Эффективные способы и аппараты для очистки промышленных пылегазовых выбросов пищевых и химических производвств на основе вихревых потоков

With increasing gas exploration activity in the Sultanate of Oman, a dedicated study of the lower Palaeozoic gas petroleum system of North Oman was undertaken in 2004. The study area covers over 50 thousand square kilometers and encompasses all major gas discoveries in the Sultanate. The study provides a 'fresh' look at the input parameters used to define both the thermal and migration models for gas expelled from source rocks of the upper Nafun Group (570–545Ma). The modelling results are calibrated against a recently analysed geochemical dataset describing the distribution and typing of North Oman gases in the lower Palaeozoic reservoirs. A uniform basal heat flow of the range of 35–40 mW/m2 was preferred based on the calibration of available palaeothermal indicators including Vitirinite Reflectance measurements (VR); Apatite Fission Track Analysis (AFTA); and corrected present data bottom-hole formation temperature (BHT) data. No thermal evidence was found in support of major rifting events. This is also supported by the lack of growth faults on the seismic section across the whole region. Alternatively, accommodation space is possibly created by subsidence in a foreland basin setting as part of regional compressional setting (SRK, 2004). The modelled maturity trend of Nafun source rocks across the North Oman Salt Basins (NOSB) shows two key expulsion peaks reflecting the basin's high subsidence during deposition of the Cambro-Ordovician Haima Supergroup and the subsequent Mesozoic carbonates. The modeling highlights areas with different expulsion histories and its impact on the risking of gas charge across the basin. The migration model highlights two key findings: Firstly, the presence of a narrow (~ 50 km wide) migration shadow zone, identified along the deepest part of the Ghaba Salt Basin (GSB) as a result of the presence of a thick section of Ara salt, supported by two dry deep wells previously drilled in this zone. Secondly, Haima-cutting faults and the presence of regional intra-Haima seals (Al Bashair and Mabrouk shale members) are identified as critical elements in providing access for a late (200-0 Ma) 'dry' gas expulsion that filled older traps. The results of this study are used to construct charge risk segment maps for the North Oman, and provide a basis for dry versus wet gas type predictions to prospective traps.

Tests on the cleaning efficiency of an experimental spiral cyclone have been conducted to determine the removal efficiency of the solid particles the dispersion of which makes <20 µm in the streamlined multi-channel cyclone. The introduced device is adapted to removing ultrafine particulate matter from contaminated air (gas) flow. A multi-channel cyclone with spiral casing has been designed at the Department of Environmental Protection (DEP) of Vilnius Gediminas Technical University. Experimental studies have disclosed that air (gas) flow cleaning efficiency of the spiral multi-cyclone (capacity 300 m3) depend on the internal structure of the device, i.e. on the number of channels and air (gas) flow distribution ratio of transit and peripheral channels. Also, the treatment efficiency of the applied equipment has been evaluated removing solid particles of different nature. AFA-VP-20 filters have been employed for conducting experimental tests. The obtained results have disclosed that solid granite particles – 95.1%, glass – 91.4% and wood – 92.2% are removed most effectively. Eksperimentiniai spiralinio ciklono valymo efektyvumo tyrimai atliekami siekiant nustatyti kietųjų dalelių, kurių dispersija x < 20 μm, pašalinimo efektyvumą patobulintame daugiakanaliame ciklone. Minėtas įrenginys pritaikytas itin smulkioms kietosioms dalelėms iš užteršto oro (dujų) srauto pašalinti. Daugiakanalis ciklonas, turintis spiralinį korpusą, sukurtas Vilniaus Gedimino technikos universiteto (VGTU) Aplinkos apsaugos katedroje (AAK). Eksperimentinių tyrimų metu nustatytas spiralinio daugiakanalio ciklono (našumas 300 m3/h) oro (dujų) srauto valymo efektyvumas priklausomai nuo vidinės įrenginio konstrukcijos, t. y. nuo kanalų skaičiaus ir oro (dujų) srauto pasiskirstymo į tranzitinį ir periferinį kanalus santykio. Taip pat įvertintas įrenginio valymo efektyvumas, šalinant skirtingos prigimties kietąsias daleles. Eksperimentiniams bandymams atlikti naudoti AFA-VP-20 filtrai. Remiantis bandymų rezultatais, nustatyta, kad efektyviausiai šalinamos granito kietosios dalelės – 95,1 %, stiklas – 91,4 %, mediena – 92,2 %.

