evaporador de efecto múltiple en la elaboración de pasta de tomate

7/23/2019 Evaporador de Efecto Mltiple en la Elaboracin de Pasta de Tomate

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Optimum design and operating conditions of multiple effect evaporators:Tomato paste

R. Simpson *, S. Almonacid, D. Lpez, A. Abakarov

Departamento de Procesos Qumicos, Biotecnolgicos, y Ambientales, Universidad Tcnica Federico Santa Mara, Casilla P.O. Box 110-V, Valparaso, Chile

a r t i c l e i n f o

Article history:

Received 22 January 2008Received in revised form 24 May 2008

Accepted 27 May 2008

Available online 10 June 2008

Keywords:

Multi-effect evaporators

Economic evaluation

Net Present Value

Quality

Lycopene

Process optimization

a b s t r a c t

Agro industry is a very important industrial sector worldwide, especially for countries like New Zealand

and Chile. The main objective of this research was to propose a new economic evaluation procedure to

optimize the design and operation of multiple effect evaporators and compare it with the traditional

chemical engineering approach of total cost minimization. The proposed strategy incorporates a quality

factor expressed as a function of lycopene concentration on the final product to find the optimal number

of effects and operating conditions through the maximization of the net present value.

The mathematical model was implemented using Microsoft Excel and considered mass and energy bal-

ances, specific relations for tomato concentration and a first order degradation kinetic for lycopene. The

results indicate that when augmenting the capacity of the evaporation system of 5 effects from 50 to

75 Ton/h, the lycopene retention increases from 95.25% to 96.27%. When evaluating the system through

the logic of the total cost minimization, an optimum of 4 effects is found, but when evaluating the system

using the maximization of the Net Present Value including lycopene as a quality parameter, the optimum

is 3 effects.

It appears of extreme relevance to consider quality as an intrinsic and integral part of the process

design, as it will then be possible to identify several potential improvements in different food processes.

2008 Published by Elsevier Ltd.

1. Introduction

Process optimization has always been a noble objective of engi-

neers entrusted with the responsibility for process development

and improvement throughout the food industry. Examples of

sophisticated mathematical approaches to process optimization,

in which some objective function is maximized or minimized

subject to chosen constraints, are widely published in literature

(Douglas, 1988). On the other hand, the chemical industry has used

cost analysis in several cases in relation to design and process opti-

mization. A classical example in the chemical industry is the deter-

mination of the optimal number of effects in a evaporation system,

were the optimum is found when there is an economic balance be-

tween energy saving and added investment, this is, a minimization

of the total cost (Kern,1999). In this vision, although correctly, qual-

ityis notconsidered as a parameter in thedetermination of theopti-

mum number of effects, so the process specifications and operating

conditions are assumed independent of both product quality as its

sale price. The purpose of this manuscript is to suggest that the

extrapolation of optimization problems from chemical industry to

the food industry may often be restricted to an unnecessarily nar-

row or local domain, and that a more global perspective may reap

greater rewards. Questions as to just what should be maximized

or minimized, or what are the real constraints, as opposed to only

those that are immediately apparent, are questions often posed

without a broad enough view of the big picture.

China continues to make inroads in the world market. China is

the worlds largest tomato products producer and exporter, fol-

lowed by the EU and the United States. China produces tomato

products mainly for the export market, with exports accounting

for more than 85% of production. Since calendar year (CY) 1999,

Chinas tomato paste exports have had an average annual increase

of 30% (USDA, 2007).

The production of tomato paste is highly seasonal, and then,

maximizing production levels in this industry is of vital impor-

tance. The process is generally done in multiple evaporation sys-

tems, with a different number of effects, through which the

content of water is diminished until a final concentration from

30 to 32Brix is acquired, and where temperatures generally do

not exceed 70 C.

