Incinerator BMS

Instrument EDC/VCM

A Training on

ContentsContents

• BMS Fundamentals• BMS Design Standards• Incineration Fundamentals• PFD For Incinerator• Engro’s Waste Streams / Vents• Control Side of Incinerator• Hard Wired BMS Interlocks• Overview of New PLC based BMS at Incinerator B• Summary

Burner Management SystemBurner Management System

• Start Up Fear

• Fuel has accumulated while burners are not operating and then is ignited when a burner is lit

• Shutdown Fear

• Fuel accumulates after a burner goes out while operating, then subsequently finds a source of ignition

BMS – Fears in Burner Units (Fired Equipment)BMS – Fears in Burner Units (Fired Equipment)

Burner Management SystemBurner Management System

• Primary Purpose

• To allow and ensure the safe start-up and shutdown of the Fired Equipment

• Secondary Purpose

• To prevent overheating fired equipment and the catastrophic release of process streams that result

BMS - PurposesBMS - Purposes

Burner Management SystemBurner Management System

• Sequence control (Permissives)

• Shutdowns/Trips (Interlocks)

How is Burner Managed?How is Burner Managed?

BMS Design – Standards BMS Design – Standards

NFPANFPA

• NFPA 85 Boiler and Combustion Systems Hazards Code

• NFPA 86 Standard for Ovens and Furnaces

What is Incineration??What is Incineration??

• Incineration is an Oxidation Reaction• The Oxidation reaction is highly Exothermic• The reaction is fairly complete.

• In presence of sufficient Oxygen :o All Carbon (C) will form Carbon Dioxide (CO2).o Most Chlorine (Cl) will form Hydrogen Chloride (HCl).o All residual Hydrogen (H) will form Water (H2O).

OHtytHClxCOOtyxClOHC tzyx 222 ]2/)[()2/)((

The Oxidation ReactionΔH

Process Flow DiagramProcess Flow Diagram

Oxidizer – Used to destroy all organic compounds.Waste Heat Boiler – Used to recover usable heat released from the waste.Quench Absorber – Used to cool hot products of combustion and remove most acid formed.Scrubber – Used to remove residual traces of acid and Chlorine

OxidizerOxidizer

WH BoilerWH Boiler

Quench AbsorberQuench Absorber

ScrubberScrubber

Engro’s Waste StreamsEngro’s Waste Streams

Direct Chlorination

Vent

OxyChlorination

Vent

HeadColumnVent

LightColumnVent

LiquidWaste

Tank Vent

Mass Flows lbs/ hr 1600 32500 1500 2100 1000 4034Average Molecular Weight lbs/ lb-mole 23.82 28.41 55.85 63.79 104 28.92

Average Density lbs/ scf 0.0628 0.0750 0.1474 0.1683 0.0763Average Higher Heating Value btu/ lb 14474 484 3166 8163 7964 0

btu/ scf 910 36 467 1374 0Volumetric Flow scfm 424 7226 170 208 881

Heat Input mmbtu/ hr 23.158 15.730 4.749 17.142 7.964 0.000Carbon % 51.2% 2.6% 17.5% 39.8% 44.4% 0.0%

Hydrogen % 14.1% 0.3% 3.7% 5.0% 3.3% 0.0%Oxygen % 14.4% 10.2% 18.3% 1.6% 0.0% 23.0%

Nitrogen % 4.0% 86.2% 0.0% 0.0% 0.0% 77.0%Chlorine % 16.4% 0.7% 60.5% 53.6% 52.4% 0.0%

Waste ConstituentsWaste Constituents

Higher Heating Value

MolecularWeight

Direct Chlorination

Vent

OxyChlorination

Vent

HeadColumnVent

LightColumnVent

LiquidWaste

Tank Vent

btu/ lb lb/ lb-moleOxygen O2 0 32.0 7.7% 7.6% 21.0%

Nitrogen N2 0 28.0 3.4% 87.5% 79.0%Carbon Monoxide CO 4347 28.0 6.0% 2.8%

Ethylene C2H4 21679 28.0 1.2%

Methane CH4 23715 16.0 72.4%

Ethane C2H6 22368 30.0 2.9% 0.4%

Propane C3H8 21706 44.0 2.1%Hydrogen Chloride HCl 0 36.5 0.4%

Ethylene Dichloride C2H2Cl2 4313 97.0 5.5% 0.1% 10.1% 48.1% 50.0%Lights 31.4%

HeaviesWater H2O 0 18.0 46.5% 6.5%

Vinyl Chloride Monomer C2H3Cl 8262 62.5 2.0%

Carbon Tetrachloride CCl4 832 154.0 6.0%

Ethyl Chloride C2H5Cl 8838 64.5 15.7% 50.0%

1,1,1 TriChloroEthylene C2HCl3 2858 131.5 0.4%

ChloroForm CHCl3 1338 119.5 10.7%

Benzene C6H6 18209 78.0 14.0%Inerts 8.6%

Total 100.0% 100.0% 100.0% 100.0% 100.0%

Heavies – assumed to be heavily chlorinated and “High” boiling Constituents. [ie C2H2Cl2, C2HCl3]

