Experimental Investigations of Sugar Concentration for Counterflow Jet Mixing of Drinks

The object of this research is mixing of fluid components (in particular, water with blend syrup) in the production of sweet non-alcoholic drinks.Today, the demand for this type of product is very large, therefore it is necessary to develop and introduce continuous mixing devices into production. These devices include jet devices, which provide a quality mixing of fluid components with minimal energy and time. It is possible to significantly increase the mixing efficiency due to the use of counterflow mixing. Today it is little explored. A single-mixing method is implemented in five zones in the counterflow jet mixer. This makes it possible to significantly increase the mixing intensity at low energy inputs, and also significantly reduce the mixing time.The paper presents a scheme of the developed counterflow jet mixer, a general view of the manufactured experimental device, variable factors of the mixing process, and a methodology for carrying out experimental studies.As a result of the analysis of the obtained experimental data, it is determined that the distance between the nozzles is a significant factor in the effect on the sugar concentration in the mixed product.The least impact is the blend syrup supply pressure. There is a very close connection between such factors as the clearance in the receiving chamber and the water supply pressure. The reason for this is an increase in the pressure in the collision zone of coaxial jets, which leads to decrease in the pressure drop at the inlet and outlet of the nozzles and, consequently, to decrease in the injection coefficient.It is determined that the optimal conditions for the production of a sweet drink «Lemonade» using sugar syrup (50 %) and injector nozzle diameter of 8 mm, are:– distance between nozzles is 24 mm;– blend syrup supply pressure is 200-450 mm;– water supply pressure is 3.5-4 atm.The obtained data are the necessary basis for further research and design of experimental samples of a counterflow jet mixer for drinks. They can also be useful in the development of counterflow jet mixers for fluid components in other branches of the national economy

Experimental Investigations of the Parameters of the Jet Milk Homogenizer with Separate Cream Supply

The jet milk homogenizer provides the cream supply in the right amount for normalization of the mixture, grinding of the fat globules and their uniform distribution in the volume of the milk plasma. In the process of technological audit, the following drawbacks are identified: lack of devices to maintain a constant temperature, low resolution of a digital camera and a microscope. In addition, it is necessary to investigate the nature of the influence of the flow and fat content of cream on the average size of fat globules.In order to level out the identified drawbacks, it is planned to increase the time of the experiment in order to exclude the possible influence on the results at the initial and final stages of each experiment. In addition, at the next stage of the study, it is planned to determine the nature of the relationship between cream supply, fat content and average size of fat globules after homogenization.The experimental studies of a jet milk homogenizer with a separate cream supply shows the values of the factors at which the grinding is carried out to the level of valve homogenizers. The average size of fat globules at a level of 0.85 microns is provided with a diameter of the cream supply channel equal to 0.6 mm and the distance of the central channel at the site of the maximal narrowing of 2 mm. It is determined that the nature of the relationship between the skim milk rate is the main factor of grinding and the average size of fat globules is directly proportional.The nature of the relationship between decrease in the size of fat globules is determined as increase in skim milk rate, the nature of which can be explained by an increase in Weber's criterion. Its growth leads to an increase in the magnitude of the tangential stress, the extracted droplet in the ribbon-like body, which subsequently collapses into a large number of small elements. This confirms the hypothesis of destruction when creating the maximum phase rate difference realized in the design of a jet milk homogenizer with a separate cream supply

Determining the Quality of Milk Fat Dispersion in A Jet-slot Milk Homogenizer

One of the urgent problems in the dairy industry is to reduce power input in the process of dispersing milk fat while ensuring a high degree of homogenization. This problem can be solved through the development and implementation of a virtually unexplored jet-slot milk homogenizer. The principle of its action implies the preliminary separation of cream from whole milk and its feed into the high-velocity flow of skim milk. The homogenization process occurs by creating a sufficient difference in velocities of the disperse and dispersing phases of the milk emulsion, which is mathematically described by Weber's criterion.Experimental studies of the effect of fat content in cream, cream feed rate, and width of the annular slot on dispersion indices during processing in the designed homogenizer have been carried out. The mathematical dependence which relates these parameters was found. It was proved that to obtain a milk emulsion with a dispersion level of 0.8 μm, the width of the annular slot should be 0.1–0.5 mm, fat content in cream 40–50 %, and the feed rate less than 40 m/s. The results of the evaluation of dispersion quality show a 7 % decrease in the average diameter of the fat globules compared to the most common values obtainable in the valve homogenizer. A refined critical value of the Weber criterion for dispersion of the fat phase of milk was determined (29 units) which indicates an increase in the intensity of the homogenization process in comparison with the jet milk homogenizer with a separate cream feed. The derived critical value of the criterion is necessary to create a theory of the process of dispersing milk fat and develop more efficient designs of milk homogenizer

Revealing New Patterns in Resource­saving Processing of Chromium­containing Ore Raw Materials by Solid­phase Reduction

The physical and chemical properties of products from the carbon-thermal reduction of oxide chromo-containing ore raw materials have been investigated. This is necessary to determine the parameters that reduce the loss of Cr in the processing of ore materials and the use of metallized chromium doping additives in steelmaking. It has been determined that the increase in processing temperature from 1,250 K to 1,450 K led to an increase in the manifestation of Cr23C6 and (Cr, Fe)7C3. In this case, the diffraction maxima of Cr2O3 corresponded to the trend of weakening and, having been treated at 1,450 K, had a residual character. Cr3C2 on the diffractograms was only evident after processing at 1,250 K. The phase of the metallic Cr was traced in the samples after processing at 1,350 K and 1,450 K with the increased intensity of manifestation when the heating temperature rose. It has been determined that the microstructure of reduction products is heterogeneous with the presence of particles of different sizes and chemical compositions. The increase in the reduction temperature from 1,250 K to 1,350 K and 1,450 K and the development of reduction processes were accompanied by particle sintering with the formation of a spongy microstructure. We have detected regions that characterized inclusions and the phases where Cr content amounted to 65.10 % by weight, Fe ‒ to 16.13 % by weight. Some local areas with particles with a relatively high content of ore impurities and carbon have also been found. It follows from the results of our study that the most acceptable temperature for reduction is 1,450 K. In this case, the reduction is ensured with a predominance in the phase composition of the metal Cr and carbides (Cr, Fe)7C3 and Cr23C6 relative to the oxide component of Cr2O3. In this case, the lower residual carbon content was due to the higher efficiency of the reducer compared to other temperature regimes.The spongy microstructure allows for a Faster dissolution compared to standard ferroalloys, thereby reducing the duration of smeltin