Which Fans are Applied in the Burner Industry?
The burner industry dates back to the industrial revolution of the 1700s, a time that can be described as the transition into a more technology-driven society. While these technologies are incomparable to the ones, we know today, this point in history has paved the way for all of these innovations to even come into existence. And their main goal was simple: to help people do and finish tasks easier, faster, and cheaper.
One of the innovations that gave rise to the industrial revolution was the coke fueled furnace. With growing opportunities to create more efficient manufacturing processes, inventions like this have influenced the use of other sources of energy to translate them into electrical or mechanical outputs. Back in the day, workers found themselves abundant with coal and used that as their main source of non-renewable resources that they could convert into energy.The more energy they needed, the more coal they harvested, and the more they realized that they needed to burn faster, continuously, consistently, and on a larger scale. They shortly found that coke – the residue left when charcoal is burnt in pits – combusted better to fuel furnaces with less impurities. Coke is achieved without the presence of air, as moisture, sulfur, ash, and tar should achieve certain content levels. It is close to pure carbon, so it can be compared to charcoal.
These burning methods were applied, most notably, when the first steam engines were built. Blast furnaces and gas combustion systems powered by these components grew in number and eventually, uses for this type of burner found its place in many processes across various industries worldwide.
This type of ingenuity isn’t new, but it plays around with the simple concept of combustion.
Importance of Fans in the Burner Industry
In a nutshell, gas combustion systems are supported by three basic components: a burning substance (the fuel), a form of gas oxygen, and a heat source.
Combustion is a chemical reaction that happens when a heat source comes into contact with a burning substance, which is then ignited by the oxygen in the air. Hence, the quality of air is a vital factor in the process of combustion.
Ever wonder why people blow onto coal to kickstart a fire? It’s because of that chemical reaction between fire and air, which contains enough oxygen to create and ignite the fire.
Fans were required to regulate this combustion and ensure that a high fuel efficiency is maintained. High fuel efficiency is measured by how much energy is created, with respect to how much is burned off or lost during the process. These combustion systems are known to be extremely versatile and have general applications in industries that support heating elements. Examples include furnaces, steamers, boilers, distilleries, and chemical processing.
However, let’s tackle the most common application of industrial burners: in the boiler room system. In a boiler room, you can observe that the process is centered on the fans. Definitely, a good heat source is a key component in any process heating system, but the system’s efficiency is also elevated by the uses of fans, because these fans are what control the air pressure inside.
Boiler Room Systems
Boiler systems, simply put, enable the conversion of water into steam energy, which is the backbone of thermal power plants or any process that requires constant and consistent heating.
How does a boiler room system convert this energy? Within that phase change, water, in the form of vapor, holds more volume and expands 1,600 times more than in its liquid state.
Boiler systems begin with feed water, which is what passes through the boiler system and gets converted to steam or heat. The same logic applies to steam engines as it also changes into water.
Feed water is heated through the boiler tubes, and in water-tube boiler systems, it is done so externally. That means the feed water circulates in tubes and is heated from an external furnace.
Fuel-heated boilers need to have enough air circulating to fuel the combustion process. Back then, they made use of the natural convection process with the help of chimneys. Chimneys do not only expel flue gases out, but they are also able to pull in fresh air. This can happen because flue gases are less dense compared to the air outside after they are heated.
This presented opportunities for more innovations to recreate this same condition. Now, large-scale industries mechanically force or induce the draught, forcing more air into the furnace, enabling heat transfer. The rate at which the air travels can also be monitored and optimized, as the heat transfer into boiler tubes is directly correlated to the current of the air movement (the draft) and rate of combustion.
In the boiler steam system, industrial fans should be able to do the following:
- Maintain air flow within the system
- Recirculate air flow
- Remove exhaust gases
With this in mind, let’s talk about which particular industrial fans cater to these requirements.
Fans Used in Boiler Rooms and in Burner Industries
Forced Draft Fans
Forced draft fans are able to push ambient air through industrial boiler systems and furnaces. This forced draft leverages on the creation of positive air pressure, which is a higher pressure found inside the containment area, compared to the atmospheric pressure outside.
As a result, these particular fans used in this application are backward-curved centrifugal fans or airfoil centrifugal fans. These fans are built to deliver the required airflow to create complete combustion. Thus, the fan types and blades selected will greatly impact on a boiler system’s efficiency rate.
In some boiler systems, burners can already preheat the air to increase efficiency. This process is then aided by forced draft fans, which can redirect a consistent airflow towards the vents to deliver even heated air through.
Induced Draft Fans
These types of fans are the opposite of forced draft fans, because it produces the negative pressure required to draw in air, instead of pushing the air out. These induced draft fans are positioned downstream between the dust collection system and the chimneys. During the combustion process, toxic gases are released. These induced draft fans prevent the exhaust gases from spreading in the air.
Ambient air is collected and redirected back into the production process, just like chimneys or flue stacks. However, with the usage of induced draft fans, optimum pressure is redirected instead of following the natural draft conditions.
For these functions, radial fans or backward-inclined centrifugal fans are usually used. It goes without saying that the industrial fans selected for this purpose should always meet the material specifications (stainless steel, aluminum), as flue gases are highly corrosive.
Should we consider whether one type is better than the other? Not really, since both fans are usually known to work in tandem with each other in a boiler system. The push provided by the forced draft creates the necessary to redirect heated air through the boiler system.
Key Considerations in the Selection Process
When it comes to a boiler room system, its operational capacity is directly correlated to how much heat is demanded to supply a process. However, it also needs to be viewed in terms of 3 other things: impact to the production, its output, and even the environment which it borrows all of these resources from.
Below, we talk about in more details what considerations have to be made in selecting the right fan for the job, as well as how each fan fits within the complete manufacturing process.
Efficiency – When it comes to thermal efficiency, the greater the temperature of the heat source usually means the more efficient a certain process cycle is, too. Efficiency is driven by the consistency in energy conversion and the ability to yield less waste. However, this is tempered by structural limitations that one must work within.
Design – Process design should consider the fan placements in each step of the production, making it fit and operationally efficient. Backward incline or curved, or induced draft or forced? When choosing a fan, you should always consider its role in your system, how well it will fit, if it’s structurally sound, operationally efficient, and easy to maintain.
Material – Select wear-resistant industrial fans are built with materials like carbon steel to withstand the harsh environment inside boiler rooms. This is a must because many of these fans have to deal with extremely high temperatures and toxic gases on a daily basis.
Environmental Impact – The combustion process is known to unavoidably emit a lot of flue gases and toxic chemicals into the atmosphere. However, to promote a safe, healthy, and sustainable working environment and world, the key is to ensure that this is minimized in all possible ways, perhaps with the help of a dust filtration system.
Boilers are able to serve their vital purpose in power generation through the simple but powerful process of combustion, as well as the capability of water to evolve into different phases. This is why boilers are crucial within the food industry, residential homes, cargo ships, and other various industrial heating applications.
The burner industry continues to lend a hand in so many processes, growing even more vital in supporting the many different industries around the globe. Over time, you can see how much innovation has grown, producing all sorts of inventions and technologies the make life easier, safer, more efficient, and more convenient for humanity.