Low Pressure Boilers Ch. 5

When burning No.6 fuel oil, the strainers should be cleaned at least once every _____ hours.

24

________ coal is a hard coal.

Anthracite

A dirty strainer results in low suction readings.

False

A fuel oil heater is required when using No. 2 fuel oil.

False

A metal scraper is used to clean deposits on a fuel oil burner nozzle.

False

Grates are only needed in hand-fired coal boilers to support the coal.

False

Hard coal has a high volatile content.

False

In an air atomizing burner, steam and fuel are discharged to the burner for combustion.

False

It is best to burn fuel oil with a low flash point.

False

Propane is lighter than natural gas and requires special handling.

False

Rotary cup burners can burn only No. 2 fuel oil.

False

Stokers were developed to reduce the amount of coal fed to the furnace.

False

The flame scanner proves the main flame only.

False

The flash point of fuel oil is the temperature at which it will resist burning.

False

The manual reset valve in the low pressure gas system closes if the boiler has a high water level.

False

The viscosity of fuel oil is the temperature at which it will burn continually when exposed to an open flame.

False

_______ coal is coal that is ground to a fine powder.

Pulverized

A fuel oil relief valve is located between the fuel oil pump and the fuel oil discharge valve.

True

A therm is the quantity of gas required to produce 100,000 Btu.

True

Air used to atomize fuel oil is primary air.

True

Anthracite coal is hard coal.

True

Bituminous coal is soft coal.

True

Boilers burning soft coal need large furnace volumes to complete combustion.

True

Cold fuel oil in the tank will give a high suction reading.

True

Complete combustion is achieved in a gas burner by supplying the proper mixture of air and gas to the furnace.

True

Fuel oil and gas are the most commonly used fuels in low pressure boilers.

True

Fuel oil burners commonly use atomizing burners.

True

Fuel oil in the storage tank must be kept below its flash point temperature.

True

Fuel oil is a liquid fossil fuel.

True

Fuel oil to be removed from the burner nozzle is purged with air.

True

Gases of combustion that contact boiler heating surfaces before combustion is completed cause soot and smoke.

True

In a low pressure gas system, before the manual reset valve can be opened, the pilot must be lit.

True

In a rotary cup burner, the solenoid valve controls the flow of fuel through the fuel tube.

True

Natural gas is a colorless and odorless fossil fuel.

True

No. 6 fuel oil must be heated to the proper temperature in order to burn.

True

Plant flexibility is increased with the use of a combination burner.

True

Pour point is the lowest temperature at which fuel oil will flow as a liquid.

True

Purging the lines and nozzles of an air atomizing burner at the end of its firing cycle keeps lines and nozzles clean for the next starting cycle.

True

Rotary cup burners atomize fuel oil using a spinning cup and high-velocity air.

True

Secondary air is needed to burn the fuel oil efficiently.

True

Smoke is a sign of incomplete combustion.

True

Smoke is less of a problem when burning hard coal as compared to soft coal.

True

Starting the fuel oil pump with its discharge valve closed causes the relief valve to open.

True

Stoker firing allowed the design of larger coal-fired boilers.

True

The air atomizing burner uses compressed air to mix with the fuel oil to achieve a high degree of atomization.

True

The fire point temperature is higher than the flash point temperature.

True

The fuel oil pump should be started with its discharge valve open.

True

The furnace must be purged after any flame failure.

True

The temperature of the fuel in the fuel oil tank should be maintained at approximately 100°F.

True

The temperature of the fuel oil in the storage tank must be kept above the recommended pour point.

True

The type of fuel used determines the fuel system accessories required.

True

The rotary cup burner uses ______ to atomize the fuel oil.

a spinning cup and high velocity air

A(n) _______ is an air pressure-activated switch that closes after proving sufficient pressure of combination air from the forced draft fan.

air proving switch

Hard coal is __________ .

anthracite coal with a high carbon content

Soft coal is ______________.

bituminous coal with a high volatile content

In a high pressure gas burner, the gas mixes with the air on the inside of the ________ .

burner

A high vacuum on fuel oil suction gauge normally indicates ________ .

cold fuel or a dirty strainer

Fuel oil burners are designed to provide fuel oil to the furnace in a ______ .

fine spray

A(n) _______ is a safety device that senses if the pilot light and/or main flame are lit.

flame scanner

A combination burner allows the operator to switch fuels ___________ .

for economy, if there is a shortage of a fuel, if there is a failure in the fuel system being used

The ____ pump draws fuel oil from the fuel oil tank.

fuel oil

When cleaning a fuel oil strainer, the ____ must be carefully replaced to prevent air from entering the system.

gasket

In a low pressure gas burner, gas is mixed with air in the ____________ .

mixing chamber before the burner register

On a low pressure gas system, the manual reset cannot be opened until the _________ .

pilot is lit

The _____ of fuel oil is the lowest temperature at which it will flow as a liquid.

pour point

In a high pressure gas system, the plant pressure ________ valve reduces gas pressure to the line pressure used in the system.

regulating

The _____ valve protects the fuel lines and pump from excessive pressure.

relief

A _______ is a mechanical device for feeding coal consistently to the burner.

stoker

A(n) ________ sensor senses light frequencies that are higher than those visible to the eye.

ultraviolet

A ____ is a narrowed portion of the tube.

venturi