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Luc Fillaudeau - One of the best experts on this subject based on the ideXlab platform.
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On-line local thermal pulse analysis sensor to monitor fouling and cleaning: Application to dairy product pasteurisation with an ohmic cell jet heater
Journal of Food Engineering, 2013Co-Authors: Jonathan Crattelet, P. Debreyne, Sami Ghnimi, Ismael Zaid, Ali Boukabache, Daniel Esteve, Laurent Auret, Luc FillaudeauAbstract:Abstract In the process industry, fouling is considered as a complex (sometimes partially known and identified) phenomenon. In this paper, a fouling sensor (FS) based on local differential thermal analysis is scrutinized and we report the comparison of two operating modes, steady (STR) and periodic (PTR) thermal regimes. Moreover, the development of alternating technologies like direct Joule Effect (ohmic) heating to pasteurise and sterilise liquid food products in a continuous process is of great scientific and industrial interest. Heat treatment by direct Joule Effect exhibits numerous advantages because rapid heating kinetics or homogeneous heat treatment is required. However, fouling of electrode surfaces in this kind of apparatus is much more problematic than in conventional heat exchangers. In the present study, a new continuous ohmic heating apparatus (Emmepiemme®, Piacenza, Italy) in which an alternating electrical current is applied directly to a jet falling between two stainless steel electrodes is investigated during pasteurisation of a dairy product. Conventional fouling measurements (pressure drop, heat transfer or electrical parameters) cannot be used in such a heater. Fouling and cleaning phases are monitored with fouling sensor and fouling quantified.
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Influence of flow regime and thermal power on residence time distribution in tubular Joule Effect heaters
Journal of Food Engineering, 2009Co-Authors: Luc Fillaudeau, K. Le-nguyen, C. AndreAbstract:To improve treatment homogeneity in tubular Joule Effect Heater (JEH), geometric modifications could be used even in laminar regime inducing flow perturbation and mixing. As a response variable, residence time distribution (RTD) is an important parameter and it has been commonly used in determining the performances of industrial heat exchangers. In present work, our objectives were (i) to investigate the impact of processing conditions (flow regime, heat flux) on RTD in an industrial JEH equipped with smooth and modified tubes, (ii) to contribute to the estimation of treatment homogeneity versus global energetic performances of heat exchanger and (iii) to validate a general reactor model.Analytical solution and systemic analysis of RTD signals were reported. The evolutions of mean reduced variance, beta(2) against efficiency number, Eff for smooth (beta(2) = 0.00129, Eff - 0.0300, R(2) = 0.992) and modified (beta(2) = 0.000547, Eff - 0.0169, R(2) = 0.979) tubes exhibited a similar and linear relationship. Under the conditions investigated (38 < Re < 10,000, 4 < Pr < 950 with Newtonian fluids), treatment homogeneity was significantly improved by modified geometry and strong interactions between heat transfer and hydrodynamics. A significant decrease in reduced variance under both laminar (beta(2)(ST) = 0.1054 . Exp(-0.00518.P/(rho.Q)), beta(2)(MT) = 0.0661 . Exp(-0.00342 . P/(rho.Q))) and turbulent (beta(2)(ST) = 0.00624 . Exp(-0.00447.P/(rho.Q)), beta(2)(MT) = 0.00108 . Exp(-0.00195.P/(rho.Q))) regimes was observed versus heat energy.However geometric modification and heat treatment affected the residence time distribution and specifically reduced variance, beta(2) within same order of magnitude. Systemic analysis of experimental data enabled to evaluate two reactor models: Dispersed Plug Flow (DPF) and Plug Flow (PF) + 2 Continuous Stirred Tank Reactor (CSTR) with and without convolution and with 1 or 2 degrees of freedom.Second model could be considered as the most accurate model to predict RTD in JEH with an accurate degree of confidence for residence time and reduced variance estimation (tau = 0.995 . t(s) R(2) = 0.64, error < 3% and beta(2) = 0.3119 . (beta(2)(exp))(0.73) R(2) = 0.98) and a simplified model with only 1 degree of freedom can be used.
