On-line industrial scale fermentation plant

Dlgi tal Computer Applications to Process Control, Van © IFAC and orth-Holland Publishing Company (1977)

auta Lemke, ed.

A8-3 SCA

c.

Jakovljevic, T.

T

s lnik, J. ~erne ic, + S.

1 a er,

K KA, pharmaceu ical and chemical works, ns i

J07ef S efan,

jubljana,

OV0

mes

0,

ivjak

Jugoslavija

g s avija

This paper a empts to present a pr~ject of computer au mation in industrial scale pr duction f an ibi ics. A th r gh descrip i f the vari us phases f projec developmen is given inc uding de ai s abou necessary equipmen comple ion, home-buil interface and computerised con rol sys em. Software system for interface and built-in instrumentation testing, data loggi g, and supervis ry con r 1 was developed in a d1llar way. Preliminary results and first experiences wi h the system implemented in the plan show ha orientati n is adequate. In c nclusi n plans for future are briefly ~utlined. TRODUCTIO

ways. During the course of fermenta ion, which in general is a long term process, microorganism changes its environment. The main s urces f the energy needed for cell growth are carbon hydrates. Quantity of microorganisms enlarges in geometrical progression every 30 to 240 minutes.

"KRKA" represen s one of the largest producers of antibiotics in ur country. In the plant a ovo mes fermentors of several en cubic meters' of v lume are in operation. Each unit is originally equipped with conventi nal analog controllers for temperature, pH, foam level and with he usual indicators for all the main operating parame ers. Encouraged by the success of process co puters in other chemical industries and also in fermentation laboratories (1, 2, 3, 4) it was decided in the year 974 to initiate a research project, through which potential benefi s of digital control in ferment a ion sh uld be explored. ork was under aken in a close cooperation with the Jozef Stefan Insti u e, Ljubljana.

The process requires sophisticated control of its environmental conditions, if a reasonable yield of antibiotic is to be expected. Because of the batch mode of fermenter operation, continuous attention of the process operator is necessary 0 supervise all phases of a prod ction cycle - beginning with charging of raw materials and finishing with product isoiation. The main reason for the introduction of computer control in the industrial fermentation plant is therefore o assis in hese two functions. Besides that the computerised sys em enables extensive data ga hering f r the purpose of process analysis and subseq e opti isa ion

objec f the h pil t-p ant

(5) •

phase of i ple en aof pro, which PROCESS

ESCRIPTIO

e origi al ins r enta 0 fer en er with so e addipa ib e se sors, 1 process co p e r ,

417

o

418

- LI E I DUSTRIAL

CALE FE

E TATIO

PLA T

A8-3

o devel pad instal 0 r pr cess-c puter r data i terface, and devel acq isi io. a d process fl)P 1~/40

UNJ8U.s

Listed below are analog and digital signals (process para eters) which are connected to computer (6).

- temperature of fermen a i n broth (also controlled) - pH of fermentation bro h (also controlled) - dissolved oxygen partial pressure in the broth - air flow rate through the fermenter - pressure in the fermen er - cooling water flow rate through the vessel jacket - cooling wa er temperature difference (inlet - nu let) - steam flow rate (needed for sterilisation and heating-up of the fermentor) - impeller speed - agitator power consumption Digital signals (on- ff) - main power switch on anal g c n roller panel - tempera ure co. - p

Fi~ure

r ller

I: Hardwar

configuration

controller

- f a

c ntroller

empera ure i dicator/rec rder - pH indica or/rec rder - diss 1 ed

x gen indica w - high, c

air-fil er

r lled)

i

- CP':

- cor e

p

f an if a

P P I

111 0

e r : 32 K

isk st rage: ge s

r

ing wa er p

- a a i ab·

!

ea ing

wer - c

r/rec rder

w

ords (16 bits per word)

RK- 5/RK-ll disK cartrid-

opera r er i als: - A- 36 c r . us da a er i al

age c

puia . ard-

. -5 board

a phan meric ke -

ispla ec

- hardware b

s rap: B

real- i. e cock: K' 1 -

EC'I/ Rl E ) as i n -

93

~:

ger.era

- B

e-freq ency

ni

de-

A8-3

o

- LI E I DUS RIAL SCALE FE

E TATIO

PL

419

T

r w-pass fil ering (f yi g ork). The .ai ni co sis s realized on standard module performs a de ii n, as indicated below.