Lights - assumed to be non chlorinated “Low” boiling constituents.[i.e. – CH4, C2H6, C2H6]

Four Major Components ofFour Major Components ofIncineratorIncinerator

• Oxidizer Chamber

• Waste Heat Boiler

• Quench Absorber

• Scrubber

Controlling the Combustion ReactionControlling the Combustion Reaction

FE

FE

FE

FE

FE

Cooling Water

Atomizing Steam

Natural Gas

Combustion Air

Oxy Vent

Heat Vent

DC Vent

Light Columns

HCl Vent

FE

Tank Farm Vent

FYratio

FYratio

FYratio

FYratio

FYratio

FYsum

FIC UY

TE

TE

AE

AIC>

TIC

TIC

O2

sp = 3%sp = 1800F

sp = 2200F

LV-60 Oxidizer To WasteHeat Boiler

Items to be Controlled:Oxidizers operating temperature and the exhaust gas oxygen content.

•Control air flow to match demands made by the waste Vent and Natural Gas•Add Natural Gas should Oxidizer Temperature drop below 1800OF•Add Cooling Water should Oxidizer Temperature rise above 2200OF•Add additional Combustion Air should the Stack Oxygen Content drop below 3%.

Between 1800OF and 2200OF, we expect no additional Fuel or Cooling water to be used

Controlling the Waste Heat BoilerControlling the Waste Heat Boiler

FE FE

LT

PT

PICFIC

UY

LIC

SteamChest

Steam Drum

>

Boiler Feed Water

Hot Products of Combustion

Product Steam

To Quench Absorber

Boiler Blow-Down

Items to be Controlled:

•Control Boiler feed water addition to match steam production rate•Add additional water, should the steam drum level drop below a pre-determined level.•Control the Steam production rate to maintain desired pressure in the steam drum

The Quench AbsorberThe Quench Absorber

The purpose of the Quench/Absorber is to cool the gases and remove most of the Acid gases formed

Boiler Exhaust

Absorber Bleed

Absorber Make-Up Water

Absorber Exhaust

AELT

LIC

AIC

Density

sp

sp

Recycle AbsorberPump

Quencher/Absorber

•Control Make-up water by maintaining tower sump level•Control bleed from the system to maintain a given density of Bleed solution.

Items to be Controlled:

The ScrubberThe Scrubber

The purpose of the Scrubber is to remove the remaining Hydrogen Chloride [HCl] and Chlorine{Cl2] from the gas stream prior to exhausting to the atmosphere.

Quench/ AbsorberExhaust

Scrubber Bleed

Scrubber Make-Up Water

Exhaust to Atmosphere

AELT

LIC

AIC

Density

sp

sp

Recycle ScrubberPump

Scrubber

Caustic Solution

AEpH

AICsp

OPTION

Items to be Controlled:Acid absorbed in solution will lower the pH of the recycle solution

•Control Caustic addition to maintain pH•Control Water addition to maintain sump level

Incinerator BMS DescriptionIncinerator BMS Description

• Hard Wired Relay Based System

• Two Burner System: Auxiliary and Main Burner

• Two Separate UV Type Flame Scanners

o Auxiliary Burner Flame Scanner – For Pilot and Auxiliaryo Main Burner Flame Scanner – Only Main Burner

Incinerator BMS InterlocksIncinerator BMS Interlocks

Different BMS Different BMS InterlocksInterlocks

Main Interlock – Start PermissivesMain Interlock – Start Permissives

• Is Air Blower Running? (Start Air Blower)• Is Flame Detected? (Fire Eye Flame Detectors)• Is Plant Instrument Air Supply OK? (PSL)• Is Combustion Pressure OK? (PSL)• In Natural Gas Pressure? (PSL)• Is Natural Gas Pressure to Auxiliary Burner OK? (PSH)• Is Natural Gas Pressure to Main Burner OK? (PSH)• Is Atomizing Steam Pressure OK? (PSL)• Is Cooling Water Supply OK? (PSL)• Is Thermal Oxidizer Temperature OK? (TSH)• Is Steam Drum LeveOK? (LSLL)• Is HCl Tower Level OK? (LSLL)• Is HCl Recirculating Flow OK? (FSL)

Pre Purge InterlockPre Purge Interlock

• Are Auxiliary Main Gas and Block Valve Closed and Vent Valve Open?

