Stress-strain state of a combined toroidal baromembrane apparatus

Introduction. Currently, the purification of wastewater and technological solutions by membrane methods is considered a promising way to neutralize liquid waste. Therefore, the task of developing an engineering method for calculating baromembrane devices is a challenge. Studies on methods involving calculation of design and process variables, membrane equipment design, research of technological features of membrane devices, selection of design schemes, as well as methods of strength and rigidity analysis, are investigated.Materials and Methods. Basic elements of the body of the combined membrane apparatus are considered, a design scheme is proposed, and a method for calculating the strength and rigidity of the main load-bearing element, the cover, is described. Results. The methods determine the required dimensions of shells and plates for the development of a combined membrane apparatus, and evaluate the strength properties of the devices of this class. The construction elements of the apparatus (primarily, the load-bearing covers) must meet not only the requirements of efficiency and quality of separation and cleaning of solutions, but also the conditions for safe operation. Therefore, the design of the device covers should be based on the optimal design dimensions (thicknesses of round plates, toroidal shells, and support rings). To test the method, the stress-strain state of the membrane apparatus structure was calculated for strength and rigidity. As an example, we consider one cover presented in the form of an open toroidal shell. The evaluation of the application of this technique, taking into account the fact that the shell is mated with a round plate in the inner diameter, and with a ring in the outer diameter, has provided the determination of the required parameters.Discussion and Conclusions. The obtained method of analytical description of the mechanical impact on the elements of the combined apparatus and the example of calculating the toroidal shell and plate, enables to evaluate the stressstrain state of the structure for strength and rigidity. The results of the calculation of covers made of various materials at different pressures are presented. Loading the combined apparatus with transmembrane pressure made it possible to determine the required dimensions of the shells and plates for its design and development.

To the Question of Designing Baromembrane Combined Type Apparatus

The paper considers works on methods for calculating design and technological parameters, design of membrane equipment, research of technological features of membrane devices, selection of design schemes, methods for calculating strength and stiffness. A method has been developed for calculating mechanical loads and determining the thickness of plates and toroidal shells of a membrane apparatus of the combined type, which makes it possible to assess the strength properties of apparatus of this class. An example of a calculation, which makes it possible to assess the adequacy of the application of this technique to devices of the combined type, is given.

Очистка бытовых сточных вод обратным осмосом

Исследована возможность обработки бытовых сточных вод методом обратного осмоса с целью получения высококачественной воды, пригодной для сброса в водоем рыбохозяйственного назначения или для технических нужд. Представлено обоснование возможности утилизации концентрата установки обратного осмоса путем радикального сокращения его расхода до величины, не превышающей 0,51 расхода поступающей на очистку воды, и выведения концентрата с установки вместе с обезвоженным осадком в виде его влажности. Проведены эксперименты, позволяющие определить изменение концентрации растворенных загрязнений в фильтрате мембранных аппаратов и снижение производительности мембран в процессе обработки сточных вод и сокращения расхода концентрата. Получены основные зависимости, позволяющие определить: требуемый расход концентрата установки в зависимости от концентрации взвешенных веществ и ХПК требуемые значения выхода фильтрата в зависимости от концентраций аммония в исходной воде. Описана методика определения площади поверхности мембран и количества мембранных аппаратов на каждой ступени обработки сточной воды. Определены оптимальные значения рабочего давления, экономические показатели установки в сравнении с другими технологиями очистки сточных вод.Possible treatment of domestic wastewater by the reverse osmosis with the purpose of producing high-quality effluent suitable for the discharge into fishery water bodies or for the use as process water has been investigated. Possible recycling of reject water from a reverse osmosis unit by drastically reducing the flow rate to the value less than 0.51 of the incoming flow and removing the reject water as a moisture component of the dewatered sludge is presented. Experiments have been carried out to determine the change in the concentration of dissolved solids in the filtrate of the membrane apparatus and a decrease in the membrane capacity in the process of wastewater treatment and reject water flow reduction. The obtained dependencies allow to determine the following: the required flow rate of the reject water depending on the concentration of suspended solids and COD the required filtrate yield depending on the concentration of ammonium in raw wastewater. The methodology for determining the surface area of membranes and the number of membrane apparatus at each stage of wastewater treatment is described. The optimal values of working pressure, economic indicators of the unit in comparison with other wastewater treatment technologies were determined.