Development of a New Column Design Software Using ... - IEEE Xplore

TSINGHUA SCIENCE AND TECHNOLOGY

ISSN 1007-0214 12/24 pp372~375 Volume 1, Number 4, December 1996

Development of a New Column Design Software Using Visual Basic Peng Jianjun ( ¿ i ^ ^ ) , Duan Zhanting ($:£ A),

Zhou Rongqi (M %t&)

Department of Chemical Engineering, Tsinghua University, Beijing 100084 Abstract: A new column design software, TCD, was developed using visual basic for windows- The TCD interfaces are very friendly to facilitate communication between the user and the connputer. TCD can be used not only to design new columns, but also to check old columns for ret ray application. TCD can be easily learned and mastered- Several design examples are using TCD to display the advantages of TCD. This paper introduces the interface design process, functions and advantages of TCD. Keywords:

column design; interface; visual basic; man-machine interaction sult is m o r e reasonable t h a n other current tray type

Introduction

column design software packages because m u c h e x p e -

Tray t y p e columns are frequently used for d i s t i l lation, refinery,

rience is included in t h e design process.

TCD can be

absorption and stripping processes in t h e oil

used b o t h to design new columns and to check old

chemical and pharmaceutical industries; so

ones. TCD has been used to design or check dozens of

the design of tray t y p e columns is very important.

industrial tray type columns with

U n f o r t u n a t e l y , current column design software, both

sults.

domestic and foreign,

are used w i t h either DOS or

U N I X operating s y s t e m s . T h e software interfaces are unfriendly and t h e m a n ^ n a c h i n e interaction is poor.

1

satisfactory

re-

TCD Interface Design T h e conventional design process in current tray

T h e design results are sometimes unreasonable and

t y p e column design software packages allows

the user has little control over t h e design process.

one-way communication as shown in Fig. 1. Since it is

Tray t y p e column design is different from o r d i -

only

very difficult for the users to control the design p r o -

nary calculations, since it depends heavily on human

cess, the design results of current software packages

experience.

are sometimes unreasonable or even ridiculous

There

are

many

kinds

of

tray

type

be-

columns, i- e- s i e v e t r a y , valve t r a y , Linde t r a y , M D

cause h u m a n experience needed in the design process

tray, slant-hole tray, perform tray, etc-

can not b e input-

Each tray

t y p e column has its own design method and requiring

T h e T CD design process shown in Fig- 2, is more

human input- Therefore, a good tray t y p e column d e -

complex than t h e conventional software-

sign software m u s t have friendly interfaces and good

design process allows two-way communication with

m a m n a c h i n e interaction.

the user easily controlling the process- M e n u s in the

A new tray type column design software,

TCD,

The TCD

main interface include design, check, r e s u l t s , print,

developed using visual basic for w i n d o w s , has a very

save, etc- T h e input interface for new column design

powerful interface design

allows the user to specify t h e initial value of several

. T h e authors are aware

of no o t h e r tray t y p e column design software for w i n -

column p a r a m e t e r s such as tray spacing,

dows at this time-

time, orifice ratio, e t c - T h e input interface for i m p r o v -

T h e TCD interfaces are very friendly and allow the user to easily control the design process if the i n i tial design result is unreasonable- T h e T CD design r e -

ing t h e current design allows the user to c h a n g e any unsatisfactory p a r a m e t e r s , such as weir height, d o w n comer gap, orifice ratio, liquid flow paths or even the t y p e of column.

Manuscript received: 1996-03-15

residence

Peng Jianjun (% A ? ) ,

et ah Development of a New Column Design Software •

373

obtain t h e best design result.

start

TCD main interface check old columns

design new columns

1

J

design new columns

2heck old columns

♦

♦.

select column type

I

*

select column type

input vapor/liquid loadings, v apor / li quid den sity, et c.

1

f

calculate column diameter, tray spacing etc.

input vapor/liquid loadings, vapor/ liquid density, etc.

T

input data of column diameter, tray spacing etc.

