Quantitative Evaluation of Frosty Mist and Foam Regenerative Ability in Beer: Development of Novel Evaluation Indices and Correlation Analysis

Process intensification of foam fractionation by successive contraction and expansion

An experimental investigation is presented of the effect of temp on the foam fractionation of the ethylhexadecyldimethylammonium bromide‐water system. Two feed concn, two foam heights, and a temp range of 14舑54C are included. For each fixed set of values of feed concn and of foam height, the greater and lesser coefficients of fractionation are both increasing functions of temp. The effect of a variation in temp on the greater coefficient is more pronounced for more dilute feed solutions, and at greater foam heights. The effect of a temp change on the lesser coefficient is more pronounced for more concd feed solutions and is not related to foam height. At any fixed temp, an increase in feed concn at constant foam height generally decreases the greater coefficient and decreases the lesser coefficient. An increase in foam height at constant feed concn increases both coefficients. The greater and lesser coefficients may be related to temp by power equations with 5% accuracy. The above results may be explained qualitatively on the basis of the response of foam stability and drainage to temp.

Structural mechanism study on the retention and slow release of aroma molecules by starch in the form of V6-type crystals.

Numerical simulation of slag foaming on bath smelting slag (CaO–SiO2–Al2O3–FeO) with population balance modeling

Possibilities for control of slag foam height by sound waves were investigated using cold models. The foaming and defoaming rates were measured under various frequencies and intensities of sound. Nitrogen gas was injected into a liquid containing a surfactant to produce the foam layer. Simultaneously, the foam surface was exposed to sound waves propagated through the gas phase to the surface. The sound waves were generated by a loudspeaker. Two liquids of different viscosities were used: water and a water-glycerin solution. It was found that sound waves can control the defoaming rate, while the foaming rate does not vary practically under the application of sound. The latter finding is associated with the fact that the height of foam, produced in the experiments, was much smaller than the steady height. The defoaming rate is essentially reduced by the sound of lower frequency (200-1000 Hz). This effect is explained in terms of a radiation force arising when the sound waves are propagated inside the foam layer. Sound waves of intermediate frequencies (1000-8000 Hz) cause the defoaming rate to increase compared with that in the absence of a sound field. The defoaming mechanism is assumed to be associated with a rupturing of the foam film accelerated by the sound waves. On the whole, the effect of sound on the defoaming rate increases as sound intensity and liquid viscosity become higher.

The article focuses on studying the foaming process in the amine solutions (diethanolamine (DEA) and methyldiethanolamine (MDEA)) on an example of the model mixtures containing different organic and inorganic impurities and their combinations: oxalic acid, formic acid, corrosion inhibitor, hydrocarbons, amine decomposition products, mechanical impurities. It has been found that the greatest influence on foaming in the DEA solution is exerted by its decomposition products containing the formic acid, and at a concentration of 3% by weight the foam height increased by more than 3 times, and the foam stability - by 20 times. Oxalic acid also has a significant effect on foaming: at a concentration of 1 g/l the foam height increased by 3 times, and the foam stability - by more than 5 times. The decomposition products of DEA containing oxalic acid have a rather noticeable effect - the height and stability of the foam increased by 2.8 and 6.8 times, respectively. The foam grew least in the presence of formic acid - by 2 times, at the same time the stability was enhanced by more than 4 times. It has been stated that hydrocarbons have the greatest influence on foaming of the MDEA solution - at a concentration of 0.5% vol. the foam height increased by more than 1.7 times, and the stability of the foam - by 5 times. Similarly, the decomposition products of MDEA made a significant impact – the foam height increased by more than 1.7 times, and the foam stability - by 11 times. Mechanical impurities caused an increase in the foam height by more than 1.6 times and in stability by 1.4 times. Introducing a corrosion inhibitor foaming gave the least result - the foam height decreased by 2.8 times, and the stability increased by 2 times. There has been found the mutual influence of impurities in the MDEA solution, which could be seen in the mutual suppression of foaming in the double and triple mixtures compared with the single-component solutions.

