Large CFB Boiler Industrial Cyclone Separator With High Speed Rotating Air Flow industrial smoke filter

CYCLONE SEPARATOR WORKING PRINCIPLE

1. In a conical system, as the rotating flow moves towards the narrow end of the cyclone, the rotational radius of the stream is reduced, thus separating the smaller particles. The cyclone geometry, together with flow rate, defines the cut point of the cyclone. Particles larger than the cut point will be removed with a greater efficiency and smaller particles with a lower efficiency.

2. There is an alternative cyclone design which uses a secondary air flow within the cyclone to avoid the collected particles from striking the walls, which helps to protect from abrasion. The primary air flow with the particulates enters from the bottom of the cyclone and is forced into spiral rotation by stationary spinner vanes.

Abstract

1. Cyclones are the most common dust-removal systems used in combined cycle fluidized bed combustion boilers. Analysis of a cyclone separator combining flow and structural aspects is carried out using detailed three dimensional finite element modeling including stiffeners and supporting arrangement. The fluid flow study involves the solution of continuity, energy and Navier-Stokes equations.

2. The fluid analysis gives the variation of pressure on cyclone shell, which in turn is imparted on the structural model using fluid structure interface routine. The pressure distribution obtained from the fluid-flow analysis is mapped on to the structure. Then a linear static analysis is performed considering thermal, wind and seismic loads besides the pressure loads. The results for various loads include the reaction forces at the supports and stress levels in the cyclone. The stresses are checked against the allowable values as per Indian Standard Structural Codes.

3. A separate computer code is developed and is interfaced with the FEM program. Results indicate higher stresses in some of the beam stiffeners and at support locations. These are suitably modified and a reanalysis confirmed the stresses to be within limits. The analysis methodology combining the fluid, structure and code requirement developed shall be very useful for the design improvement and safe operation of a cyclone separator.