Common fault analysis of concrete mixing plant batching system

 

Concrete mixing plant in the daily production of some occasional failures, especially the batching system, there will be inaccurate batching, silo does not participate in the batching, silo does not unload and so on, the following I will share the common failure analysis of concrete mixing plant batching system, come and see.

 

Concrete mixing plant batching system common fault analysis.

First, the batching accuracy is super poor.

 

It is manifested that in the process of batching, the weighing value displayed by the batching control instrument is accurate, but the weighing value of the batching does not match with the set value, and the accuracy of the batching is beyond the allowed range. There are many reasons for this kind of failure, including: the set value of fast and slow dosage is not suitable; the feed flow fluctuates a lot, and the overshoot changes a lot; the dryness and humidity of the material changes a lot; the set value of tolerance range is too big; the time setting of over-checking delay is too short; the automatic compensation of instrument parameters and over-checking set value are not reasonable; the digital filter and the time parameter of dosage are not reasonable.

 

The following measures should be taken for the above causes: the initial overshoot should be as close as possible to the actual value; reduce the dosage flow appropriately; ensure the dryness and humidity balance of the material; set the allowable deviation value to not exceed the dosage accuracy range; set the delay time of over-checking to more than 2.5 s, set the automatic compensation of instrument parameters and over-checking to "1 "; set the suitable parameter value when dosage.

 

Second, the bin is not involved in the dosage.

 

Its performance is that in the process of dosage a bin does not participate in dosage, the instrument and the related dosage indicator light on the operation panel, but the motor or solenoid valve does not act. The reasons of this fault may be: insufficient air pressure of material scale; damage of relevant dosage execution element (motor or solenoid valve); loose and false connection of wiring between AC contactor and motor; damage of intermediate relay and contactor of relevant circuit and abnormal wiring.

 

In this case, you should check the air compressor and the air connection, use the multimeter to check the motor, solenoid valve and the related wiring, and replace the intermediate relay or AC contactor in time. This fault occurs if the relevant dosage indicator light does not light up, the meter display does not move, it may be the dosage control instrument damage or power supply is not normal.

 

Third, the bin does not unload material.

 

The performance of the automatic working condition of a bin does not unload, and the operation panel on the bin unloading indicator and material scale unloading indicator light does not light. The cause of this failure may be: mixer discharge door has been fully closed, but the closing signal is not feedback to the controller; limit switch damage or displacement; a bin does not start batching. At this time, you should check the feedback circuit of limit control, adjust or replace the limit switch, start the "dosage tool" to make up the material in time, and finish the current batch production in a semi-automatic way.

 

If this fault occurs, the indicator light of bin unloading on the operation panel is on, the reason may be insufficient air pressure or serious leakage in the unloading cylinder, should check the air circuit and replace the worn parts in time; if the solenoid valve has no 220 V AC power supply, it may be the intermediate relay coil burned, bad wiring of solenoid valve power supply line, should check the wiring and replace the relay in time; if the solenoid valve has 220 V AC power supply, it may be the solenoid valve coil burned, bad wiring of solenoid valve power supply line, should check the wiring and replace the relay in time. If the solenoid valve has 220 V AC power supply, it may be burned solenoid valve coil, spool jam, valve body seal damage, should be timely replacement of the solenoid valve.

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