In order to clarify the hydrodynamic performance of the gas-liquid mixture above a gas distributor, the gas void fraction and the froth height for the foam layer with a low clear liquid height on a perforated plate under liquid stagnant flow were studied theoretically. In the present work, it was assumed that the shape of a bubble in the foam layer was a spherical capped bubble. Further, it was considered that the bubble rising through the liquid was accompanied by some volume of liquid as the wake behind it. As a result, it was found that the gas void fraction and the froth height are given by a function of the Froude number based on the clear liquid height and the liquid hold-up. Furthermore, these equations were compared with the results obtained by Azbel and Kim.

Hydrodynamics and local heat transfer measurements in a bubble column with suspension of yeast

Numerical Simulation of Slag Foaming in High Temperature Molten Metal with Population Balance Modeling

This study was carried out to prepare polyurethane foam modified with rice husk. The water absorption ratio of modified polyurethane was studied and the decreases in the absorption of water was explained in term of high cross linking, beside the rice husks particles fill the space between the polymeric chains. Also, the researchers studied its effect on wheat properties like growth, decimation productivity and spike height, Chibayish marshes water was used for irrigation. The increases in polyurethane foam height from 1 cm to 3 cm decreased the percentage of germination to zero. The increases in the height of polyurethane foam prevent the longitudinal growth of superficial roots of wheat. The wheat decimation is studied for the period (from October 1st 2019 to May 1st 2020). The wheat productivity is also studied and it was (4.1 gm/100 seeds) coma paring with control (3.7gm/100 seeds). The productivity also increased to 4.5gm/100 seeds. Finally, the uses of marshes water in irrigation increased the seeds of each spike by almost 20%.

Modelling of entrainment in industrial flotation cells: Water recovery and degree of entrainment

The present study aimed to improve the quality of fried soybean, sunflower, palm and cottonseed oils. Synthetic (Magnesol XL) and natural (diatomaceous earth and kaolin) filter aids were used at various levels (1, 2 and 4%) to adsorb the secondary oxidation products of the oil. The metal patterns (the cations Si, Mg, Ca, Fe, Na, K, Al, Cu, Mn, Zn and the anions CO32−, HCO3−, Cl−, NO3−, NO2−, SO42−) of Magnesol XL, diatomaceous earth and kaolin were determined. Some physical and chemical properties (refractive index, viscosity, colour, foam height, acid value, peroxide value, thiobarbituric acid value, iodine value, and conjugated diene and polymer contents) of non‐fried, fried and fried–treated soybean, sunflower, palm and cottonseed oils were determined. The frying process was performed at 180 °C ± 5 °C for 12 h continuous heating. The fried oils were treated with the synthetic and natural filter aids at 105 °C for 15 min. The results indicate that Magnesol XL, diatomaceous earth and kaolin contained Si + Mg, Si + Ca and Si + Al, respectively, as the basic metals. Frying soybean, sunflower, palm and cottonseed oils led to significant increases in refractive index, colour, foam height, viscosity, acid value, peroxide value, TBA value, conjugated diene and polymer contents and decrease in iodine value. Treatment of fried oils with Magnesol XL, diatomaceous earth and kaolin at the 1, 2 and 4% levels greatly improved the quality of fried oils. These findings indicate the high efficiency of the filter aids used in the present study in adsorbing the products of oil degradation. Copyright © 2006 Society of Chemical Industry

Experimental Study of Free Convection in Open-cell Aluminum Foam

Thermo-hydraulic study of a single row heat exchanger consisting of metal foam covered round tubes

Open cell metal foam offers an interesting combination of materials properties from a heat exchanger point of view such as a high specific surface area, tortuous flow paths for flow mixing and low weight. A heat exchanger design with metal foams is studied in this work, aimed at low airside pressure drop. It consists of a single row of Al tubes covered with thin layers (4–8 mm) of metal foam. Through wind tunnel testing the impact of various parameters on the thermo-hydraulic performance was considered, including the Reynolds number, the tube spacing, the foam height and the type of foam. The results indicated that if a good metallic bonding between the foam and the tubes can be achieved, metal foam covered tubes with a small tube spacing, small foam heights and made of foam with a high specific surface area potentially offer strong benefits at higher air velocities (> 4 m/s) compared to helically finned tubes. The bonding was done by conductive epoxy glue and was found to have a strong impact on the final results, showing a strong need for a cost-effective and efficient brazing process to connect metal foams to the tube surfaces.