• Are Main Burner Main Gas and Block Valve Closed and Vent Valve Open?

• Are Pilot Burner Main Gas and Block Valve Closed and Vent Valve Open?

• Are All Vents Main Valve and Block Valve Closed and Vent Valve Open?

System PurgeSystem Purge

• Start Permissive and Pre Purge Interlock is OK, BMS signals Combustion Air Control Valve to Open

• 10 minutes time delay holds, to verify Combustion Valve Open (Limit Switch) and Flow is normal.

• A Purge Period of 5 Minutes.

• DCS Analog Output Signal Drives the Combustion Air and Natural Gas Control Valve to Open. (Verified by Limit Switches)

Ignition and Pilot TrialIgnition and Pilot Trial

• DCS Analog Output Signal Drives the Combustion Air and Natural Gas Control Valve to Open. (Verified by Limit Switches)

• 10 sec pilot trial for Ignition begins

• Is Pilot Flame Detected Within 10 sec?

Auxiliary Burner TrialAuxiliary Burner Trial

• Once Pilot Burner Sensed, Auxiliary Burner Trial is Initiated.

• A 10 sec Timing Period

• Is Auxiliary Flame Detected by Flame Scanner Within 10 sec?

Auxiliary Burner Ramp UpAuxiliary Burner Ramp Up

• Auxiliary Burner maintains Low Fire Position and release control to DCS for process control.

• Two Control Strategies:

Main Burner TrialMain Burner Trial

• With Flame On and Chamber Temperature above 760 Deg Centigrade, Main Burner Light Up is Enabled.

• Main Burner combustion and gas control valves driven to Low Fire Position.

• A 10 sec Timing Period

• Is Main Flame Detected by Flame Scanner Within 10 sec?

Waste Admit ControlWaste Admit Control

• Vents Line Up and Air demand ratio control is implemented in the DCS

• Is Chamber Above Waste Admission Temperature? (TSL)• Is Individual Waste or Vent Pressure OK? (PSL)

• Vents are Line Up from DCS

Incinerator BMS InterlocksIncinerator BMS Interlocks

Different BMS Different BMS InterlocksInterlocks

New BMS System Overview & New BMS System Overview & AdvantagesAdvantages

• PLC bases Burner Management System• Interactive HMI for Operator access• Advance capabilities of monitoring and diagnosis• Interlocks are displayed on HMI through cause and effect diagram• Provision to display first in cause of tripping• Soft bypassing of securities for maintenance requirement• Dedicated sequence of Pilot trial to facilitate ratio adjustment during

Auxiliary burner startup• Adjustable settings of Flame Scanner Module (UV / IR)• More than 350 loops termination carried out in new BMS Panel along with

termination of more than 200 loops in DCS Marshalling

Pre Commissioning IssuesPre Commissioning Issues

• Limited capabilities of monitoring and diagnosis• No HMI for overall system and field operations monitoring • Time consuming troubleshooting • No latching of faults• Too many relays creating point of failure• Flame Scanner setting adjustment not possible• Logic modification was difficult• By passing was done through hard wired

New BMS PanelNew BMS Panel

Commissioning Phase ChallengesCommissioning Phase Challenges

• Safe Removal of loops from DCS during running plant– Inactive points from DCS– Safe removal of more than 400 terminations from DCS Marshalling– Protocol for loop isolation followed (PVC tape application, safe keep)– Time taken 2 days vs. initially planned half day, plus 2 days for reinstallation and back in

service

• Number of terminations and cables rerouting– Removal of more than 1100 terminations from field panel– Pulling of all cables from old panel followed by panel removal– New panel installation– Cables insertion in new panel from individual glands– Cable rerouting, termination and dressing inside new panel

Commissioning Phase Challenges Commissioning Phase Challenges

• Cables Short length Issue– Identified during cables routing and installation in new panel – Installation of new cable segments and butt jointing

• Loop testing and verification– Individual loop testing from field to BMS– Individual loop testing from BMS to DCS

• Pre Start-up Logic Issues– Reverse indications of low pressure switches on field HMI and DCS– Difference in temperature reading on field HMI vs. temperature on TI’s head– Modification of 24v supply going in field for energizing relay in old panel

Thank YouThank You