ψ E y U i P M E N T

Heat Exchange in Nuclear Reactors Ca!der Ha!! atomic power station uses giant ex­changers to make steam. Reactors cooled by CO2

X HIS WEDNESDAY, Oct. 17, Queen Elizabeth is scheduled to open formally England's 150,000-kilowatt atomic power plant at Calder Hall (C&EM, Feb. 28 ,1955 , page 868) . This plant, which has been under construction for over two years, is believed to be the world's first full-scale nuclear power plant to generate electricity for com­mercial consumption.

The Calder Hall generating station uses two reactors, fueled with natural uranium and cooled by recirculation of carbon dioxide. The heat absorbed from the reactors by the C 0 2 is used to develop steam; electricity is generated from the steam by standard procedures.

"The design of the equipment to exchange the heat between the carbon dioxide and the steam is an excellent

This huge heat exchanger, 75 ft. high and 18 ft. in diameter, handles only one eighthythe Heat from Calder Hall's two -nuclear reactors. The exchanger is shown here Being erected in place

example of chemical engineering in ac­tion/* says Ε. Β. Watton, assistant edi­tor of Nuclear Engineering. "Many factors had to be considered: the quantity of heat; the flow rates of both the steam and the C 0 2 ; the types of flow—laminar, turbulent, or intermedi­ate; the heat transfer characteristics of the exchanger metal and of the two fluids; safety needs; and many others," he continued.

Here are some of the conditions of the exchange system, according to Watton:

• Carbon dioxide is circulated through both reactors at a pressure of about 100 p.s.i., entering at about 140° C. and leaving at about 336° C.

• Carbon dioxide flow rate is about 8,250,000 lb. per hr.

• Steam is generated differendy in the two reactors. In one, the pressure is about 185 p.s.i., while in the other, the pressure is around 57 p.s.i. Both systems must be capable of operating at the higher pressure.

• Size α Problem. To keep the size of the equipment down to reasonable limits, each reactor has four separate heat exchangers. Even so, each ex­changer is about 75 ft. high and 18 ft. in diameter. Babcock and Wilcox Ltd., who built the units, had to divide the bodies up into six pieces each to move them from the fabricating shops to the plant site. The skirted support­ing rings were so large that they were made in two halves and welded to­gether at the site.

Β & W engineers decided upon a shell and tube design for the exchang­ers but with some modifications. The first hurdle was finding some way to increase the heat transfer surface without a considerable increase of pres­sure drop through the exchanger. Β & W did this by welding to the tubes a series of studs. These studs, of oval shape for aerodynamic reasons, were machine welded to the tubes, with par­ticular attention being paid to uniform­ity of positioning, pressure, current, and forging time.

By the time the job was done, each of the eight exchangers had some 10.7 million studs welded to it, giving to the tubes a total surface about five times the original.

Within the exchanger, the tubes are horizontally arranged in banks, Watton says, with each bank consisting of a number of multiloop sections in paral­lel. The number of tubes and the heat transfer surface in each section are as follows:

' High pressure

superheater Low pressure

superheater High pressure

evaporator Low pressure

evaporator Economizer

No. of Elements

in Parallel

64

32

64

64 84

Total surface

Total Heat-ing Surface,

Sq. Ft.

4710

790

31,600

31,600 31,600

100,300

Design engineers also faced the pos­sibility of leakage caused by tube ex­pansion. In order to prevent any mix­ing of carbon dioxide and steam from leaks thus caused, Β & W brought the tubes through the shell wall and made all joints on the outside. A thermal sleeve completed the seal.

For gas-cooled, graphite-moderated reactors which will be built from now on, Watton says, the exchangers will, in general, follow the design of the Calder Hall equipment. Some details will be modified, he says, such as use of tubing smaller than the present 2 in. and use of integral fins (easier to fabricate) in place of the studs for surface extension.

How Wet Is It? A simple hand computer for calculat­

ing the water content of gases has been developed by National Bureau of Standards.

Designed by A. W. Diniak and E . R. Weaver of the bureau, the computer figures moisture content and dew point of gases by measurements of the elec­trical conductance of a hygroscopic film as it absorbs water. Corrections are made automatically for deviations of the gases from ideality,

The computer consists of a plastic base disk about 4 in. in diameter, upon which are mounted two rotating disks marked with the appropriate tempera­ture, pressure, and altitude scales.

Some uses foreseen for the computer are calculation of the water content of aviators' oxygen, rocket fuels, and fire extinguisher gases.

The computer is not being manufac­tured commercially.

• Conical dryer-blender of glassed steel is now being made by Pfaudler in an 8-ft. size. The unit can handle any

5 0 7 0 C & E N OCT. 15, 1 9 5 6

~?%Β5Ζ&ί 11Γ

Λ" . .

ryi—^r-

CARBON

UNLIMITED! Manufacturers of viscose rayon, cellophane, grain fumigants and special solvents can look to Staufïer for Carbon Bisulfide of highest purity.

Nine plants throughout the country assure a steady supply of this basic chemical. Anticipating future needs, Stauffer has one new plant under construction and another in process of enlargement.

For Carbon Bisulfide of highest purity in drums and tank cars .. . talk with any Staufïer representative.

