Investigation Of Cleaning Mechanism And Cleaning System Design Method Of Rotary Reverse Bag House

Rotary reverse bag house is widely applied because of the advantages of good collection efficiency and simple structure. It is well known that dust cleaning efficiency is a key technology to ensure the good running of the baghouse. However, at present, the theoretical and experimental research about the reverse flow cleaning mechanism is little. There was no complete theoretical research which can guide the design of the cleaning system. Therefore, the investigation on air flow inside of the bag house, to determine cleaning system design relevant parameters, such as cleaning load, reverse discharge, reverse flow pressure and critical slenderness ratio of the filter bag aspect ratio are practically significant.In order to study the regularity of the gas flow in the filter-bag during reverse flow cleaning, energy equation of the incompressible fluid is applied. Theoretical analysis about the reverse flow field in the filter-bag is worked out. And axial flow velocity and radial reverse flow velocity in the filter-bag can be calculated. According to the analysis to the radial reverse flow velocity in the filter-bag, the uneven distribution of reverse flow cleaning only depends on the length of the bags under a certain dust load and flow discharge. Critical slenderness ratio of the filter bag is suggested so that the distribution of the radial reverse flow velocity is adequate. This provides reference for the appropriate size of the filter-bag. And actual axial flow velocity is measured on a bag house model with diameter of 100mm and length of 6000mm to compare to the theoretical analysis results. It is showed that actual measurement result and theoretical calculation result have a good consistency.Through the experiment test, it shows the relationship between the reverse flow velocity and the dust cleaning efficiency under the different dust loads. It is shown that the faster the reverse flow velocity is, the more effective the cleaning efficiency is under a certain dust load. Under a certain reverse flow velocity, the more dust load is, the more effective the cleaning efficiency is. And with the increasing of the reverse flow velocity, the detached dusts are more. Even the dust load is still increasing when the velocity reaches to 0.058 m/s, the detachment efficiency has already became gently. Sorting out the experimental data, it is found that the dust detachment stress cause by the reverse flow has a good relevance with the dust cleaning efficiency. This explains the cleaning efficiency of the reverse flow baghouse mainly depends on the dust detachment stress cause by the reverse flow.On base of understanding the cleaning mechanism of rotary reverse bag house, a design method of cleaning system of rotary reverse bag house is proposed. If the dust detachment efficiency is concerned, detachment stress can be determined. And according to it, the reverse flow discharge and pressure of the reverse cleaning system can be calculated under two conditions of inhale from outdoor and clean gas room. Then, a proper fan can be selected. This provides the theoretical basis of the design of the reverse flow cleaning system.