Russia An element which concentrations in coals are ≤ 0.1% is called a trace element (TE). Such elements are divided into two groups: potentially valuable (PVE - Ge, Ga, U, Se, Te, Co, Ni, V, Re, Hg, Mo, W, Zn, Pb, Cr, Bi, Zr, Nb, Ta), TRE (rare earth metals including Y and Sc), PM (precious metals – Ag, Au, Pt and other platinoids); and potentially toxic (PTE - As, Be, Cl, Co, Cr, F, Hg, Mn, Ni, V, Pb, Sr, Sb, Se, Te, Tl, V, Zn, U, Th, Ra, Rn, 40K). According to our calculations, for the majority of cases related to production of TE marketable compounds or industrial concentrates it is economically feasible to use by-products (called the primary concentrates, or PRTE, containing PVE) of coal processing, i.e. with maximally possible utilization of coal energochemical potential. There are proposed quantitative equations allowing selection of these products on the calculations basis (by the programs of chemical thermodynamics) or with help of experimental studies on laboratory pilot scale or industrial installations. Results of these studies can also be used to develop recommendations for the implementation of measures to reduce to acceptable levels the adverse environmental impact of PTE compounds formed during the processing of coals and other fossil fuels.According to the studies, for almost all the PTE, the PRTE may be obtained as captured fly-ashes or their mixtures with slags with the minimum expenditures while coal combustion. aimed at production of heat and electricity energy. The selection of combustion devices and modes of coal burning to produce primary concentrates with optimal composition for various PVE, and also development of proposals to reduce the adverse environmental impact of PTE compounds depend on their distribution between the combustion products. Summing up the study’s results, PVE and PTE may be divided into three groups. 1st group contains TE forming gaseous compounds in zones of combustion devices with the highest temperature values. Such compounds are being removed from these zones by gas flow along with the other combustion products and are then after cooling condensed under temperature intervals of 800-120°C (Ge, Ga, Mo, W, Ag, Au, As Pb, Sb, Tl, Zn, partially Cl, F, Hg, Se, Те and Re). 2nd group contains mostly such compounds that are formed in solid or liquid phases in the high temperature zones and are being distributed between slag and fly ashes. Fly ashes are removed with gaseous combustion products to purification equipments (fiber or electrostatic filters), caught there with other solid particles before throwing into the atmosphere (Be, Co, Cr, Mn, Ni, V, Pb, Sr, Cr, Co,Ni, Zr, TRE, Th, U, Be). The 3rd group contains TE forming gaseous compounds in the high temperature zones of furnaces. Such compounds are removed there along with other combustion products and are not condensed after cooling of the latter (partially Hg, and, depending on coals mineral matter composition, Se, Cl, F, Те and Re).Fly ashes with PVE of the 1st group, fly ashes and slags with the PVE of the 2nd group could be considered as PRTE. Maximal extraction of PVE of 1st and 2nd groups from gas flow could be reached at purification of gas flow from solid particles at degrees of ≥ 98% with the fiber or electrostatic filters applied to gaseous compounds of combustion products evolved into the atmosphere. Under such conditions also a minimal hazardous effect of PTE of 1st and 2nd groups is reached. In order to achieve it for PTE of the 3rd group it is mandatory to utilize the special methods of gaseous compounds purification before releasing them into the atmosphere.

The turbulent pulsating flow and heat transfer in straight and 90° curved square pipes are investigated in this study. Both experimental temperature field measurements at the cross-sections of the pipes and conjugate heat transfer (CHT) simulation were performed. The steady turbulent flow was investigated and compared to the pulsating flow under the same time-averaged Reynolds number. The time-averaged Reynolds number of the pulsating flow, as well as the steady flow, was approximately 60,000. The Womersley number of the pulsating flow was 43.1, corresponding to a 30 Hz pulsating frequency. Meanwhile, the Dean number in the curved pipe was approximately 31,000. The results showed that the local heat flux of the pulsating flow was greater than that of the steady flow when the location was closer to the upstream pulsation generator. However, the total heat flux of the pulsating flow was less than that of the steady flow. Moreover, the instantaneous velocity and temperature fields of the simulation were used to demonstrate the heat transfer mechanism of the pulsating flow. The behaviors, such as the obvious separation between the air and pipe wall, the low-temperature core impingement, and the reverse flow, suppress the heat transfer.

