TL;DR
Bag ejection failures are most often caused by a worn ejector arm, a failed pneumatic cylinder, or a proximity sensor misalignment. Check the pneumatic supply and sensor gap before dismantling the ejector.
What you might see
- bags not ejecting at the discharge chute
- bag remaining on spout after fill signal
- ejector sensor alarm active
- bag tears at the spout neck during ejection
Likely causes
Ejector pneumatic cylinder seal worn, reducing ejection force
Ejector proximity sensor misaligned or fouled with cement dust
Bag seat rubber gripper worn, allowing the bag to stick on the spout
Pneumatic solenoid valve for the ejector circuit failed
Required tools
- Pressure gauge for pneumatic circuit
- Sensor gap gauge
- Replacement cylinder seal kit
- LOTO kit
Safety first
- Lock out pneumatic and electrical supply before opening the ejector mechanism.
- Cement dust respiratory hazard. Wear P100 respiratory protection.
Procedure
- 1
Stop the packer and lock out the drive and air supply before working on any ejector component.
- 2
Manually operate the ejector pneumatic circuit from the DCS or local panel. Confirm the cylinder extends and retracts fully.[1]
- 3
If the cylinder does not extend fully, measure the air supply pressure at the cylinder port. Low pressure indicates a solenoid valve fault.[1]
- 4
Clean the ejector proximity sensor face with a dry cloth. Check the sensor mounting gap against the specification.
- 5
Inspect the bag seat rubber gripper for wear or cement hardening. Replace if grip contact is degraded.
- 6
If the cylinder retracts slowly or incompletely, replace the cylinder seals or the full cylinder if the rod is scored.
Sources
Haver & Boecker Haver Roto-Packer ROTO Cement Bagging Machine general technical documentation, Haver & Boecker
Haver & Boecker packing machine maintenance documentation, ejector and bag placement system procedures (general)
More guides for Haver & Boecker Haver Roto-Packer ROTO
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Stop fixing the same fault twice.
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