2.9.1.1
Vacuum Regulator
The vacuum regulator shall mount directly on the chlorine supply cylinder
and shall regulate the flow of gas from the cylinder into the system. If
vacuum is lost, the regulator shall seal off the gas supply from the
cylinder. A vent valve shall be provided on the regulator to release any
gas in the system that is under positive pressure to the outdoors through a
vent line.
2.9.1.2
Flow Meter
The flow meter shall be of the rotometer type and shall indicate flow rate
in kg pounds of gas per 24 hours. The meter range shall be from 0 to
[_____] kg pounds per 24 hours.
2.9.1.3
Flow Proportioning Valve
The flow proportioning valve shall meter the chlorine gas as it passes the
ejector. The position of the valve, as set by the proportioner, shall
determine the chlorine flow rate. The unit shall allow for manual
adjustment of chlorine dosage between l and 8 mg/L. The dosage shall
remain constant from low wastewater flows to peak flow conditions through
the action of the flow proportioning valve.
2.9.1.4
Proportioner
The proportioner shall position the flow proportioning valve in response to
electric signals received from a wastewater flow measuring device specified
in paragraph FLOW METERING AND CONTROL. Control devices shall conform to
NEMA ICS 1. The proportioner shall move the proportioning valve by way of
a bidirectional electric motor/actuator NEMA Type 4X conforming to NEMA MG 1.
Enclosures shall be NEMA 250 [Type 12] [_____]. Feedback signals from the
valve shall indicate to the proportioner when it is in the proper position
relative to the wastewater flow signal.
2.9.1.5
Ejector
The ejector shall create a vacuum on the chlorine gas system and shall mix
the gas with the water flowing through the ejector. A check valve shall be
incorporated with the ejector to prevent water from flowing into the gas
system. The ejector shall be constructed of PVC plastic or other material
suitable for service in the highly corrosive wet chlorine atmosphere. The
ejector shall be sized to provide sufficient vacuum for operating the
system over its full range. The ejector shall be mounted in the piping
which connects the booster pump to the diffuser and shall be located as
close to the diffuser as practicable.
2.9.2
Booster Pump
An electric motor driven, close-coupled, centrifugal pump shall be provided
to supply water to the chlorinator ejector assembly. The pump shall be
designed for continuous duty and shall be sized as required for proper
operation of the ejector. The pump and motor shall be suitable for outdoor
service or shall be enclosed in a weatherproof housing. A magnetic starter
with start and stop push buttons and a circuit breaker with manual reset
pushbutton in accordance with NEMA ICS 1 shall be provided, all enclosed
within a NEMA 250, Type 4 enclosure. The pump motor shall be totally
enclosed fan cooled conforming to NEMA MG 1 and shall be [_____] volts ac
SECTION 11390
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