CASE STUDIES (SUCCESS STORIES)
CASE I :: Kiln Feed Bin Level Fluctuation Optimisation..
ISSUE :: Bin Level Fluctuating with repeated cycle 81.2 to 86.5 Tons
ACTION :: Gate Opening for 1 & 2 readjusted. Other Gate Operation Optimized.
Diagnosis::Fluctuations coming due to malfunctioning of the discharge gates
(Mechanical issue,No where related to Controller tuning / PID).
RESULT :: 70% reduction in fluctuations. Bin level maintained between 85 to 86 Tons.
BENEFIT :: Reduces effect on Kiln Feed Rate fluctuation.
CASE II ::Kiln Feed Flow Meter Fluctuation…
ISSUE ::Sudden Peaks in Kiln Feed.
DIAGNOSIS::Abnormal (non-linearity) Sensor response at higher feed flow rates.
>> Sensor Anomaly detected as source of Major fluctuations >>
Action: PV Filter for kiln feed PID.
RESULT:: The Instrument Related spikes were detected & eliminated which reduced the side effect of False Alarm.
CASE III ::PC Temperature Fluctuation Assessment
Optimisation of Fluctuations in PC temperature (Master Loop Optimisation)
ISSUE::Manual mode operation & Suboptimal PID Settings.
ACTION:: Manual mode Operation was shifted to AUTO mode Operation and the response were corrected by Optimizing PID settings.
RESULT::Stable Pre-Calciner Temperature.
BENEFIT:: Small amount of coal TPH reduction can lead to big savings..3.6 TPD coal being saved ~ nearly 22000 Rs/day saving.
CASE IV ::Cooler Under Grate Pressure AUTO operation..
ISSUE::Cooler Chamber Pressure vs. Cooler Grate Speed PID was running in Manual mode as it is not stable in AUTO mode.
Diagnosis:: Operation in Manual.
Action:: Operated in AUTO mode + Fine Tuning of Controller parameters.
Result :: Actual Under grate pressure is fluctuating around the required set point (+/-20 mmWC).
Stable and consistently above 400 oC Mid Tap Temperature.. >> stable WHR operation.
BENEFITS:: Cooler operation optimized to achieve higher outlet gas temperature (stable above 400 deg C). Which helps them to achieve higher power generation in WHR (waste heat recovery) plant.
CASE V ::Assessment of Diffuser Amps for Drum Level Control
* CAPTIVE POWER PLANT * Drum Level Control
ISSUE:: Variability in Boiler Drum Level. Optimisation of variability in Boiler Drum level..
Diagnosis:: Sub-Optimal PID Settings. Action: PID Tuning.
Result:: Lower deviation in drum level.
BENEFITS:: lower thermal shocks + lower variation in boiler pressure.
CASE VI ::Assessment of ID fan related fluctuation
Boiler House Draft Control (ID Fan) Stabilisation
ISSUE:: Variability in Boiler Outlet Draft + Unstable operation of ID Fan (speed).
Diagnosis:: External Random Disturbances.
Action:: Applied PV Filter.
RESULT:: Reduction in variability in boiler outlet draft.
BENEFIT::Stable Induced Draft fan (speed)..
CASE VII ::Hood Draft PID optimisation.
CASE VIII::Cooler Vent Fan VFD optimisation.
Kiln Hood Draft regulation using Cooler ESP fan operation (VFD tuning in panel).
CASE I::Gypsum Feeder (in Cement Mill) Fluctuation Optimisation
ISSUE:: Gypsum Weigh Feeder showing higher variability (>5%) even for fixed set point.
Diagnosis:: Weight Feeder speed response issue (Panel Settings to be optimized).
Action:: Parameters adjusted in Schenck Panel (Gain factor increased from 0.2 to 0.6 mA%)
Result:: More than 70% reduction in variability. No its operating with SP +/- .05 TPH (<1% variability) as compared to SP +/- 0.2 TPH (>5% variability across Set Point)).
CASE II::Optimization of Fly Ash Feeding (SFM) Fluctuations (critical to open circuit).
RESULTS:: Stable Fly ash Feeding with lower Controller Error.
Benefit:: Almost 2KW of Power saving per Ton of Cement.
CASE III::TWO Chamber Ball Mill (Closed Circuit) – OPC Grinding
Sound level vs Feed PID optimisation
ACTION:: PID Tuning.
CASE IV::PROGRESSIVE OPTIMISATION OF TWO CHAMBER CEMENT MILL – UAE
CASE V::Progressive Assessment/ Optimisation of Raw Mill (Roller Press + Ball Mill) Operation.
CASE I :: Drum Level Control
Observation :: Low controller performance,5.8% error.
Diagnosis :: Oscillations due to Agressive tuning.
Correction :: ‘I’ action reduced by 20%.
Result :: Zero Oscillations, Average error < 1%.
Effect :: Stable Steam Pressure / Quality (better Steam Economy)
CASE I :: Assessment/Diagnosis of Fluctuations in Reagent Quality
BENEFITS / SAVINGS
REDUCED VARIABILITY IN OPERATION
Higher % in OPTIMUM range (Stable operation, consistent quality)
Lower % of > 1% OWL (higher utility BCTMP, Lower Reagent Requirement)
Lower % of < 0.5% (Lower O2 consumption).
Lower wear and tear of valves/actuators (low replacement cost)
CASE I:: Assessment/Diagnosis of Fluctuations in Mill Section (Flow and Level Variation)
Diagnosis : Oscillations due to High Gain (P setting).
Correction : ‘P’ action reduced as suggested by OPTIMakx (no trial and error).
Result : >75% lower Oscillations: Average Error reduced by >35%.
Benefits : Lower Quality Fluctuation, Stable Recovery, Lower Re-agent Consumption.
CASE II:: Optimisation of Fluctuations in PCT temperature.
CASE I :: Assessment/Diagnosis of Fluctuations in Nutrient Quality
Variance Diagnosis: Spot Sampling Effect, Unmeasured Disturbance, Oscillating Inputs,Slow Controller Response, Valve Related Issues.
Actions suggested : AUTOsampler (composite sampling), PID tuning, New Measurements for external disturbances, Valve servicing.
CASE I::Tablet Coating Machine Control Optimization.
Result:: 82% reduction in Start-up cycle time.
Benefits :: 82% reduction in Idle Time (higher machine and labour productivity) + 87% reduction in Steam Wastage (during the start Up period and also for Re-Starts during Power Failures) + Quality consistency as the Set Point is not allowed to deviate for longer time during any unscheduled stoppage
CASE I::Oxygen Plant O2 Purity ImprovemenT.
O2 Plant Optimisation:: Impact on LOX Consumption