The words ‘blower’ and ‘exhauster’ are often used interchange-ably, but they are slightly different. Blowers usually produce higher pressure than exhausters, so they’re used where more energy output is required. Blowers and exhausters have a variety of functions, such as running the heating and cooling systems in HVAC equipment. Here are a few more uses.
Dewatering construction and mining sites
Sludge dewatering systems are an essential part of any construction operation. Sometimes, while excavating the foundation of a building, the water table is exposed, releasing massive amounts of water. Other times, water is deliberately poured onto the site to cure the concrete base of the foundation. This wastewater can’t just be released into the sewers, since it contains sand, soil, silt, mineral salts, and construction materials that could clog the system.
The wastewater is therefore passed through a sludge dewatering system to separate the solids into a cake and make the water safe for re-use. Blowers and exhausters are used to create a vacuum beneath the filtration membrane, pulling down the water and leaving silt and substrate on the surface. Blowers are also used to dry the solid waste into a disposable cake. The same process is used to filter wastewater after rinsing metal ore and rock quarry products.
There are lots of different situations where the movement of air is crucial. We have already mentioned heat distribution in domestic and commercial air conditioning systems. Exhausters and blowers can be used manually or they can be automated in the form of a thermostat. External ventilation is a common application as well.
Examples of the use of blowers and exhausters outdoors includes the reduction of air pollution at landfills. Smelly, potentially toxic emissions are sucked out and disposed in a safer way. In underground mines, coal shafts, and quarries, blowers are used to extract methane and increase oxygen levels. It’s an essential part of mining and prevents miners from suffocating. Exhausters are equally helpful for extracting vapour from soil deposits.
Food and beverage applications
Blowers and exhausters are a key component of filtration systems in the food and beverage industries. Spinning centrifugal filters are used to separate edible wastewater filled with items like fruit pulp or vegetable starch. The equipment is utilised in canning factories, wineries, and snack packers. Potato factories apply exhausters and blowers in the early stages of production when they wash, peel, and slice, and rinse potatoes.
Blowers can also be used in the fermentation stage of alcohol production, to dry out the barley, hops, and other grains as they are extracted from the spirits and beer. Centrifuges divide the liquid from the floating solids. Blowers are sometimes applied to the top of a centrifugal vat, to blow the surface foam and debris into a dedicated chamber where it can be further dried using an exhauster and a filtration media.
From cooling heated metal and filtering coolant fluid to drying sheets of powder coated spikes, roofs, or construction panels, blowers and exhausters are involved. Roofing products like Zincalume and Colorbond, as well as galvanised balustrades and fencing materials are all treated with multiple layers of film. From the primer that coats the surface to the ultra violet protectant, each stage must be applied, baked on high heat, and then dried completely before another coat is applied.
Blowers and exhausters dry the layers more evenly than air or sun-drying. The controlled action of an exhauster or blower also gives a well-timed effect that prevents the coating from scratching or drying. On a much smaller scale, blowers can be used to clean out the components of computers, heaters, or even car interiors.
Centrifugal technology is used in unlikely areas as well. Blenders, vacuum cleaners, and hand mixers all use centrifuges to spin their blades. They often have tiny fans inside them to cool down the overheating parts as well, and while they’re not industrial blowers, they’re miniatures based on the same technology, so technically, they’re in the same family.
Blowers and centrifugal exhausters are two commercial devices are often taken for granted, but as we can see, there’s a lot to be said for blowing hot (and cold) air, and there’s so much that can’t be done without these massive powerhouse fans.