Scalable sampling solutions for in-process particle size monitoring

Scalable sampling solutions for in-process particle size monitoring

Stuart Barton. Bangkok 22nd June 2015

The drive for tighter process control

• Cement fineness is critical for its performance• It has always been monitored as one of the

primary controls of product quality.• Until recently this has been carried out by

various techniques in a laboratory.• Blaine apparatus• Sieves, and more recently• Laser diffraction


• All these techniques give valuable information on the finished product.

• There are advantages and disadvantages to each technique.

• Arguably, laser diffraction gives the most information, but there are serious questions, on how to apply what is potentially an overload of information.


• Some benefits are.• Fast reproducible measurement.• A complete distribution of the particle size is

given• Less operator-operator dependency• The possibility to automate the process for in-

process operation

The evolution of in-process measurement

Some disadvantages are.• Different parameters and results (what do

they mean).• Non agreement with other techniques (which

is correct).• More training required (user competence)• Nevertheless, the technology is now widely

used.

The evolution of in-process measurement (prior art)

Advantages• Potential for more

frequent analysis• Less operator

intervention• Possible to measure

multi parameters, eg size, XRF, XRD

Robotic labs were one option for automation.

The evolution of in-process measurement (prior art)

Disadvantages• Sampling still relatively

infrequent• Reliance on less rugged

laboratory equipment• Still not possible for

closed loop control• VERY EXPENSIVE

Robotic labs were one option for automation.

Xoptix Sizer

X50: 24.5 umLoading: 46.3%

Xoptix Sizer

Control Computer

Screw Feeder

Main Flow

Air

Air

Isolation Valves

Process DCS or PLC

Ethernet Link

Real time control a reality Prior art?

Realising the potentialNow process changes can be seen immediately, finally giving process engineers

the ability to really fine tune the operation

x50 Trend Graph

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889

2.00 2.20 2.40 2.60 2.80 3.00 3.20

OnlineLab

Realising the potentialThe graph below clearly shows 2 things

1. Online and offline measurement both agree and track each other.

2. Online measurement is more precise than offline measurement

Instrument to Instrument variation

05

101520253035404550

% Error

Typical Errors in MeasurementWhy is online measurement more precise?


Sample handling

unit varia-tion

05

101520253035404550

% Error



Sample handling

unit varia-tion

Sampling05

101520253035404550

% Error



Sample handling

unit varia-tion

Sampling User-User variation

05

101520253035404550

% Error

Typical Errors in MeasurementLaboratory measuring systems


Sample handling

unit varia-tion

Sampling User-User variation

05

101520253035404550

% Error


The biggest errors are human errorsin taking and measuring the sample.

Automated in-process measurementremoves this error completely

Can reduce this error to a negligible size

And this error disappears too!

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889

2.00 2.20 2.40 2.60 2.80 3.00 3.20

OnlineLab

Realising the potentialThe offline measurements took a very diligant technician several hours to measure and

collate.

The online measurements took no time from anybody to collate……

Requirements for in process

• Robust systems to cope with the ‘hostile’ production environments.

• Fast calculations to ensure real time feedback.• OPC and other industrial standard communications

protocols.• Wear resistant ceramic linings to transport the

sampled cement through the measurement region.• A minimum number of moving parts to ensure

trouble free operation.

Xoptix Sizer

X50: 24.5 umLoading: 46.3%

Xoptix Sizer

Control Computer

Screw Feeder

Main Flow

Air

Air

Isolation Valves

Process DCS or PLC

This meets most of the design requirements from the previous slide, and indeed is a viable solution

OPC communication via Ethernet Link

Xoptix Sizer

X50: 24.5 umLoading: 46.3%

Xoptix Sizer

Control Computer

Screw Feeder

Main Flow

Air

Air

Isolation Valves

Process DCS or PLC

However, the moving parts with the auger are non ideal.


Xoptix Sizer

X50: 24.5 umLoading: 46.3%

Xoptix Sizer

Control Computer

Screw Feeder

Main Flow

Air

Isolation Valves

Process DCS or PLC

It would be a simpler installation to remove all moving parts.However product loading in cement processes make standard sampling unreliable


Xoptix Sizer

X50: 24.5 umLoading: 46.3%

Xoptix Sizer

Control Computer

Screw Feeder

Main Flow

Air

Isolation Valves

Process DCS or PLC

The new Compound Iso-kinetic probe solves this

Air


Air

The patented Interstitial Iso-Kinetic Probe (IIKP) is easily

installed, and gives unparalleled control of

sample extraction

Air

Interstitial Iso-kinetic Probe

• Quickly and easily installed (just as simple as a standard probe)

• Minimal additional set up procedure• Fix and forget (abrasive resistant parts) low

maintenance.• Suitable for smaller scale output up to 120T/hr• For greater output...........

This new patented Multi Stage Dilution Probe (MSDP) with no moving parts dilutes the powder flow in the cement process to a level that is compatible with in-process analysers

Xoptix Sizer

X50: 24.5 umLoading: 46.3%

Xoptix Sizer

Control Computer

Main Flow

Air

Isolation Valves

Process DCS or PLC


Sampler

This decreases the complexity, the cost, and increases the reliability of the installation, and extends sampling to processesof >300T/hr

Performance• The plots here show that

the performance of both systems (conventional auger and new sampler) both give the same superb real time performance

• Note also, that this measurement trend plot is continuous (per second) giving full ability for closed loop control.

• Some claimed in process systems have a recommended 20 minute per sample measurement time.

Particle size trend plot conventional sampling Particle size trend plot new sampler

Conclusion

• Real time in-process analysis is now able to be

readily integrated into any cement process.

• The cost is often lower than conventional

laboratory equipment

• With the following benefits of the latest in

process particle sizing technology…………

Conclusion

• Maximised on-spec Product Throughput

• Improved Product Specification/Tolerance

• Optimised Consistency of Product

• Reduced Energy Costs

• Reduced Waste/Rejected product

• Minimised Production Cost

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889

2.00 2.20 2.40 2.60 2.80 3.00 3.20

OnlineLab

Closing the loopThe vertical line at ~record 40 shows the point a closed loop PID controller was

started, feeding the particle size to the process DCS to automatically adjust the mill

control using the particle size data

ONLY POSSIBLE WITH IN-PROCESS MEASUREMENT

Conclusion

• Independently documented studies have shown that the return on investment (ROI) for this technology can be measured in weeks (3 weeks in 1 recent case)

Technology

Scalable sampling solutions for in-process particle size monitoring