Basic Technological Parameters Research Articles

Basic Technological Parameters of the Activation Process for Two Bioreactor Configurations

Abstract Technological parameters of the activation process in wastewater treatment plant activation systems are analyzed for basic bioreactor configurations, for the chemostat and for the plug flow, both with the recirculation of concentrated activated sludge. The first type of bioreactors represents conventional aerated tanks, but also loop bioreactors. The second type of bioreactors includes, for example, oxidation ditches. The paper presents an evaluation of the basic technological parameters of the activation process for the two mentioned configurations of bioreactor systems with recirculation of concentrated activated sludge. In addition, a new relation for sludge age evaluation is proposed for an activation system with a plug flow bioreactor. The article also provides examples of connections between the values of the technological parameters of the activation process for the two analyzed types of bioreactor systems.

Wpływ stanu nierównoważnego gazów rzeczywistych na ich właściwości

"This scientific work presents a study of areas of application and improvement for the Clapeyron–Mendeleev equation to determine the technological parameters of natural and associated petroleum gas under field conditions. As a result of scientific and practical research and laboratory work, the authors, based on the molecular kinetic theory of gases, developed and improved the Clapeyron–Mendeleev equations of state of real gases by adding some genuine parameters for natural and associated petroleum gases produced from oil and gas condensate fields. In this regard, two additional parameters are introduced in the Clapeyron–Mendeleev equation-relative density and relative velocity of gas: and this, as a new scientific result, helps determine any parameter from the seven included in the equation of state of natural and associated petroleum gases developed by the authors. Continuous technological process according to the system of “production, collection, preparation and transportation of products (oil + gas)”, including, separately in non-equilibrium conditions of “collection, preparation and transportation of gas” due to internal energy, causes a natural change in a wide range of basic technological parameters that contribute to frequent changes in the physical and chemical state of the gas. Therefore, this work establishes that one of the main tasks is to show the composition of natural and associated petroleum gas as a result of irreversible transformations of hydrocarbon and acidic components of its internal energy, as a result of which the gas is characterised by a number of patterns in the composition and distribution of components of various hydrocarbon and heterogeneous compositions (i.e., physically and chemically heterogeneous). In these conditions, a practical calculation of gas facilities (gas treatment point, selection of gas separators, field gas pipelines, compressor stations) is carried out to determine process parameters using the Clapeyron–Mendeleev equation of state for real gases, and the results show large errors. This proves once again that many authors have developed equations of state for real gases based on the results of laboratory studies with single-atomic and laboratory gases (hydrogen, nitrogen, oxygen, carbon dioxide, etc.). However, the authors here carried out laboratory studies with products and associated petroleum gas. According to the results of laboratory studies, the authors recommend an improvement of the equation of state of natural and associated petroleum gases.

The Injection Molding of Biodegradable Polydioxanone-A Study of the Dependence of the Structural and Mechanical Properties on Thermal Processing Conditions.

Recent years have observed a significant increase in the use of degradable materials in medicine due to their minimal impact on the patient and broad range of applicability. The biodegradable polymer Polydioxanone (PDO) provides a good example of the use of such one polymer that can represent the aforementioned medical materials in the field of medicine, due to its high level of biocompatibility and interesting mechanical properties. PDO is used to produce absorbable medical devices such as sutures and stents, and is also suitable for the fabrication of certain orthopedic implants. Polydioxanone can be processed using the injection molding method due to its thermoplastic nature; this method allows for the precise and easily-controllable production of medical materials without the need for toxic additives. A number of small commercial polymer implants have recently been introduced onto the market based on this processing method. It is important to note that, to date, no relevant information on the molding of PDO is available either for the scientific or the general public, and no study has been published that describes the potential of the injection molding of PDO. Hence, we present our research on the basic technological and material parameters that allow for the processing of PDO using the laboratory microinjection molding method. In addition to determining the basic parameters of the process, the research also focused on the study of the structural and mechanical properties of samples based on the thermal conditions during processing. A technological frame work was successfully determined for the processing of PDO via the microinjection molding approach that allows for the production of samples with the required homogeneity, shape stability and surface quality in a laboratory scale. The research revealed that PDO is a polymer with a major share of crystalline phases, and that it is sensitive to the annealing temperature profile in the mold, which has the potential to impact the final crystalline structure, the fracture morphology and the mechanical properties.