Lycopene is the main carotenoid found in tomatoes and many

studies have showed its inhibiting effect on carcinogenic cell

growth (Shi et al, 2007). It is also the component which generates

the red characteristic color in tomatoes, among other fruits and

vegetables (Goula and Adamopoulos, 2006). A study developed

by the University of Harvard, revealed that the consumption of

lycopene reduced the probabilities of generating prostate cancer

0260-8774/$ - see front matter 2008 Published by Elsevier Ltd.doi:10.1016/j.jfoodeng.2008.05.033

* Corresponding author. Tel.: +56 32 2654302; fax: +56 32 2654478.

E-mail address: [email protected](R. Simpson).

Journal of Food Engineering 89 (2008) 488497

Contents lists available at ScienceDirect

Journal of Food Engineering

j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / j f o o d e n g
mailto:[email protected]://www.sciencedirect.com/science/journal/02608774http://www.elsevier.com/locate/jfoodenghttp://www.elsevier.com/locate/jfoodenghttp://www.sciencedirect.com/science/journal/02608774mailto:[email protected]


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by 45%, in a population of 48,000 subjects who had at least 10 ra-

tions of tomatoes or sub products in their weekly diet. Other re-

search discovered that lycopene also reduces cholesterol levels in

the form of a lipoprotein of low density (LDL), which produces ath-

erosclerosis; this means that the consumption of tomatoes reduces

the effects produced by cardiovascular diseases.

Lycopene as the main organic compound presents a denatural-

ization reaction rate that is time and temperature dependent. Then,

for the mathematical model of the behavior of multi-effect evapo-

rators, it is very important to have a good overview of the general

fluctuation of lycopene retention or loss under different system de-

signs and operating conditions.

As aforementioned, most food processes have been adapted and

extrapolated from the chemical engineering industry without an

adequate consideration of product quality during system designand process optimization. That is certainly a good start, but maybe

somewhat limited and might have inhibited us to take a more glo-

bal view. For example, it appears of extreme relevance to consider

quality more frequently as an intrinsic and integral part of process

design. In the food industry, the main effort is commonly related to

the maximization of the quality of the product, which is not neces-

sarily the case in the chemical industry. Generally the optimization

of food processes have been restricted to determining the optimal

operating conditions of an allegedly, well designed food process.

Nevertheless, if quality is considered as a parameter in the system

design, it is very probable that the new design will differ from the

original one.

For example, in the case of a multiple effect evaporator system

for the processing of tomatoes, the optimization of the design isonly focused on an economic analysis which combines the invest-

ment (number of effects) and the operating costs (steam consump-

tion) (Kern, 1999). This strategy does not include quality as an

integral part of the economic evaluation, even though previous

studies have demonstrated the dependence of the final product

price towards quality of the final product (Schoorl and Holt, 1983).

The main objective of this research work is to propose a new

economic evaluation procedure to optimize the system design

and operation of tomato juice, multiple effect evaporator and com-

pare it to the traditional chemical engineering approach of total

cost minimization. The proposed strategy will incorporate a quality

factor which will be expressed as a function of lycopene concentra-

tion on the final product to find the optimal number of effects and

operating conditions through the maximization of the Net PresentValue (NPV).

2. Methodology

2.1. Problem description

Cost analysis has been extensively and correctly utilized in find-

ing the best process design in several chemical engineering plants.

A classical example is multi-effect distillation. In this case, cost

analysis should aim to determine the optimum number of effects

in multiple-stage equipment. According to the literature in chemi-

cal engineering The optimum number of effects must be found from

an economic balance between the savings in steam obtained by multi-

ple effect operation and added investment. It is important to eluci-

date whether the aforementioned approach is recommendable in

the optimization of food processes? From a microeconomics point

of view, this approach is correct but, it is important to consider thatthe different equipment configurations are producing exactly the

same quality of the end product. Meaning that, independent of

the numberof effects, not onlywill webe able to reach the samede-

gree of concentration, but also the same quality. In addition, by

changing the equipment configuration it is possible to attain the

same degree of concentration but with different product quality.

