I’d like to ask some questions regarding powder conveying technology

Hello! Based on your description, you want to achieve the transfer of powder from the second floor to the fourth floor, with a vertical height difference of 35 meters and a horizontal distance of 50 meters, and the transfer rate is approximately 2.5 m3/h. For this situation, positive pressure dense-phase conveying can be considered. Positive pressure dense-phase conveying is a technology that suspends powders in a closed pipeline using air flow for transportation. It primarily relies on the pressure difference of gases to transport powder, without depending on gravity or mechanical transmission devices. The conveying speed is primarily controlled by the gas velocity. According to the powder conveying technology manual you mentioned, the recommended conveying speed is 3~8 m/s. This speed is achieved by controlling the flow rate and pressure of the gas in the compressed air supply system. Specific control methods may include adjusting the compressor operating pressure, pipe diameter, and the opening degree of the throttle valve, in order to achieve the desired gas flow rate. It should be noted that positive pressure dense-phase conveying is suitable for some relatively uniform powders, and may not be appropriate for powders that tend to clog or undergo plastic deformation. In addition, the choice of pipeline material must also be considered; it needs to be able to withstand the conveying pressure and powder wear. I hope this will be helpful to you! If you have any other questions, feel free to ask me. .

Control the flow rate of the gas output by the compressor.

Okay, thank you. The substances being transported are lauric acid and stearic acid, among others. These materials are absorbent of water, have a relatively low melting point of only 42°C, and are flammable with a flash point of 160°C. At present, we are considering using low-temperature nitrogen for transportation. Since the nitrogen produced by pressure swing adsorption units already has a high pressure, it needs to be cooled to below 15°C; therefore, dense-phase transportation is being considered as it requires less gas and results in lower energy consumption

Another option is to use negative pressure for transportation; it’s not clear whether negative pressure will meet the requirements, as the vertical distance is quite large, and each conveyor line has 6 bends. The conveyor lines utilize DN50 sanitary-grade polished pipes

In a positive-pressure dense-phase conveying system, a throttle valve can be installed before the gas usage point to control the gas flow rate and velocity. The throttle valve can adjust the pressure difference of the gas passing through the pipeline, thereby controlling the conveying speed of the powder. The desired gas flow rate can be achieved by adjusting the opening degree of the throttle valve. Please note that when selecting a throttle valve, its adaptability and wear resistance should be taken into account to ensure it can meet the requirements of powder transportation. At the same time, attention must also be paid to the matching of the inlet and outlet pipe diameters with the throttle valve to ensure stable system operation. .

I’ve heard of this method of transportation for the first time; could any teachers who use it share their experiences? Is it prone to clogging the pipes, or do materials tend to accumulate at the bends? There’s also the final stage of transportation – how is the material blown out there? Is pulse blasting still used? If it can’t be blown clean, how can we prevent materials of different specifications from getting mixed up?

Pneumatic conveying or scraper conveyor conveying

It can be transported by sealed cyclic positive-pressure pulse delivery using nitrogen or by chain conveyor

A pitot tube can be used to measure speed; I’m not sure whether it’s suitable for this type of operating condition, so I would appreciate some guidance from experts. Additionally, a definite wind speed can be obtained after passing through a throttle.