Grain separating and throwing machine in inline grain processing

At present there is no grain processing machine capable of performing all operations on the processing of grain material. Therefore, a grain separating and throwing machine capable of processing grain material in a single operation is being developed. The machine performs grain material drying, its cleaning from impurities and cooling in the air flow. Theoretical studies were carried out to determine the basic design, geometric and technological parameters of the grain separating and throwing machine. By methods of mathematical analysis, the equations of grain motion in grain throwing machine and in the air stream were obtained. In order to confirm the theoretical expressions and data, experimental research on the laboratory setting was carried out. Experimental studies confirmed the adequacy of the theoretical conclusions. This machine can be used in the new technology of in-line grain material processing. The use of grain separating and throwing machine in the in-line processing of grain material will reduce the cost of grain processing.

Hydrogen Internal Combustion Engine Vehicles: A Review

Motor vehicles are the backbone of global transport. In recent years, due to the rising costs of fossil fuels and increasing concerns about their negative impact on the natural environment, the development of low-emission power supply systems for vehicles has been observed. In order to create a stable and safe global transport system, an important issue seems to be the diversification of propulsion systems for vehicles, which can be achieved through the simultaneous development of conventional internal combustion vehicles, electric vehicles (both battery and fuel cell powered) as well as combustion hydrogen-powered vehicles. This publication presents an overview of commercial vehicles (available on the market) powered by internal combustion hydrogen engines. The work focuses on presenting the development of technology from the point of view of introducing ready-made hydrogen-powered vehicles to the market or technical solutions enabling the use of hydrogen mixtures in internal combustion engines. The study covers the history of the technology, dedicated hydrogen and bi-fuel vehicles, and vehicles with an engine powered by a mixture of conventional fuels and hydrogen. It presents basic technology parameters and solutions introduced by leading vehicle manufacturers in the vehicle market.

Optimization of Process Parameters for Powder Bed Fusion Additive Manufacturing Using a Linear Programming Method: A Conceptual Framework

At present, the selection of optimal technological parameters for laser powder bed fusion (LPBF) is determined by the requirements of the fusion process. The main parameters that are commonly varied include laser power (P), scanning speed (v), hatch spacing (h), and layer thickness (t). The productivity of the LPBF process (the increment in the fused volume of the material) is equal to the product of the last three parameters, and the mechanical properties are largely determined by the volumetric fusion energy density, which is equal to the ratio of laser power to productivity. While ensuring maximum process productivity, it is possible to obtain acceptable quality characteristics—mechanical properties, surface roughness, etc.—for a certain range of LPBF technological parameters. In these cases, several quality characteristics act as constraints on the optimization process, and productivity and the key quality characteristics become components of the objective function. Therefore, this article proposes a formalized representation of the optimization problem for the LPBF process, including the derivation of the objective function with the constraint matrix, and provides a solution to the problem using the linear programming (LP) method. The advantages of the proposed method include the guaranteed convergence of the solution with an unlimited number of constraints; the disadvantage concerns the adequacy of the solution, which is limited by a relatively narrow range of parameter changes. The proposed method was tested in determining the optimal LPBF parameters for an HN58MBYu powder LP model that included 13 constraints and an objective function with two target parameters. The obtained results made it possible to increase the productivity by 15% relative to the basic technological parameters.

