Abstract: Ice slurries are considered as a promising phase-changing secondary fluids for air-conditioning, packaging or cooling industrial processes. An experimental study has been here carried out to measure the rheological characteristics of ice slurries. Ice slurries consist in a solid phase (flake ice crystals) and a liquid phase. The later is composed of a mixture of liquid water and an additive being here either (1) Propylene-Glycol (PG) or (2) Ethylene-Glycol (EG) used to lower the freezing point of water. Concentrations of 5%, 14% and 24% of both additives are investigated with ice mass fractions ranging from 5% to 85%. The rheological measurements are carried out using a Discovery HR-2 vane-concentric cylinder with four full-length blades. The experimental results show that the behavior of ice slurries is generally non-Newtonian with shear-thinning or shear-thickening behaviors depending on the experimental conditions. In order to determine the consistency and the flow index, the Herschel-Bulkley model is used to describe the behavior of ice slurries. The present results are finally validated against an experimental database found in the literature and the predictions of an Artificial Neural Network model.
Abstract: The freezing point of milk is in important indicator of
the milk quality. The freezing point of milk is determined primarily
to prove milk adulteration with water and to determine the amount of
water in it. Chemical composition and properties of milk, thermal
treatment and presence of any substance can influence freezing point
of product. There are different substances, which can be added to
milk with main purpose to prolong shelf-life of raw milk. There are
detergent, preservatives, formaldehyde, hydrogen peroxide,
antibiotics, sodium carbonate, and hydrogen peroxide. Therefore the
aim of the present study was to determine freezing point of milk,
skimmed milk, pasteurized milk and milk with different substances
(formaldehyde, antibiotics, sodium carbonate, hydrogen peroxide,
disinfectant, and detergent) in different concentrations. The thermal
treatment and different undesirable substances presence in milk have
significant influence on freezing point of it.
Abstract: This paper reports the influence of sucrose on the
preservation of CO2 hydrate crystal samples. The particle diameter of
hydrate samples were 1.0 and 5.6-8.0 mm. Mass fraction of sucrose in
the sample was 0.16. The samples were stored at the aerated condition
under atmospheric pressure and at the temperature of 253 or 258 K.
The results indicated that the mass fractions of CO2 hydrate in the
samples with sucrose were 0.10 ± 0.03 at the end of 3-week
preservation, regardless of temperature and particle diameter. Mass
fraction of CO2 hydrate in the samples with sucrose was higher than
that of pure CO2 hydrate for 1.0 mm particle diameter, while was
lower than that of pure CO2 hydrate for 5.6-8.0 mm particle diameter.
Discussion is made on the influence of sucrose on the dissociation of
CO2 hydrate and the resulting formation of ice.