Solution for Low Througput of SGB-200-2R1

Problem Description

• The output can not reach the required 200kg/hr.
• Misinformation of material shortage by material tank 3.
• Occasional pressure insufficiency and failure of security doors.

Analysis

Check the parameter settings: processing volume=2.8kg, tank 1 (PS materials) =95%, tank 3 (color master batch) =5%, agitation time=2 seconds, discharging time=3 seconds, discharging time of mixing bucket=3 seconds, discharging time of tank 1=2 seconds, discharging time of tank 3=2 seconds, pulse discharging time of tank 3 and 4 OFF=0.2 seconds; ON=0.3 seconds. The pulse discharging time setting for tank 3 and tank 4 is wrong.

The weighing system has a drift of 30~40g and is adjusted back to normality.

Compressed air pressure is only 4kgf/cm2 which is lower than required 6kgf/cm2.When rotating the adjustment knob, the pressure dose not change, which indicates the maximal pressure is 4kgf/cm2 and is not stable.

Based on observation, the machine has a maximal production capacity fluctuated between 140~170kg/hr after changing the parameter, which is lower than the demanded 200kg/hr. The machine fails at high material level because a lot of materials glued on the inner wall of the mixing tank trigger the level switch. The condition is back to normality after readjusting the level switch.

Based on observation, the machine has a maximal production capacity fluctuated between 140~170kg/hr after changing the parameter, which is lower than the demanded 200kg/hr. The machine fails at high material level because a lot of materials glue on the inner wall of the mixing tank and trigger the level switch. The condition is back to normality after readjusting the level switch.

After the above steps, the machine runs smoothly without alarming within 1.5 hours. The output is only 160kg/hr, which is lower than 240kg/hr, because the customer employs PS materials and 5% color master batch with a bulk density of 0.5kg/hr.

Solution

• Enlarge the metering screw of the color master batch.
• Set the pulse charging time of tank 3 and tank 4 OFF=0.0; ON=0.0.
• Check whether the dryer and pipes leak or not, improve it if necessary.
• Set the pressure switch at 1kgf/cm2 temporarily (with instability).
• The client should ensure a pressure above 6kgf/cm2 to solve this problem completely.

After the above steps, the machine runs stably without alarms, and continuous production can be fulfilled without any problem.

Suggestion

The maximal handling capacity identified in the catalogue is fulfilled when the bulk density is 0.8kg/L; different proportion of raw materials may bring about different maximal handling capacity, and this should be used with flexibility.