WATER TREATMENT

Transcription

WATER TREATMENT
WATER TREATMENT
Vecom Marine
clean ships - clean seas
LOW PRESSURE BOILER
WATER TREATMENT
UP TO 28 KG/CM2
Treatment:
BOILER TREAT
CONDENSATE CONTROL
(if necessary - in case of oxygen corrosion)
Test Kit:
"P" ALKALINITY
CHLORIDES (or TDS)
pH (for condensate)
Initial Dosage:
BOILER TREAT
1 lt./ton
CONDENSATE CONTROL 250 ml/ton/
daily
Recommended Limits:
“P” ALKALINITY 100 - 150 PPM
CHLORIDES
max 100 PPM
if using distilled water.
Never exceed 300 PPM
if using raw water
pH (condensate) 8,3 - 9,0
Total Dissolved Solids:
Above 600 PPM of TDS
Increase top & bottom blowdown
Below 600 PPM of TDS
IDEAL - reduce daily blowdown to avoid
wasting chemicals, water & energy
This information is not to be taken as a warranty or representation for which we assume legal responsibility, nor as
a permission, inducement or recommendation to practice
any patented invention without a license. The information
is offered solely for your consideration, investigation and
verification.
INTRODUCTION
The VECOM TEST SET 3 for motor vessel, is designed for routine testing of
water samples to ensure that correct operating conditions are maintained.
The SINGLE TUBE low-pressure boilers, I.E. QUICK VAPORIZATION BOILERS
(without accumulation of steam) are subject to corrosion even after only
one or two years of operation under the action of oxygen which becomes
more active in the presence of a carbonic acid. That can occur despite
the use of distilled water and treatment with BWT ONE SHOT. In order to
reduce the corrosive effect of oxygen, when that type of boiler is used for
production of steam only occasionally, one should leave a reserve of sulfite
of 20 to 30 PPM (mg/l) in the water to protect the serpentine from corrosion.
When the boiler is in use, the level of hydrazine should be maintained at
0,05 to 0,10 PPM.
GENERAL
All tests of boiler and cooling water should be carried out on cooled,
representative samples of water. Such samples are best obtained through
a sample cooler after allowing adequate time for pipe-work and the cooler
to be thoroughly flushed through. In the case of boilers, samples taken from
gauge cocks may be used provided that:
1. It is recognized that such samples will be slightly concentrated by the
evolution of flash steam.
2. The correct sampling procedure is followed, to avoid dilution of the
sample with gauge glass condensate.
3. Your VECOM MARINE representative will demonstrate the correct
technique for doing this.
The order in which tests are conducted does not really matter, but most tests
depend on counting drops of liquid. Do the tests when you are not likely to
be interrupted. If you lose count, discard the sample and start again. The
reliability of any chemical test depends upon a few simple rules, suggested
good practices are:
1. Always keep your equipment clean.
2. Before testing a sample, wash out the sample-testing jar with some of
the water of the sample. Discard this washing before filling the bottle
to its mark.
3. Use only dropping bottles with clean nozzles. Dried reagent affects the
size of drop dispensed. Wipe off any crystals or other incrustation with
a clean paper tissue before use and dispose of the tissue in a safe place.
RECOMMENDATIONS
• If pH rises at the same time of conductivity, seawater contamination has
probably occurred.
• If rapid increase of conductivity occurs, check for chlorides
contamination in reserve FEED WATER TANKS.
• If feed supply is acceptable, check condensate combined returns.
• The pH of condensate is affected mainly by formation of carbonic acid
as a result of carbon dioxide being present in the system. Once typical
levels for a system are found, the dosage should not vary dramatically,
but fluctuate a little with load charge.
Note: If BOILER “SALTS” are high, CO2 levels in condensate increase, lowering
pH, due to carbonic acid formation.
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The majority of loss in treatment levels will be due to leakage and
subsequent dilution by make-up water.
DISTILLED WATER SHOULD BE USED AT ALL TIMES.
Always add CONDENSATE CONTROL to the circuit at a point where
circulation is high.
A simple electronic pump and tank unit can be supplied to direct inject
CONDENSATE CONTROL into cooling circuit.
Vecom Marine is a joint venture of Vecom Group & Unimarine Group - Version 3.1 - Chapter 11 - Page 44
WATER TREATMENT
LOW-PRESSURE BOILERS
LOW PRESSURE BOILERS UP TO 20 KG/CM2
The Organic Boiler Water Treatment developed by VECOM MARINE is presented with two environmentally safe
products: BOILER TREAT MULTI and CONDENSATE TREAT
BOILER TREAT MULTI is a liquid combination of low molecular weight components, neutralized organic acids,
corrosion scale and sludge conditioners. pH is elevated to figures which reduce corrosion to the minimum possible
levels in boiler as 10.5 - 11.0.
DOSAGE
BOILER TREAT MULTI is dosed at 0,4 Liters per metric ton boiler water. After 24 hours adjust dosage as necessary to
obtain P-Alkalinity 100-150 PPM. A minimum daily dosage of 0,2 lt. per day, according the boiler size, should be always
maintained in conjunction with top and bottom blow down. Determine also chlorides content. If too high give to
boiler top and bottom blowdown.
CONDENSATE TREAT is a superior oxygen scavenger based on neutralized organic acids and a blend of volatile
neutralizing amines.
DOSAGE
Initial dosage should be rated at 0,2 Lt. per metric ton. If system is suspected of corrosion, increase dosage up to 0,7
lt. per metric ton. After the initial dose, start metering at 0,4 Lt. continuously in 24 hours in order to maintain a pH of
8.3 - 9.0 in the condensate returns. Oxygen entrainment largely depends on hotwell temperatures and if these are
maintained above 80°C. A condensate pH range of 8.3 - 9.0 is adequate. If hotwell temperature control is erratic and
averages less than 80°C. tighter control is necessary and condensate return should be kept in the range of pH 9.0 - 9.5.
Oxygen or product residual tests are not necessary.
Boilers
Recommended levels
Adjustment
P-Alkalinity, PPM
100 - 150
BOILER TREAT MULTI
Chlorides, PPM
max. 100 - never exceed 300
Blowdown to reduce
Conductivity, TDS, PPM
400 - 1000
Blowdown to reduce
pH
10,5 - 11
BOILER TREAT MULTI
Condensate
Recommended levels
Adjustment
pH
8,3 - 9,0
CONDENSATE TREAT
Vecom Marine is a joint venture of Vecom Group & Unimarine Group - Version 3.1 - Chapter 11 - Page 45