E.E.S. REPORT 010058H

9 FEBRUARY 1954

□ 59.

i

1 UNITED STATES NAVAL

' ENGINEERING EXPERIMENT STATION

REPORT

TEST OF CEPI-COMAV UNIT FOR PREVENTION OF SCALE IN

^ VAPOR-COMpRESSION.SEA-WATER STILLS

; . .S-ho-O.. -

ueescyH 0 J b b

ANNAPOL1S. MARYLAND

publlc.rcloasa; 1 i uiil i t s d

0 2 MAY 1380

E.E.S. REPORT 010058H

NS-140-001

U. S. NAVAL ENGINEERING EXPERIMENT STATION

Annapolis, Maryland

TEST OF GEPI-COMAV UNIT FOR PREVENTION • OF SCALE IN

VAPOR -COMPRESSION SEA-WATER STILLS

By

R. C. Francis Process Branch

Forwarded by Approved by

F. W. Walton R. C. Adams ^ Captain. USN Superintendent . . Di"^ctor

Chemical Engineering Laboratory „ . 1 .

E.E.S. REPORT 010058H

TABLE OF CONTENTS

Introduction

The CEPI-COMAV Unit

Details of Test I

Results of Test

Appendix

Page

1

1

1

2

Plate

Photographs - 1 CEPI-COMAV Unit 2

CEPI-COMAV Installation ^

Specimen Log Sheet Photographs - „ f • ^ f 't

4

Clean Still Intenor Before lest / 5 Scaled Still, Untreated Run 6 Scaled Still. CEPI-COMAV Run 7

Deposit Data Performance Curves - g

Heat Transfer Coefficients ^ Compressor Discharge Pressure 10

Distillate Output ^ rr • +e K > " H

Comparison of Heat Transfer Coefficients

E. E.S. REPORT 010058H

INTRODUCTION

1 Scale formation is a serious Umitation in sea-water evaporators Ma.y at^nts and devices have been proposed to eH-nate th.s p. b

ThU^s a report onThe CEPI-COMAV Un.t suppUed by the European

Igenc.es Company. Incorpo.ated. New Orleans 12. Lou^ana.

THE CEPI-COMAV UNIT

2 The CEPI-COMAV (conditionnement magnetique Vermeiren) is Said

t2o condition water by magnetical induction. The ünit supp ^Jor t^

panied it. The Unit is shown on Plate 1.

3. The manufacturer's brochure described the principle of Operation as , ^ follows.

"üs the liquid to be treated passes throufh the aPParatuS lt

enc ounters a stron, rna^eUc field „hich ^ ^n. cules of the encrustrng saLts unt/i an elect ottose tial resultinP in a superficiaL tcnsion which wiU.oppose _

crystaröuiidin^ of the salts. »hat actualLy haPPens rs

that as the moLecuLes of encrustmg salts prtcxpxtate out Ipon Heatine or co.ce.tr.Uon, insteaä of tH.se - s combining .ith voter of crystall ization S tAe

chareed molecules settle out in the amorphous form;.ScaLe. foStion cannot result vherc crystzl fornaUon of the encr

ing solids is prevented. "

DETAILS OF TEST

4 The CEPI-COMAV Unit was tested on a Standard Navy. 1000-gallon-

feed pump and ahead of the regulating d.aphragm. The , l .n Plate 2 The still operated at its normal feedwater r-.te of

~ ÄÄ sä HSFH

Reference runs with untrcated sea ;vcre {or approximately CEPI-COMAV test. In each case the sUll was operated for npp

1

E.E.S. REPORT 010058H

mo 'Ta ■ rrtdi.g. «.« m. the tube ends, and the heater wells. A thin, sharp upper tube sheet the tube e ' deposit down to the metal surface

spatula was used to cleaned with dilute

murLu^d^neuTralUed with alkali and thoroughly flushed ^th ^esh

water The scale samples were subjected to spectrographic. X-ray Tf "ction and chemical analyses to determine the composU.on and amracxioti, arid sample was analyzed

probable combinaüon of components^ ^ ao P ^

both to determine the gross amount of scale deposite s

and to estimate its average composition.

