NeSSI*: Defining an Intrinsically SafeSensor/Actuator Network for Hazardous Areas

NISTJuly 30, 2003

Rob Dubois

C PΛΛ C

“the best way to predict the future is to create it”

*New Sampling/Sensor Initiative

2

Presentation Outline

• Today’s Process Analytical Technology vs. theNeSSI Vision of Success

• A Quick Look at Electrically HazardousEnvironments and Methods of Protection

• NeSSI Development Roadmap & Generations• Key Aspects of the NeSSI Gen II Networking

Requirements and Specification• Summary

Explosion Proof Fittings

and Conduit SealsCustom each job

Skilled electrician

Multiple fittings, valvestubed by skilled

inst. fitter

IS Solenoids Valve and

Pneumatic ValvesZ-purge

assemblies

Today’s Technology

Armored rotameters and X proof

flow switches

ManualP, F control

4

Vision of Success - I

Move Analysis By-LineTypical Analyzer House - Dow Freeport, TX

5

Vision of Success - II

• Lego Like Assembly• Reduce Engineering Time

– software “configurator”• Reliability Centered Maint.

– Full Automation

Design, assemble & configure an analytical system on the work bench.

Courtesy of J. Warwowski/D. Mitchell. Swagelok/Panametrics

Courtesy of U. Bonne. Honeywell.

6

NeSSI Generation Segmentation

Gen III

Gen II

Gen IMechanical Components

(with conventional 4-20 mA)

Electrical Transducers using

IS Multi-Drop Network

Wireless, Advanced Gas & Liq. Sensors

& Platform for microAnalytical End User Value

Time (years)

03 04

NeSSI Roadmap

02

Mechanical Component Availability e.g. filters, valves, etc.

Mechanical Field Installations

ANSI/ISA SP76 Standard Approved

NeSSI/CPAC Vision & Roadmap

2000

Design /Prototype - Gen II Smart/Heating/SAM

Smart Field Installations

MechanicalGen. I

Smart/”Electrified”Gen. II

µµAnalytical & WirelessGen. III

01 0605

July 2003

uAnalytical Field Installations

Simple Analyzers (H2O, O2, pH, UV/VIS, etc.)

8

The Penitent - We’ve come along way!

Courtesy of Health and Safety Executive, Sheffield, England

9

Major Industries which Operate inElectrically Hazardous Locations

• Petrochemical Production• Fine Chemical Manufacture• Refining• Oil and Gas Distribution (Pipeline)• The “Oil Patch”• Industrial Gas Producers (e.g. hydrogen)

10

Hazardous AreaClassifications

North American Gas GroupingsEuropean Gas Groupings

NOT hazardous duringnormal operations

Div 2NOT hazardous duringnormal operations

Zone 2

Propane, acetone, benzeneType DPropaneIIA

Ethylene, Ethel etherType CEthyleneIIB

Hydrogen, Propylene oxideType B

AcetyleneType A

Acetylene + HydrogenIIC

Frequently hazardousduring normal operations

Zone 1

Usually or Frequentlyhazardous vapors presentduring normal operations

Div 1

Usually hazardous duringnormal operations

Zone 0

North American Area DefinitionsEuropean Area Definitions

11

Methods of Protection forElectrically Hazardous Areas

Table 2. IEC Recognized Methods of Protection (for reference)

Technique IEC Symbol Permitted Zone

Oil Immersion Ex o 1 & 2

Pressurization Ex p 1 & 2

Powder Filling Ex q 1 & 2

Flameproofing (Explosion Proof) Ex d 1 & 2

Increased Safety Ex e 1 & 2

Intrinsic Safety (2 fault tolerant) Ex ia 0, 1 & 2

Intrinsic Safety (1 fault tolerant) Ex ib 1 & 2

Non-incendive Ex n 2

Encapsulation Ex m 1 & 2

Special Protection Ex s 0, 1 & 2

3 Techniques: Containment, Segregation or Prevention

12

Intrinsically Safe OperatingRegion Ex ia and ib

Acetylene + Hydrogen Ignition Curve

Limits electricalenergy and keepsthe surfacetemperature belowthe level needed tocause ignition of aflammable gasmixture.

13

Explosion Proof Enclosure - Ex d

Courtesy of Adalet

Contains anyexplosionwithin theenclosure.

14

Purging System - Ex p

Purging uses air or aninert gas to pressurizean enclosure in orderto keep an explosivemixture from beingignited by an arcing orsparking device.

