Fdny A35 Exam Questions and Answers 100% Pass
How do air compressors work - ANSWER -take the air in a room and force it into
a container UNDER PRESSURE. The more air forced into the container, the
greater the pressure. Compressed air can be discharged from the container at a
controlled rate.
Most common air compressor - ANSWER -Reciprocating
Air compressors are sometimes called - ANSWER -air pumps
Air compressors can be powered by: - ANSWER -(1) electric motors;
(2) internal combustion engines; or
(3) steam turbines
Explosions & air compressors - ANSWER -If there is a build up of flammable
gases (ex: in service stations and workshops), those gases are heavier than air and
fall to the floor before spreading outward. These gases are easily ignited by sparks
and high temperatures--which INCLUDES the heat generated by an air
compressor.
To avoid explosions w/ air compressors - ANSWER -Raise air compressor at
LEAST 5 feet above ground level so that no flammable gases are drawn into the
compressor. To meet the height requirement you can place compressor on a shelf
or bench OR the air receiver tank may be turned and stood on end w/ the air
compressor bolted to the top of the tank.
Power to air compressor - ANSWER -entire unit is driven by an electric motor.
Motor activates a series of drive belts. Belts power the moving parts of the unit--
like w/ power steering and alternator in automobile
Compression Chamber operation - ANSWER -Air is compressed in compression
chamber which consists of a PISTON inside a CYLINDER. Piston moves up and
down.
, When piston moves down -->draws air into cylinder, through INTAKE VALVE
(valve automatically opens when piston moves down).
When piston moves up-->air is compressed (intake vale automatically closes to
avoid air escaping from cylinder).
Air Reciever Operation - ANSWER -When air pressure reaches a certain level, it
forces open a DISCHARGE VALVE (which is spring loaded). This releases
compressed air into air reciever (aka air tank), which is what supplies compressed
air when needed.
Single Stage Air Compressor - ANSWER -with one cylinder and one piston
Multi Stage Air Compressor - ANSWER -with more than one piston and cylinder.
Each cylinder will increase the pressure of the air by taking air from the discharge
side of the previous cylinder and increasing the pressure to a new level. Once it
reaches the last level, the pressurized air is discharged into the reciever.
As air is compressed it becomes - ANSWER -heated.
This is why in a multi stage air compressor there is an intercooler between stages
of compressor.
Exception to single stage/multi stage distinction - ANSWER -CAVEAT: there are
air compressors with multiple pistons and cylinders that are single stage but these
are only the ones where each cylinder discharges directly into air receiver (unlike a
true multi stage air compressor).
Storage containers - ANSWER -some systems force the compressed air from the
receiver into storage containers allowing it to be used later as needed.
How do air compressors work - ANSWER -take the air in a room and force it into
a container UNDER PRESSURE. The more air forced into the container, the
greater the pressure. Compressed air can be discharged from the container at a
controlled rate.
Most common air compressor - ANSWER -Reciprocating
Air compressors are sometimes called - ANSWER -air pumps
Air compressors can be powered by: - ANSWER -(1) electric motors;
(2) internal combustion engines; or
(3) steam turbines
Explosions & air compressors - ANSWER -If there is a build up of flammable
gases (ex: in service stations and workshops), those gases are heavier than air and
fall to the floor before spreading outward. These gases are easily ignited by sparks
and high temperatures--which INCLUDES the heat generated by an air
compressor.
To avoid explosions w/ air compressors - ANSWER -Raise air compressor at
LEAST 5 feet above ground level so that no flammable gases are drawn into the
compressor. To meet the height requirement you can place compressor on a shelf
or bench OR the air receiver tank may be turned and stood on end w/ the air
compressor bolted to the top of the tank.
Power to air compressor - ANSWER -entire unit is driven by an electric motor.
Motor activates a series of drive belts. Belts power the moving parts of the unit--
like w/ power steering and alternator in automobile
Compression Chamber operation - ANSWER -Air is compressed in compression
chamber which consists of a PISTON inside a CYLINDER. Piston moves up and
down.
, When piston moves down -->draws air into cylinder, through INTAKE VALVE
(valve automatically opens when piston moves down).
When piston moves up-->air is compressed (intake vale automatically closes to
avoid air escaping from cylinder).
Air Reciever Operation - ANSWER -When air pressure reaches a certain level, it
forces open a DISCHARGE VALVE (which is spring loaded). This releases
compressed air into air reciever (aka air tank), which is what supplies compressed
air when needed.
Single Stage Air Compressor - ANSWER -with one cylinder and one piston
Multi Stage Air Compressor - ANSWER -with more than one piston and cylinder.
Each cylinder will increase the pressure of the air by taking air from the discharge
side of the previous cylinder and increasing the pressure to a new level. Once it
reaches the last level, the pressurized air is discharged into the reciever.
As air is compressed it becomes - ANSWER -heated.
This is why in a multi stage air compressor there is an intercooler between stages
of compressor.
Exception to single stage/multi stage distinction - ANSWER -CAVEAT: there are
air compressors with multiple pistons and cylinders that are single stage but these
are only the ones where each cylinder discharges directly into air receiver (unlike a
true multi stage air compressor).
Storage containers - ANSWER -some systems force the compressed air from the
receiver into storage containers allowing it to be used later as needed.
