37-1-614 Page 20
FIGURE 3-2– INLET WATER INJECTION DIAGRAM
TYPE OF SERVICE
– The blower can be operated in either pressure or vacuum service.
Pressure
– Never operate the blower above the maximum pressure shown in
FIGURE 3-1, page 19. Excessive pressure may cause overheating and blower failure, it is therefore most
important to have an accurate pressure gauge in the discharge line as close to the blower discharge as
possible. Reduced speeds have a direct affect on allowable pressure (FIGURE 3-6 page 23 ). A bypass
valve to bleed air from the discharge to atmosphere (
FIGURE 2-2
, page 11) may be used to control the
pressure. NEVER reduce the blower speed to maintain a certain pressure before it is determined if the
reduced speed is adequate for that pressure. An accurate pressure gauge must be maintained.
7CDL11 7CDL14 7CDL17
Liquid Rate
(GPM)
2 2 2
FIGURE 3-3 – LIQUID RATE
Vacuum
– The blower may be operated either in dry vacuum or wet vacuum service. Do not operate the
blower above the maximum vacuums shown in
FIGURE 3-1, page 19, or below the minimum speed shown in FIGURE 3-6, page 19. All vacuum ratings
are based on standard atmospheric discharge. An accurate vacuum gauge and vacuum relief valve must
be used as close to the blower inlet as possible.
Wet vacuum service employs a suitable liquid, normally water, injected into the system near the blower
inlet to control temperature rise and increase the degree of vacuum developed. The liquid used MUST
BE clean and free of foreign matter, chemical contaminants and hardness, which may cause corrosion,
deposits, or damage in the rotor chamber. See
FIGURE 3-2
, for typical installation, and
FIGURE 3-4
,
page 21 for water quality requirements. If the proposed water supply is questionable, or does not meet
the water specification, a reputable water treatment service company should be contacted. They can
recommend treatment and equipment to satisfy this specification.