At least, for multi-effect evaporation in food processing, the re-

ferred approach is not necessarily the right micro-economic tool

to find the optimum number of effects. For this kind of application,

a correct micro-economic analysis should consider not only all

costs but also the expected benefits. According to the relevant tech-

nical literature, an adequate micro-economic procedure is to max-

imize the NPV.

In the case of the evaporation process for tomato paste, the pro-duction is highly seasonal, and, in addition, the product quality

could be highly affected by the operating conditions. Therefore, it

is important to consider the impact of the installed capacity and

the final product quality. In the following, we will compare two dif-

ferent economic approaches: (a) determination of the optimal

number of effects by minimizing the total cost and, (b) maximiza-

tion of the NPV, considering quality as an intrinsic parameter of the

modeled system.

2.2. Product quality

To reach the objective of the present research work, a quality

parameter must be considered to the mathematical model of theevaporation system. The chosen parameter is lycopene, because,

Nomenclature

A heat transfer area, m2

Cu cost per unit, US$/kgCp specific heat of concentrate (kJ kg

1C1)

Deb boiling point elevation (BPE) or Boiling point rise (BPR)(C)

E activation energy (kJ/mol)F mass flowrate (kg/h)H enthalpy (kJ/kg)i annual interest rateI total investment (US$)k reaction rate constant (1/h)k0 frequency factor (1/h)K0 constantM mass in the evaporator (kg)m project shelf life, yearsn number of effectsNPV net present value (US$)O evaporation system operation

P pressure (kPa)Pu unit sales price (US$/kg)Q heat flow (kJ)Q*j annual production at periodj (units/year)R ideal gases constant (CkJ/mol)

T temperature (C)t time (h)X concentration of soluble solids, kgss/kgY lycopene concentration kgL/kgss

Subscriptsc condensingd downloade coolingi evaporator effect, i

j evaluation period,jp losses

R. Simpson et al. / Journal of Food Engineering 89 (2008) 488497 489


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as mentioned before, this carotenoid pigment is what gives toma-

toes their characteristic color, and, in addition, it has some medical

benefits.

Usually, degradation rates in sensitive food components are

modeled as a first order kinetic, as follows:

r kY or dY

dt kY 1

The Arrhenius equation relates specific reaction rate constant to

temperature according to:

k k0 exp E

R T

2

The first order kinetic for lycopene degradation has been con-

firmed by Goula and Adamopoulos (2006). In the same research

study an equation was obtained to determine the reaction rate in

the lycopene degradation, as a function of temperature and soluble

solids concentrationXexpressed in Brix.

For X 55; K 0:121238 exp0:0188X

exp 2317

T 273:15 min1

3

ForX 55; k 0:275271exp 0:00241X

exp 2207

T 273:15

min

1 4

In our research study, the system to be modeled should con-

sider tomato concentration in the range of 535 Brix, so only Eq.

(4)will be required.

2.3. Model development

The evaporation process involves mass and heat transfer (Him-

melblau and Bischoff, 1968). The tomato juice was considered as a

binary solution of water and soluble solids, both considered inertin a chemical sense. Under these considerations, one effect of the

industrial evaporator can be shown in the manuscript by Miranda

and Simpson, 2005.

So the macroscopic model is of the knowledge-type based on

conservation laws and also empirical relationships which describe

the equilibrium phases. These relationships have been rearranged

from non-linear algebraic equations from literature, with the expe-

rience taken from the experimental site. Only the juice phase is

considered for modeling.

The modeling assumptions are:

Homogenous composition and temperature inside each

evaporator. Constant juice level in each evaporator. Thermodynamic equilibrium (liquidvapor) for the whole mod-

eled system.

The mathematical model developed in this research study in-

cluded specific relationships for lycopene degradation. The general

system that must be solved (seeFig. 1for a schematic representa-

tion of the system), operates on countercurrent and the total num-

ber of effects varies from 1 to n. The value of n and the

operating conditions will be determined at the end of this work

through the maximization of the NPV.

