The days of the industrial workplace being one of choking, pollutant laden air are, thankfully long gone. Manufacturing and materials processing companies now strive to provide a clean and healthy environment in which to work. These improvements come partly through legal compliance and partly due to our environmental awareness.
Material processing and manufacturing across the globe is as varied as the world itself. There are a plethora of problems facing industry in keeping high standards of air quality in the workplace. The ventilation of industrial spaces and the extraction of a multitude of airborne pollutants is a challenge with no one single remedy.
From Aggregates to oil and gas, steel, glass and ceramics, food, shipping and agriculture, there is virtually no industry that does not require ventilation or extraction. Thankfully there are specialists in the field that can solve the problems that any company may face in their drive for a clean and safe working environment.
The answer to each problem is individually specific, as such, the ventilation and extraction required must be assessed on a case by case basis. This will ensure the installation of the correct units to combat the challenge of each and every air purity problem.
With such a broad based challenge numerous differing ventilation and extraction units are available and it’s important to know the optimum usage for each one. Most commonly fans are of either centrifugal or axial design.
These are sometimes referred to as radial fans. With the centrifugal fan, at entry the flow is primarily axial, it is then changed to be mainly radial at the point of impeller exit. Centrifugal fans are used in environments where there are high levels of contamination of high temperature air or gas. These fan tend to be house in a volute casing allowing directional flow or connection to a ducting system.
There are two main variations of these fans, the tubular centrifugal fan and the centrifugal plug fan. The tubular centrifugal fan has the impeller inside a cylindrical housing which captures and directs the flow in an axial direction. With the centrifugal plug fan impeller is not enclosed by any housing. Units of this type are commonly used at plants in industrial areas such as the steel, cement, thermal power and chemical industries.
With an axial flow fan, the flow through the impeller is primarily parallel to the axis of the impeller rotation. The impeller has a close housing with blades drawing air from a process and expelling the air along the same axis. Axil fans use a low level of power and yet produce high flow rates. There are numerous variations of the axial fan.
Fixed Pitch Axial Fan
With a fixed pitch axial fan, the blades of the fan are attached to the impeller hub to a fixed angle of pitch. The angle of pitch cannot be altered.
Variable Pitch Axial Fan
The variable pitch fan allows the fan blades angle of pitch to be altered. The altering of the pitch changes each blade simultaneously, maintaining universal efficiency. The changing of pitch can be carried out while the fan is in operation.
Adjustable Pitch Axial Fan
With the adjustable pitch fan, the blades can be altered when the impeller is in a stationary position. Each blade has clamping bolts which, when slackened, allows each blade to be adjusted by hand to the desired angle of pitch.
The vanexial fan is an axial fan with flow guide vanes at the inlet, at its point of discharge, or at both. This straightens the directional flow which greatly improves efficiency. These tend to be used in medium flow environments and are capable of operating at high pressure. The general opinion is that these are the most efficient of all the axial fans
For simple industrial usage, tubeaxial fans are the ideal option. Basically, they are axial fans without the flow vanes and offer good air flow efficiency. Uses included toxic fume exhausting and drying ovens.
This is an axial flow fan with a propeller type impeller. The impeller is mounted within an orifice plate. They are capable of handling a large flow volume at low pressure with low to moderate temperatures.
With numerous fan designs it is important to have expert assessment of the work place to ascertain requirements and ensure the correct unit is installed which is applicable to each individual process and situation.
Visit Ferrari Asia Ventilation for more information about industrial ventilation and exhaust fans.