Industrial fans in biomass applications
12 October 2017
As the demand for an efficient form of renewable energy increases, biomass is now very much in the spotlight. Axair Fans Sales Engineer Andrew Ward explains the importance of industrial fan selection.
Biomass energy is produced using matter from vegetation and waste, 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.
The method can 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. Biomass is a key energy production method in a world that is increasingly demanding sustainability.
New technology to increase the efficiency of this plentiful resource is under constant development. One important technology is industrial fans, ranging from low to high pressure which can be used in a number of separate areas within the biomass operation.
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, low pressure centrifugal fans are useful for space heating.
In biomass generation from wood, the process begins when logs are sourced from regulated woodland areas. These logs are turned into woodchips of the required size, but will at this point contain 60% moisture. The woodchips are then loaded into an air vented drying bin that has hot air blown through. The drying bin has a walking floor which moves the woodchip through the bin and onto the conveyor, carrying the now 30% moisture chips into a dry building.
To achieve this level of moisture removal a heavy duty single inlet centrifugal fan with high performance, all steel backward curved impellers can be used. These fans must have IP55 environmental protection against dust and liquid ingress due to the particles and vapour in the atmosphere.
The correct level of moisture in the woodchip is crucial to ensure the biomass boiler runs efficiently and reliably. If the woodchip is too low in moisture it will burn too quickly, while too much moisture could make the burner cut out.
In biofuel applications, there are a number of other important factors to consider when selecting industrial fans.
If using an industrial fan in a heavy application, the fan selector must ensure that there is enough pressure generated by the fan to achieve the desired result. 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, 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.
Typical life expectancy of biofuel projects might be around 20 years making an effective maintenance programme essential. It is important to know how often to check and maintain industrial fan components to keep the equipment running optimally.
Fan control is important because circumstances change. In the instance of woodchip boilers, the fire could be blown out if airflow is too strong, and it would not do the job if is not strong enough. Controlling airflow closely can also help achieve cost savings on energy consumption.
If using heat exchangers, the temperature will be too hot for certain industrial fans and high temperatures are common 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.
Biomass technology is safe, clean, reliable and sustainable, and with the right equipment, a company can save up to 70% on heating and 50% on fuel costs. With savings such as these, it is no surprise that companies in the sector are looking closely at new technology, and given their importance within the biomass generation process, the latest generation of industrial fans will have a key role to play.
Contact Details and Archive...