The total mass balance in evaporator effect i is:

dMi

dt Fi1 Fvi Fi 5

If the mass within the evaporator effect is controlled, then, un-

der steady state, Eq.(5)can be written as:

0 Fi1 Fvi Fi 6

In the same way, a mass balance for soluble solids at effect i, can

be written as:

dMiXi

dt Fi1 Xi1 Fi Xi 7

Under steady state condition:

0 Fi1 Xi1 Fi Xi 8

The corresponding energy balance for the evaporator effect i, is:

dHiMi

dt Fi1 Hi1 Fvi1 Hvi1 Fi Hi Fvi Hvi Fci Hci Qp

9

Under steady state condition:

0 Fi1 Hi1 Fvi1 Hvi1 Fi Hi Fvi Hvi Fci Hci Qp

10

The enthalpy of the tomato paste was estimated through the

specific heat (Cp), utilizing the following expression (Tonelli et

al., 1990):

Hi 4:184 2:9337 Xi Ti 11

The following thermodynamic relationship describes the boil-

ing point rise (BPR) or boiling point elevation (BPE), whose param-eters have been determined experimentally, it is one of the three

important properties (specific heat, viscosity and boiling point

rise), that must be specified in a multiple effects evaporator (Rizvi

and Mittal, 1992). This property (BPR) is significant at high soluble

solids concentration. On a multiple effect equipment, the effective

temperature differences decrease for the combination of boiling

point. The following correlation reported byMiranda and Simpson,

2005, was utilized.

Deb 0:175X1:11e3:86XP0:43 12

Vapor was considered saturated within the evaporator. The fol-

lowing correlations were obtained fromPerry and Chilton (1973),

and allow for the estimation of vapor properties with an error of

less than 1%.For 40 C


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For 70C


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the restriction was equal areas for each evaporator effect. The input

values to the model, shown inTable 1, were the same for all of the

systems and obtained from an actual industrial plant, comple-

mented with available online information from manufacturers.

3.1. Steady state conditions

From the mass and energy balance equations, liquidvaporequilibrium equation and specific relations for the tomato paste,

a steady state model for the evaporator system was developed,

considering one up to seven effects. From this information, it is

possible to verify the decrease in vapor flowrate necessary for

the operational process and an increase in the total system area,

when augmenting the number of effects (Fig. 2).

To have a more precise view of the product behavior in the

evaporation system, residence time and their respective tempera-

tures, are presented inTable 2for each one of the effects in the dif-

ferent systems.

3.2. Lycopene retention

Lycopene retention in the final product was estimated for each

one of the alternative systems from the data obtained under steady

state operation. From the results shown in Fig. 3, it is clear that

lycopene concentration in the final product has a linear decay

when augmenting the number of effects in the evaporation system.

The previous result gives a clue of how the content of lycopene in

the final product is affected as a function of the residence time in

the evaporation system. While the number of effects increases in

the evaporation system, the total residence time increases as well

as the temperature at which the product is exposed, and, therefore,

there is also an increase of the lycopene degradation.

Lycopene retention for the theoretical evaporation system for

tomato paste are shown inFig. 4. Clearly, lycopene retention de-

creases as the number of effects increase, which is justified bythe augmentation of the total residence time of the system and also

because of the temperature rise at which the tomato paste is ex-

posed to. In regards to the supply flowrate, there is an increase

in the lycopene retention when augmenting the flowrate. The in-

crease in lycopene retention is less abrupt when the supply flow-

rate is over 100 ton/h.

3.3. Changes in processing capacity

To have a more precise idea of the effect of temperature and res-

idence time effect on lycopene degradation process capacity was

set to different values in a specific range. This was done by main-

taining the heat exchange area, and consequently, the number of

effects (a 5 effect lineup system was considered, as it is the number

that is regularly used in the tomato paste industry). Increasing the

processing capacity of the system, results in a increment of the

required energy, therefore steam inlet pressure Pv0 will also be

increased. This also implies a rise of temperature in the evapora-

tors effects. As shown in Fig. 5, the required vapor flowrate

increases proportionally to the evaporation system input flowrate,

steam inlet pressure increases in a second order polynomial way.