Development and Modeling of an Onion Harvester with an Automated Separation System

One of the most important problems during the implementation of any technology is to reduce labor costs, energy, and resource conservation while increasing the yield of cultivated crops and, as a result, reducing the cost of production. Despite a significant amount of scientific research devoted to the problem of energy and resource conservation in the cultivation and harvesting of agricultural crops and the development of mechanization tools that ensure the high-quality performance of technological operations, there remain issues that have not been fully resolved to date. In addition, not all the results of known theoretical and experimental studies can be directly applied to intensify the process of harvesting root crops since the quality indicators of marketable products depend on the type and technological parameters of the separating working bodies. This article presents the design of a rod elevator with an adjustable angle of inclination of the web, which reduces damage to commercial products of root crops and bulbs with maximum completeness of separation. A laboratory facility has been developed to substantiate the design and technological parameters of a separating system with an adjustable web inclination angle. Based on the results of theoretical and experimental studies, a machine for harvesting onions with an adjustable blade inclination angle has been developed, which provides an increase in the quality indicators of onion harvesting at optimal values of the parameters: (1) translational speed of movement of the rod elevator with an adjustable web inclination angle of 1.7 m/s with a 98.4% completeness of separation and 1.7% damage to the bulbs; (2) translational speed of the movement of the machine for harvesting root crops and onions 1.0 m/s with a 98.5% separation completeness and 1.1% damage to the bulbs; (3) digging depth of the digging plowshare equal to 0.02 m, with an onion heap separation completeness of more than 98% and product damage of less than 1.4%. The results of theoretical and experimental studies of a rod elevator to substantiate the design and technological parameters during its interaction with a heap of onion are presented. Basic design and technological parameters of the studied rod elevator are substantiated, namely, the distance S1 of the movement of the rod of the actuators, the angle a1 of the longitudinal inclination of the surface of the rod elevator relative to the horizon, and differential equations of motion of the onion-sowing pile element on the surface of the rod elevator with an adjustable angle of inclination of the web.

Strain-balanced InAs/GaSb superlattices used for the detection of VLWIR radiation

This work reports on the impact of defects on the parameters of type II InAs/GaSb superlattices (SLs) and photoconductors (PCs) from the very long wavelength infrared region. SLs were grown by means of molecular beam epitaxy and characterised using microscopes, high-resolution X-ray diffractometry (HRXRD) and low-temperature photoluminescence (LT-PL). PCs were investigated using Fourier-transform infrared spectroscopy and a current–voltage measurements. The basic technological parameters were optimised using 30-period SLs. Tests on the growth temperature showed that different defect types dominated in SL samples of different thicknesses. The diffuse scattering in reciprocal space maps (RSMs) taken for 200-period SLs was the mirror image of that for 30-period SLs. Scanning electron microscope (SEM) images of 200 period SLs revealed three types of defects: holes, slits and others not belonging to the first two groups. Slits were the predominant type. The diameter of the defects determined by SEM and HRXRD was about 2.5 μm. The cross section along the defects was made using focus-ion beam technique. The investigations using high-resolution transmission electron microscopy revealed the origins of the defects: holes were formed at the SL/buffer interface and propagated throughout entire SL, while slits were created in the volume of the SL without disturbing the surrounding crystal lattice. The lowest defect density was found for an SL grown at 425 °C. The highest overall crystal quality, measured using an HRXRD rocking curve, was obtained for an SL deposited at 405 °C, while the highest optical quality was determined for an SL at 445 °C by means of LT-PL. The best parameters were achieved for PCs grown at two lower temperatures. The difference in the effective bandgaps of the PCs made it difficult to determine the optimal value of the growth temperature. The effective bandgap for three PCs was determined based on the spectral dependences of the photoresponse measured at 20 K. Activation energies for high (150–300 K) and low (<50 K) temperature ranges were estimated from R(1000/T) dependence.

