1 HVACR214 – Mechanical for Oil Oil Nozzles Air Mixing Oil Nozzles Air Mixing

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HVACR214 – Mechanical for OilHVACR214 – Mechanical for Oil

Oil Nozzles

Air Mixing

Oil Nozzles

Air Mixing

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Oil NozzleOil Nozzle

• The oil nozzle is responsible for delivering the fuel, in the correct pattern, angle and quantity to sustain proper combustion.

• The oil nozzle is responsible for delivering the fuel, in the correct pattern, angle and quantity to sustain proper combustion.

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Oil NozzleOil Nozzle

• In order to find the proper nozzle we must know:– The required gallons per hour– The spray angle– The spray Pattern

• Solid• Hollow• Semi-Hollow

• In order to find the proper nozzle we must know:– The required gallons per hour– The spray angle– The spray Pattern

• Solid• Hollow• Semi-Hollow

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Nozzle ConstructionNozzle Construction

• Nozzles are made of a stainless steel tip, sometimes the whole body is stainless steel.

• The stainless steel is a highly polished and reflective surface which prevents gumming.

• Some manufactures use a brass body and a stainless steel tip.

• Nozzles are made of a stainless steel tip, sometimes the whole body is stainless steel.

• The stainless steel is a highly polished and reflective surface which prevents gumming.

• Some manufactures use a brass body and a stainless steel tip.

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Nozzle ConstructionNozzle Construction

• Inside the nozzle:– A nozzle stem (or distributor) or a valve stem brings the

oil from the filter to the swirl chamber.– The nozzle orifice is located at the end of the swirl

chamber which allows the oil to leave the nozzle.

• Inside the nozzle:– A nozzle stem (or distributor) or a valve stem brings the

oil from the filter to the swirl chamber.– The nozzle orifice is located at the end of the swirl

chamber which allows the oil to leave the nozzle.

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Nozzle ConstructionNozzle Construction

• The porous filter is made of brass or steel and catches any sediment that may have bypassed the tank filter and the pump strainer.

• The filters purpose is to prevent blockage of the nozzle orifice.

• The porous filter is made of brass or steel and catches any sediment that may have bypassed the tank filter and the pump strainer.

• The filters purpose is to prevent blockage of the nozzle orifice.

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Oil Nozzle ConstructionOil Nozzle Construction

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Nozzle FunctionsNozzle Functions

• Atomizes fuel oil into tiny droplets– Results in a quicker vaporization when exposed to heat.

• Meters the fuel (metering device)– + or -5% of the rated capacity

• Atomizes fuel oil into tiny droplets– Results in a quicker vaporization when exposed to heat.

• Meters the fuel (metering device)– + or -5% of the rated capacity

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Nozzle FunctionsNozzle Functions

• Delivers the fuel in a specific pattern• This pattern must match the air delivery pattern

– Solid– Semi Solid– Hollow

• Delivers the fuel in a specific pattern• This pattern must match the air delivery pattern

– Solid– Semi Solid– Hollow

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Hollow PatternHollow Pattern

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Hollow PatternHollow Pattern

• Is used on shell head burners• The center of the spray is void of oil droplets• Used for a heavy center air pattern (lots of air in

the middle)• Used on 2.0 GPH and up nozzles.

• Is used on shell head burners• The center of the spray is void of oil droplets• Used for a heavy center air pattern (lots of air in

the middle)• Used on 2.0 GPH and up nozzles.

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Solid PatternSolid Pattern

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Solid PatternSolid Pattern

• Solid spray is used with– Standard oil burner (With end cone)– It sends tiny oil droplets through the entire cone.– Oil is placed directly into the air stream.

• Solid spray is used with– Standard oil burner (With end cone)– It sends tiny oil droplets through the entire cone.– Oil is placed directly into the air stream.

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Semi-Hollow (Semi-Solid)Semi-Hollow (Semi-Solid)

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Semi-Solid SpraySemi-Solid Spray

• Semi-Solid Spray is used:– With retention head burners– When there is a very small space inside the end cone

where there should be no oil droplets and no swirling air.

• Semi-Solid Spray is used:– With retention head burners– When there is a very small space inside the end cone

where there should be no oil droplets and no swirling air.

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Spray PatternSpray Pattern

• These are a rule of thumb. With the advent of newer and higher efficiency systems you must use the manufacturer recommended nozzles.

• These are a rule of thumb. With the advent of newer and higher efficiency systems you must use the manufacturer recommended nozzles.

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Nozzle FunctionsNozzle Functions

• Delivers the oil in a specific angle of spray.– The resulting flame must fit into the combustion

chamber– It can not hit on (or impinge on) the floor or the side

walls– It must have a uniform spray angle

• Delivers the oil in a specific angle of spray.– The resulting flame must fit into the combustion

chamber– It can not hit on (or impinge on) the floor or the side

walls– It must have a uniform spray angle

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ImpingementImpingement

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Solved ImpingementSolved Impingement

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Nozzle FunctionsNozzle Functions

• The nozzle cleans the oil up by the inline strainer.• The nozzle cleans the oil up by the inline strainer.

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How it worksHow it works

• The oil enters the swirl chamber at the end of the nozzle at 100 psi.

• The swirl chamber converts this pressure into velocity and rotation.

• The swirl chamber creates the:– Hollow spray pattern– Solid spray pattern– Special or semi-solid spray patterns

• The oil enters the swirl chamber at the end of the nozzle at 100 psi.

• The swirl chamber converts this pressure into velocity and rotation.