Fig. 6shows a decrease in the systems total residence time as well

as an increase in each evaporators temperature.

As it was expected, temperature inside each evaporator in-

creases due to the augmentation of the system energy require-

ments. The systems residence time decreases because of the

increase of input flowrate and the conservation of the holdup va-

lue. As it is observed in Fig. 7, there is an increase in lycopene

retention when augmenting the input flowrate associated to theproducts residence time which decreases in the evaporation sys-

tem, with no regard to the increase of the evaporator temperature

increment.

This is of great importance, because it demonstrates that lyco-

pene is not an obstacle to increase the processing capacity of the

evaporation system, therefore the maximum capacity will only

Table 1

Input data for mathematical model implementation

Name Variable Value

Input flowrate FAl, kg/h 50,000

Input temperature TAl, C 98

Initial soluble solids

concentration

XAl, kg ss/kg 0.05

Input concentration

of lycopene

YAl, kg Lic/kg SS 0.01

Final soluble solids

concentration

X1, kg ss/kg 0.3

Steam inlet pressure Pv0, kPa 143.4

Temperature change

in condensator

Tvn Td, C 2

Operation pressure in

evaporator n

Pn, kPa 16.5

Fig. 2. Total transfer area m2 and steam inlet flowrate ton/h vs. number of effects.

492 R. Simpson et al. / Journal of Food Engineering 89 (2008) 488497


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Table 2

Temperature data C and residence time h for systems from 1 to 7 effects with an input flowrate of 50 ton/ha,b

Effect

number

Number of effects in the system

1 2 3 4 5 6 7

Residence

time

Temp. Residence

time

Temp. Residence

time

Temp. Residence

time

Temp. Residence

time

Temp. Residence

time

Temp. Residence

time

Temp.

1 1.10 55.9 0.23 55.6 0.17 55.6 0.15 55.6 0.14 55.6 0.13 55.6 0.13 55.6

2 0.84 76.8 0.28 67.5 0.20 63.8 0.17 61.8 0.15 60.5 0.14 59.63 0.78 84.7 0.31 74.3 0.22 69.3 0.19 66.3 0.17 64.3

4 0.75 89.3 0.34 78.9 0.24 73.3 0.20 69.8

5 0.73 92.3 0.36 82.3 0.26 76.4

6 0.71 94.4 0.38 84.8

7 0.70 96.1

1 effect 2 effects 3 effects 4 effects 5 effects 6 effects 7 effects

Output pressure at each effect

P1, kPa 16.5 40.18 56.4 67.7 76.05 82.41 87.5

P2, kPa 16.5 27.7 36.5 44.76 51.6 57.31

P3, kPa 16.5 23.8 29.75 34.91 40.15

P4, kPa 16.5 21.82 26.38 30.32

P5, kPa 16.5 20.65 24.28

P6, kPa 16.5 19.86

P7, kPa 16.5

a Feed enters effect 1.b Fresh vapor pressure: 143.4 kPa.

Fig. 3. Lycopene retention% vs. number of effects for an input of 50 ton/h.

Fig. 4. Lycopene retention% for a system from 1 to 7 effects.



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Fig. 5. Changes in energy consumption represented by the vapor flowrate kg/h and steam inlet pressure kPa as a function of the input flowrate ton/h.

Fig. 6. Residence time (min) and temperature C as a function of the input flowrate ton/h.

Fig. 7. Lycopene retention% as a function of the input flowrate ton/h.



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be restricted by available vapor pressure, minimum specific hold-up, pumps power among others.

3.4. Economic evaluation

The economic evaluation consists of determining the optimum

number of effects and operating conditions of the system. The eco-

nomic evaluation of the system was done in two different ways.

Firstly, an economic evaluation with the concept of minimizing

the total costs, and secondly, an economic evaluation to maximize

the NPV taking into account the impact of the process design and

operating conditions on product quality.

3.5. Optimum number of effects

The economic evaluation was carried out by simple inspection.