On the external and internal resonance phenomena of the elastic bodies with the complex oscillations

Complex nonlinear oscillations in the elastic bodies are studied using a priori information about the oscillations form and taking into account a refined mathematical model of the second (other) form of oscillations. Application of existing methods or development of the new ones for the analysis of received non-autonomous boundary value problems is proposed. The effectiveness of the practical implementation of the discussed methodology significantly increases in cases where the magnitude of the elastic body displacements due to the one form of oscillations is much higher than the other one. To analyze the problem one can use the well-known tested analytical methods for the systems with the small nonlinearity. Torsional and bending oscillations of the elastic body are shown as the example. It is also demonstrated that especially dangerous resonant processes can be caused not only by the external perturbations but also by the internal influence between some forms of oscillations. The obtained results allow to choose the basic technological and operational parameters of the machine oscillating elements in order to avoid the resonance phenomena.

OPTIMISATION OF LOCATION AND PERFORMANCE PARAMETERS FOR THE CRUSHING AND TRANSFER STATIONS IN THE DEEP OPEN PIT MINES

When designing the strip mining methods at the deep open pits at the stage of preliminary studies, it is necessary to determine the optimum number and succession of relocation of crushing and transfer stations while developing the open pit. This cuts the transport costs and reduces the number of dump trucks required. An analytical dependence has been established to determine the optimum number of transfer points with their uniform location along the length and height of the open pit working area. The features of changes in the basic technological parameters of truck operation, depending on the number of crushing and transfer stations, the open pit size and output are studied. The conditions for simultaneous use of several crushing and transfer stations, their optimum number and performance have been determined; the economic benefits of using the flowcharts with multiple transfer points have been estimated. Optimisation of the number of transfer points reduces the required capacity of each crushing and transfer plant of up to 10-20 million tons/year. Reducing the required capacity of transfer points makes it possible to equip them with primary jaw crushers.

The complex of machines for low-cost artificial reforestation in the taiga zone

Problems of mechanization of artificial reforestation in the taiga zone are increasing the productivity of manual labour and reducing the costs of subsequent young stand treatment (early tending and early pre-commercial thinning). Petrozavodsk State University has developed the complex of machines and technologies capable to solve these problems. This complex includes: seeder, root-cutter, dynamic hole-maker and mechanical mounder. Seeder and root-cutter are intended for growing enlarged seedlings with an open root system in forest nurseries. Seeder provides mechanization of sowing seeds. Root-cutter is used for pruning the root systems of seedlings during cultivation. Dynamic hole-maker provides strip soil clearing, surface tillage and preparation of holes for manual planting of seedlings. The hole-maker is also capable to make soil scarification and sowing forest seeds. Mechanical mounder provides strip clearing in the forest plot and creation of humus mounds with mineral soil cover for manual planting of seedlings. Basic technological parameters of the complex of machines have been also substantiated at the Petrozavodsk State University.

DEVELOPMENT OF TECHNOLOGY AND CREATION OF TEST EQUIPMENT FOR PRESSURE WELDING OF HIGH-LOAD THIN-WALLED HETEROGENEOUS STEEL TUBULAR PARTS

