Accessories Used in Centrifugal Fans
The important reason for using accessories in centrifugal fans is to reduce the level of sound produced while working and protect the parts from weather if they are exposed outside. The main noise in the centrifugal fans is due to the vibrations caused in the equipment. Hence, there is a necessity to regulate these vibrations in order to reduce the sound level. For controlling vibrations in centrifugal fans, vibrator isolators are used. It is important to note that the accessories used in the industries must meet the safety of government norms.
Given below are some of the accessories used in centrifugal fans -
Centrifugal fans contain many electrical systems such as electric motors and wiring that may get damaged in bad weather conditions. They must be kept completely weather-proof to avoid destruction by corrosion. Hence, weather-hoods are used to protect motor and drive components from weather conditions like moisture, dust, dirt, rain, snow etc.
In fans the main source of mechanical energy is transferred by belt drive. Apart from providing protection, belt guards have importance while servicing the belts and pulleys. Belt guards have two openings, one to fix tachometer for monitoring fan speed and another for testing belt tension.
Shaft guards are designed to cover bearings on arrangements. Shaft guards are provided with extended lubrication lines to lubricate the bearings without removal of the guard.
Inlet and outlet guards:
In non-ducted installations, removable inlet and outlet guards provide protection for equipment as well as the individuals working in the industry.
Inlet and outlet flanges:
Flanges are required for attaching inlet bells, inlet boxes, guards and control dampers. Flanges are present in two types either punched flanges or un-punched flanges.
In centrifugal fans air changes its direction twice once during the inlet and the other while exiting. During the process of entry and exit, air loses its energy due to friction and bend. So, inlet boxes are used to minimize the entry losses when there is a shift in direction of air. After the air is let into the impeller, it changes the air direction with its rotation and comes out with less energy.
Access doors provide quick access for cleaning or inspection. Access doors are usually bolted or equipped with quick opening arrangement.
Shaft seals are provided for exhausting contaminated air. Shaft seals are made of neoprene to sustain high temperatures. Shaft seals are important as the shaft is exposed to conditions which are exposed by impeller.
Vibrations in fan are produced due to imbalance and air-flow. These vibrations produce lot of noise in fans. The sounds produced by vibrations can be controlled by using vibration isolators. The isolators are placed on top of the structural bases to reduce the transmitted vibrations which eventually control the sounds produced. Similarly, some sounds are made due do to the capacity of the motor used. Sound silencers find great application in restricting these noises produced by the motors. There can be other sounds that are made due to motion of air and its travel inside the system. Usage of dampers will reduce these sounds as they help to regulate the air-flow inside the system.
Accessories used in fans will help to increase the performance and durability of the system. Fans may also contain additional accessories depending on the industrial needs.
Reitz India, manufacturer of centrifugal fans and blowers is committed to provide tailor-made solutions to various industrial processes and air pollution control systems in India and other neighboring countries. Reitz India centrifugal fans find wide applications in pollution control, ventilation, dust collection, fume extraction, ID, FD and PA fans in boilers and furnaces etc.