Ethanol Corn Mash pH Monitoring with Automatic Cleaning System
Ethanol corn mash slurry tanks contain liquids and fine solids particles. The thick slurry can quickly plug the junction/diaphragm of a pH sensor causing it to drift. This often requires frequent maintenance to clean the junction and recalibrate the sensor. In some cases, operators just replace it with a new sensor. Removing a pH sensor by hand from the process can be dangerous due to high temperatures and pressures. For this reason, standard sensor maintenance typically causes shutdowns of corn slurry tanks.
Automated Cleaning System
M4 Knick’s CL-90 automatic retraction and cleaning system is the ideal solution for ethanol corn mash slurries. When combined with a Stratos Multi transmitter and pneumatically driven SensoGate WA 131 holder, the CL-90 cleaning system is a fully programmable solution.
The CL-90 cleaning system features:
- Automatic retraction and insertion of the pH electrode while the process is running
- Programmable cleaning cycles to remove buildup coating the pH probe
- Manual switch for retraction on demand
- Option for remote operation from PLC/DCS
In most ethanol corn mash applications, the cleaning cycle runs every 4 hours. This process takes less than 5 minutes, including one minute rest period for temperature stabilization before the sensor is reinserted.
Pre-Calibrated pH Sensors
The SE 554 Memosens pH sensor is specifically designed for use in applications with suspended solids. The sensor’s open junction is resistant to plugging media found in corn mash applications. The solid electrolyte prevents fouling and extends sensor life.
Technicians can pre-calibrate Memosens sensors in the shop or lab ahead of time. The microprocessor in the sensor head stores calibration data. The technician can simply carry it out to the transmitter, disconnect the existing sensor, and do a “hot-swap” with no additional calibration or configuration. Pre-calibration significantly reduces downtime.
When a sensor needs to be replaced, the SensoGate WA 131 retractable holder enables quick and safe service to the pH loop. The holder completely retracts the sensor and shuts it off from the running process, ensuring that there is little chance the operator might come in contact with the process.
Furthermore, the Stratos Multi transmitter is Memosens compatible. The new Memosens sensor automatically shares calibration information with the transmitter, and the system is ready to measure without any additional steps. The color display on the Stratos Multi gives the operator “data at-a-glance” diagnostics.
Value of an Automated pH System on Ethanol Corn Mash
- Reduced downtime:
The CL-90 and SE 554 pH sensors greatly reduce process downtime and unscheduled maintenance by preventing drift and failure caused by buildup on the sensor. - Reduced maintenance costs:
Pre-calibrated Memosens smart digital technology reduces the need for troubleshooting and calibrations done in the field. The system eliminates the need for technicians to manually clean pH sensors. In addition, the system also significantly extends the pH sensor life. As a result, better sensor life reduces maintenance costs from frequent sensor replacement in ethanol corn mash applications. - Increased operator safety:
Both the SensoGate WA 131 pneumatic retractable holder and CL-90 system eliminate the need for manual retraction of pH sensors. As a result, operators have little chance of coming in contact with the high process temperature and pressures in the slurry tank.
