What Is a Dust Arrester?
A dust arrester is a device designed to remove not only dust particles but also algae, small fish, and similar debris from water, ensuring the provision of clean water. These devices are predominantly utilized in power plants and irrigation canals.
A dust arrester’s functionality extends beyond mere dust removal. It also conveys the extracted matter to a primary storage facility and separates water from it. Consequently, the system comprises multiple components, including screens, dust arresters, conveyors, storage units, and control equipment, each fulfilling a specific role.
Uses of Dust Arresters
Dust arresters play a crucial role in supplying dust-free water, particularly in thermal and nuclear power plants.
These power plants require substantial quantities of cooling water. Sea water, however, often contains various forms of debris like jellyfish, seaweed, and small fish, rendering it unsuitable for this purpose. Dust arresters, therefore, are installed at the water intakes of these plants to filter out such particles.
Principles of Dust Arresters
Dust arresters operate by employing a screen to trap dust and debris in the water. This trapped material is then collected by a dust collector, which is subsequently scooped up for removal. There are primarily two types of dust collectors: rake-type and net-type.
Rake-type dust collectors come in two variations: stationary and mobile. The stationary type is affixed to a single location, while the mobile type is mounted on a cart, allowing for movement. The mobile variety is more cost-effective but less efficient in movement, whereas the stationary type boasts a higher dust removal capacity.
Rakes in dust arresters are categorized into rotary and reciprocating types, based on their movement. In the rotary type, the rake moves upstream or downstream of the screen, lifting the trapped dust as it ascends. Conversely, the reciprocating type descends in front of the screen and rises along its surface, effectively collecting dust. Large-scale equipment typically employs wire rope-driven reciprocating rakes, while smaller equipment uses a chain rack mechanism.
Net-type dust collectors are available in dual-flow and straight-flow designs. The straight-flow model poses a risk of downstream dust spillage during cleaning, a problem that dual-flow models do not encounter.