Determination of Thermal Inactivation Kinetics by the Multipoint Method in a Pilot Plant Tubular Heat Exchanger

2015 ◽  
Vol 8 (7) ◽  
pp. 1543-1551 ◽  
Author(s):  
Juan-Pablo Huertas ◽  
María Ros-Chumillas ◽  
María-Dolores Esteban ◽  
Arturo Esnoz ◽  
Alfredo Palop
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.


Author(s):  
Marina Pereira Jovetta ◽  
Pedro Esteves Duarte Augusto ◽  
Alline Artigiani Lima Tribst ◽  
Maria Josiane Conti ◽  
Marcelo Cristianini

Thermal process is among the safer and most used food preservation technique. The utilization of model foods in thermal processes studies has several advantages, and the determination of microorganisms thermal inactivation kinetics in model foods is extremely interesting for studying thermal processes and heat transfer. This work has determined the thermal inactivation kinetics of Alicyclobacillus acidoterretris in a liquid model food, thus providing subsidies for thermal process studies and design. The A. acidoterretris thermal inactivation was determined through the three-neck flask method, and was well described according to a first order kinetics. The D85°C, D88°C, D92°C and D95°C values were 105.4 min, 2.75 min, 7.0 min and 2.3 min, respectively. The observed z-value was 6.1°C. Due to the lack of such data in literature, the obtained results contribute to future studies on food thermal processes.


2018 ◽  
Vol 91 (6) ◽  
pp. 1486-1495
Author(s):  
E. A. Pitsukha ◽  
Yu. S. Teplitskii ◽  
A. R. Roslik ◽  
É. K. Buchilko

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manuel S. Krommweh ◽  
Wolfgang Büscher

AbstractExhaust air treatment systems (EATS) are used in animal husbandry to reduce emissions. However, EATS are associated with high acquisition and operating costs. Therefore, a plant technology is being developed that integrates a recuperative heat exchanger into a biological air scrubber. The overall aim is to reduce total costs of livestock buildings with EATS by saving heating costs and to improve animal environment. In this study, a special pilot-plant on a small-scale, using clean exhaust air, was constructed to evaluate the heating performance on laboratory scale. Three assembly situations of the heat exchanger into trickle-bed reactor were part of a trial with two different defined air flow rates. In all three assembly situations, preheating of cold outside air was observed. The heating performance of the assembly situation with the sprayed heat exchanger arranged below showed an average of 4.4 kW at 1800 m3 h−1 (outside air temperature range 0.0–7.9 °C). This is up to 18% higher than the other two experimental setups. The heating performance of the pilot-plant is particularly influenced by the outside air temperature. Further research on the pilot-plant is required to test the system under field conditions.


Sign in / Sign up

Export Citation Format

Share Document