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"Oil-Less" Scroll Laboratory Air
1.0 General Information
1.1 Component Description
NOTE: The features listed in this section are
standard for laboratory air systems. In the case of
special system confi gurations, these features may
or may not be included with the system.
System Design
The Scroll Laboratory Air SPC (Single Point
Connection) system consists of a single point
connection, base mounted design including the
following:
•
Oil-less scroll compressors and motors
•
Duplexed desiccant drying system with purge
control
•
Duplexed line fi lters and regulators
•
Dew Point transmitter
•
Integral, pre-wired, U.L. labeled control panel
•
Corrosion resistant air receiver
The complete package is pre-wired, pre-piped, and
assembled on one common base with single point
connections for electrical, intake air, discharge air,
and condensation drain. Each system includes
valving to allow complete air receiver bypass, as
well as air sampling port.
Compressor Module
The compressor is a continuous duty rated scroll
type compressor. The design is single stage, air-
cooled, consisting of one fi xed and one orbiting
scroll sealed with PTFE tip seals between the
scroll halves and rated for 120 psig discharge
pressure. The scrolls are protected from dust or
contamination with a two part face seal. Orbiting
bearings for scrolls are grease fi lled which require
grease lubrication. See Section 5 for recommended
compressor maintenance. The drive bearing is
grease fi lled and lip sealed for its maintenance
interval. The scroll case is constructed of diecast
aluminum. Maximum heat dissipation is achieved
through an integral cooling fan and air ducting.
Compressor Drive and Motor
The compressor is v-belt driven and protected by
an OSHA approved totally enclosed beltguard. A
sliding motor mounting base that is fully adjustable
with two adjusting screws is incorporated to
achieve belt tensioning. The motor is a NEMA
rated, open dripproof, with 1.15 service factor
suitable for 208 or 230/460V electrical service.
Intake
Each compressor has one inlet air fi lter. The inlet
fi lter removes dust from the incoming air through
cyclonic action and through an element.
Discharge Piping
Each compressor is equipped with an integral
air-cooled aftercooler designed for a maximum
approach temperature of 15° F complete with
automatic solenoid drain valve. Each compressor
is equipped with a wired high discharge air
temperature shutdown RTD. The compressor
discharge line includes a fl ex connector, safety
relief valve, isolation valve and check valve. The
discharge piping of each compressor incorporates
an integral valve to provide load-less starting and
rapid air evacuation between the check valve and
scroll discharge at shutdown to minimize reverse
rotation of the scroll. The discharge air piping is
made of brass and/or stainless steel. The discharge
fl ex connector is braided, 304 stainless steel, brass,
or bronze.
Isolation System
The compressor and motor shall be fully isolated
from the system base by means of a four-point,
heavy duty, isolation system for a minimum of 95%
isolation effi ciency. Seismic isolation is optional.
Dryer
Each desiccant dryer is individually sized for peak
calculated demand and capable of producing
a 10°F (-12°C) pressure dew point. Dryer purge
fl ow is minimized through a demand-based purge
saving control system that includes a 441™ transfer
valve utilizing two ceramic slide plates. The inlet
to each dryer includes a mounted prefi lter with
automatic drain and element change indicator.
1-1
4107 9006 25.11
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