Centrifugal Fans In Industrial Ventilation

An Industrial building is often a closed building. We want an environment inside the building to be comfortable. There are various types of industrial processes going inside the industrial building. These different processes can make the temperature inside the building higher. This extra heat has to be vented out of the building using an external equipments like fans, louvres, gravity vents, heaters.

Industrial ventilation differs from the air conditioning. It pushes outside air to ventilate interiors of the building. Most of the industrial buildings are insulated from outside to maintain operational efficiency. In this scenario the best thing that can be done is to bring the temperature inside the building close to the temperature outside the building. Air conditioning is far more expensive than the general ventilation. Air conditioning requires condensers which is a type of induction motor and it consumes lot of power to run. Low cost of industrial ventilation makes it lucrative to managers and plant owners.

The four common methods of industrial ventilation

Powered forced supply/ Powered forced exhaust
As the name connotes supply fans and exhaust fans, both are motorized. The advantage of having both the fans motorized is that the airflow in and out is always regulated. The rate of ventilation doesn’t depend on external parameters like type of building, outside temperature and shear of wind etc.

Powered forced supply/ Natural exhaust
In this ventilation system supply fans are motorized and exhaust fans are natural vents (gravity vents). The natural exhaust vents are mounted in the roofs and takes a shape of hood ventilator. The type of vent generally depends on conditions which helps in maintaining a low pressure of air and allows maximum volume of air to move. Special care has to be taken to design ventilation so that rate of air flow doesn’t depend on external factors like wind, temperature difference and dimensions of the building. It is cheaper than Powered forced supply/Powered forced exhaust.

Natural supply/ Powered forced exhaust
Powered forced exhaust fan creates a low pressure condition inside the building. As we know the movement of air is from high pressure to low pressure, the air outside the building moves inside the building through any vent on the building. The ventilation system is accepted if the low pressure inside the building is acceptable. In this system also rate of air exchange is independent of external factors like wind and dimensions of the building.

Natural supply/ Natural Exhaust
This works on natural phenomenon that warm air becomes lighter and moves upwards creating an area of low pressure. To fill this area of low pressure cooler air rushes in. For this phenomenon to occur in our building we have to provide vents on the side of the building and vents on roof of the building. For this system to work effectively we need to have tall building, there should be significant temperature difference and dimension and shapes of the vents should be designed properly.

Centrifugal fans in ventilation
Centrifugal fans appear like a squirrel cage. In a centrifugal fan the direction of flow of air is at 90 degrees to the shaft. Since these fans are capable of displacing constant volume of air or gas at increased speed, they are widely used in industrial ventilation and application processing. They are common in chemical processing plants and big industrial complexes. Industrial ventilation takes into consideration the type of building, floor area of the building, building height and work flow process. It also depends on the outside summer and winter temperatures.

Benefits
Having good ventilation using centrifugal fans can prevent people from diseases. People working in different industries are exposed to different environment which makes them prone to hazardous diseases. Adopting a good ventilation system using centrifugal fans prevent such adverse environment being created inside the industry.

1. Pharmaceutical industry
When dealing with chemical optimum supply of oxygen is required. Moreover temperature and relative humidity should not spoil the product during the manufacturing or storage. A good ventilation makes sure the abundance of oxygen and the quality of the product.

2. Cement industry
The cement industry suffers from dust pollution. Occupational hazards include respiratory ailments. In addition to dust there are chemicals like gypsum, calcium oxides and aluminium silicate. The industry also requires cooling effect because high temperature is caused due to the presence of kiln. Ventilation provides double benefits of removing dust and maintaining ambient temperature.

3. Iron and steel industry
This industry is characterised by high temperature because of heating processes. Small metal particles also get into the environment. This in turn may cause respiratory problems. Ventilation removes this heat from the chambers of industry and small metal particles are also removed.

4. Glass manufacturing industry
Glass industry makes use of heat to manufacture and mould glass. In this process lots of fumes are generated. So, it becomes indispensable to remove the heat and fumes by having proper ventilation.