A large company who supplies high quality titanium metal products was searching for a reliable way to detect any plugged chute conditions that may arise in their process. Titanium is used in hundered of diverse aerospace, industrial and emerging applications where no other metal is as reliable or economical, especially on a lifecycle costing basis.
The customer was looking for a level control to be successfully used as a plugged chute detector; the customer had experienced problems with RF probes from another manufacturer. Plugged chute detection is critical to make sure the material is flowing properly through a process. A plugged chute condition can cause problems with transfer rates, mix ratios, and production “down stream”. Monitor offers several options for plugged chute detection. For this situation, the high temperature SafePoint® rotary paddle bin indicator was the best choice.
The target materials are Rutile Ore with a bulk density of 150 lbs per cubic foot and Petroleum Coke with a bulk density of 53 lbs per cubic foot. The material characteristics of the Rutile Ore can be described as having a “sand texture” and the Petroleum Coke is “granular”.
This application is made even more challenging due to the extremely high temperatures involved, the ambient temperature ranged from 100°F to 150°F and the internal process temperature could be as high as 750°F. But wait, this gets even better; the internal air in the feed pipe being monitored for a plugged chute condition is a gaseous chlorine, which if combined with moisture of any kind creates Hydrochloric Acid!
The Sales Engineers with Ball Sales, the Monitor Rep in CA, OR, WA, AZ, NM, NV, worked with the customer by gathering additional details and suggested that the best solution would be for the customer to install a high-temperature SafePoint rotary bin indicator. The high-temp SafePoint unit can be used in applications up to 750°F.
The SafePoint will not be challenged by the fluctuating dielectric constant of the target material or the possible changing temperature that caused the issues with the RF Probe they first tried.
The SafePOint® rotary paddle point level sensor is a self-validating device that detacts material presence plus continuously monitors its own ability to function. Should the self evaluation detect an internal fault, an ouput will react accordingly, This includes fault due to power loss.
The built-in microcontroller performs self-validating diagnostics and monitors both shaft and motor mounting plate rotation. This allows the SafePoint to easily distinguish between material presence and any electrical and mechanical failure of the unit. When material presence is detected, the SENSE relay changes state and the drive motor is de-energized to extend motor life. This output is available to control a process function or alarm circuit. When the material level drops, a tension spring returns the drive motor to its original posrunning condition and it is reactivated.
A unit failure is detected by sensing a lack of shaft rotation while material presense has not been detected by rotation of the motor mounting plate. In a failure condition the independent FAULT relay will change state. Monitoring the state of both the SENSE and FAULT relays provides the most flexiablity for control and monitoring that is beyond just “fail-safe”.
Features of the SafePoint®
Rugged cast aluminum construction
Motor shut-off when paddle becomes impeded by material to increase motor life
Twist On/Off Cover
Choice of process connections and accessories
High Temp model available
Hazardous location approals available
Typical applications include High and Low level sensing in bins, silos, tanks, hoppers, and other vessels.