1. Wrong startup sequence

开机时先送风后放料，如果操作有误，顺序颠倒，会使系统不畅，有可能出现返料现象。一般在正常输送时，先通风，在不带料的情况下，让系统空吹一段时间，将原来系统下的料冲出管道，不于出现堵料现象。

When starting the machine, the air is supplied first and then the material is discharged. If the operation is wrong and the sequence is reversed, the system will be blocked and the material may be returned. In general, during normal transportation, ventilation should be carried out first. Under the condition of no material, the system should be allowed to air for a period of time to flush the material left by the original system out of the pipeline, so as not to block the material.

2.关机顺序不正确

2. The shutdown sequence is incorrect

关停料泵时先停料后停风，在停送操作时由于操作不熟，若先停机后停料，会造成管道内有积存的物料，下次开机时会导致阻力增大。故要注意操作顺序，不能误操作。

When stopping the material pump, stop the material first and then stop the air. Due to the inexperienced operation during the stopping operation, if you stop the material first and then stop the material, there will be accumulated material in the pipeline, and the resistance will increase when you start the next time. Therefore, pay attention to the operation sequence and do not operate by mistake.

3.换库风阀开关顺序不妥

3. The opening and closing sequence of the air valve for changing the warehouse is incorrect

水泥输送系统中，在入库端安装有换库阀门，在换库时应当先开要入库的阀门，再关闭库满的阀门，其目的是让气力输送系统始终畅通。若是先关闭库满的阀门，后开入库的阀门，会造成系统正压上升，系统阻力增加，罗茨风机阻力加大，负荷增加，同时使物料在泵内向上返料，泵上方的水泥料罐出现憋气。

In the cement conveying system, the warehouse changing valve is installed at the warehousing end. When changing the warehouse, the valve to be stored in the warehouse should be opened first, and then the valve to be filled in the warehouse should be closed. The purpose is to keep the pneumatic conveying system unblocked. If the valve in the warehouse is closed first and then the valve in the warehouse is opened, the positive pressure of the system will rise, the resistance of the system will increase, the resistance of the Roots blower will increase, and the load will increase. At the same time, the material will return upward in the pump, and the cement tank above the pump will suffocate.

4.开停频繁

4. Frequent start and stop

在调试过程要摸索送料阀门的开度，调节手柄，当输送量与磨机产量相匹配时，记下手柄旋转的角度位置。但一般的操作者较保守，为防止泵上方的料仓满仓出现溢料，往往将送料阀门开得大，这易导致泵上方料位不足，只好停泵，等料位达到需求后再开泵，这样造成料泵.开开停停较频繁。每次开停，对风机不利，同时对滤布也有影响，滤布一旦因此出现漏洞，停料停风后，气室没有正压，料会沿滤布孔洞漏入气室，使其积料堵塞。

In the process of commissioning, the opening of the feeding valve should be felt, and the handle should be adjusted. When the conveying volume matches the output of the mill, the rotation angle of the handle should be recorded. However, the general operator is conservative. In order to prevent the overflow of the hopper above the pump, the feeding valve is often opened too large, which may lead to insufficient material level above the pump, so the pump has to be stopped, and the pump can only be started after the material level reaches the demand, which leads to frequent start and stop of the material pump. Each start and stop is not good for the fan, but also has an impact on the filter cloth. Once the filter cloth has a leak, the air chamber has no positive pressure after the material stop and the air stop, and the material will leak into the air chamber along the hole of the filter cloth, causing its accumulated material to be blocked.