Decanters & Centrifuges - Vibration Monitoring for Decanters and Centrifuges (Rolling Element Bearings)
Last Updated: 05/22/2017
Machinery Applications Include: Decanter, Industrial Decanter, Worm/Screw Centrifuge, Separator, Peeler, Centrifuge, Bowl Centrifuge, Peeler Centrifuge, Industrial Centrifuge, Condition Monitoring, Vibration Monitoring, Protection System, VMS.
Decanters for separating liquids and solids have many drive configurations as the Bowl and Scroll turn at slightly different speeds. Drive methods include, Two Electric Motors, Single Electric Motor w/2 Sheave Speeds, Single Electric Motor with Planetary Gearbox and Dual Hydraulic Drive Motors with Electric Motor Driven Hydraulic Pump as examples.
Centrifuges may be horizontal or vertical and are Electric Motor Driven, Sheave Driven or have an integrated Gearbox. Sensors should always be mounted in direction of load for best results.
As Rolling Element Bearings have a finite life and lifespan is dependent on load, a basic monitoring system will warn of excess vibration that can then be corrected and thus extend bearing life. Do to the high speeds and changing load conditions involved a Permanent Condition Monitoring System is recommended as opposed to PdM Only.
For purposes of this article the Drives are ignored. If history, cost or criticality of the drives or gearbox is an issue then they should be included in the condition monitoring plan.
Protection System BOM using Local PLC or Control System:
The Protection System using the CMCP420VT Loop Powered Velocity Transmitter BOM (Bill of Materials) provides a simple low cost approach to Vibration Monitoring making use of the machines local PLC or Control System for alarming and trending of the vibration values. STIís CMCP420VT Loop Powered Vibration Transmitters are mounted to the machines bearings or case and the 4-20 mA Output proportional to Velocity signal is wired to the local control system. Alarms and Time Delay are then programmed in the PLC/Control System.
Protection System BOM (Vibration Switch):
The Stand Alone Protection System BOM provides all the features of the above Transmitter System with the addition of an Alarm Module for standalone operation. The Alarm Module provides two (2) programmable alarms (alert & danger) with 5 Amp Relays, programmable alarm time delay, LCD Display in engineering units, LED Alarm indication and a 4-20 mA output. An internal Push Button for alarm reset and a terminal for wiring a remote reset is also provided. The CMCP-EVS is a complete system, simply supply 24 VDC.
Protection System BOM (API-670):
The Stand Alone Protection System BOM meets the requirements of API-670 and provides all the features of the above Protection System with the addition of Relay Modules and Displays. OK, Alert and Danger Alarms and 5 amp Relays are provided for each channel. The ability to select alarm delay, trip multiply, latching or non-latching relays are provided. Terminal for remote reset is also provided. The CMCP5304 is a complete system simply supply AC line power and connect sensors.
Recommended Installation Accessories (All Systems):
The following are STIís recommended Installation Accessories. Quantities vary as shown depending on the BOM selected above. More details and instructions on Transmitter Installation can be found under our Application Notes at this link: http://www.stiweb.com/appnotes/Accelerometer_Installation_Guide.html