Technical Data Sheet: Water Systems

pH-Adjustment /RehardeningFilter Type RF

Description of pH-Adjustment / Rehardening Filter Type RFThe acid reaction of distillate in fresh water generators iscaused by dissolved Carbon-dioxide (CO2), which is releasedfrom sea water during evaporation.

To avoid corrosion in the subsequent parts of the shipsdistribution system (e.g. piping, storage tanks etc.), thepH-correction of produced distillate is absolutely necessary.The pH-adjustment of the distillate is effected during itsflow through the corresponding active Juraperle JW® layerin the pH-Adjustment/Rehardening Filter Type RF. Inaddition, the Juraperle JW® layer rehardens(remineralisation) the pH corrected distillate.

Juraperle JW® is a pure calcium carbonate from Jurassic:CaCO3

The solubility of Juraperle JW® in water is low and is notinsignificantly influenced by the water temperature. Inabsence of Carbondioxide the solubility amounts to approx.25 - 35 mg/litre; corresponding to a hardness of approx. 1,5 -2,0 °dH. Simultaneously to this rehardening process, the pH-value increases from pH 5,5 - 6,0 (typical pH-value ofuntreated distillate) up to pH 7,5 - 8,5.

In the presence of carbondioxide in distillate, the resultinghardness increases proportionally to the Carbondioxidecontent according to the below mentioned reactionbetween Juraperle JW®, Carbondioxide and water byformation of the readily soluble compounds:Calciumhydrogencarbonate (= Calciumbicarbonate)

CaCO3 + CO2 + H2O > Ca(HCO3)2

Proportionality factor: 10mg/l = ppm Carbondioxidegenerate an additional water hardness of 1,3 °dH.

The consumption of rehardening material amounts toapprox. 25 - 35 g/t distillate. Refilling is neccesary afterapprox 1000 - 1400 operating hours. Values depending fromCO2 content in the distillate.

The Juraperle JW® filter material is combined with pure quartzsand as a basic layer in order to retain fine Juraperle JW®

particles and iron/manganese precipitations generated duringthe filtration process.

Operating of pH-Adjustment / Rehardening Filter Type RF

Initial FillingPlease refer to the information for basic layer (quartz sand) andmain layer (rehardening material Juraperle JW®) stated in thetable on the back page. After start up, the water should flowinto the bilge until it is clear.

Topping upIn order to maintain constant pH-adjustment/rehardening of thedistillate as far as possible, it is necessary to refill the unit whenthe filter rehardening material has been consumed down to thesight glass. The rehardening material has to be topped up to theupper weld seam as with initial filling.

RefillingAfter approx. one year of operation, or if the taste of waterdeterioates, the whole filling has to be renewed.

Back-flushingIf the pressure loss through the filter has increased by approx.0,5 bar, the back-flushing process has to be carried out.

For further information, please refer to the technical data fordimensions and filling quantities.

ref:

HW

S005

6 10

07

Filter Type RF Water Systems

Capacity 15 30 60 120 180 250 400 500 700m3/24h

Diameter (D) 273 355 457 610 711 813 1100 1200 1400(mm)

Height (H) 1120 1160 1360 1510 1700 1800 1850 1950 2000approx. (mm)

Operation pressure 6 6 6 6 6 6 6 6 6maximum bar (g)

Nominal 36 63 132 264 405 636 1220 1720 2210volume (litre)

Weight 54 69 88 130 164 250 410 650 750empty (kg)

Weight 114 174 308 560 820 1240 2300 3250 4100in operation (kg)

Filling Quantities

Basic Layer 10 15 30 60 90 140 350 450 650

Main Layer 35 65 135 260 390 500 900 1200 1500

Technical data of pH-Adjustment / Rehardening Filter Type RF

The manufacturers reserve the right to alter thespecification and data to incorporate improvements in design.Certified drawings will be issued on request.

© All details copyright Hamworthy plc.

Hamworthy Serck Como GmbHPankower Str. 16 - 18D-21502 Geesthacht, Germanytel: ++49 4152-805-0 fax: ++49 4152-805-105e-mail: geesthacht@hamworthy.com website: www.hamworthy.com

a subsidiary of Hamworthy plcApproval Certificate No. 202595

RF 30-15

RF 60-30

Filter Size/type

RF 120-60

RF 250-120

RF 400-180

RF 500-250

RF 900-400

RF 1200-500

RF 1500-700

SERCKCOMO

1

2

3

4

5

D H

Drain

By-pass

Drain

O = OpenC = Closed

1 2

C

O

C

3

O

C

C

4

O

O

C

5

C

C

O

Basic Layer = Quartz Sand

Main Layer = Rehardening Material Juraperle JW®

Distillate from evaporator

Drinking water to the tanks

Filter Casing = Stainless SteelLarger sizes on request

Normal Operation

SERCK COMO Supply Limit

Valve No.

Valve Positions

Back flushing