Introduction. Magnetically impelled arc butt welding (MIAB) method differs from the existing arc methods by high productivity, stable quality of welded joints, high degree of mechanization and automation of the technological process and so on. Welding is performed automatically, which significantly reduces the influence of theoperator-welder on the quality of welded joints. The optimal values of the magnetic field induction components for thin-walled tubular parts with a diameter of 212 mm are determined. The basic technological parameters on welding of tubular details in stationary conditions are defined, it is: qualitative preparation of end faces of pipes;optimal distribution of induction of the control magnetic field (CMF); arc voltage; the magnitude and order of programming the welding current; the rate of closure of the arc gap in the process of upset. The influence of liquid metal melt in the arc gap during upset on the formation of welded joints of pipes is determined. Metallographicstudies showed no defects in the weld line and a relatively small area of thermal impact. Mechanical properties of welded joints at the level of mechanical properties of the base metal. Studies have been conducted to determine theparameters that affect the stable movement of the arc along the thin-walled edges of tubular parts and the influence of liquid metal melt in the arc gap during heating on the formation of welded joints.Problem Statement. Pipes of small diameters (up to 220 mm) are used in various industrial enterprises and construction of pipelines. The work requires high-performance automatic welding methods that allow obtaining stable and reliable welded joints.Purpose. The purpose is to raise labor productivity and to save materials by using equipment and technology for press welding of magnetically controlled arc of thin-walled tubular parts.Materials and Methods. Steel thin-walled tubular parts with a diameter of 42mm and 212 mm, with a wall thickness of 2.5… 3 mm were used for research on press welding. To create a control magnetic field, magnetic systems for tubular parts with a diameter of 212 mm were developed. Experimental welding was performed andsamples of welded joints of pipes with a diameter of 212 mm with a wall thickness of 3 mm were investigated. In the course of the research, the main parameters are recorded and the welding process is controlled by computer. Results. The main technological parameters: preparation of pipe ends; magnitude and distribution of control magnetic field induction; the arc voltage; the magnitude and order of programming the welding current; the rateof closure of the arc gap during upset, which affects the formation of welds have been determined. The experimental industrial technology for welding of thin-walled tubular details with a diameter up to 212 mm for thepurpose of its industrial use and the concept of the welding equipment has been developed, patents for the invention have been received.Conclusions. The mechanical and metallographic tests have shown that the properties of welded joints are at the level of the properties of the base metal. The use of press welding technology for tubular parts increases productivity and automates the welding process. The influence of the bandwidth of the liquid molten metal in the arc gap, while heating, on the formation of welded joints of pipes has been experimentally established. The main technological parameters and their influence on the quality of welded joints in the process of heating, the ends, and the upset of thin-walled tubular parts have been determined. Experimental industrial technology for press welding of thin-walled tubular parts has been developed and industrial tests have been conducted, in accordance with the customer's requirements.

ИССЛЕДОВАНИЯ ВЛИЯНИЯ ТЕХНОЛОГИЧЕСКИХ ПАРАМЕТРОВ НА ФОРМИРОВАНИЯ КАЧЕСТВА ПОВЕРХНОСТНОГО СЛОЯ ДЕТАЛЕЙ ПРИ ЦЕНТРОБЕЖНО РОТАЦИОННОЙ ОБРАБОТКЕ

In the paper there are carried out investigations on the definition of the basic technological parameters impact of centrifugal-rotary processing in abrasive environment upon formation of surface layer quality in the parts worked. &#x0D; There is used a finite element method of deformation modeling in granulated massive rotating under the impact of centrifugal forces with the use of the (Comsol Multiphysics) packet. On the basis of computer the high-speed shooting processing and theoretical investigations of the process dynamics there are defined distributions of pressures and granule motion speed in the working chamber. &#x0D; A specified model of abrasive granule encounter with the surface worked at the centrifugal rotary processing on the basis of the modern researches and analysis with the use of the Ansys software. &#x0D; The dependences are obtained for the definition of the maximum penetration depth of environment particles into the surface of the part worked, metal removal, surface roughness which adequacy is confirmed by the results of experimental investigations. There is developed a specified procedure for the computation of roughness height parameters of the surface worked and machining capacity. A specified procedure for the computation of metal removal from the surface worked of parts is offered. An algorithm for the optimization of an engineering process is developed. The investigation results are introduced into production.

Designing of technological process of concreting of vertical structures of a monolithic building

