CASE  STUDY  1

Analytical Ferrography Provides Early Warning of Kiln Main Gear Box Failure

Cement Industry Overview

Cement  manufacturing  involves  abrasion  of  the  machinery  which  is  brought  about  by  particles  from  the  raw materials.  Therefore,  it  becomes  necessary  to  have  a  wear  detection  technology  to  increase  the  service  life  of  the machinery. These abrasive particles can create secondary wear and damage the equipment internals.

Ferrography  helps  to  examine  wear  rate  of  the  system  internals  irrespective  of  particle  sizes  along  with  material composition effectively and provides early warning of machine failures.

Plant:  PENNA CEMENTS INDUSTRIES LIMITED

Location : Boyareddypalli, Andhra Pradesh

Lubricant : IOCL SMSP-320

Equipment : Kiln Main Gear Box

Sample Date: 14/07/11

Received Date:17/07/11

Test Date:07/08/11

Observations in Ferrography:

Case hardened steel gear wear (fatigue, scuffing & scoring)) particles of size ranging up to 90 microns are observed in abnormal quantities.

Low alloy steel bearing wear (fatigue) particles of size ranging up to 64 microns are observed in high concentrations. Sand/dirt particles are also observed in large quantities.

Recommendation:

The report is rated marginal due to the presence of high concentration of gear wear and bearing wear particles. Change the lubricant as wear particle concentration is high. Note: Flush the system throughly before oil change. Resample after 20-25 days of equipment run to trend the generation of gear wear and bearing wear particles as the particles observed indicate fatigue and pitting in the gears and bearings. Close monitoring of internals is also advised.

 Note : Vibration readings were normal.

Plant Officials Inspection:

Plant officials taken initiative based on Veda’s recommendations gear box inspection was carried out on 09/08/11 and observations found that pitting, scuffing&scoring marks on the third stage main gear teeth.

The oil was drained from the unit and all the debris was thoroughly flushed from the gear box. The unit was then filled with new oil.

This timely identification prevented the unexpected breakdown of the entire unit, by requiring the replacement of only the single gear. Without this analysis, the unit would have continued operation until total failure.

Cost saving due to early detection including production cost is Approx.50 lakhs.

Case Study 2

Raw Mill main Gear Box drained Oil purification

Plant: The India Cements Limited - Vishnupuram

Location : Raw Mill

Lubricant : Servo Mesh - 460

Component : Gear Box Oil

Sample Date: 17/05/10

Received Date:20/05/10

Test Date:25/05/10

Raw mill main gear box oil of quantity 5000 ltrs was highly contaminated with water and particulate contamination. Mr.Vidyasagar who was working for plant as a Chief Manager-Mechanical asked me to test the oil for purification. We have tested physical & chemical parameters of oil along contamination test.

Oil condition was O.K but contamination levels were high.

Contamination Levels Before Filtration:-

Sample Date{s) 17 May 2010

Size Range    No. of Particles     Class 

>4 microns           271348            25

>6 microns            29334             22

>14 microns           2096              18

ISO 4406:99 Results 25/22/18 

The above results indicates that oil contamination levels are in unacceptable range.

After electrostatic filtration contamination levels were decreased to normal levels.

Sample Date{s) 17 May 2010

Size Range    No. of Particles     Class

>4 microns           3893             19

>6 microns             813             17

>14 microns           579             16

SO 4406:99 Results 19/17/16

Cost of Servomesh-460 per Ltr is approx.Rs.120/-,

Cost saving due to filtration is

5000 ltrs X Rs.120/- = Rs.6,00,000/-