S s e

per.

nit in the in-h se developmen of pu er in erface and the applica i , sof was induce mainly by eco omic reas ns. user-nrie ed appr ach was co sidere t be be er sui ed for his (ini ia ly) ra her li i ed and experimental pr °ect, tha purchasing a comple e and powerful sys em. On he 0 her side, indepe .. dency of impor ed k nw-how, u ilizati 0 exis ing k owledge an broadening f experie ces are impor an~ reaso. s in our par icular circums ances, wi h regard to natio al economy.

~he

This cn cep of developmen has pr ved tha availabili y f standardized in egra ed-circuit electronic c mponen s and a p werful higher level computer language such as FORTRA enable greater flexibility i economically adapti g a hardware r software s s em o a particular applicati , a well desig. ed combination of interface and s f ware sys em can be used in ther process applicai ns af er only minor rearrangeme s or difica ions, a d in a wel k w. system, c m i c a i n pr ble s be ween hardware and s ftware are easier ma age. .~_~.l(~

.(!~·"'C'r.

r, ~

r

....

-:. r

.

(

~

.

:

...

(

:'

ul iplexing of analog and digi al inp signals - a al g

0

digital conversion

- digital mul iplexing of data words to the computer inp t - digi al em he c . p er digital t

iplexing of data words from u pu

analog conversion

- demultiplexing of anal g and digi al output signals - dec ding f interrupt and/or alarm and other critical requests - s nri ma io -

of device s atus a d c n rnl

f

r-

c~ r 1 of commu ica i ns be ween the compu er, he in erface and ther connec ions

- s nchro iza ion wi h real if he c pu er has n cl ck) - conversi n of serial impulses int paralel rans i ed inf r a io wi h pari y r 1 ( P inal, e.g. f r rans issi n f da a r fr . an as nchr n us device as a ele pewri er, paper ape reader/ uncher etc.)

?:K

~.

rare

h

- ir.i e -

s .. s

e.

firs~_:'

;:c

era

r c

::icati

n

sas: a

a

o

420

-

pr cess para e ers acquisi i simple data fi

The

- LI E I DUSTRIAL SCALE

-

n

s are

ther f nc

p i nal:

rec rding

- data fil ering anip la i - basic pr cess da a variab es) putati n of indirec -

(e.g.

co -

process monit ring wi h alarm messages t the operator and/or a arm triggering

- monitoring of the sequence of (batch) process operations -

sequence control

-

set pint control

The package was designed s following features:

as

a have

he

- m dular structure flexibility f r m dificati ns a d vemen s -

easy to adapt f r

- suited for small application

possibility for ex ensions

-

easy syste

perat r

-

c

munica in 1)

- different scanning interval f r riable

each va-

n f indirec r syn he ic fr direc ly measured paraers (als cal ed "ga eway eas ree s", which are p r an i fer ena i ana ysis) - efficien ex e sive

-

sys e

re)

e

r

wi

pr cess

s in egri y pr

s: -

ini a d

e s s e

n of syste

ines i

e with rea

-

scanning of pr cess variables (para e ers) processi.g

-

s s em -

-

execu i

f variables

operator c mmu ica io n of process con rol routi es.