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Residence time distribution in tubular Joule Effect heaters with and without geometric modifications
Chemical Engineering & Technology, 2006Co-Authors: Christophe Andre, Benjamin Boissier, Luc FillaudeauAbstract:In the food industry, heat treatment of highly viscous fluids in continuous processes is becoming more and more common, and the process should perform as a homogenous thermal treatment, in order to ensure quality and safety of the final product. To improve treatment homogeneity, geometric modifications can be used even in the laminar regime, to induce flow perturbation and mixing. The objectives of this work include: (i) Investigation of the residence time distribution (RTD) for industrial indirect Joule Effect heaters (JEH), with smooth (ST) and modified (MT) tubes, (ii) Demonstration and quantification of the efficiency of the geometrical modifications, and (iii) Proposition of a single semi-empirical model including the flow regime (10
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Modelling and measurement of residence time distribution in tubular Joule Effect heaters with and without geometric modifications
2006Co-Authors: Christophe Andre, Benjamin Boissier, Luc FillaudeauAbstract:In food industry, heat treatment of highly viscous fluids in continuous process is more and more common and the process should perform homogenous thermal treatment in order to ensure quality and safety of the final product. To improve treatment homogeneity, geometric modifications could be used even in laminar regime inducing flow perturbation and mixing. In this work, our objectives were (i) to investigate residence time distribution (RTD) for industrial indirect Joule Effect heaters (JEH) with smooth (ST) and modified (MT) tubes, (ii) to demonstrate and quantify the efficiency of geometrical modifications and (iii) to propose a general reactor model including flow regime (10
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Impact of processing conditions (flow regime, heating) on residence time distribution in tubular Joule Effect heaters.
2006Co-Authors: Luc Fillaudeau, Alexi Detavernier, Benjamin Boissier, Christophe AndreAbstract:Impact of processing conditions (flow regime, heating) on residence time distribution in tubular Joule Effect heaters.. IUFOST, 13. World Congress of Food Science and Technology "Food is Life
C. Andre - One of the best experts on this subject based on the ideXlab platform.
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Influence of flow regime and thermal power on residence time distribution in tubular Joule Effect heaters
Journal of Food Engineering, 2009Co-Authors: Luc Fillaudeau, K. Le-nguyen, C. AndreAbstract:To improve treatment homogeneity in tubular Joule Effect Heater (JEH), geometric modifications could be used even in laminar regime inducing flow perturbation and mixing. As a response variable, residence time distribution (RTD) is an important parameter and it has been commonly used in determining the performances of industrial heat exchangers. In present work, our objectives were (i) to investigate the impact of processing conditions (flow regime, heat flux) on RTD in an industrial JEH equipped with smooth and modified tubes, (ii) to contribute to the estimation of treatment homogeneity versus global energetic performances of heat exchanger and (iii) to validate a general reactor model.Analytical solution and systemic analysis of RTD signals were reported. The evolutions of mean reduced variance, beta(2) against efficiency number, Eff for smooth (beta(2) = 0.00129, Eff - 0.0300, R(2) = 0.992) and modified (beta(2) = 0.000547, Eff - 0.0169, R(2) = 0.979) tubes exhibited a similar and linear relationship. Under the conditions investigated (38 < Re < 10,000, 4 < Pr < 950 with Newtonian fluids), treatment homogeneity was significantly improved by modified geometry and strong interactions between heat transfer and hydrodynamics. A significant decrease in reduced variance under both laminar (beta(2)(ST) = 0.1054 . Exp(-0.00518.P/(rho.Q)), beta(2)(MT) = 0.0661 . Exp(-0.00342 . P/(rho.Q))) and turbulent (beta(2)(ST) = 0.00624 . Exp(-0.00447.P/(rho.Q)), beta(2)(MT) = 0.00108 . Exp(-0.00195.P/(rho.Q))) regimes was observed versus heat energy.However geometric modification and heat treatment affected the residence time distribution and specifically reduced variance, beta(2) within same order of magnitude. Systemic analysis of experimental data enabled to evaluate two reactor models: Dispersed Plug Flow (DPF) and Plug Flow (PF) + 2 Continuous Stirred Tank Reactor (CSTR) with and without convolution and with 1 or 2 degrees of freedom.Second model could be considered as the most accurate model to predict RTD in JEH with an accurate degree of confidence for residence time and reduced variance estimation (tau = 0.995 . t(s) R(2) = 0.64, error < 3% and beta(2) = 0.3119 . (beta(2)(exp))(0.73) R(2) = 0.98) and a simplified model with only 1 degree of freedom can be used.
