:
If the life expectancy of the project is around 20 years, an effective maintenance programme is essential. It is important to know how often to maintain and check the industrial fan components in order to keep the equipment running smoothly and to its optimum performance.
Control:
Control is important because it can be set for the benefit of the application. In the instance of wood chip boilers, the fire could be blown out if it is too strong and would also lose the fire if not strong enough. Setting efficient control may also assist in achieving cost effective saving on energy consumption and can be done automatically saving time in the future.
Temperature:
If using heat exchangers, the temperature will be too hot for certain industrial fans. It is very common for high temperatures in biomass applications. Therefore the selected fan must be suitable for the application.
Volume of Air:
The right selection of air volume helps with the heat transfer in biomass applications. Too much and the heat cannot be felt, too little and there would be too much heat. Not only will the desired effect not be achieved but energy could be wasted in the process.
So why should we concentrate on Biomass as a renewable energy source, well, with the future of sustainable heating technology, the ability to maximise business returns and Government incentives on offer, what better time to jump on board?