The article is devoted to design of technological process of concreting the vertical structures of a monolithic building. The technology of construction the reinforced concrete structures today is widespread. A necessary condition for design of technological process of building construction is the use of information computer-aided design technology. The use of software allows you to solve more effectively a number of problems in design of technological processes of building construction, namely: variant design, search for optimal solutions, forecasting. The urgency of determining the rational parameters of the multivariate technological process of building constructions and structures by use of software of technological design was emphasized. Determination of the rational number of workers and scaffolding in the concreting of vertical monolithic structures of building by comparing such criteria as cost of construction and its complexity has been performed. The scheme of working area and construction-technological analysis of basic parameters of the monolithic building has been given. Modern Fortran software has been used to calculate the parameters of multivariate technological problems. The mathematical equations for calculation of the basic technological parameters of construction process of a monolithic building has been given. An algorithm for performing calculations has been developed. A program has been developed to determine the general characteristics of the concreting process (volume of monolithic works, time of concreting elements, cost and labor intensity, number of units and number of workers). Analyze of technological parameters and the choice on their basis the rational technological solutions for construction work has been performed by using of Microsoft Excel graphs. According to the results of research, a rational number of workers and scaffolding for concreting vertical monolithic structures of building has been determined by comparing such criteria as cost of construction and complexity.

ТЕХНОЛОГИЧЕСКОЕ ПРОЕКТИРОВАНИЕ ТОКАРНЫХ СТАНКОВ С ЧПУ НА ОСНОВЕРЕГИОНАЛЬНОГО БАНКА ДАННЫХ О ДЕТАЛЯХ МАШИН И ПРИБОРОВ

The manufacturers of NC machine-tools pay little attention to the analysis of consumer requests that is to production and technological conditions typical to the majority of equipment customers. The work purpose consists in the optimization of NC lathe (NCL) technological potentialities based on the analysis of machinery and device characteristics. The scientific novelty of the work consists in a new approach to the substantiation of NC lathes parameters based on their interconnection with machinery characteristics, formation of original data bank on parts of the Uliyanovsk region companies (200,000 of items) presenting different branches of industry: aircraft manufacturing, shipbuilding, machine tool construction, automotive industry, instrument making et al. stage-by-stage parts grouping on the basis of ESKD classifier and the application of a cluster analysis. As a result of investigations there are revealed eight parts groups of revolution solids, design-technological characteristics which should be used as a technological basis for designing and choice of NC lathes (NCL). For all groups of parts there are developed complex parts (CP) generalizing all design-technological characteristics of group parts and group technological operations (GTO) for their production. The substantiation of GTO formation scheme was carried out according to shown costs Cmanuf. for machining a complex part. The design-technological characteristics and schemes of GTO formation are initial data for the definition of basic technological parameters of a new range of NCLs or the choice of the most suitable existing NCL. As a result there are substantiated NCL basic parameters for machining eight groups of parts. The design and production of all eight NCLs should be organized according to block-modular principle that is on a single common element base. To realize this principle there is substantiated a unified structure of functional units of the machine for the creation of all NCLs with different technological potentialities.

Architectural Localization Design Strategies for Small and Medium-Sized Terminals in Africa

With the ever-enhanced comprehensive national strength, China plays an increasingly important role on the international arena, and it has participated in more and more terminal projects on the African continent. By summarizing the three aspects of comparing basic parameters and technological parameters, this paper analyzes three practical projects of micromidi airport terminal buildings in Africa that were designed and constructed with Chinese participation. Finally, in the aspects of design standard, construction scale, service standard, technological process, the response of natural environment elements and the response of cultural elements, this paper compares and analyzes with the airport terminal in China. How to respond to the local cultures and realize the localization design was discussed when Chinese architecture marched into the world construction market.

Use of non-traditional reducing agents to expand the resource base of OJSC Uzmetkombinat

The article considers the problems of obtaining metallized iron concentrates from low-grade raw materials. Useful information is given on the theoretical foundations of the processes that occur during the reduction of iron from its oxides and iron-containing materials. And also, the basic technological parameters for the production of pellets by coke-free reduction formed during the metallization process are determined. Of these materials can be used as raw material for steel. The purpose of the study is to improve the production of metallized pellets purified from sulfur. And also, reducing the total costs in the production of iron from ore and the extraction of metal (iron) cord from waste tires. The essence of the study is that in the process of producing pellets, lime is used &ndash; as a desulfurizer and waste of automobile tires &ndash; as a reducing agent. After pelletizing, the obtained pellets are fed to heat treatment and processed at 1150&ndash;1350 &deg;C in tube-rotating furnaces. Then, the metallized pellets are sent to magnetic separation and a rich iron concentrate is obtained. The degree of metallization of the resulting product is 80&ndash;90 %.