Keiji Ogura - One of the best experts on this subject based on the ideXlab platform.
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under Joule Effect heating
2017Co-Authors: Takahide Sakagami, Keiji OguraAbstract:The thermographic NDT based on the transient temperature distribution under the Joule Effect heating by an electric current was discussed. Two different types of inspection methods, i.e., the singular method and the insulation method wei examined. The singular method based on the heat concentration at the crack tip was successfully applied to the identification of the through-thickness and surface cracks embedded in steel plates. The resolution of the crack identification by the singular method was examined by the cunent intensity factor and the thermal diffusion length. The insulation method based on the temperature turbulence appears on the sample surface due to the thennal insulation of the defect was tested for the identification of the delaminated defect in CFRP. Two methods of the Joule Effect heating, the direct current application and the induction heating, were successfully applied for the thermographic NDT of the delaminated defects in CFRP samples. The thermographic NDT developed in this study was found to be applicable to nondestructive flaw- and defect-inspection both in metallic and composite materials.
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New Flaw Inspection Technique Based on Infrared Thermal Images under Joule Effect Heating
JSME international journal. Series A mechanics and material engineering, 1994Co-Authors: Takahide Sakagami, Keiji OguraAbstract:Joule Effect heating by electric current was employed to heat up the sample instantaneously. Both numerical and experimental studies were made on the resolution and the applicability in the detection of the through thickness and surface cracks embedded in steel plate samples
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Thermographic NDT based on transient temperature field under Joule Effect heating
Thermosense XVI: An International Conference on Thermal Sensing and Imaging Diagnostic Applications, 1994Co-Authors: Takahide Sakagami, Keiji OguraAbstract:Thermographic NDT based on the transient temperature distribution under the Joule Effect heating by an electric current was discussed. Two different types of inspection methods, the singular method and the insulation method, were examined. The singular method based on the heat concentration at the crack tip was successfully applied to the identification of the through- thickness and surface cracks embedded in steel plates. The resolution of the crack identification by the singular method was examined by the current intensity factor and the thermal diffusion length. The insulation method based on the temperature turbulence appears on the sample surface due to the thermal insulation of the defect was tested for the identification of the delaminated defect in CFRP. Two methods of the Joule Effect heating, the direct current application and the induction heating, were successfully applied for the thermographic NDT of the delaminated defects in CFRP samples. The thermographic NDT developed in this study was found to be applicable to nondestructive flaw- and defect- inspection both in metallic and composite materials.
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Development of Thermographic NDT for Delaminated Defects in Fiber Reinforced Plastics.
Transactions of the Japan Society of Mechanical Engineers. A, 1993Co-Authors: Takahide Sakagami, Keiji Ogura, Shuusuke YamanakaAbstract:Thermographic NDT is developed for the inspection of the delaminated defects embedded in fiber reinforced plastic samples. The location and shape of the defects are identified from the surface temperature distribution appear on the sample by the heat insulation Effect of the defects, when the sample is under heating and/or cooling. The resolution is examined for the artificial delaminated defects both in CFRP and GFRP samples, when the conventional infrared radiation heating is adopted. Experimental results show that the radiation heating is not Effective for the accurate defect inspection of the CFRP sample due to its high thermal conductivity. The Joule Effect heating, on the other hand, is found to be Effective for the similar sample. Two methods of the Joule Effect heating, a direct current application and an induction heating, are investigated. The induction heating thermographic NDT is degraded in the resolution of the defects, compared with the direct current thermographic NDT, because of the inhomogeneity in the induced current field. This can be improved by the use of an image processing technique in the analysis of the thermal images. Further the present thermographic NDT technique is applied for the inspection of the GFRP sample with the actual delaminated damage under cyclic straining. The possible detection of the subsurface damage is discussed.
