title: An insight into the heat and mass transfer mechanisms of eggshells hatching broiler chicks and its effects to the hatcher environment.
abstract: Thermodynamic study of incubated eggs is an important component in the optimisation of incubation processes. However, research on the interaction of heat and moisture transfer mechanisms in eggs is rather limited and does not focus on the hatching stage of incubation. During hatch, both the recently hatched chick and the broken eggshell add extra heat and moisture contents to the hatcher environment. In this study, we have proposed a novel way to estimate thermodynamically the amount of water evaporated from a broken eggshell during hatch. The hypothesis of this study considers that previously reported drops in eggshell temperature during hatching of chicks is the result remaining water content evaporating from the eggshell, released on the inner membrane by the recently hatched wet chick, just before hatch. To reproduce this process, water was sprayed on eggshells to mimic the water-fluid from the wet body of a chick. For each sample of eggshell, the shell geometry and weight, surface area and eggshell temperature were measured. Water evaporation losses and convection coefficient were calculated using a novel model approach considering the simultaneous heat and mass transfer profiles in an eggshell. The calculated average convective coefficient was 23.9 ± 7.5 W/m(2) °C, similar to previously reported coefficients in literature as a function of 0.5-1m/s air speed range. Comparison between measured and calculated values for the water evaporation showed 68% probability accuracy, associated to the use of an experimentally derived single heat transfer coefficient. The results support our proposed modelling approach of heat and mass transfer mechanisms. Furthermore, by estimating the amount of evaporated water in an eggshell post-hatch, air humidity levels inside the hatcher can be optimised to ensure wet chicks dry properly while not dehydrating early hatching chicks.
authors: Division M3-BIORES: Measure, Model & Manage Bioresponses, KU Leuven, Kasteelpark Arenberg 30, Box 2456, B-3001 Leuven, Belgium.
authors: C E B
authors: CE
authors: Romanini
authors: Division M3-BIORES: Measure, Model & Manage Bioresponses, KU Leuven, Kasteelpark Arenberg 30, Box 2456, B-3001 Leuven, Belgium.
authors: V
authors: V
authors: Exadaktylos
authors: Division M3-BIORES: Measure, Model & Manage Bioresponses, KU Leuven, Kasteelpark Arenberg 30, Box 2456, B-3001 Leuven, Belgium.
authors: S W
authors: SW
authors: Hong
authors: Centre for Animal Welfare, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA Hertfordshire, United Kingdom.
authors: Q
authors: Q
authors: Tong
authors: Centre for Animal Welfare, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA Hertfordshire, United Kingdom.
authors: I
authors: I
authors: McGonnell
authors: Centre for Animal Welfare, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA Hertfordshire, United Kingdom.
authors: T G M
authors: TG
authors: Demmers
authors: UEB-ANSES, Ploufragan-Plouzané Laboratory, Avian and Rabbit Epidemiology and Welfare Unit, BP 53, 22440 Ploufragan, France.
authors: H
authors: H
authors: Bergoug
authors: UEB-ANSES, Ploufragan-Plouzané Laboratory, Avian and Rabbit Epidemiology and Welfare Unit, BP 53, 22440 Ploufragan, France.
authors: M
authors: M
authors: Guinebretière
authors: UEB-ANSES, Ploufragan-Plouzané Laboratory, Avian and Rabbit Epidemiology and Welfare Unit, BP 53, 22440 Ploufragan, France.
authors: N
authors: N
authors: Eterradossi
authors: Research and Development, Petersime N.V., Centrumstraat 125, B-9870 Zulte (Olsene), Belgium.
authors: N
authors: N
authors: Roulston
authors: Research and Development, Petersime N.V., Centrumstraat 125, B-9870 Zulte (Olsene), Belgium.
authors: R
authors: R
authors: Verhelst
authors: Division M3-BIORES: Measure, Model & Manage Bioresponses, KU Leuven, Kasteelpark Arenberg 30, Box 2456, B-3001 Leuven, Belgium.
authors: C
authors: C
authors: Bahr
authors: Division M3-BIORES: Measure, Model & Manage Bioresponses, KU Leuven, Kasteelpark Arenberg 30, Box 2456, B-3001 Leuven, Belgium. Electronic address: daniel.berckmans@biw.kuleuven.be.
authors: D
authors: D
authors: Berckmans
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D002645:Chickens / Q000502:physiology*; D004531:Eggs; D006358:Hot Temperature; D006813:Humidity; D008962:Models, Theoretical; D013696:Temperature; D013816:Thermodynamics; D014867:Water
chemical_list: D014867:Water
keywords: Convective drying; Eggshell temperature; Evaporative cooling; Hatcher humidity; Hatching thermodynamics