S T A U F F E R C H E M I C A L C O M P A N Y

380 Madison Avenue, New York Τ 7, Ν . Υ. Telephone: OXfo rd 7-0600

^/kjc^^t^teaM £&(i/C££+

O C T . 15, Î 9 5 6 C & E N 5 0 7 1

BISULFIDE...

the way Υξβϊ want it

**>;€? s&

Λ,Ο

Αθ

A ^

. * * * -

^O1 ̂ Î.Ô-AO

to* ̂v

specify

CELANESE FORMCELS (Formaldehyde in alcohols)

Celanese Formcels are low water content for­maldehyde solutions in a variety of alcohols. They are developed to meet specific processing requirements and, b y replacing formalin, can often provide economic a s well a s quality ad­vantages. The ratio oi formaldehyde to water in Formcels is about ten times greater on a weight basis than 37% formalin.

Formcels form a continuous phase with most organic compounds . . . react faster than formal­in because the formaldehyde is in more intimate

contact with the other reactants. Formcels do not require depolymerization, and, because they offer an alcohol medium in which all reactants are soluble, they contribute to faster reaction cycles.

Investigate Celanese Formcels: a s organic chemical intermediates . . . for resin condensa­tion reactions . . . for curing zein coatings . . . as an embalming fluid component. Mail coupon for Bulletin.

Celanese® Formcel®

Celanese Corporation of America, Chemical Division, Depf. 754-J 180 Madison Avenue, New York 16, Ν. Υ.

Send me Product Bulletin S-23-5. I am interested in Celanese Formcels for —

(type of application) NAME-

TfTLE-

COMPANY-

ADDRESS—

CITY

In Canada: Canadian Chemical Co., Limited, Montreal, Toronto and Vancouver. Export Sales: Amcel Co., Inc. and Pan Amcel Co., Inc., 180 Madison Avenue, New York 16, Κ. Υ.

5 0 7 2 C&EN OCT. 15. 195 6

ίοτ FORMALDEHYDE

EQUIPMENT

Ψ For Removing Air The largest vacuum deaerator ever made (capacity about 52,000 gal.)* built by Cochrane Corp. and rubber-lined by Raybestos-Manhattan, is shown here en route to Linden, N. J. It will be used in the ion exchange treatment of makeup water for high pressure boilers at Linden's new gen­erator station.

acid except hydrofluoric and alkalies up to pH of 12 at temperatures up to 212° F., according to Pfaudler. Ε 1 • Charlotte colloid mills, by Chemi-colloid Laboratories, have been rede­signed to include a front end removable shaft seal, a flushed seal for abrasive service, or conventional packing. Con­stant pressure is maintained on the feed to minimize aeration. Έ 2

• Electron microscope featuring a hinged objective lens, magnetic com­pensator, objective diaphragm with multiple apertures, and insert screen with binoculars for ultra-thin specimens is now being made by North American Philips" instrument division. Ε 3

• Lubricant testing machine, manu­factured by Alpha Molykote, is de­signed to test both bonded coatings and liquid lubricants. In operation, a sta­tionary rectangular block is pressed with a predetermined load against a rotating test ring. Friction is trans­ferred to a dial indicator and the num­ber of revolutions of the specimen is registered on a counter. Tests are based either on reaching a preselected temperature or on reaching a pre­selected friction maximum. Ε 4

• Flexible hose for conveying liquid oxygen, made of stainless steel lapped with Terylene, has been produced ex­perimentally by Compoflex (London). The hose is said to have advantages over metallic flexible hoses used previ­ously for this purpose, because they do not allow heat feedback to the cold container, have better low temperature flexibility, and longer service life, ac­cording to Compoflex. Ε 5

• Pressure and temperature recorders and recording controllers are the latest addition to products available from A. W. Cash Co. On-off, duplex on-off, and 1 to 1007© proportional control are available. Pressure ranges from 0 to 5 p.s.i. to 0 to 5000 p.s.i., and tempera­ture ranges from -350° to 1200° F. are being manufactured. Ε 6 • Stepwise scanning spectrometer system, developed by Tracerlab, is de­signed to assay radioactive samples quantitatively and to perform isotopic separation by the analysis of nuclear radiation spectra. The unit consists of a radiation spectrometry detector, the analyzer itself, and a data printer. Ε 7 • Portable scaler, by Beckman Instru­ments, uses a high voltage supply stable to within three volts for precision and has a built-in timer to collect counting rate data without auxiliary equipment.

Beckman claims the scaler to be most useful in countincT ^amma scintillations.

• Polyvinyl chloride pipe with a uni­form pressure rating in all sizes has been added to Carpenter Steel's line of

has high chemical resistance and a maximum working pressure of 150 p.s.i. at 75° F., while the other has high impact strength and a rating of 125 p.s.i. at the same temperature. Sizes from l/o in. to 4 in. are available.

Ε 9

Further useful information on keyed Equipment items men­tioned is readily available . . .

Use handy coupon on page 5074 ^ j

October 15, 1 9 5 6

Readers' Information Service Use this h a n d / self mailer to obtain further information or literature.

Simply mark, clip coupon, fold, and mail

Every week C&EN's editors survey a large volume of valuable scien­tific, technical, and business information issued in the form of product announcements, booklets, catalogs, data sheets, etc. This material is digested and presented :n several departments. For your conven­ience this coupon is provided to facilitate requests for further informa­tion on these items as well as on products and services mentioned in advertisements.

N a m e . . Position

Company-

Street

City -Zone- -State (Please print or type)

^ CLIP COUPON—Fold A l o n g This Line—Fasten (Staple, Tape, G l e e ) — M A I L

To:

3 c

STAMP

Readers' Information Service Chemical and Engineering News 43Θ Park Avenue N e w York 22, Ν. Υ.

FASTEh4 HERE O N L Y $ ^ FASTEN HERE ONLY