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A New Flaw Inspection Technique Based on Infrared Thermal Images Under Joule Effect Heating.
Transactions of the Japan Society of Mechanical Engineers. A, 1992Co-Authors: Takahide Sakagami, Keiji OguraAbstract:A new nondestructive inspection technique using infrared thermography was proposed, in which the thermal image of the surface temperature on a heated sample was used to identify flaws and defects. Joule Effect heating by an electric current was employed to heat the sample instantaneously. Both numerical and experimental studies were conducted on the resolution and the availability in the detection of the through-thickness and surface cracks embedded in steel plates. The results showed that a singular concentration was observed at the crack tips in the surface temperature field in the transient stage of heat conduction, and the cracks were found to be sensitively detected from such a singular temperature field in the early transient stage. This technique was also applied to the inspection of the delamination defect in carbon-fiber reinforced plastics (CFRP), again using Joule Effect heating. The subsurface defect was found to be identified from the localized low-temperature region appearing on the sample surface. It was found that the proposed technique is applicable to the damage inspection in CFRP as well as the flaw inspection in metallic materials.
M. Berthou - One of the best experts on this subject based on the ideXlab platform.
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Heat Treatment of Whole Milk by the Direct Joule Effect—Experimental and Numerical Approaches to Fouling Mechanisms
Journal of Dairy Science, 2006Co-Authors: L. Fillaudeau, P. Winterton, J.c. Leuliet, J.-p. Tissier, V. Maury, F. Semet, P. Debreyne, M. Berthou, Fabrice ChopardAbstract:Abstract The development of alternative technologies such as the direct Joule Effect to pasteurize and sterilize food products is of great scientific and industrial interest. Our objective was 1) to gain insight into the ability to ensure ultra-high-temperature treatment of milk and 2) to investigate the links among thermal, hydraulic, and electrical phenomena in relation to fouling in a direct Joule Effect heater. The ohmic heater [OH; E → ⊥ υ → (where E is the electrical field and v is the velocity); P (power) = 15 kW] was composed of 5 flat rectangular cells [ e (space between the plate and electrode) = 15mm, w (wall) = 76mm, and L (length of the plate in plate heat exchanger or electrode) = 246 mm]—3 active cells to ensure heating and 2 (at the extremities) for electrical insulation and the recovery of leakage currents. In the first step, the thermal performance of the OH was investigated vs. the flow regimen [50 Re (Reynolds number) P 20°C T w − T b (where T w is the wall temperature and T b is the product temperature) under clean conditions (without fouling) and was used to define operating conditions for pure-volume and direct-resistance heating. In the second step, the ability of OH to ensure the ultra-high-temperature treatment of whole milk was investigated and compared with a plate heat exchanger. Special care was taken to investigate the heat transfer phenomena occurring over a range of temperatures from 105 to 138°C. This temperature range corresponds to the part of the process made critical by protein and mineral fouling. The objectives were 1) to demonstrate the ability of an OH to ensure heat treatment of milk, 2) to study the thermal and hydraulic performance with an increasing power and temperature difference between the inlet and outlet of the OH, 3) to define and validate a criterion to follow heat dissipation efficiency, and 4) to compare the fouling propensity with the different configurations. A heat dissipation coefficient, Rh CO , was defined and validated to monitor the fouling propensity through global electrical and thermal parameters. Finally, a numerical simulation was developed to analyze heat profiles (wall, deposit, bulk). Because of an increasing Joule Effect in the static deposit, the simulation showed how wall overheating would definitively cause fouling to spiral out of control.
