Estimation of fouling resistance in a phosphoric acid/steam heat exchanger using inverse method

Author(s):  
Ali Fguiri ◽  
Christophe Marvillet ◽  
Mohamed Razak Jeday
Author(s):  
Rania Jradi ◽  
Ali Fguiri ◽  
Christophe Marvillet ◽  
Mohamed Razak Jeday

Fouling in phosphoric acid concentration is a persistent operational problem that compromises energy recovery in this process. Progress is hampered by the lack of quantitative knowledge of fouling dynamic effects on heat exchanger transfer. The object of this work is an experimental determination of the thermal fouling resistance in the tubular heat exchanger of phosphoric acid preheated installed in phosphoric acid concentration process. By measuring the inlet and outlet temperatures of phosphoric acid, steam temperature, suction and discharge pressure of the pump and acid density measurement, the overall heat transfer coefficient has been determined. The determination of the overall heat transfer coefficient with clean and fouled surfaces, allowed calculating the fouling resistance. The results from the heat exchanger studies showed that the fouling resistance increased with time and presented an asymptotic evolution in compliant with the proposed model by Kern and Seaton, with the existence of fluctuation. The poorly cleaned heat exchanger implied the absence of the induction period and caused, consequently, high values of the fouling resistance in a relatively short-time period.


2020 ◽  
Vol 330 ◽  
pp. 01038
Author(s):  
Rania Jradi ◽  
Christophe Marvillet ◽  
Mohamed Razak Jeday

Fouling in phosphoric acid concentration process of preheat exchangers is a chronic operational problem that compromises energy recovery in these systems. Progress is hindered by the lack of quantitative knowledge of the dynamic effects of fouling on heat exchanger transfer. The subject of this work is an experimental determination of the thermal fouling resistance in the graphite blocks heat exchanger installed in a phosphoric acid concentration process. By measuring the inlet and outlet temperatures and mass flows of fluids, the overall heat transfer coefficient has been determined. Determining the overall heat transfer coefficient for the heat exchanger with clean and fouled surfaces, the fouling resistance was calculated. The results obtained from the heat exchanger studied, show that the fouling resistance increase with time presenting an exponential evolution in agreement with the model suggested by Kern and Seaton, with the existence of fluctuation caused by the instability of the flow rate and the temperature. Bad cleaning of the heat exchanger involves the absence of the induction period and consequently, causes high values of the fouling resistance and of the deposit fouling during a relatively short period of time.


1975 ◽  
Vol 97 (4) ◽  
pp. 504-508 ◽  
Author(s):  
A. P. Watkinson ◽  
O. Martinez

Scaling of copper heat exchanger tubes has been studied under conditions that promote rapid and severe scaling. Artificially hardened water of high dissolved and suspended solids is recirculated through a heated test section operated at constant steam temperature. The effects of flow velocity, tube diameter, and bulk temperature on the asymptotic fouling resistance have been determined. Results are interpreted in terms of mathematical models of the scaling process.


Author(s):  
Qun Zheng ◽  
Minghong Li ◽  
Yufeng Sun

Thermodynamic performance of wet compression and regenerative (WCR) gas turbine are investigated in this paper. The regenerative process can be achieved by a gas/air (and steam) heat exchanger, a regenerator, or by a heat recovery steam generator and then the steam injected into the gas turbine. Several schemes of the above wet compression and regenerative cycles are computed and analyzed. The calculated results indicate that not only a significant specific power can be obtained, but also is the WCR gas turbine an economic competitive option of efficient gas turbines.


1982 ◽  
Vol 15 (4) ◽  
pp. 223-228 ◽  
Author(s):  
S. Bittanti ◽  
A. Cividini ◽  
R. Scattolini

1986 ◽  
Vol 108 (1) ◽  
pp. 147-152 ◽  
Author(s):  
R. Sheikholeslami ◽  
A. P. Watkinson

The performance of copper and mild steel plain heat exchanger tubes and an externally finned mild steel tube was studied under calcium carbonate scaling conditions. Under a constant heat flux for 70-h periods the fouling resistance generally increased linearly with time. The effect of velocity on the rate of scale formation is presented for the three tubes and results compared with the model of Hasson.


2013 ◽  
Vol 459 ◽  
pp. 153-158
Author(s):  
Xiao Qiang Wen

Fouling characteristic of plate heat exchanger was studied through the experimental system, with the Songhua River water as working fluid. Several water quality parameters: pH value, conductivity, dissolved oxygen, turbidity, hardness, alkalinity, chloride ion, iron ion, chemical oxygen demand, total bacterial count, which had great influence on the formation of fouling, as well as running condition, fouling resistance and other parameters were measured through the experimental system built. A group of fouling data of the typical water quality was obtained. Two prediction models of fouling characteristics of the plate heat exchanger were built based on partial least squares algorithm (PLS) and support vector regression machine (SVR) with water quality parameters as independent variables and fouling resistance as dependent variable, and the impact of water quality parameter on predicting accuracy was analyzed. Research results showed that: the prediction accuracy of two methods could be controlled within 12.5% and meet the requirements of the project. Through the comparison of the prediction results, it was proved that the SVR method was better than the method of PLS. The impact of the water quality parameters on prediction model was discussed by the means of deleting the water quality parameters one by one.


2019 ◽  
Vol 8 (4) ◽  
pp. 4829-4833

Fouling is a major problem which affects technical performance and economics of the plate type heat exchanger used for the pasteurization of milk and dairy products. In the present work, experiments were conducted with milk- water system using corrugated plate type heat exchanger (model: M3-FG Alfa Laval) with 13 plates. Experiments were conducted to determine the heat transfer characteristics and fouling resistance by varying the temperature and the flow rate. The enhancement of heat transfer by fouling minimization with the coating of plates with epoxy coating was also studied and reported


Sign in / Sign up

Export Citation Format

Share Document