T

T

±

input column diameter, tray spacing, etc.

specify initial tray spacing, orifice ratio, etc.

T

calculate the hydraulic properties

T

t end

calculate column diameter, tray spacing, etc.

Fig. 1 The design process in conventional column design software T h e user can easily shift among the interfaces and control the design p r o c e s s . T h e improved design function,

T

±

±

display design resultd, performance diagram

display hydraulic properties, performance diagram

which is unique in T C D , is very useful for

the optimization of design p a r a m e t e r s .

T h e user can

easily change unsatisfactory p a r a m e t e r s and optimize the design

parameters

by

checking

the

improved design

hydraulic

properties and the performance diagram. T h e optimization capability will be s t r e n g t h e n e d in the next version of T C D .

2

calculate hydraulic properties

Main Functions and Advantages of TCD T C D has user-friendly interfaces t h r o u g h which

yes

yes re "enter unsatisfied parameters

I calculate hydraulic properties

the user can easily control t h e design process. It can b e used b o t h to design new columns and to check old ones. W i t h T C D t h e ordinary user can get reliable d e sign results while the experienced user can get o p t i -

display hydraulic properties, performance diagram

I

mized design results. T h e main functions in TCD include t h e f o l l o w ing:

2. 1 Designing new columns When

users

input

the

yes

necessary

parameters

*

save or print results, performance diagram

needed to design a new column, such as vapor/liquid loadings, vapor/liquid density, liquid surface tension, etc. , T C D produces t h e design results and a detailed performance d i a g r a m . Users can select different types of column and directly compare t h e design results to

end

Fig. 2 The design process of TCD

Ts inghua Science and Techno logy, December 1996, 1 (4): 3 72 ~ 3 75

374

Experienced users can m a k e full use of their e x perience w i t h T CD. T hey can specify t h e initial values of some p a r a m e t e r s ,

such as tray spacing,

residence

time, orifice ratio, etc. , based on their experience. T h e

re functions with improved friendliness and reliability.

3

design result and t h e detailed performance diagram can help the users correct any unsatisfactory p a r a m e -

Design Examples Using TCD T C D has been used successfully

to design or

check dozens of industrial c o l u m n s , including distilla-

ters to obtain t h e best design-

tion columns, absorption columns, stripping columns,

2. 2 Checking old columns

etc-

When

users

input

the

necessary

parameters

needed to check an old column, TCD immediately c a l culates t h e hydraulic properties and produces the p e r formance diagram.

If t h e column is operating a b n o r -

mally, T C D will report the problems and give s u g g e s tions to solve the problems. T h e users can adjust the design p a r a m e t e r s and re~design the columnT C D has t h e following advantages over o t h e r

M o r e than 10 columns in poor operating c o n d i -

tion w e r e re-designed w i t h TCD-

Example 1 illus-

trates t h e design of a new column-

Example 2 i l l u s -

trates T C D ' s ability to check and re-design an old column.

Several columns designed or checked with

T C D are listed in T a b l e 4 . Example 1. A fractional column in an oil refinery o riginally designed by a designing i n s t i t u t e . A fractional column w a s re-designed with T C D with results listed in T a b l e 2. T h e diameter and the

column design software: ( 1 ) T C D has user friendly interfaces and users can easily control t h e design process-

height of the column designed with T C D are both smaller than that of the originally designed column.

( 2 ) T C D design results are m o r e reliable-

Therefore,

( 3 ) T C D can provide a detailed performance d i a -

less expensive than t h e original one.

gram which is very useful for column d e sign.

Each line in t h e performance diagram

has a unique color so t h e users can easily d e -

t h e column designed with T C D is much

Table 2 Fractional column design results using TCD original

TCD

6 000

5 400

tray type

jet

slant hole

liquid flow paths

one

two

tray spacing,

900

600

36

26

5 161

5 200 X 2

123. 6

59.4

1421

657

9.47

12. 41

termine the operating condition of t h e c o l -

design results

umn.

diameter,

( 4 ) T C D can design several columns s i m u l t a n e ously and directly compare t h e design r e sults. T O W is t h e column design package included in ECSS developed by Qingdao I n s t i t u t e of Chemical Technology.

