Wallace & Tiernan SERIES V-2000, Manual

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WT.025.055.004.UA.IM.0814
MANUAL CHLORINATOR - 3000LB/24HR
EVOQUA W3T109620
3.3 Theory of Operation
Evoqua Water Technologies Gas Feeders and accessories are designed to control
and indicate the rate of flow of chlorine, to provide a simple means of manually
setting the feed rate at any value within the range of the machine, to mix the
gas with water, and to deliver the resultant solution to the point of application.
In the gas feeder described in this manual, the function of the injector is to
produce a vacuum to draw gas from the control module and to mix this gas
with the water flowing through the injector. A diaphragm check is built into the
injector to prevent a back flow of water into the control module if the injector
water supply is shut off with pressure on the injector discharge or if the injector
discharge line is restricted. Proper operation of the injector is dependent on
the inlet pressure being sufficiently higher than the discharge pressure. In the
control module, the differential regulating valve throttles the injector vacuum
to maintain a constant drop across the V-notch variable orifice. Thus the flow
through the orifice is entirely a function of the size of the orifice as determined
by the position of the V-notch plug as manually set by the operator.
Gas under pressure enters the vacuum regulator. From the vacuum regulator,
the gas, under a controlled vacuum, passes to the control module through con-
necting pipes and then through a rotameter (feed rate indicator) causing the
float to indicate the rate of flow on an easily read scale. As stated above, the
rate of flow is controlled by the position of the V-notch variable orifice across
which a constant differential at less than atmospheric pressure is maintained
by the operation of the differential regulating valve. From the differential
regulating valve, gas passes to the injector where it is mixed with water. The
resultant solution is discharged to the point of application.
3.3.1 2" Injector Manual Operation (See Dwg. 25.100.181.011)
• Application Against Pressure
When the three-way valve is in the ON position, water flows from the injec-
tor inlet through a strainer (A) and the three-way valve (B) to the chamber
(C). Pressure in the chamber (C) overcomes the force of the spring (D) and
opens the plug (E) the distance determined by the setting on the adjuster
screw (F), permitting water to flow through the injector. The flow of water
through the injector creates a vacuum, which pulls the diaphragm (G),
which opens the seat (H) and permits gas to be drawn from the gas feeder.
When the three-way valve is turned to the OFF position, pressure in the
chamber (C) is relieved and a spurt of water passes through the OFF port
in the three-way valve to waste. The spring (D) closes the plug (E) and, with
no water flowing through the injector to create a vacuum, the spring (J)
closes the seat (H) to prevent water on the injector discharge from backing
up into the gas feeder.