his basic struct re can be combined with application orien ed lower level modules to accomplish the desired process control tasks. At he present version, the system is completed for passive c ntrol (monitoring and supervision) of an industrial batch- ype fer en er. In the f llowing, a short descripti n f main odules is given. System initializatio. his module reads from a prepared (formatted) file into memory all process and contr 1 da a, thereby initiallizing he system: basic da a about process variables involved, i.e. their alphanumeric names, interface channel numbers, sampling intervals, type, calibration parameters, total number of phases in the c ntrol procedure,

asks data and the contr 1 algowhich action i which condiexecu e each asks (execu ion

e gineering

- mare than tw reference values f variables (f r comparing wi h he act al values of pr cess para aters)

-

in roduct ry service r

reference values for process variables in each c n r 1 phase (more than nly minim a d maximum are p ssible),

f system (c n r

anal g pr cess para e ers i s

A8-3

-

-

- minimum hardware needed in the basic version -

PLA

pro-

a particular application

-line difica ion parame ers

TATIO

synchr niza i ti e

ering.

- data 1 gging and/ r

FEm~

cion f sy chr niin ernal pr gram-sys em by means of he hardware

o

A8-3

- LI E I DUSTRIAL SCALE FERME TATIO

f variab es. This odule c mpaval e f a variable with a se ive reference va es. each variable w r more processing phases can be all ca ed, each phase having its wn se of reference values. Pr cessing f a variable de ermines - in dependence of its current val e - which-if any-contr 1 ac ion is be reques ed fr m he system. Execu tasks. By eans of his func i n PRODIP sys~ ul imately accomplishes logical and procedural c n rol of a process. Control task is defined here as any action of the computer system, hat is directly r indirectl oriented toward some kind f interven ion in the controlled process. C mplete con rol strategy for a par icular application can be designed by pr per concatenation (chaining or linking) of elementary control actions, in combination with·the table of reference values for process variables. F r effective use f the system, it is possible to include any user defined control actions. System - operat r communication. Communicati n is activated by the process operator or possibly also by the system itself, as the regular control activity. This function enables the operat r, the process engineer r the system's designer 0 examine any current available data ab u he c n rolled pr cess, to dify s e sys em (c n rol) parameters, and t in ervene directly in the contr 1 pr cedure. Opera or's co ands are simple, requiring nly a few ax rules. They can be yped in free f rma and heref re are sui able als f r rained pers nnel. Eac c and is exec ed nly after i was rec gnized as c rrect in respec he passw rd a d i s parameters. RES

S

C

r

PL

T

421

in a c ndensed a ner. Production plan staff is a imated and their ideas f r odificati ) ex e si n and fur her devel p en of the system are brough int realisation continuously. t he momen he data analyses modules for the so called internal process state parameters are under development. Also statis ical analysis f gathered process daa and si ulation is currently under expansi n and software packages for it in prepara io • To conclude: first experiences with the system regarding process data achievment as well as production plant staff enthusiasm provide us with a firm base for future work. e hope to continue by further widening the degree of automation in the industrial fermentation plant: to obtain simultaneous control of several bioreactor units and transition to some kind of active control tasks (multilevel control structure) as well as with introduction of additional types of control loops with more sophisticated sensors and more complex algorithms. REFERE CES 1.

yiri L.K., Toth G.M., Biotechnology & Bioengineering, Vol. XVII, p. 1663 - 1678,

1975 ?

yiri .K., Knishnaswami, C.S., Diamond Jubilee Meeting of merican Society for icr biol gy, Chicag, 974

3. Kon

T., Asai T., Biotechnol gy & Bioengineeri g, V 1. XI, p. 293 - 321, 1969

4. Cons an inides ., Rai .R., Biotechno1 gy & Bi engi eering Sir p. o. 4, p. 663 - 6 0, 97 5. 0 a er . e al., SBK ork Rep r , v e s t , 1975, 1976 6. Jakov eV1C C. e al., Pr c. I FOR A ICA 76, Bed, p. 5.107, 975 , B ed, 7. Div'ak S. , roc. .? , 97 p. IC 76, Cerne ic e al. , Proc. B ed, p. 5. , 1976 et al. , DEC S !: ropa s·J p . , 9. akov evic ich, 976