The diameter of the powder conveying pipe should not be too large, as it is not conducive to forming a stable material column. Generally, the diameter does not exceed 100mm, and the commonly used diameter is between 38-75mm. Especially for loose powder, it is difficult to form a material column with a large diameter. The inner wall of the pipeline should not be raised, and it is required to be smooth with low friction coefficient, so thin-walled seamless steel pipes are generally used.

输送管道的布置

Layout of conveying pipelines

管路布置好采用倾斜和水平形式，因为垂直管道中上面的料柱易落下与下面的料柱合并而产生堵塞，在布置空间允许的情况下弯管愈少愈好，弯管曲率半径不能太小，至少R/D>10，两个弯管之间也不能太接近，要做到料柱的移动在离开一个弯管前不受下游另一个弯管的阻碍。

The pipeline layout should be inclined and horizontal, as the upper material column in the vertical pipeline is prone to falling and merging with the lower material column, resulting in blockage. If the layout space allows, it is better to have fewer bends. The curvature radius of the bend should not be too small, at least R/D>10, and the two bends should not be too close. It is necessary to ensure that the movement of the material column is not hindered by another bend downstream before leaving one bend.

在给料罐出口与管道连接处，管道内物料要满管，因此该处的弯管曲率半径要大。输送管道的起始段好有一定长度的水平管段，至少要比一个料柱长，如必须提升需采用很大半径的弯管，以使一个料杜稳定成形后再上升，无论如何不要在料罐出口后立即提升。

At the connection between the outlet of the feeding tank and the pipeline, the pipeline should be filled with materials, so the curvature radius of the bend at this location should be large. The starting section of the conveying pipeline should be a horizontal section with a certain length, at least longer than a material column. If lifting is necessary, a large radius bend should be used to stabilize the formation of a material column and then rise again. In any case, do not lift immediately after the outlet of the material tank.

输送完毕一般直接进料仓卸料，为了避免卸料时破碎物料，应从料仓侧面进料，如果料仓直径不够大，会冲到对面的仓壁上，可将进料管从料仓侧面水平伸进料仓，在进料管下部开口下料。为进料仓而垂直提升的料管，在保证足够弯管半径的前提下，要尽星靠近料仓以避免料柱提前溃散和压差过早增大。

After the conveying is completed, the material is usually directly fed into the material bin for unloading. In order to avoid crushing the material during unloading, the material should be fed from the side of the material bin. If the diameter of the material bin is not large enough, it will rush onto the opposite wall of the material bin. The feeding pipe can be extended horizontally from the side of the material bin into the material bin, and the material can be discharged through the lower opening of the feeding pipe. The material pipe that is vertically lifted for feeding into the silo should be as close to the silo as possible to avoid premature collapse of the material column and premature increase in pressure difference, while ensuring sufficient bend radius.

物料的输送距离

Conveying distance of materials

输送距离增大到一定程度后，输送压力就要提高，但输送压力太高会不利于料柱的形成，如果用增加气柱的方法来增加输送距离则输送量就要降低，所以目前对某些物料如不中途补气就很难实现长距离输送。

After the conveying distance increases to a certain extent, the conveying pressure will increase. However, if the conveying pressure is too high, it will be unfavorable for the formation of the material column. If the conveying distance is increased by increasing the gas column, the conveying volume will decrease. Therefore, it is difficult to achieve long-distance conveying of certain materials without supplementing air midway.

料柱、气柱的长度

Length of material column and gas column

料柱比气柱越长，混合比越大，耗气量越低，但是料柱长了，压缩空气的压力也要提高，而且容易造成堵塞。如果料柱太短了，料柱容易崩溃，尤其松散、流动性好的物料更易出现这种现象。所以，要根据物料性质和装置的具体情况来确定料气柱比和具体的料柱长度。

The longer the material column is compared to the gas column, the higher the mixing ratio and the lower the gas consumption. However, as the material column is longer, the pressure of compressed air also increases, which can easily cause blockage. If the material column is too short, it is prone to collapse, especially loose and flowable materials. So, it is necessary to determine the material to gas column ratio and the specific length of the material column based on the properties of the material and the specific situation of the device.