122.6006.9
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2.2.3
Reconnect nozzle and check valve assembly to diffuser. The nozzle may extend through the
assembly from either side. A gasket should be on each side. Screw the nozzle into the diffuser
HAND TIGHT.
(The check valve assembly may be installed in any position.)
2.2.4
Other types of diffuser and ejector installations may be desired for certain applications:
a.
The ejector (nozzle and check valve assembly) may be located near the vacuum regulator.
A wall mounting bracket is available for field assembly, and the universal diffuser can be
modified for a pipe or hose connection.
b.
The entire diffuser-ejector assembly may be submersed in an open channel or tank.
c.
Diffuser tubes with corporation stops can be supplied for either close-coupled or remote
ejectors.
2.3
Ejector Vacuum
The ejector creates a vacuum only when sufficient pressure differential exists between the ejector inlet
water versus the water outlet pressure.
For example, if the diffuser were discharging into an empty basin (zero back pressure), the supply
pressure to the nozzle requires about 25 psig (2 bar) to create enough vacuum to operate a 50 PPD
(1 kg/h) vacuum regulator. A lower supply pressure or a higher back pressure would reduce the gas
flow rate.
Then for each 1 psig (0.07 bar) of back pressure above zero, the supply pressure must be increased
about 2 to 3 psig (0.1 to 0.2 bar) above 25 psig (2 bar). A back pressure of 10 psig (0.7 bar) would
therefore require about 55 psig (4 bar) supply pressure in order to operate the 50 PPD (1 kg/h) vacuum
regulator. Also, the water supply line to the nozzle must be large enough to allow sufficient water flow
(3/4" or larger pipe is recommended) and minimize friction losses.
2.4
Piping
For most installations, the ejector water supply line should be brought to within 4-6 ft. (1-2 m) of the
nozzle with rigid copper or iron pipe. A shutoff valve followed by a Y-strainer, and a hose adapter or pipe
union should be installed to allow removal for service. A pressure gauge between the Y-strainer and the
ejector can be a useful service tool.
If the hose is used, connect the hose between the hose adapter or pipe union and the ejector nozzle.
Clamp the hose securely at both ends with single or double clamps.
2.5
Vacuum Connections
- See Figure 1 and Introduction, Gas Flow section Table A.
Black polyethylene tubing is normally used for the vacuum line between the vacuum regulator and
ejector. Use enough length for each line to allow vacuum regulator movement from one cylinder to
another.
2.5.1
Remove the connector nut from the vacuum regulator connection and slip onto the tubing. Push
the tubing onto the connector and tighten connector nut
HAND TIGHT
.
