Project Engineering of Process Plants

Project Engineering of Process Plants

(Parte 1 de 10)


RASE, H. F. AKD B.<RROW, Y. H. Project Engineering of Process Plants

RASE, 1. F.

Pipi~ig Design for Process Plants PROJECT ENGINEERING of Process Plants

Associate Professor of Chemical Engineering The University of Texas and

Project Engineer Foster Ti7heeler Corporation

Original Illustrations by

Assistant Professor of Drawing The University of Texas

NEW YORK . JOHN WlLEY 8 SONS, INC. london . Sydney

In the early days oi the chemical industry, new plants were des~gned by a chemist and a mechanical engineer \~ith the assistance of one or two draftsmen. The design work progressed slowly, but since the processes were simple, the job could be completed in a reasonable amount of time.

The simplicity of design methods used in industry's early days con- trasts sharply with the complexity of modern plant design. The joint efforts of specialists in engineering, construction, and management and a close interrelationship between them are necessary ior the design and construction of a modern plant.

The supervision and coordination of these specialists has become the job of a specialist. He is called the project engineer.

In many cases the project cnginccr has a background in chemical engineering. In addition to chemical engineering he must understand mechanical, electrical, and civil engineering problems. He must keep informed on procurement practices and he well schooled in the ways of office management. In the past this vast amount of know-how not included in a chemical engineering education has been gained by trial and error or from experienced project engineers. It is the purpose of this book to record information and techniques used in plant design and to discuss ideas that many project engineers have developed through years of practice. It is written from the point vii

... vtlo Preface of vier!- of a project engineer, hut is not intended only for him or for the indiridual aspiring to becolne a project engineer. It should he useful to any engineer wlro designs process equipment, since he must know the tlicories and techniques of mechanical design, procurement, and construction, in addition to hasic chelniral engineering principles.

Project Engineeririg of Process Plnnts is also intended as a test for chemical engineering plant design courses. Most chemical engineering curricula in the United States hare courses in process plant design. The student finds such courses inraluable for three reasons. He is able to integrate the compartmentalized knodedge obtained from bmic courses. He has greater opportunity for original thinking. And, third, he gains the healthy self-assurance that conles with being able to apply his kno\dedge to n comprehensive practical problen~. 'l'l~e principles of chelnicnl engineering have been nhly rcconled in sucli texts as Hougcn and \V:~tson's Chei,iici~l Process principle, and Brown's Vnit Operations, and the student s-ill hare such hooks ior reference in making process design calculations.

The cwnvcrsion of these process calculations to a workable plant de- sign is project mgincering. Project Engineering of Process Plants has hccn planned to acquaint the student ivith the niethods, organization. and pliilosopliy of project engineering.

The book is rlivided into four sections. The major steps in plant design are outlined in the first section, and the business and 1eg:l phases of plant design are discussed in part tw. P:~rt three gives principles of cquip- mcnt design and selection and design of structure foundations and piping.

Equipent common to all process plants is considered in detail dlerras otl~cr equipment is treated briefly in a single chapter, althougli refer- ences to more conil~lcte sources of inforlilation are given. Xo attelnpt has heen made to providc n handbook or guide to the selection of all types of equipment. Technological progress is too rapid to make such an undertaking n-ortlinMe. Instead design principles and reasons for current practices arc elnpha~izcil so that the reader can derelop a sound basis for his own decisions.

The last part of the book is a clcscription of construction operations, and any enginecr cngaged in plant dasign is adrised to accept the first opportunity to observe the coi~stroctioll of a plant from start to finish.

After that experience the engineer 11iua11y becomes a much better designer.

To aid in making the book useRrl to both student and practical engi- neer, an effort is made to adhere to the follo~ing principles:

Preface ix

2. Yisualization rif equilment is facilitated hy isonirtric and pictorial viem or rross-sections supplemented by other riexs. 3. Design equations, unless con~pletelp einpirical, should be developed sn that their lin~itation~ will he unrlerstond. 4. Oily ronrlnonly wrd drsign mrthorl. -iio~llrl hf pr?smtrd

;i. EXRIII~I~S 01 achl:d ci ciliiti~iis specifications, and con- tracts are at times prefcmblc to detailed eslhnations. 6. Conipilations of design data arid sources of inforniation sliorrld he given tliroughout the text. 7. Economics sl~oulrl be discusse<l in relation to each phase of plant design and procurement. rather than isolatcd ill a separate chaptcr. 8. Tl~c young engineer vill profit from the definition and usc of terxni- nology common to the cor~stsrictiun inilrlstry.

The authors are grateful to the illany conipanics which furnished illua- tratiuns. Specific nrknordedgments arc made in the text. Thanks are :rko due Professor hl. !-an \\'inklc for his many helpful suggestions.