This is where the steady state conditions for systems with 17 ef-

fects were found, and then total cost minimization and NPV max-

imization methodologies were used. The search was focused to

find the number of effects that minimize the total cost and, in addi-

tion, to find the number of effects that maximize the NPV.

The results for each evaluation systems are shown in Figs. 8

and 9. The total cost minimization (Fig. 8) shows an optimum of

4 effects. Nevertheless, when doing NPV maximization (Fig. 9),the number of optimum effects was 3 due to the inclusion of the

quality parameter on the evaluation procedure. Naturally, for dif-

ferent processing capacities, the optimum number of effects varies

for both evaluation procedures. This is why differences are encoun-

tered in the optimum number of effects in some operation ranges.

InFig. 10, the optimum number of effects is presented for different

operation ranges. As it is observed inFig. 10, when evaluating the

evaporation system, including the quality parameter, in the range

of 25 ton/h through 50 ton/h, the optimum number of effects de-

creases, in comparison to the evaluation done based on total costs

only. This is explained with previous results where a decrease of

lycopene retention was a result of the increase of the number of ef-

fects. It is for this reason that the NPV maximization, in this partic-

ular case tends to be a lower number of effects.

3.6. Optimum operating conditions

In the search for the optimum operating conditions of evapora-

tion system, the system was economically evaluated under a vari-

able steam inlet pressure (Pv0) where the inclusion of lycopene as a

quality parameter was considered. As a constraint to the problem,

it was estimated that the output temperature of the tomato paste

Fig. 8. Cost evaluation for an evaporator system with an input flowrate of 50 ton/h.

Fig. 9. Net Present Value evaluation for evaporator systems with input flow of 50 ton/h.



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(highest temperature), with the optimum number of effects for adefined vapor pressure, could not be higher than 95 C. Results ob-

tained shown an increase in the project profitability when steam

inlet pressure is augmented. Optimum operating conditions, with

the previous stated constraints, is found to be a 3 effects system

with a steam inlet pressure of 260 kPa (seeTable 3). This result dif-

fers from that obtained from the evaluation based on the total cost

minimization (5 effects system).

Table 4depicts the results obtained by both economics ways;

total cost minimization and NPV maximization.

4. Conclusions

The steady state values of the evaporator system were able to

be linked to the reaction kinetics of the target attribute, lycopene.A mathematical model was successfully developed, and then an

economic evaluation of the optimum design and operating condi-

tions of the evaporation system (17 effects operated under coun-

tercurrent) was carried out.

It was possible to determine that the lycopene retention has a

linear decay respect to the number of effects used in the evapora-

tion system.

When analyzing the behavior of a 5 effect evaporator system, an

increase in the processing capacity from 50 ton/h to 75 ton/h aug-

ments the lycopene retention in the final product from 95.25% to

96.27%.

The previous result is due to the decrease in residence time, and

independent of an increase in the evaporators temperature. This

result is important because it indicates that the increment in toma-to paste production, in this particular case, is restricted only by

mechanical factors like available vapor pressure, maximum speci-

fied holdup, and pump power, etc.

The total cost minimization allows the determination of the

best equipment design (optimum number of effects), but no

information on operating conditions and product quality is ob-

tained. On the other hand, with the NPV approach, it is possible

to optimize the system design and operating conditions simulta-

neously. In addition, the NPV approach considers the final product

quality as an intrinsic parameter of the system.

With the inclusion of lycopene as a quality parameter (NPV), the

optimum number of effects decreases from 4 to 3 when compared

with total cost analysis. In addition, it was also possible to deter-

mine the optimum operating conditions of the 3 effects systemat 260 kPa.

Fig. 10. Optimum number of effects for different input flow rates ton/h according to total cost minimization and Net Present Value maximization.