X-Purge System

15

Key Aspects of the NeSSI GenII Specification

A Conceptual and Functional Specification Describing the Use of Miniature, Modular (and Smart) Electrical Components for adaptation to the ANSI/ISA SP76 Substratein Electrically Hazardous Environments

Please refer to Gen II Spec draft version d6...http://www.cpac.washington.edu/NeSSI/NeSSI.htm

16

Programmable Substrate Heater

VP

A

F SAM

CANbus

Auxiliary Heating/Cooling

SubstrateT

T

Ethernet LANDCS o&muser

microClimate Enclosure

NeSSI Gen II Elements

Div 1/Zone 1inside the Enclosure

Typ. Div/Zone2

17

NeSSI Architecture

Sensor - Level 0 LANDeviceNet <100 ft

Information - Level 2 LAN (Ethernet)

OPCGateway

V TPA

Sample System

Control Room

At-LineSample Point

PLC Enclosure Class 1 Div 2

Class 1 Div 1

WirelessHandheld

HMI GasAnalyzer

Field

Field - Level 1 LAN(Wireless)

Field - Level 1 LAN(Wireless)

DeviceNet

Segment 1

Segment 2

IS B

arrier

SensorActuatorManager

24 VDC

18

Why a digital, Intrinsically Safenetwork for NeSSI?

PLC with conventional I/O,.X-purged. This is costly andcomplex to design and buildand not practical for usewith a tightly packedminiature, mod. system.

Gen I+

19

…and therefore the need for amulti-drop, IS, simple network

POCA* with 8M DeviceNet Connector (Honeywell)

“Freedom 55” for processanalytical practitioners (inelectrically hazardous areas) isthe ability to connect &disconnect an electrical device -without the need for conduits,electrical seals, cable glands,gas “sniff” tests, purgingsystems, interlocks or safework permits.

*POCA = Proof of Concept Apparatus

20

Global Certification of theNetwork - single agency

• Approved for all Zone and Divisiongeographies. (ATEX, UL, CSA)

• Why Intrinsically Safe?– Best safety for high risk areas (eg. inside an

enclosure handling hazardous, flowing fluidssuch as ethylene.)

– A globally approved method of protection– However, the most compelling reason for IS is

the ability to use plug and play miniature,modular sensors using “normal” wiring.

21

Gateway to an Ethernet LAN(DCS/maintenance systems) can use multiple com protocols

- OPC/HTTP/FF, etc.

- Remote Wireless (Gen III)

- 802.11 Wi-FiHost Port for a…

Sensor/Actuator Bus

- Two Channels

PDA Field Port

- Local Wireless

-e.g. Bluetooth™

Software Applets for certainRepetitive Tasks (Appl-I)

- System Health (P, T, F)

- Analyzer Validation

- Sample Conditioning/controlProvides “Open” Development

Space for Custom Software

SAM

The Bluetooth and the Bluetooth trademark are owned by Bluetooth SIG, Inc.

Distributed Control is Essential- Sensor Actuator Manager

22

Maximizing the Number ofNetwork Devices is Essential

• NeSSI Gen II spec suggests a min. of 25devices per channel/port for a Class IIC(worst case) hazardous environment– makes a system cost-effective– allows sharing among analytical systems– simplifies installations– justifies the use of multiple sensors

23

A Single, Low Voltage Power SupplyIntegrated with an IS Barrier

• Minimizes complexity (packaging, wiring)• Low voltage assists power budget• Single voltage spec gives clear design

objective for component makers• Larger power supplies (e.g. 24 VDC takes

up precious space)• NeSSI suggests 12 VDC max.

24

Key Network Attributes

• Hot Disconnect (w/o shutting down)• Distance (typ within 30’ - max. 500’)• Approx. 10 updates/second

– physical (analogue) transducers (P, T, F,Vo, Vm) - low data throughput

– microAnalytical (chromatography,spectroscopy) - high data throughput

• Mission Critical Performance in aRobust Environment

25

Key Transducer-NetworkAttributes

• Industry standard connector• Simple diagnostics (traffic light analogy)• Simple Configuration

– Transducer Ambiguous• Low cost - “Open” and Interoperable• Optical isolation [for certain devices which

may need to be powered remotely]

26

Superb Power Management - I“Hazardous Intrinsic Power Profile*”

* HIPP

We envision that each transducer, once certified, will have non-volatile embedded Power, Current, Inductance, Capacitance, T-rating and other parameters associated with its safe operation which helps define its Hazardous Intrinsic Power Profile. (HIPP) Once attached to a network the system manager (SAM) willautomatically upload each device’s parameters and accept or rejectthe device according to built in limits set by the system.

For example, SAM is configured for a Class IIC (hydrogen service)with a fixed pool of current/power, etc. and maximum temperature.

27

Superb Power Management - II“Hazardous Intrinsic Power Profile*”

Power management is analogous to memorymanagement

PT-1FT-2TT-3AT-5Vm-6Free

* HIPP

28

User Friendly Network

• Adding a component to the networkshould be a simple & quick task.– Maintenance time is spread thin - a

cumbersome or inflexible interface orneeding expert assistance, for a simplejob, will not be well accepted.

• Wireless transmission for local andremote communication.

29

Related Applications

• Pilot Plants/MicroReactors• Laboratories• Low Power Applications

– battery powered systems– wireless– remote systems

• Auxiliary analytical systems– heat tracing

30

To Summarize - NeSSI Definesan Unmet Networking Need

Current practice requiresmany skilled people and high cost to assemble, install andmaintain our analytical systems invarious global geographies. The introduction of a low cost ISnetwork meets an unmet need in industry. Providing smart, fullyautomated systems willfundamentally change how we doprocess analytics.