1. The rclationahip between each design phase ran be hetter under- stood if the scrpencc of chapters fo1lon.s the usual steps in plant design.

1 The Pro,j~ct Engineer


Plant Location Preliminary Data for Construction Projects

Process Engineering

Flow Diagrams Plot Plans

Scheduling the Project Engineering Design and Drafting


9 Procurement Operatims

10 Office Procedure - 1 Contracts and Contractors


12 Vessels 13 Heat Exchangers


Process Punips Colllpressurs mil Tar~u~n Pun~ps

Motors :ind Turl~incs Other Process Equipment

Piping Design Thermal Insulation Process Instrunlents Plant Ctilitics

Foundatious Structures and Buildings

Safety in Plant Design

Part 4 CONSTRUCTION OF THE PLANT 25 Construction



ENGINEER The design and erection of a process plant could nerer i~e completed solcly by nlelnhers of one branch uf cngineering. Instead such an undertaking must result from courdiuatcd efforts of chemical, mechani- cal, electrical, and civil mgincera, chemists, and specialists from man:- other fields. This combined effort, horvercr, must be directed by a single individual wlio can guide the engineering, anticipate the routine problems, and nchcdule the rarious phascs of work. It has, therefore.

hecome the practice in process industries to assign this overall respon- sibility for thc entire design and erection of a process plant to a singlc! individual called the project engineer or manager. The duties of thc project engineer for a process plant, other than requiring a round chemical engineering background,' demand knowledge of other engi- neering fields, hueiness administrationl and economics. Although it is not neressary for him to he an expert in any of these, he must have sufficient knorvledge to cr~ordinatc the activities in all of them.

The larger operating companies in the process industries, wch as chemical and petroleum, maintain extensive staffs of technologist, in all hranchcs of engineering for research, de~clol)ment, and plant main- tenance. Such a firm will ordinarily explore any new process under consirleration both tecllnirally and economically. However, rvhen an

*Sonre practicing projrcl engineers have mechanical engineering training and additional study in chemistry.

2 Project Engineering of Process Plants

~q~erating corr~pany ~leciclvs tu build :I couil~lrte plaut or a binglr process unit, an engineering and condrnction fir111 sjieriiilizing in such work is usually retained.

Kumerous variatirmi art> ilo-silllt in I iiior of vork hetween the engineering and euu;tructiou fir111 co~trctr iind the opcrating company (customer).

1. Prorrsa rlerciopnit.nt, pruress ~lesign. euginecring and construction by contractor. Examples: Fort4gu customers desiring plants of

American deaign. it] Sen-ly i~rii~d young process industry firms. IcJ Established firms uot having the pcrsmnel available for active participation in any pilase of the iiesign or firnls which prefer to have contrartor hantllc all phases. id I Contrnctor frmishing patented process or developing a snitable process.

2. Process developed by customer, pri~rs design a joint effort, engineering and ronstrnctiun hy contrnct(~r. This is a common ar- rangenlent when the customer lins. tlrrol~gli i~envlr scale and pilot plant uwrk, developed a proccss arirl ~vishet. to luilcl a full-scale plant. The contractor use? the customer':: basic (latn.

3. All process design done by customer. When the customer has a large process design group that has been cli~scly associated mith a process, it is often advisable for this group to upp ply a complete proc- ess deaign to the contractor. It is not uncmlruon, lio~ever, for the customer to rcquest the contractor to check the dcsign.

Other variations of tbe division of responsibility are possible. It is important to note, however, that the projert enginecr's role is extremely important in any arrangement. \\-lien both the contractor and cus- touier are participating, the customer's project ellginerr nud the contrac- tor's project eugineer havc dutics essentially ralll; and the chart in Fig. 1-1 depicts the duties of both.

The customer's project engineer niust supply tile contractor's project engineer with all the information concerning the custnmer's require- ments and preferences. He must check and approve all designs, and obtain comments from various design and operating groups in his own organization. The contractor's project engineer must be responsible for transmitting information to the rarious groups in his own organiza- tion, for guarding both the contractor'y and customer's interest in all engineering decisions, for contractual obligations, and above all for seeing t'hat the plant is completed on time and that it operates arcord- ing to specifications.

Referring again to Fig. 1-1, the dutics of a project engineer can be briefly traced in a clockwise manner around the chart starting at the top. Assume that a process plant, Fir111 A, has, after economic studies

The Project Engineer 3

Fig. 1-1. Project al.gmiznlion and basic research, decided to construct a plant. Firm A sends out inquiries to various contractors xvhich are prepared hy A's process dc- partmcnt and project engineer, These includc a dcscription of the proposed location of the plant, tlic scope of the project, the production required, and any other inforiuation not available to the contractor.