• The swirl chamber creates the:– Hollow spray pattern– Solid spray pattern– Special or semi-solid spray patterns

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Nozzle PerformanceNozzle Performance

• All nozzles are rated for 100 psi of pressure.• If the pressure changes the rating is no longer

valid.

• All nozzles are rated for 100 psi of pressure.• If the pressure changes the rating is no longer

valid.

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Low PressureLow Pressure

• A nozzle at low pressure will have– A weak spray pattern– Under fires burner– Droplets of oil are larger and that lowers efficiency and

increases smoke.

• A nozzle at low pressure will have– A weak spray pattern– Under fires burner– Droplets of oil are larger and that lowers efficiency and

increases smoke.

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High PressureHigh Pressure

• High pressure nozzles:– Create smaller droplets– Increase the flow rate– Are sometimes better for cold oil and ignition problems.

• High pressure nozzles:– Create smaller droplets– Increase the flow rate– Are sometimes better for cold oil and ignition problems.

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Effects of pressureEffects of pressure

• Some manufacturers are:– Using higher pump pressures, up to 300 psi.– Lowering nozzle size– Gaining efficiency (makes the burners burn cleaner)

• Some manufacturers are:– Using higher pump pressures, up to 300 psi.– Lowering nozzle size– Gaining efficiency (makes the burners burn cleaner)

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Temperature and the nozzleTemperature and the nozzle

• The higher the temperature the lower the viscosity of the oil.

• As the temperature drops:– The oil thickens– Less swirl in the chamber– Higher flow– More fuel and larger droplets are created.

• This problem is called “cold oil”

• The higher the temperature the lower the viscosity of the oil.

• As the temperature drops:– The oil thickens– Less swirl in the chamber– Higher flow– More fuel and larger droplets are created.

• This problem is called “cold oil”

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Nozzle Spray AngleNozzle Spray Angle

• The spray angle of the nozzle is 30 to 90 degrees.

• Most common are:– 30– 45– 60– 70– 80– 90

• The spray angle of the nozzle is 30 to 90 degrees.

• Most common are:– 30– 45– 60– 70– 80– 90

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Nozzle Spray AngleNozzle Spray Angle

• The nozzle spray needs to fit the combustion chamber.– Round or square combustion chambers use a 70-90

degree nozzle. • With a hollow or semi-solid pattern

– Long and narrow combustion chambers use a 30 - 70 degree nozzle

• With a solid pattern

• The nozzle spray needs to fit the combustion chamber.– Round or square combustion chambers use a 70-90

degree nozzle. • With a hollow or semi-solid pattern

– Long and narrow combustion chambers use a 30 - 70 degree nozzle

• With a solid pattern

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Nozzle Spray AnglesNozzle Spray Angles

• The spray angle must allow the flame to burn in suspension, meaning it will not hit any walls or floor in the combustion chamber.

• If it hits the walls it will cause smoke and soot. This is called impingement.

• The spray angle must allow the flame to burn in suspension, meaning it will not hit any walls or floor in the combustion chamber.

• If it hits the walls it will cause smoke and soot. This is called impingement.

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Nozzle Care and ServiceNozzle Care and Service

• Never change the inner parts.• Keep in carton until ready to use.• Keep clean when handling• Clean nozzle line with clean oil (J-Tube or Jet

Tube)• If you spot oil drops on nozzle tip or chamber

floor this indicates a bad adaptor or nozzle, change them.

• Never change the inner parts.• Keep in carton until ready to use.• Keep clean when handling• Clean nozzle line with clean oil (J-Tube or Jet

Tube)• If you spot oil drops on nozzle tip or chamber

floor this indicates a bad adaptor or nozzle, change them.

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Nozzle Care and ServiceNozzle Care and Service

• Never re-use an old nozzle. They CAN NOT BE CLEANED!

• In case of a clogged nozzle orifice you can clean with a toothpick, never use metal. Then you must change it at first opportunity.

• ALWAYS REPLACE A NOZZLE WITH A NEW ONE!

• Never re-use an old nozzle. They CAN NOT BE CLEANED!

• In case of a clogged nozzle orifice you can clean with a toothpick, never use metal. Then you must change it at first opportunity.

• ALWAYS REPLACE A NOZZLE WITH A NEW ONE!

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Nozzle SizingNozzle Sizing

• The gallons per hour must be sized correctly.• Under sizing a nozzle will reduce capacity and

possibly increase smoke.• Over sizing the nozzle will reduce the life of

equipment by burning out heat exchanges and combustion chambers.

• The gallons per hour must be sized correctly.• Under sizing a nozzle will reduce capacity and

possibly increase smoke.• Over sizing the nozzle will reduce the life of

equipment by burning out heat exchanges and combustion chambers.

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Nozzle SizingNozzle Sizing

• Name plate will have the nozzle size or BTU ratings.

• If missing use the following:– GPH = BTU INPUT/140,000

• If BTU Input is missing use the output divided by 112,000 (GPH of oil at 80%)

• Name plate will have the nozzle size or BTU ratings.

• If missing use the following:– GPH = BTU INPUT/140,000

• If BTU Input is missing use the output divided by 112,000 (GPH of oil at 80%)

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Nozzle SizingNozzle Sizing

• If the name plate indicates the square feet of steam convert the square feet of steam to Output BTU’s by:– Ft2 Steam X 240

• If the name plate indicates the square feet of hot water, convert to Output BTU’s by:– Ft2 of Hot Water x 165

• If the name plate indicates the square feet of steam convert the square feet of steam to Output BTU’s by:– Ft2 Steam X 240

• If the name plate indicates the square feet of hot water, convert to Output BTU’s by:– Ft2 of Hot Water x 165

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