Product specifications

6
UNIT FEATURES: SCROLL COMPRESSORS (CONT.)
Scroll
No Valves
Piston
Suction & Discharge Valves
No Valve Losses
Complete & Continuous
Compression
Valve Losses
Re-expansion Volume
Suction Valve Discharge Valve
Suction
Pocket
High Pressure
Pocket
Intermediate
Pocket
Discharge
12
3
4
2 Parts
9 Parts Per Cylinder
Fixed
Scroll
Orbiting
Scroll
Piston
Ring
Suction
Reed
Piston
Valve
Plate
Discharge
Reed
Gasket
Body
Rod
Wrist
Pin
High Pressure Gas
Low Pressure Gas High Pressure Gas
Low
Pressure
Gas
Scroll Compressor Design is based around two
identical spirals or scrolls that, when inserted together,
form crescent-shaped compression pockets. During a
compression cycle, one scroll remains stationary while
the other orbits around the first. As this motion occurs,
gas is drawn into the scrolls and moved in increasingly
smaller pockets toward the center. At this point, the
gas, now compressed to a high pressure, is discharged
from a port in the center of the fixed scroll to the
condenser.
During each orbit, several pockets of gas are compressed
simultaneously, creating smooth, nearly continuous
compression. Figures 3a, 3b and 3c show the
compression cycle and comparisons to reciprocating
compressors.
Suction and Compression Cycles occur
simultaneously but only four portions of the continuous
Compression Cycle are shown for clarity purposes. (See
Figure 3a).
•1.The suction cycle occurs when the suction
pocket opens and enlarges, causing a low
pressure area in the suction pocket, drawing
suction gas into the chamber. The suction
pocket then closes and the compression cycle
begins.
•2.The Intermediate Compression Cycle is
continuous as the orbiting scroll moves and
compresses the refrigerant gas.
•3.The high pressure pocket forces the high
pressure gas to the discharge port at the top
of the fixed scroll.
•4.The high pressure gas is forced through the
discharge port and the discharge check valve
at the top of the fixed scroll.
Scroll Compressors have few moving parts, as
compared to Reciprocating Compressors. Fewer moving
parts, and the smooth continuous rotary scroll
compression cycle, ensures a long, quiet operating,
compressor life. (See Figure 3b).
Complete and Continuous Compression
Cycle of the Scroll Compressor, with no Valve or Re-
Expansion Volume losses, provide a smooth running,
quiet, efficient, compressor. (See Figure 3c).
Figure 3a Scroll Compression Cycle—How A
Scroll Works
Figure 3b Scroll vs. Reciprocating
Few Moving Parts
Figure 3c Complete and Continuous
Compression Cycle