The contractor assigns a project engineer to the job, who immediately becomes the liaison beheen the customer and all dcpartments of the con- tractor. Thc project engineer works with his process design and estimating groups in preparing an estimate for thc cost oi designing and construct- ing the proposed plant. The estimate is presented to the customer in

4 Project Engineering of Process Plants hound fornl. It c:ircfuIIy outlin(>> all duties and oblign tionr of cwtom- cr and contrartor, decrrihee the proreis units an11 equipmrnt, givrs the design spccifirationi, opera~ion:~l and merirnnir:rl gnnrnnters, and .sets a completion rlatc,.

Aseume that the contract is an-:irdcd to Contwctor B. H'.? project engineer then immediately starts organizing tlre jol, The project nlanager of '4 is r~ntactetl ;rnd tlic prnr~v requiren~ents are firmly establislled by agrerlucnt wit11 -1's IIrocess groul~. using the proposal as a basis. The contr;~vtor'> prorr.s group tlrrn proweds Kit11 the final process dmign. As the rlcign is l~cing developed, n~cclianiral specifi- cations are !!-rittc~~ an11 :~greerl uptm and :dl pl~nies of tlw projcrt arc scl~dulcd so that tlir c~~~nplctir~n il;rtt r:rn bc met. Thr procr~s infor- ination is transmitted to tlit- various dezign and ~lrnfting groups by tire project engineer and his nsist:mts. They interpret and ilcvelol~ this infornrntion and ?e? that tl~c 11roc~~s requirrn~rnts are ronll~letely satisfied in the layout and ilrsigu and that euston~er specification are met.

-4s -eon as the debiyn begins to talcc forin, purchnsing conrmit~nents are n~nde to wsurr j~ro~irpt rlrlivery. Purr,lr;~ncs that require engineering judgment arc rcvicn.ed 11y the projcct engineer an11 specialty enginerrs before being purrl~arcd so that the lwrt available crgiipnrmt vill he obtaincrl at a mti~factory price. .Is the design ilevelq~s, rel~rcscntntiws of the conetrurtion ricpart-

11mt are hiefed by the project engineer Crn the .scope :lnd details of the prujcct so that construction may be plannctl and lrcparation of the zitc 11t,gu11. l\Irml)ws uf the 01)ernting deprtmrnts (~f hot11 custo~ner and contractor are askd to revie~v tlrc design and to ~~ggcst ilnprorclncnts.

r. I liruoglrout ;ill this activity thc. cuetonl~r's project engineer mtl tire contm~tor'~ 1,rvjcct enginecr and tlicir nsiktants 1:ivc been icrir~i-ing all dra~i-ings :ind n~:~lerinl rquisitionr. Cmrnrent.? arc assemt~lc~l and returnd tr~ the design groups so that thc 1~rrisary clranycs ran 1,c madr. The oontractrds project engineer nus st see that these c11ange.i are pro]wrly ext,cutetl and that hoth tlic custon~er's and contr:~ct~~r't: interests are gunrrled. Changw niust not alter the original prow?. re- quircnients, scope of !!-nrk," or specifications. 1 fnct, the prujrrt en- gineer's responsibilities do not end until the c,pcrating department 113s si~own that the plant meets tlre design specifications and process and meclranical guarantees.

*If changes in thc scupe of work nw desired by tlre customer, he must ask for thwe changes in wcordance with the hnrs oi tile contract. The contrario~. can ;,+I, fur :~rlditionnl fees for tliesp elumgcs. (See Chapter 1.)

T HE project engineer coordinates and directs the entire design project. His active participation increases after the completion of process engineering, but in many in- stances he also takes part in the early stages of job planning. He may assist management in the selection of a site and will also direct the gathering of preliminary data. His rnost intensive work, however, comes during the period of detailed engineering design and drafting, for it is this work that culminates in the selection of equip- ment and production of drawings for use in construction.


The proper location of a plant is as important to its success as the selection of a process. Xot only must many tangible factors such as labor supply and raw material sources be carefully considered, but ulw a numbcr of intangible factors which are morc difficult to evaluate. The selection of a plant site must be based upon a very detailed study in which all factors are weighed as well as possible. Such a study often requires a substantial outlay of money, hut false ecmou~ies at this pint may lead to great losses in the future. Tl~cre is cmsiderahle literature on t11c subject of plant location ranging from practical considerations to the theory of plant locati~m r. Ll~e theoretical aspects are rxtretncly interesting, and in grnrral stc~n from the classical work of \Veber~~~ublizhed in 1909 in thc German and translated in 1928 in English. Many excellent outlines or chcck lists hare bccn puhlishcd which aid in illant location studies by listing factors that must be considcrcd. 4n aht~reviated listing of mule of thc literature in this ficld appears at the end of this ~hapter. Tlresr references will incvitably lead tlre interested reader to tile entire litera- ture on plant location.

(Parte 1 de 10)