Thermal Mass Flow Meters

Thermal Mass Flow Meters

Market and applications

Geographic Sales

34% 23% 12%

3%6%10%

10%

3%

Competition

Competition

Industry

Applications

Pipe Size

TYPE

Technology

Location

Sage Metering SalesRepresentative Sales

Applications Green House Gases Natural Gas Combustion Air Compressed Air Flare Digester gas/Bio gas/Landfill gas

Green House Gases 40 CFR 98

– Mandatory reporting of Green House Gas EmissionsCO2, CH4, N2O

– Subpart C – Stationary Combustion sources– Other subparts are Industry specific

Natural Gas IndustryLandfill operationsChemical PlantsRefineriesMore

Carbon Credits

Natural Gas Flows Boilers/Combustion Process

– Reporting GHG (EPA requirements)– Reporting Emissions (Local requirements)– Combustion efficiency– Typical Conditions

2 – 3 inch pipe Temperatures 60 – 80F Pressures max 5 psig Flow rates:

– 2” = 10,000 SCFH– 3” = 20,000 SCFH (6,000 SFPM)

– Burner Size 20 MM BTU/hr

Natural Gas Flow Sub-metering

– Internal cost allocation within a facility– Typical Conditions:

Pipe Size 6” Pressure – 20 psi Flow rate = 250,000 SCFH (20,000 SFPM)

Natural Gas Flow “Check” meter

– Gas Company distribution center– Repeatable, relative flow measurements– Check relative time of day flow in different distribution sections– Typical operating Conditions

18” pipe 80 – 100 psig Flow Rate 65,000 SCFM (40,000 SFPM)

Natural Gas Flow Avoid

– Transmission LinesPressure too high = 500 to 2,000 psi

– Custody TransferNot AGA approvedProvide entire meter run

ISO 50001

Energy Management Systems Reduce Energy Usage

– Continually review and monitor energy usage– Goal of improve energy performance

Program supported by US Department of Energy (DOE)

Opportunities for Sage:– Improvement in combustion efficiency

Natural gas – Compressed air measurement to reduce leakage

Stoichiometric CombustionTheoretical combustion of all the fuel when mixed with the correct amount of air

Fuel + air = Heat + CO2 + H2O + CO + Unburned Fuel + Waste Heat up stack

Does not occur in reality – some excess air is neededo Control Air Fuel Ratios

o Ratio based on the mass of fuel compared to the mass of air

Increases as Combustion

Air Decreases

Increases as Combustion

Air Decreases

Stoichiometric Combustion Optimum ratio of combustion air to fuel flow

– Does not existSome excess air is required

– Want to minimize excess air– Amount of excess air dependent on boiler load

Proper Air to fuel control requires mass flow measurement of air and fuel flow rates.

Combustion Air DP flow measurement typically used

– Flow element:Averaging pitot tubePressure drop around an obstruction in

the ductVenturi

DP - Combustion Air Flow Limitations:• Require pressure and temperature

compensation to get mass flow• Loss of signal at low flow rates

Typical velocity in duct gives 1” w.g. pressure drop.

• Square root relationship between flow and signal

Limits turndown Advantages:– “Sample” multiple points or

“entire” flow

Thermal – Combustion Air Flow Advantages:

– Measures mass flow without pressure or temperature compensation

Desired for combustion air to fuel ratio– Excellent low flow sensitivity– High turndown capabilities

Disadvantages:– Single point measurement

How representative is flow measurement Multi point averaging arrays

– Accuracy limitations due to straight run/flow profile However, repeatability is required

Combustion Air - Conclusion Suitable for “small”

ducts

Not suitable for “large” ducts

Compressed Air DOE estimates 30% compressed air produced

is lost due to leakage– ¼” leak at 100 psi = 100 CFM

$8,000 - $20,000 per year Cost Allocation Compressor efficiency

Flare/Vent Varying gas composition

Natural Gas

Tank venting (Gas Production)

Process Operations (CPI/HPI)

– Refineries40 CFR part 60, subpart Ja (modified August 2012)

– Emissions on non-emergency flares

Sage Selling Points Compact enclosure

– Prime - Smaller enclosure than other suppliers Insitu calibration verification Calibration on actual gas

– Ability to provide adjustment factors for varying gas composition

– Competitive calibration prices– Good delivery

Flow conditioner Great organization – good people to work with