for normal operating conditions. At times, however,
use this system if the continuous injection system is
contamination levels will present hazards to engineering
inoperative, if the system needs additional chemicals to
compensate for an improper pump stroke setting, or
equipment and systems. In these cases, you must use
during a casualty. The procedure for batch injecting
special procedures to correct the problems. In the
chemicals is described in the EOSS (WHBP). You must
following paragraphs, we will discuss the procedures
strictly adhere to this procedure.
you will use for both normal and abnormal
contamination levels. First, let's look at the normal
SPECIAL PROCEDURES.-- You can control low
routines.
levels of seawater contamination by using the normal
dosage tables and blowdowns as long as you first
ROUTINE PROCEDURES.-- Using the correct
identify the source of contamination and correct it.
routine chemical treatment procedures will help you
There are times, however, when contamination levels
keep boiler water contamination levels under control.
may exceed the normal control limits. At these times,
During normal boiler operations and when a normal
you may need to use special treatment procedures.
depletion of treatment chemicals has occurred, you
While assigned to the oil lab, you must be able to
should follow the steps in the logic chart shown in figure
recognize the symptoms of excessive contamination and
2-12. Study these steps and pay particular attention to
the steps you need to take to correct them. Some of the
the options associated with each step.
abnormal conditions you may face are excessive
For normal operations, you can generally provide
seawater contamination, chemical hideout, and
the recommended control limits by using two methods:
chemical carryover. For some of these problems, you
(1) the continuous chemical injection system and (2) the
must use special chemical treatment plans; for others,
batch chemical injection system. First, let's talk about
you must use blowdowns. Before you start to treat a
the preferred method, the continuous chemical injection
problem, however, you must first identify the condition
system.
or agent that caused it.
Continuous Chemical Injection System.-- For
Seawater.-- You can recognize serious seawater
Navy ships, the continuous chemical injection system is
contamination by the following symptoms:
the preferred treatment method. You should check this
Alkalinity of 0.00 epm
system to make sure it is operating properly. When the
system is operating properly and outside contamination
Chloride greater than 2.0 epm
has not occurred, you should have very few cases
This condition is serious. You should recognize these
requiring batch chemical injections. Normally, the
symptoms and realize that this condition requires special
continuous injection pump stroke setting is 60 percent
treatment. When serious contamination occurs, inject
(1 gallon per hour of treatment chemical). This setting
only TSP according to the following formula:
can be changed if two consecutive samples show low
levels of alkalinity and phosphates. In this case, you can
CONSECO TSP = 60 x chloride
increase the injection pump stroke in 10 percent
CE
TSP = 30 x chloride
increments until the proper levels are maintained. If the
alkalinity and phosphates are continually over the upper
where: TSP = grams trisodium phosphate, dodeca-
limit, then reduce the pump stroke in 10 percent
hydrate chloride = tiller water chloride, epm
increments until proper levels are maintained.
Remember, the continuous injection system does
NOTE
not operate automatically when the generator is started.
You must start the system within 30 minutes after the
generator is started and secure it as soon as the generator
Do not inject more than 500 grams (18
is stopped. You must also monitor the tank level to make
ounces) of TSP at one time.
sure the treatment solution is entering the boiler. Record
the tank level and the pump stroke in the boiler water
Chemical hideout and carryover also contribute to
log within 30 minutes after start-up and at least every 8
chemistry control problems. These two conditions, if not
hours thereafter. Refill the injection tank when the level
properly handled, can also cause boiler damage.
drops to between 10 and 20 gallons.
Chemical Hideout.-- The chemical hideout seen
Batch Injection System.-- In certain occasions, you
in waste heat boilers is caused by concentration of
will need to use the batch injection system. You should
boiler water chemicals. The symptoms of chemical