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Heat treatment of whole milk by direct Joule Effect – Experimental and numerical approaches to fouling phenomena
Journal of Dairy Science, 2006Co-Authors: Luc Fillaudeau, P. Winterton, J.c. Leuliet, J.-p. Tissier, V. Maury, F. Semet, P. Debreyne, M. Berthou, Fabrice ChopardAbstract:The development of alternative technologies such as the direct Joule Effect to pasteurize and sterilize food products is of great scientific and industrial interest. Our objective was 1) to gain insight into the ability to ensure ultra-high-temperature treatment of milk and 2) to investigate the links among thermal, hydraulic, and electrical phenomena in relation to fouling in a direct Joule Effect heater. The ohmic heater [OH; E perpendicular to v.(where E is the electrical field and v is the velocity); P (power) = 15 kW] was composed of 5 flat rectangular cells [e(space between the plate and electrode) = 15 mm, w (wall) = 76 mm, and L (length of the plate in plate heat exchanger or electrode) = 246 mm]-3 active cells to ensure heating and 2 (at the extremities) for electrical insulation and the recovery of leakage currents. In the first step, the thermal performance of the OH was investigated vs. the flow regimen [50 < Re (Reynolds number) < 5,000], supplied power (0 < P < 15 kW), and electrical conductivity of fluids (0.1 < sigma(20 degrees C) < 2 S/m) under clean conditions with model fluids. This protocol enabled a global thermal approach (thermal and electrical balance, modeling of the temperature profile of a fluid) and local analysis of the wall temperature of the electrode. An empirical correlation was established to estimate the temperature gradient, T-w - T-b (where T-w is the wall temperature and Tb is the product temperature) under clean conditions (without fouling) and was used to define operating conditions for pure-volume and direct-resistance heating. In the second step, the ability of OH to ensure the ultra-high-temperature treatment of whole milk was investigated and compared with a plate heat exchanger. Special care was taken to investigate the heat transfer phenomena occurring over a range of temperatures from 105 to 138 degrees C. This temperature range corresponds to the part of the process made critical by protein and mineral fouling. The objectives were 1) to demonstrate the ability of an OH to ensure heat treatment of milk, 2) to study the thermal and hydraulic performance with an increasing power and temperature difference between the inlet and outlet of the OH, 3) to define and validate a criterion to follow heat dissipation efficiency, and 4) to compare the fouling propensity with the different configurations. A heat dissipation coefficient, Rh-CO, was defined and validated to monitor the fouling propensity through global electrical and thermal parameters. Finally, a numerical simulation was developed to analyze heat profiles (wall, deposit, bulk). Because of an increasing Joule Effect in the static deposit, the simulation showed how wall overheating would definitively cause fouling to spiral out of control.
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Etude de l'encrassement lors du traitement thermique du lait entier par effet Joule Direct
Industries Agro-Alimentaires, 2006Co-Authors: Luc Fillaudeau, J.c. Leuliet, J.-p. Tissier, V. Maury, F. Semet, P. Debreyne, M. BerthouAbstract:Development of alternative technology like direct Joule Effect in order to pasteurize and sterilize food products is of great scientific and industrial interests. This paper investigates the links between thermal, hydraulic and electric phenomena in relation with fouling mechanism in a Direct Joule Effect heater. The ohmic heater ( , P=15kW)) is composed of 5 flat rectangular cells, 3 cells ensure heating and two (at the extremities) the electrical insulation. In a first step, the wall overheating was investigated with two model fluids (without fouling) in order to analyze and model the temperature difference between wall (electrode) and fluid versus operating conditions. In a second step, the impact of fouling phenomena was studied through experiments based on whole milk sterilisation. A heat dissipation coefficient, RhCO was defined and validated to monitor fouling propensity through global electrical and thermal parameters. Finally, a numerical simulation was developed in order to analyze thermal profiles (wall, deposit, fluid) and enabled to explain and demonstrate the "Snow ball Effect" of fouling mechanism.
Takahide Sakagami - One of the best experts on this subject based on the ideXlab platform.
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under Joule Effect heating
2017Co-Authors: Takahide Sakagami, Keiji OguraAbstract:The thermographic NDT based on the transient temperature distribution under the Joule Effect heating by an electric current was discussed. Two different types of inspection methods, i.e., the singular method and the insulation method wei examined. The singular method based on the heat concentration at the crack tip was successfully applied to the identification of the through-thickness and surface cracks embedded in steel plates. The resolution of the crack identification by the singular method was examined by the cunent intensity factor and the thermal diffusion length. The insulation method based on the temperature turbulence appears on the sample surface due to the thennal insulation of the defect was tested for the identification of the delaminated defect in CFRP. Two methods of the Joule Effect heating, the direct current application and the induction heating, were successfully applied for the thermographic NDT of the delaminated defects in CFRP samples. The thermographic NDT developed in this study was found to be applicable to nondestructive flaw- and defect-inspection both in metallic and composite materials.