Competence approach to the study of disciplines students of the specialty "Chemical technology &amp; engineering"

The basis of training of chemists-technologists of chemical profile is the formation of their professional competence. It is necessary that future professionals gain knowledge of modern innovative chemical engineering technologies for modern production and be able to apply them in practical conditions when preparing bachelors in the specialty 161 "Chemical Technology and Engineering". The proposed approach is the development and formation of students' theoretical ideas and knowledge about processes, effective use of technological means, process development, training with design and technical documentation, using modern methods of computer design. It was argued that the specifics of classroom and independent work of students in basic and elective disciplines - is the result of a competency-based approach. Specialized-professional competencies include knowledge of technological processes, knowledge of technological documentation, skills to map technological processes; knowledge of technological process design and skills to conduct various types of project analysis; knowledge of research methods and skills of organizing research and analysis of their results; ability to use theoretical knowledge and practical skills to master the basics of entrepreneurship. The prospect of a competent approach to the study of disciplines in students of this specialty is the formation of theoretical knowledge and practical skills of calculation and choice. The purpose of this approach is to provide students with knowledge of technical means and systems of automatic control and regulation of basic technological parameters of chemical-technological processes through modern information technologies used to create and manage technological parameters.

Determining the kinetic and energy parameters for a combined technique of drying apple raw materials using direct electric heating

The development of technology and drying equipment tackles a triune task: to intensify drying processes, to save energy, to ensure that proper product quality is achieved. This issue is resolved by modern advancements by supplying thermal energy throughout the entire sample volume. The simplest option among the known techniques is to heat wet raw materials by passing an electric current directly, with an external blowing by a hot heat carrier.&#x0D; This paper reports an experimental study of the combined process of drying apple raw materials using direct electric heating.&#x0D; The influence of control factors such as the field intensity and a heat carrier temperature on the kinetic parameters of the process has been determined, namely: the duration of the combined drying of apples, the rate of moisture removal, and a change in the temperature of the sample.&#x0D; It was established that the application of additional electric heating with an electric field intensity of 20–40 V/cm during convective drying with a heat carrier temperature of 25–55 °C reduces the duration of apple dehydration by 3‒5 times.&#x0D; Permissible limits for changing the combinations of basic technological parameters have been determined, as well as the rational modes for treating raw materials in order to ensure the predefined quality of finished products. Such combinations of technological parameters of heating, in particular the intensity of the electric field and air in the dryer, are 30 V/cm+40 °C, and 25 V/cm+55 °C.&#x0D; The energy parameters of the proposed combined technique of drying apple raw materials have been determined. It was established that the specific energy consumption for the removal of 1 kg of moisture at direct electric heating is 2,350–2,400 kJ/kg (0.66 kWh/kg).&#x0D; The study performed could provide a prerequisite for devising an energy-efficient technique for the combined drying of fruit and vegetable raw materials using direct electric heating

Extrudate dehydration rate increase by modernization of the extruder vacuum chamber

This paper proposes to upgrade the vacuum chamber of the extruder to enhance the impact of thermovacuum effect on extrudate due to dispensing air into the working volume of the vacuum chamber of the extruder. An air valve is installed in the upgraded extruder chamber. This valve allows faster removal of the wet steam with the extrudate surface. Analytical expressions, which allow determining the volumetric flow rate of intake air of the machine in the vacuum chamber and determining its influence on the basic design and technological parameters of the system, were obtained. The obtained results can be useful and taken into account in the process of subsequent theoretical studies of extruders with a vacuum chamber and will improve the efficiency of machines that perform thermal vacuum extrusion of plant materials.