RESULTS OF TEST

A Inspection of the tube^j—tub^sh^et^——

depo^Ttsranging from.0.03 to U.Ub unc. --rrr" ^ , samples indicated typical vapor^ompression-still composite scale samPleS with minor quantities of calcium

Hpnosits of magnesium hydroxiae, wiin miuu m aeposu . ™d silica The Variation in percentage of cnlfate calcium carbonate, ana siiica. j. ^ ^ r ,

amount of scaJe^ii.^Ldurin^^^ '-^T^Y^^Tffprpntjr^ntheuntreate? runs, as shov^T Plate^

7 Granhs showing the Variation of compressor-discharge pressure. heat-transfer coefficients, and distillate production f^ ^e three run

i x-.i x o 1 1 The mdividual povnts on tnese

the individual points. ..i

„f v^at-iransfer rates on Plate 11 shows that the

CEPTI-COmTv raTstarted at a slighüy lower value than the reference

2

E.E.S. REPORT 010058H

runs declined somewhat more slowly than those runs during ^e Hrst • M davs and then exceeded them in rate ot decline to the end o£ the

500 hour test TheJncreas^jTi cQmpressor-dischaxgfi pressure 500-hour te ^^{T^^TI^and tbe decl^ThTdUtillate product^on

identical in the CEPI-COMAALrun^ndJhe^e^

reference run.

//

's.

K

E.E.S. REFORT 010058H

O ►—< H <

yA < H

Z

> <

O u t—i 0. w u

-• — %

PLATE 2

;f *•: -!.' •. :-. .^3».

E.E.S. REPORT 010058H

INTERNATIONAL NICKEL COMPANY,. INC. Marine Testing Station, Wrightsville Baach, N. C.

Badger Vapor Compression Still, 1000 GPD Capacity

SPECIMEN LOG SHEET CEPI-COMAV RUN

•'i.

Tim« in }{our > 0100 0200 0300 04 00 0500 0600 0700 0800 0900 1000 1 100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400

Shell Pre»»ur« (+ or -) •'Water

T +6 ♦ 3 + 6 + 3 +4 ♦ 2 t4 + 2 + 5 + 5 + 5 + 2 + 6 + 3 + 4 + 5 + 5 + 3 + 4 ♦ 3 + 4 + 3 ♦ 3 ♦ 3

Com- ■ pressor

Speed RPM T 2000 2000 1950 1950 1900 1950 195Q 2000 2000 2000 2000 2000 2000

. 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000

Com- pressor

Preisure IG

4.70 4.70 4.60 4.70 4. 60 4.60 4.60 4.60 4.60 4.60 4.60 4.60 4.60 4.70 4.70 4.70 4. 60 4.60 4.60 4.60 4.60 4.60

*4.50 4.60

Com- pressor Motor

Ampere* ^

10. 0 9.9 9.8 9.8

• 9.8 9. 5 9.5 9.6 9.7 9.7 9.7 9.7 9.6 9.6 9.6 9.6 9. 5 9.6 9.6 9.6 9.6 9.8 9.7 9.7*

Heater Ammele r

R c .iding

F eed- water

to Still •F

T 5.5-

16. 5- 5. 5-

16.5- 16.5- 6.0- 5.5-

16. 5- 5.0-

16.2- 16.5- 16.4- 5.0- 5. 0- 5.0-

16.0- 16. 0- 16. 5- 16. 5- 16. 5- 16.5- 16.5- 16.0- 6.0-

5.0 15.5 5.0

15.0 15.0 5.0 5.0

15.3 5.0

15.0 15.0 15.0 5.0 5.0 5.0

15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 5.0

T 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198 198

Feod- water to Heat Ex- changer

•F

85 85 85 85 85 85 86 85 83 83 83 85 85 85 86 83 83 85 85 85 85 85 85 88

Con- densale

to He^t Ex- changer

•F

220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220 220

Con- densate F rotn

Heat Ex- changer

•F

92 93 93 93 94 94 94 93 92 92 92 92 94 94 94 90 92 92 93 94 94 94 94 94

Br ine to

Heat Ex- changer

•F 10 198 200 200 200 200 200 198 200 196 198 198 198 198 198 198 198 195 198 198 198 198 198 198 194

Dr ine F rom

Heat Ex- changer

•F _ 1 1 96 97 97 97. 97 97 96 96 90 92 95 96 94 96 94 94 99 95 95 96 95 95' 95 96

Feed- water t-j Heat Ex- changer

IC 1 2

238 229 229 229 229 229 229 228 226 228 228 228 228 228 228 230 230 229 229 230 230 230 230 229