Table 3

Optimum operating conditions

1st effect 2nd effect 3rd effect

Heat transfer area, m2 209.6 209.2 209.1

Global heat transfer coefficient,

kJ/C/m2/h

4494.5 6767.2 8475.4

Heat transferred, MJ/h 32803.8 30941.1 28727.7

Boiling point raise, C 0.53 0.07 0.03

Holdup, kg 5320 4907 4815

Residence time, h 0.639 0.224 0.141

DTNukiyama 34.8 21.9 16.2

Steady state values

Steam inlet flowr at e, k g/h 1 501 2.9

Steam inlet pressure, kPa 260

Steam inlet temperature, C 129.1

Steam inlet ent halpy , k J/ kg 2 72 5.45Output flowrate, kg/h 8322.5 21930.0 34265.4

Temperature,C 94.26 71.88 55.60

Concentration SS, kg/kg 0.300 0.114 0.073

Lycopene concentration, kg/kg SS 0.0096790 0.0099130 0.0099724

% Lycopene retention 96.79% 99.13% 99.72%

Concentrate enthalpy, kJ/kg 311.3 276.7 220.7

Vapor flowrate, kg/h 13607.5 12335.4 15734.6

Vapor pressure, kPa 81.84 32.9 16.5

Vapor temperature, C 93.73 71.81 55.57

Vapor enthalpy, kJ/kg 2666.3 2629.6 2602.4

Condensed flowrate, kg/h 15012.9 13607.46 12335.4

Condensation temperature, C 129.08 93.7 71.81

Condensed enthalpy, kJ/kg 540.4 392.4 300.7

Table 4

Optimum number of effects for different steam inlet pressures

Pv0, kPa Number of optimum effects

Minimum total cost Maximum NPV

110 4 2

120 4 2

130 4 3

140 4 3

150 4 3

160 4 3

170 4 3

200 4 3

230 4 3

260 5 3



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It appears of extreme relevanceto consider quality as an intrinsic

and integral part of the process design, as it will then be possible to

identify several potential improvements in different food processes.

Acknowledgements

Author Ricardo Simpson is grateful for the financial support

provided by CONICYT through the FONDECYT project number1070946. Author Sergio Almonacid is grateful for the financial sup-

port provided by CONICYT through the FONDECYT project number

1070512.

References

Douglas, J.M., 1988. Conceptual Design of Chemical Processes. ChemicalEngineering Series. McGraw-Hill International Editions.

Goula, A., Adamopoulos, K., 2006. Prediction of Lycopene degradation during adrying process of tomato pulp. J. Food Eng. 74 (1), 3746.

Himmelblau, D.M., Bischoff, K.B., 1968. Process analysis and simulation:deterministic system. Wiley, New York, USA.

Kern, D. 1999. Procesos de Transferencia de Calor. Editorial Continental S.A. Mexico.Maroulis, A.Z., Maroulis, Z.B., 2005. Cost data analysis for the food industry. J. Food

Eng. 67 (3), 289299.Miranda, V., Simpson, R., 2005. Modeling and simulation of an industrial multiple

effect evaporator: tomato concentrate. J. Food Eng. 66 (2), 203210.Perry, J., Chilton, C., 1973. Chemical Engineers Handbook. Editorial Mc Graw-Hill,

USA.Peters, M., Timmerhaus, K., West, R., 2003. Plant Design and Economics for Chemical

Engineers. Editorial Mc Graw-Hill, USA.Rizvi S.H., Mittal G.S. 1992. In: Van Nostrand Reinhold (Ed.), Experimental Methods

in Food Engineering..Schoorl, D., Holt, J.E., 1983. An analysis of the effect of quality on prices of

horticultural procedure. Agricultural Systems 12 (2), 7599.Shi, J., Qu, Q., Kakuda, Y., Jun, S., Jiang, Y., Koide, S., Shim, Y., 2007. Investigation of

the antioxidant and synergistic activity of Lycopene and other naturalantioxidants using LAME and AMVN model systems. J. Food Compos. Anal. 20(7), 603608.

Tonelli, M., Romagnoli, J., Porras, J., 1990. Computer package fortransient analysis ofindustrial multiple-effect evaporators. J. Food Eng. 12 (4), 267281.

USDA, 2007. Tomatoes and Tomato Products. World Markets and Trade.


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