Influence of secondary pressurization on the powder spraying effect of heavy-duty powder elevating fire trucks
In view of the problem of insufficient powder spraying distance of heavy-duty powder fire trucks,it is proposed to use secondary pressurization to improve the spraying distance of heavy-duty powder,and the influence of the position of second-ary pressurization,the number of pressurized ports and the pres-sure on the spraying effect of powder in fire trucks is analyzed through theoretical analysis,numerical simulation and experimen-tal study.Research indicates that,compared with directly raising the pressure of the main driving gas source,the secondary pres-surization through the transportation pipeline can more effectively reduce the pressure loss of gas-solid two-phase flow to enhance the exit velocity and range of the powder.The position of the pres-surized port has a greater impact on the powder injection range,and the powder injection effect of secondary pressurization in the middle of the boom is better than that of pressurization at both ends of the boom.The powder injection distance increases with the increase of pressurization pressure,and the secondary pressur-ization at 0.15 MPa in the middle of the boom can increase the maximum exit velocity and effective powder coverage by 61.8%and 28.4%,respectively,showing the best injection effect.
elevating fire truckpneumatic conveyingsecondary pressurizationspraying distancegas-solid two-phase flow