Bearing temperature

Improved sensors allow computer monitoring of the system for safety and protection of the equipment from damage. Sensors include lubrication-flow monitors and alarms, bearing-temperature sensors, belt scales, rotation sensors, and proximity sensors to detect ore level under the crusher. The latter prevent jamming of the output with too high an ore level, and protect the conveyor from impact of lumps with too low an ore level. Motion detectors assure that the conveyor is moving. Control applied to crusher systems including conveyors can facilitate use of mobile crushers in quarries and mines, since these can be controlled remotely by computer with reduced labor. 

Various protective instruments are used to provide a shutdown signal (to a fast-acting trip valve at the expander inlet) that senses various things, such as overspeed, lubricant pressure, bearing temperature, lubricant temperature, shaft runout, icing, lubricant level, thrustbearing load, and process variables such as sensitive temperatures, levels, pressures, etc. However, too many safety shutdown devices may lead to excessive nuisance shutdowns. 

Hot running Preventive maintenance bearings., Monitor bearings temperature Purging and sealing to keep solvents out, if solvent (even vapor) exposure is possible Use improved bearing lubricant CCPS G-29... 

Heat build-up Ensure frequent preventive maintenance checks due to worn or on bearings overloaded, Monitor and alarm bearing temperature bearings. Ensure proper belt tension CCPS G-12 CCPS G-23 CCPS G-29... 

It is recommended that the motor should have separate terminal boxes for the main supply and for the accessories such as space heaters, embedded teinpertiture detectors, bearing temperature indicators and moisture detector terminals, etc. In LT motors, however, if it is not possible to provide a separate terminal box for these accessories, the main terminal box may be adequately spaced to segregate the.se terminals from the main terminals within the box. 

Any of the above reasons tnay result in noise and an increase in temperature and must be corrected. Critical installations such as a refinery, a petrochemical plant, a chemical plant or a petroleum pipeline may require special precautions and control to avert any excessive heating of the bearings, which may become fire hazards. For these installations, bearing temperature detectors with a relay and alarm facility may also be installed in the control circuit of the switching device to give warning or trip the motor if the temperature of the bearing exceeds the preset safe value. 

Motors are also recommended to have one bearing temperature detector in each bearing. This can be fitted within the threaded walls of the bearing that reach up to the bottom of the bearing shell, i.e. close to where the heat is produced. Each detector may have two sets of contacts, each having 2-NO contacts, rated for 5 A at 240 V a.c. and 0.5 A at 220 V d.c. One set can be set at a lower value to provide an audio-visual alarm and the other at a higher value to trip the motor. 

You need to investigate an unexplained ri.se in the bearing temperature. This could indicate imminent failure. You can add one more shot of grease, but if the temperature doesn t reduce immediately, don t continue adding more grease. First, rule out obsious reasons for the increase. It could be that the temperature in the surrounding area has... 

Typieally, speed is inereased to maximum eontinuous speed in approximately 25% (of maximum eontinuous speed) inerements. The expander-eompressor should be held at eaeh speed inerement for a suffieient time to reeord pertinent data (i.e., vibration and bearing temperatures). 

Cheek expander bearing temperature in eontrol room a minimum temperature of 70°F is desired for startup. 

API Std 614 Lubrieation, Shaft-Sealing, and Control-Oil Systems for Speeial-Purpose Applieations API Std 670 Vibration, Axial-Position, and Bearing-Temperature Monitoring Systems ASME BPV Seet 11 Materials... 

Provides a purchase specification to facilitate the manufacture, procurement, installation, and testing of vibration, axial position, and bearing temperature monitoring systems for petroleum, chemical, and gas industry services. Covers the minimum requirements for monitoring radial shaft... 

A funetional alternative to the use of proximity probes for bearing proteetion is bearing temperature, bearing temperature rise (bearing temperature... 

When possible, gears should be run-in on initial startup. Speeds and loads should be inereased in pereentage inerements. Lube oil temperature, and pressure and bearing temperatures should be observed and adjustments made to the lube system as required. The number of adjustments made will depend on the eomplexity of the system. Oil pressure is of primary importanee. When an auxiliary pump has been provided, oil should be eireulated before the aetual start. If not, the pump should be primed, and the journals wetted with oil. Primer holes are sometimes provided or alternate journals ean be oiled through the holes provided for bearing temperature deteetors. 

Mechanical analysis. This includes detailed analysis of the bearing temperatures, lube, and seal oil systems and other mechanical subsystems. 

Proeess flow measurement at inlet or diseharge of maehine Radial-bearing temperature thermoeouple or resistanee temperature element embedded in eaeh bearing, or temperature at lube oil diseharge of eaeh bearing. 

Figure 8-27. Typical radial bearing temperature sensor installation.

API Standard 670, Vibration, Axial Position and Bearing Temperature Monitoring System, Third Edition, Washington, D.C. American Petroleum Institute, 1993. 

After the heat run, the compressor continues to run on air and the highest pressure practical is imposed, while the speed is set to the normal operating speed. The capacity and power should be noted as well as bearing temperature and the other instrumentation used during the test. If oil buffered seals are used and the test run is expected to exceed 250°F, the test procedure may have to be modified to avoid the possibility of an explosion hazard. 

Automatic trip of heat transport pump on high bearing temperature to prevent bearing damage service water is lost and the operator fails to take corrective action... 

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