T h e functions

provided by TCD

and

T O W are listed in T a b l e 1. T CD clearly provides m o Table 1 Comparison between TCD and TOW

mm

mm

trayed column height, m weir length,

mm 3

highest weir loading, m / m • h highest pressure drop per tray, F factor

Pa

comparison items

TCD

TOW

operating system

windows good

DOS bad

interfaces

friendly

unfriendly

flexibility

good

average

reliability

good

average

improved design function

good

bad

detailed performance diagram

yes

no

new type column design

yes

no

enabled t h e t w o columns to operate properly

new flow pattern design

yes

no

saved a large amount of m o n e y . T h e hydraulic p r o p -

multiple simultaneous design

yes

no

erties of t h e two columns a r e listed in T a b l e 3.

man-machine interaction

Example 2 . T w o absorption columns. T h e design of t w o absorption columns m a d e of an expensive type of stainless steel w e r e checked with T C D . It was found that t h e two columns could not operate normally due to excessive e n t r a i n m e n t .

Re-

placing the original valve tray with a slant hole tray and

Peng Jianjun (% A ? ) ,

375

et ah Development of a New Column Design Software ■

Table 3

Checking of absorption column design with TCD original

re-designed with TCD

HT400

HT401

HT400

HT401

774

674

774

674

valve

valve

slant hole

slant hole

500

500

500

500

orifice ratio, %

10. 66

12. 05

11. 00

12.00

F factor

17. 6

20. 9

17. 1

21. 0

1072. 1

1 398. 5

539

686

> 10

> 10

0. 9

0.6

column code diameter, mm tray type tray spacing, mm

pressure drop per tray, P a entrainment

Table 4

Columns checked or designed with TCD

diameter/mm

liquid flow paths

Perform tray

4 200

two

slant hole tray

2 600

o ne/ tw o

new column

valve tray

2 600

two

new column

valve tray

3 400

two

new column

valve tray

3 200/ 3 600

two

new column

tray type

note retrayed with slant hole tray

sieve tray

1 220

one

checking of old column

valve tray

674

one

retrayed with slant hole tray

valve tray

1 800/ 2 200

o ne/ tw o

4

References

Conclusions T C D is a newly developed column design

soft-

w a r e with u s e r ^ r i e n d l y interfaces a n d effective m a n m a c h i n e interaction. T C D is flexible a n d p r o v i d e s r e liable design r e s u l t s . T CD can b e used b o t h to design new columns and to check old ones. Dozens of i n d u s trial columns such as distillation c o l u m n s ,

absorption

c o l u m n s , stripping c o l u m n s , etc. , have been checked or designed with T C D w i t h satisfactory design sults.

M o r e t h a n 10 industrialized c o l u m n s that

reper-

formed a b n o r m a l l y h a v e been re-designed with T C D with excellent r e s u l t s .

retrayed with MD tray

113). 1 JK, itM: ft ^ X i k i U M f c , 1979 Xiao Chengji, Yu Hongshou. Handbook of Chemical E n g i neering ( 13) . 1st Edition, Beijing: Chemical Industry Press, 1979 # / n P f . Visual Basic for MS Windows ® f f i £ t f \ H 1 /¡g, itM: f 4 f í Ü M Í , 1994 Lin Qilong. Programming with Visual Basic for Microsoft Windows. 1st Edition, Beijing: Science Press( China), 1994 Gary Entsminger- Secrets of the Visual Basic 3 Masters2nd Edition, Sams Publishing, 1994

nmm, g£ji, *sa. windows imrmmzmm

W ? F £ . IfMU^&mt^, 1996, 1 3 ( 1 ) : 4 9 - 5 4 Peng Jianjun, Duan Zhanting, Li Baojin. Development of column design software for windows- Computers and A p plied Chemistry, 1996, 1 3 ( 1 ) : 4 9 - 5 4