key areas for consideration in sample handling design

| Document Number | March 23, 2016 | © Yokogawa Electric Corporation

Yokogawa Information Exchange

Sample Systems Chance or Choice?

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Trevor Hibdige C.Eng MInstMC BSc(Hons) Analyser Consultant and Data System Designer [email protected]


Key Areas for Sample Handling Design

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1.  Classic Pitfalls 2.  Basic Design Strategies 3.  Where should we focus? 4.  Understanding Response Times 5.  Future Trends



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Classic Pitfalls

Reliability - Perception or Fact? n Most Analyser problems are caused by

inadequate Sample System designs

It doesn’t matter if its real or perceived. If the system has a bad reputation then it will not be used fully or maintained fully

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Classic Pitfalls

Response Time “An Analyser (system) that responds so slowly as to be boring or irritating to those using it or maintaining it will receive little attention and poor maintenance” Publication Date: September 1959 Copyright © 1959 American Chemical Society

(With the exception of model based control where precision outweighs speed this still is true)

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Classic Pitfalls

n Forgetting who the “Customer” is n Overloading the Technician n Pushing for an unrealistic response time n Freezing up a regulator n Too long sample lines n Changing Phases n Diffusion or adsorption n Sample Pumps

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Basic Design Strategies

n What the Analyser needs vs What comes out of the process

n Understand the pressure drops n Maintainability

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Where to Focus

n Understand the pressure drops (basic design strategy)

n Pressure Stability n Flow Control n Material Compatibility

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Where to Focus



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Where to Focus

n Pressure Drops (basic stuff)

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Where to Focus

n Pressure Drops (real world)

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Where to Focus



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Where to Focus

n Pressure Stability & Flow Control

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Where to Focus



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Where to Focus

n Pressure Stability & Flow Control

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Where to Focus



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Where to Focus

Material Compatibility n Metals

We all know that Stainless Steel is better than Carbon Steel

n Elastomers We think we know that PTFE is better than Viton is better than Nitrile BUT…….

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Response Times

n What is Analyser Response Time? n What is Sample Response Time?

u Agreeing u Calculating u Optimising

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Response Times

n Agreeing

u What is needed u Is it achievable u Is it safe and realistic u Is it maintainable

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Response Times

n Agreeing – What is needed

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Response Times


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Response Times


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Response Times


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Response Times

n Calculating There are 7 different ways to calculate pressure loss in a flowing gas tube or pipe……(no wonder we all come up with different answers)

Ø  Laminar Flow Ø  Pressure Loss <10%of P1 (incompressible model) Ø  Pressure Loss <40%P1 (average line pressure) Ø  Integrate pressure loss along the whole length Ø  P2>40% of P1 (compressible model)

•  Weymouth (1912) •  Panhandle A (1940s) •  Panhandle B (1956)

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Response Times

n Calculating

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Response Times

n Optimising

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Response Times

n Optimising (increase analyser flow)

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Response Times

n Optimising (decrease probe volume)

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Future Trends

n In Line Analysers n Fibre Optics n Data Systems n Self Diagnostic Systems n The dreaded NESSI

(not so much have you got the money more can you generate the return)

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Future Trends

n NESSI Increasing the reliability of these systems through the use of increased automation Shrinking their physical size and energy use by means of miniaturization Promoting the creation and use of industry standards for process analytical systems Helping create the infrastructure needed to support the use of the emerging class of robust and selective microAnalytical sensors

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Tomorrow Our Industry will still need sample systems Our Industry will still complain about the costs Our Industry will still do it wrong

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Tomorrow Our Industry will need more people to understand how to do it before we lose the “art”

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QUESTIONS

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Contact Details The Presenter – Trevor Hibdige [email protected] Dale Cathey Yokogawa [email protected]

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key areas for consideration in sample handling design

Engineering