Performance optimization of liquid ring pumps based on Gappy POD surrogate model

To solve the problems of high calculation cost and difficult optimization caused by the complex gas–liquid two-phase flow in liquid ring pumps, an optimization method of a liquid ring pump impeller based on the proper orthogonal decomposition (POD) surrogate model was proposed. The impeller blade shape was parameterized by using the quartic Bezier curve. The sample was obtained from the uniform experimental design of blade shape design parameters. The POD surrogate model was constructed by the parameters of sample blade shape and its corresponding flow field data, which was used instead of CFD numerical simulation to predict the flow field variables under the perturbations of blade design parameters in the optimization process. And then, the gradient vector of the objective function to design variables was predicted quickly and accurately. The blade shape was updated continuously along the negative direction of the gradient vector, and then, the optimal design of the impeller was acquired. The calculation case results show that the relative error between the pressure field in the impeller predicted by the POD method and that of CFD simulation is less than 5%, and the calculation cost is only 1/8460 of CFD simulation. Compared with the original model, the flow field distribution in the optimized model is significantly improved, and the efficiency is promoted by 3.8%.

Prospects of using a liquid ring vacuum pump with automatic adjustable discharge window when grinding grape seeds and pomace

Для повышения сохранения биологически активных веществ, уменьшения энергопотребления в процессе измельчения и получения порошка заданной степени помола из виноградных выжимок и семян предлагается использование установки двухступенчатой дисково-шаровой вакуумной мельницы. Предложенная конструкция двухступенчатой мельницы оказывает влияние на безопасность работы (исключаются взрывы) и экологичность (не создает запыленности окружающей среды). В конструкции разработанной установки важным объектом является вакуумный насос. Приведены устройство и основные принципы работы классического одноступенчатого водокольцевого вакуумного насоса производства ОАО «БЕСКОМ» и жидкостно-кольцевого вакуумного насоса с возможностью автоматического регулирования размеров нагнетательного окна, разработанного в ФГБОУ ВО «ТГТУ» на кафедре «МИГ». Показаны основные преимущества предлагаемого насоса по сравнению с классическим вариантом. На основе испытаний был проведен сравнительный анализ разработанного жидкостно-кольцевого вакуумного насоса с автоматическим регулируемым размером нагнетательного окна и классического вакуумного насоса равной быстроты действия, результаты которого продемонстрировали существенную эффективность использования первой машины. Установлено, что затраты удельной мощности в процессе транспортирования растительных порошков на 20-25% ниже при равной быстроте действия. Экономический расчет демонстрирует эффективность применения новой конструкции разработанного вакуумного насоса в технологическом процессе тонкого измельчения сухих растительных продуктов за счет вакуумного отвода заданной фракции помола. Поэтому разработанный насос рекомендуется использовать для измельчения сухих сыпучих растительных продуктов на крупных перерабатывающих предприятиях агропромышленного комплекса, пищевой, фармацевтической и парфюмерной отраслях промышленности. To increase the preservation of biologically active substances, reduce energy consumption in the grinding process and obtain a powder of a given degree of grinding from grape pomace and seeds, it is proposed to use a two-stage disk-ball vacuum mill. The proposed design of a two-stage mill affects the safety of work (excluding explosions) and environmental friendliness (does not create a dusty environment). An important object in the design of the developed installation is the vacuum pump. The device and basic principles of operation of a classic single-stage liquid ring vacuum pump manufactured by JSC "BESCOM" and a liquid ring vacuum pump with the ability to automatically adjust the size of the discharge window, developed at the TSTU Department of MIG are presented. The main advantages of the proposed pump in comparison with the classic version are shown.Based on the tests, a comparative analysis of the developed liquid ring vacuum pump with an automatically adjustable discharge window size and a classical vacuum pump of equal action speed was carried out, the results of which demonstrated the significant efficiency of using the first machine. It has been established that the specific power consumption in the process of transporting plant powders is 20-25% lower with the same speed of action. An economic calculation demonstrates the effectiveness of using a new design of the developed vacuum pump in the technological process of fine grinding of dry plant products due to the vacuum removal of a given grinding fraction. Therefore, the developed pump is recommended to be used for grinding dry bulk plant products at large processing enterprises of the agro-industrial complex, food, pharmaceutical and perfumery industries.

Liquid Ring Vacuum Pumps for Heat and Mass Transfer Processes

The paper examines the calculation of a liquid ring vacuum pump, using the example of the drying process of various materials. It was found that for two-stage convective vacuum-impulse drying it is economically efficient to use a two-stage liquid ring vacuum pump with the ability to turn off the second stage. A method for calculating the specific power of one-stage and two-stage liquid ring vacuum pumps, taking into account heat and mass transfer and thermal processes that occur during operation is proposed.

Wetting of a liquid annulus in a capillary tube

In this paper, we systematically investigate the static wetting behavior of a liquid ring in a cylindrical capillary tube.