1. Sistema de pesaje de cemento inexacto

Descripción del fallo

El sistema de pesaje de cemento puede mostrar valores correctos después de la calibración con pesos estándar, pero después de descargar, la pantalla no vuelve a cero. Después de restablecer y cargar los pesos de nuevo, el valor mostrado cambia significativamente.

Aunque el valor de resistencia del sensor está dentro del intervalo normal y el indicador de pesaje no tiene problemas, la precisión de pesaje permanece inestable.

Posibles causas

Las principales razones pueden incluir:

• Los soportes de fijación de transporte del bastidor de pesaje no se han retirado

• La cabeza de presión o la placa de presión está atascada

• El sistema de pesaje entra en contacto con las estructuras circundantes

• Tres células de carga no son el mismo modelo

• La carga del material es desigual, causando un desequilibrio de pesaje

Soluciones

• Retire los soportes de fijación de transporte antes de la operación

• Compruebe y limpie la cabeza de presión y la placa de presión para garantizar un movimiento suave

• Separe el sistema de pesaje de los objetos circundantes para evitar interferencias

• Reemplazar las células de carga inconsistentes con el mismo modelo

• Ajuste la posición de alimentación del material para evitar una carga desigual

La calibración y inspección regulares del sistema de pesaje son esenciales para mantener la calidad del hormigón.

2. La puerta de descarga del contenedor agregado se abre lentamente sin material

Descripción del fallo

Cuando no hay material dentro de la tolva de agregado, la puerta de descarga se abre y cierra lentamente con un movimiento débil del cilindro.

Sin embargo, la inspección muestra:

• Sin fricción mecánica ni bloqueo

• La válvula solenoide funciona normalmente

• El cilindro de aire no tiene fugas de aire

Posibles causas

Las razones comunes incluyen:

• Pobre suministro de aire causado por un elemento de filtro sucio en la unidad de tratamiento de aire

• Silenciador bloqueado que reduce la diferencia de presión del aire dentro del cilindro

Solutions

• Clean or replace the filter element of the pneumatic system

• Clean the muffler regularly to ensure smooth airflow

Maintaining the pneumatic system can improve the response speed of discharge gates.

3. Powder Outlet Does Not Discharge Material

Fault Description

When the contactor is activated and the motor rotates clockwise, the screw conveyor outlet does not discharge powder.

After running for a short time, the circuit breaker trips.

Restarting the motor causes the same problem, while inspection shows that the powder material is not hardened.

Possible Causes

Possible reasons include:

• Screw conveyor motor running in reverse direction

• Damaged circuit breaker

• Poor contact of one phase in motor wiring

Solutions

• If the motor rotates reversely, exchange any two motor wires to change the rotation direction

• Replace the damaged circuit breaker

• Check and repair motor wiring connections

Correct motor rotation direction is critical for screw conveyor operation.

4. Mixer Shaft Stuck or Motor Overloaded

Fault Description

During concrete mixing, the mixer shaft rotates with difficulty or stops completely.

This problem is commonly called mixer shaft "stuck" or motor overload failure.

Possible Causes

The reasons may include:

• Severe overloading of the mixer

• Excessive material wrapping around the mixing shaft

• Incorrect operation causing secondary feeding

• Inaccurate weighing system

• Large gap between mixing blades and tank wall

• Foreign objects stuck between blades and lining plate

• Low power supply voltage

• Incorrect mixing parameter settings

Solutions

• Reduce mixing load and remove hardened concrete materials

• Remove excess materials caused by incorrect feeding operations

• Recalibrate the weighing system

• Adjust the gap between mixing blades and tank wall (normally not more than 5 mm)

• Remove foreign objects inside the mixer

• Check and stabilize power supply voltage

• Correct mixing parameters in the control system

Regular inspection of mixing blades and liners can effectively prevent mixer overload.

5. Main Mixer Discharge Door Cannot Open

Fault Description

During automatic operation, the main mixer discharge door fails to open after mixing is completed, and the discharge indicator light does not turn on.

Possible Causes

The causes may include:

• Foreign materials or accumulated concrete between discharge door and sealing plate

• Insufficient air pressure in the pneumatic system

• Air cylinder internal leakage

• Damaged oil mist lubricator

• Loose wiring between solenoid valve and relay

• Damaged relay

• Burned solenoid valve coil

• Solenoid valve spool stuck

• Damaged time relay causing PLC signal failure

Solutions

• Remove foreign materials and clean the discharge door

• Check air pressure, cylinder, joints, and lubricator condition

• Repair wiring connections and replace damaged relays

• Replace damaged solenoid valves

• Replace faulty time relays

Regular inspection of pneumatic and electrical systems can prevent discharge failures.

6. Conveyor Belt Misalignment

Fault Description

Conveyor belt deviation is one of the most common problems in concrete batching plants.

There are mainly three situations:

Situation 1:

The belt continuously moves toward one side during both empty and loaded operation.

Situation 2:

The belt moves left and right randomly without a fixed direction.

Situation 3:

The belt deviates only in the middle section of the conveyor.

Possible Causes

Common causes include:

• Uneven conveyor foundation

• Material accumulation on rollers

• Uneven installation of trough rollers

• Improper adjustment of driving and return rollers

• Loose conveyor belt tension