Con- densate

Ex- nger C

90 90 90 90 90 90 85 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

50 50 50 50 50 50 50 55 55 55 55 55 55 50 50 50 50 50 50 50 50 50 50 50

Distillate Meter

R eading Callons

TT 3:59 3:58 3:56 3:51 3:55 3:55 3:55 3:54 3:57 3:46 3:46 3:41 4:00 3:51 3:46 3:45 3:45 3:50 3:45 3:46 3:46 3:46 3:44 3:58

Distillate Com- puted

in C PH

2:58 2:59 2:55 2:58 2:59

5

Conden- sate

Salinity Cr/Cal

16

Com- pressor Motor Speed.

R PM 19

1750 HiO 1750 1750 1800 1800 1800 1850 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800

PLATE 3

E.E.S. REPORT 010058H

.

H t/} W H

W er: o

W PQ

H to

< W

u

PLATE 4

^ ;..v -..v^ ^ —..•■••..■•4 •. ■ • ^ ,Jy. *

E.E.S. REPORT 010058H

PLATE 5

.'J- «r; r - W-! ^■•'r ,Twi>^ ^'"■ " f"A"^s'''"*j,^":'i^ v'V:'' ''[•*'^/'

SCALED STILL, CEPI-COMAV RUN

H

CT*

P p 01

X O

H

o o u> c» X

~rrrr rr?" wrv-T 3iyr

E. E. S. REPORT 0 10058H

DEPOSIT DATA

Probable

Component

Magnesium

Hydroxide,

Mg(OH)2

Calcium

Sulfate,

CaSO^

Calcium

Carbonate,

CaC03

Silica,

Si02

Copper

Oxide,

CuO '

Zinc

Oxide,

ZnO

Organic

Matter

Total

Composite Scale Sample Percent

Untreated Runs

1

86.78

6.30

1. 28

86.34

3.96

3. 77

2.75

CEPI- COMAV

Run

64.97

14. 00

10. 35

3. 58

Deposit in Cleaning Acid Pounds

CEPI-

Untreated Runs

1 I 2

4.91

12.05 12.82

1.25 0.48

5.36 1.23

0. 10 0. 10

0. 10 r 01

0. 10 0. 10

COMAV

Run

18.76 15.64

14. 66

0.57

1. 20

0. 23

16. 66

.PLATE 7

E.E.S. REPORT 010058H

HEAT TRANSFER COEFFICIENTS

OPERAHNC TIME-OAYS

E.E.S. REPORT 010058H

! • * '

• COMPRESSOR DISCHARGE PRESSURE

6

5

4

3

2

I

O

, J. J — —

JNTF —t } 1 r-y r r-i

c EPI — C OMAV l - 1 .

6 8 »O 12 14 16 IB 20 22 24 OPERATlNG TIME-OAYS

E.E.S. REPORT 0iC058H

DISTILLATE OUTPUT

( >-t —< v-< >-1 — v-j —^ —< 1 1

U 4TR 1

EATEO RUN NO. 1 1 1 1 |

K 3 O X ff UJ CL

o z o o. V- 3 0. H D O UJ H < -I -J H ■ Vt o

600

500

400

3 00

200

100

0

600

B00

400

300

2 00

100

0

■ < —<

Uf

E.E.S. REPORT 010058H

COMPARISON OF HEAT TRANSFER COEFFICIENTS

cc X \ 3 H ffi CC lü u. V) z < cc

< bJ X u. o

600

500

400

^

w- * -

-- r •• •>

-

—

D — JNT RE A1 fed RU N N 0 1

24 ..

CEPl-COMAV —•

l i r 1 i- l 1 1 . a ic in ?0 22

OPERATING TIME- DAYS

.PLATE 11