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New Flaw Inspection Technique Based on Infrared Thermal Images under Joule Effect Heating
JSME international journal. Series A mechanics and material engineering, 1994Co-Authors: Takahide Sakagami, Keiji OguraAbstract:Joule Effect heating by electric current was employed to heat up the sample instantaneously. Both numerical and experimental studies were made on the resolution and the applicability in the detection of the through thickness and surface cracks embedded in steel plate samples
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Thermographic NDT based on transient temperature field under Joule Effect heating
Thermosense XVI: An International Conference on Thermal Sensing and Imaging Diagnostic Applications, 1994Co-Authors: Takahide Sakagami, Keiji OguraAbstract:Thermographic NDT based on the transient temperature distribution under the Joule Effect heating by an electric current was discussed. Two different types of inspection methods, the singular method and the insulation method, were examined. The singular method based on the heat concentration at the crack tip was successfully applied to the identification of the through- thickness and surface cracks embedded in steel plates. The resolution of the crack identification by the singular method was examined by the current intensity factor and the thermal diffusion length. The insulation method based on the temperature turbulence appears on the sample surface due to the thermal insulation of the defect was tested for the identification of the delaminated defect in CFRP. Two methods of the Joule Effect heating, the direct current application and the induction heating, were successfully applied for the thermographic NDT of the delaminated defects in CFRP samples. The thermographic NDT developed in this study was found to be applicable to nondestructive flaw- and defect- inspection both in metallic and composite materials.
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Development of Thermographic NDT for Delaminated Defects in Fiber Reinforced Plastics.
Transactions of the Japan Society of Mechanical Engineers. A, 1993Co-Authors: Takahide Sakagami, Keiji Ogura, Shuusuke YamanakaAbstract:Thermographic NDT is developed for the inspection of the delaminated defects embedded in fiber reinforced plastic samples. The location and shape of the defects are identified from the surface temperature distribution appear on the sample by the heat insulation Effect of the defects, when the sample is under heating and/or cooling. The resolution is examined for the artificial delaminated defects both in CFRP and GFRP samples, when the conventional infrared radiation heating is adopted. Experimental results show that the radiation heating is not Effective for the accurate defect inspection of the CFRP sample due to its high thermal conductivity. The Joule Effect heating, on the other hand, is found to be Effective for the similar sample. Two methods of the Joule Effect heating, a direct current application and an induction heating, are investigated. The induction heating thermographic NDT is degraded in the resolution of the defects, compared with the direct current thermographic NDT, because of the inhomogeneity in the induced current field. This can be improved by the use of an image processing technique in the analysis of the thermal images. Further the present thermographic NDT technique is applied for the inspection of the GFRP sample with the actual delaminated damage under cyclic straining. The possible detection of the subsurface damage is discussed.
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A New Flaw Inspection Technique Based on Infrared Thermal Images Under Joule Effect Heating.
Transactions of the Japan Society of Mechanical Engineers. A, 1992Co-Authors: Takahide Sakagami, Keiji OguraAbstract:A new nondestructive inspection technique using infrared thermography was proposed, in which the thermal image of the surface temperature on a heated sample was used to identify flaws and defects. Joule Effect heating by an electric current was employed to heat the sample instantaneously. Both numerical and experimental studies were conducted on the resolution and the availability in the detection of the through-thickness and surface cracks embedded in steel plates. The results showed that a singular concentration was observed at the crack tips in the surface temperature field in the transient stage of heat conduction, and the cracks were found to be sensitively detected from such a singular temperature field in the early transient stage. This technique was also applied to the inspection of the delamination defect in carbon-fiber reinforced plastics (CFRP), again using Joule Effect heating. The subsurface defect was found to be identified from the localized low-temperature region appearing on the sample surface. It was found that the proposed technique is applicable to the damage inspection in CFRP as well as the flaw inspection in metallic materials.
