Some aspects of the multi-stage method of production of dry dairy products

Последовательное сочетание различных методов обезвоживания является одним из традиционных направлений при организации эффективного производства концентрированных, сгущенных и сухих молочных продуктов. Этот подход призван обеспечить заданные качества конечного продукта при минимальных энергозатратах технологии. Расчеты подобных многоэтапных процессов в силу высокой сложности постоянно являются предметом исследований. Оценка влияния стадийности обезвоживания при выработке концентрированных, сгущенных и сухих молочных продуктов на энергоемкость процесса является целью данной работы. Объектами исследования были жидкие, концентрированные и сухие молочные продукты, а также параметры процессов их обезвоживания. Ведение процесса сушки в две стадии позволяет получить экономию энергии до 10-15 %. Предварительная обработка исходного продукта мембранными методами (ультрафильтрация, нанофильтрация, обратный осмос) также дает возможность получать определенный эффект в энергозатратах. Применительно к распылительной сушке молочных продуктов широкое применение находит процесс, включающий предварительную концентрацию исходного продукта тем или иным мембранным методом, сгущение продукта методом вакуум-выпаривания, распылительную сушку горячим воздухом до влажности, на 2-4 % превышающую требуемую, окончательную досушку продукта в «псевдокипящем» слое до требуемой влажности и, наконец, охлаждение продукта также в «псевдокипящем» слое. На основании условий материального и энергетического баланса получено выражение для оценки удельных затрат в процессе многостадийного обезвоживания, позволяющее проводить сравнительную оценку затрат на производство сухих молочных продуктов, определять целесообразность их создания или реконструкции, исходя из планируемых объемов переработки и финансовых возможностей. Целевыми функциями, описывающими процесс обезвоживания, следует рассматривать функции, описывающие изменение влажности продукта, удельные затраты энергии на обработку продукта и качество конечного продукта. A consistent combination of different methods of dehydration is one of the promising directions in the organization of the production of concentrated, condensed and dry dairy products. This ensures the desired quality of the final product at the lowest possible energy consumption. Calculations of such multi-stage processes, due to their high complexity, are constantly the subject of ongoing research. The purpose of this paper is to assess the effect of the stages of dehydration in the production of concentrated, condensed and dry dairy products on the energy intensity of the process. The objects of the study were liquid, concentrated and dry dairy products, as well as the parameters of their dehydration processes. Conducting the drying process in two stages allows you to get energy savings of up to 10-15 %. Pretreatment of the initial product by membran methods (ultrafiltration, nanofiltration, reverse osmosis) also makes it possible to obtain a certain gain in energy consumption. In relation to the spray drying of dairy products, a process is widely used, including the preliminary concentration of the initial product by one or another membrane method, the thickening of the product by vacuum evaporation, spray drying with hot air to a humidity 2-4 % higher than the required, the final drying of the product in the «pseudo-boiling» layer to the required humidity and, finally, the cooling of the product also in the «pseudo-boiling» layer. Based on the conditions of the material and energy balances, an expression is obtained for estimating the unit costs in the process of multi-stage dewatering, which allows for a comparative assessment of the costs of producing dry dairy products, determining the feasibility of its creation or reconstruction, based on the planned processing volumes and financial capabilities. The target functions describing the dewatering process should be considered functions describing the change in product moisture, the specific energy consumption for processing the product, and the quality of the final product.

Features of Hydrodynamics of a Bedisperse Boiling Layer

An experimental study of fluidization of two types of bidispersed layer with a pronounced bimodal particle size distribution has been carried out. The possibility of using the equivalent diameter of the mixture particles, calculated from the weight average diameter of the particles constituting the mixture, is shown.

Research of the heat of physical characteristics of fruit ossicles

Utilization of fruit seeds plays a special role, since they are a valuable raw material for the oil and fat industry, at the enterprises of which the complex processing of seeds is carried out: oil is obtained from kernels, crumbs and powder are obtained from shells. Before placing the seeds in the oil and fat enterprises, they must be cleaned of impurities and dried, since the seeds extracted from the fruits have an increased humidity of 25-60% and contain a significant amount of impurities in the form of pulp and squeezes. However, due to the lack of specialized equipment for drying fruit seeds in canneries, their supply to the kernel oil plants is declining every year. In this case, tons of seeds are simply destroyed. Attempts to use existing industrial dryers proved to be ineffective, since they do not take into account the structural features of fruit seeds, and are also not very adapted to significant fluctuations in the moisture of raw seeds and the unevenness of their receipt on drying. The most appropriate method of drying fruit seeds is the use of infrared radiation and a vibro-boiling layer.

Kinetics of the drying process of fermented wheat raw materials in a vibratory boiling layer

The analysis of the influence of the main factors on the kinetics of the drying process of fermented wheat raw materials in a vibro-boiling layer is presented. The purpose of the study is to study the influence of the main technological parameters on the kinetics of the drying process of fermented wheat raw materials in a vibrating boiling overflowing layer at atmospheric pressure. The main factors affecting the drying process were selected: the temperature of the drying agent supplied to the dryer, the speed of the drying agent, the vibration amplitude of the gas distribution shelves, the vibration frequency of the gas distribution shelves. The influence of temperature and air velocity on the drying process of raw materials, the influence of the amplitude and frequency of oscillations of the gas distribution grid on the kinetics of the drying process of the fermented product, as well as the influence of the specific load of the product on the process of moisture removal are shown An analysis of the curves shows that with an increase in the amplitude of the oscillation, it reduces the drying time, and an increase in the frequency of oscillation of the shelves contributes to a decrease in the drying time. In this case, a uniform increase in the drying intensity is observed over the entire range of the amplitudes considered. An increase in the oscillation frequency of the gas distribution grid also helps to reduce the duration of the drying process of fermented wheat raw materials. It should be noted that the amplitude of the oscillations more strongly affects the decrease in the drying time of the raw material than the frequency Thus, we concluded that in the intervals under study the changes in the amplitude and frequency of vibrations of perforated shelves on the drying process of fermented wheat raw materials are more strongly affected by the amplitude of vibrations. In addition, when choosing vibration parameters, the specific load of the material on the grate and its initial humidity should be taken into account..

Determination of the magnetic separator separation function

The article considers the design of magnetic separators for separation of iron-containing powders. The technology of separation of waste (tailings) of production by means of a separator of a boiling layer is offered. A technique for determining the separation coefficient and the dependence of the separation coefficient at different operating modes is presented. The efficiency of separation of the proposed separator above the traditional ones is shown.