The purpose of the article is to compare the efficiency of using electro-pulse and ultrasonic mufflers for cleaning exhaust gases from internal combustion engines of automobiles. The authors have developed full-size stands for conducting experiments with both types of mufflers on gasoline and diesel engines. Experimental studies have shown that electro-pulse mufflers are more effective in reducing the smoke of diesel engine exhausts, while ultrasonic mufflers are promising for cleaning exhaust gases from solid particles of gasoline engines. In the electro-pulse muffler, at the considered values of the angular velocity of the engine, the smoke indicators of the gas decreased to approximately 30%, while in the ultrasonic one, to 15%. The changes in the mass of the sold particles in the ultrasonic muffler of a diesel engine and a comparison with a gasoline engine show that ultrasonic mufflers have a lot of potential to stop solid particles from forming in the gas flow. In particular, the mass of the precipitated particles in a gasoline engine is 3 times greater than in a diesel engine. The alternative mufflers studied in the article allow for the purification of exhaust gases from solid particles, reducing their negative impact on the environment and giving impetus to the development of environmentally friendly motor transport.

Experimental study of the connecting tube at the cold end of a U-shaped pulse tube cryocooler

Experimental study of counter-current gas–droplet flow limitation in a 30 cm pipe

Knowledge from recent investigations on sloshing motion in a liquid pool with solid particles for severe accident analyses of sodium-cooled fast reactor

The purpose of this study is to investigate factors that affect the formation of fluid banks during gravity-driven counter-current flow in porous media. To our knowledge, development of a fluid bank has been observed in only one previous counter-current flow experiment, although there are some hints of fluid banks in other experiments. We have undertaken experimental and simulation studies to confirm the presence of such banks and to delineate factors which enhance or inhibit their formation. Experiments were performed using glass bead packs and X-ray Computed Tomography to monitor saturation distribution as a function of time. The simulation approach considers saturation history at every point in the sample, defining conditions at each time point from hysteresis in capillary pressure and relative permeability. The model proved to reproduce experimental observations accurately. The experiments and associated model show that a minimal vertical sample height is needed for the development of a fluid bank. In addition, round sample boundaries and higher average nonwetting phase saturation tend to prevent the formation of a bank. The validated model can improve our ability to predict and optimize counter-current flow processes, both in the laboratory and in the field (e.g. exploration and hydrocarbon extraction).

Sliding bearings with sintered bronze bush lubricated by contaminated water with solid particles – Theoretical and experimental studies

The application of a bipolar corona discharge for the electrical purification of gases is considered. The design and operation principle of the developed unit based on the simultaneous use of centrifugal and electrostatic forces for the trapping of solid particles are described. The charge distribution in the field of the bipolar corona is illustrated. Electrodes of different polarity with a small radius generate a bipolar corona discharge, passing through which some of the particles are charged positively, while others are charged negatively. This promotes a more intense coagulation process, owing to which the level of gas purification increases under the action of centrifugal forces. Particular attention is paid to the testing results of a centrifugal electrostatic precipitator to assess its efficiency. The experiments have been conducted using a D242 diesel engine that acted as a “generator” of a gas flow containing solid particles of soot. A current–voltage curve has been plotted for the electrostatic precipitator prototype, and the mass concentration of pollutants depending on the diesel power has been experimentally obtained. The experimental data have confirmed that the centrifugal electrostatic precipitator for gas purification from solid particles is highly efficient.

This paper presents an experimental study of gas-liquid slug flow on solid particle transport inside a horizontal pipe with two types of experiments conducted. The influence of slug length on solid particle transportation is characterized using high speed photography. Using combined Particle Image Velocimetry (PIV) with Refractive Index Matching (RIM) and fluorescent tracers (two-phase oil-air loop) the velocity distribution inside the slug body is measured. Combining these experimental analyses, an insight is provided into the physical mechanism of solid particle transportation due to slug flow. It was observed that the slug body significantly influences solid particle mobility. The physical mechanism of solid particle transportation was found to be discontinuous. The inactive region (in terms of solid particle transport) upstream of the slug nose was quantified as a function of gas-liquid composition and solid particle size. Measured velocity distributions showed a significant drop in velocity magnitude immediately upstream of the slug nose and therefore the critical velocity for solid particle lifting is reached further upstream.

A review of the results from experimental and theoretical studies on fundamental, scientific, technical, and applied orientation are presented for two-phase flows with different structures according to materials of two significant and already traditional scientific forums: the Russian National Conference on Heat Transfer (RNKT-7) and the International Heat Transfer Conference (IHTC 16). Particular attention therein was paid to the classification of gas-liquid and vapor-liquid flows, bubble flows, gas-droplet and gas-dust (gas + solid particles) structures, and plotting flow-pattern diagrams for flowing both in the channels of traditional shape and size and in minichannels of a capillary type. Problems are considered concerning the hydrodynamics and heat-and-mass transfer, increasing heat-transfer efficiency under cooling heated solid surfaces by impact jets. Modern noncontact optical experimental methods for measuring the local characteristics of flows are described in detail, which make it possible to determine, for example, phase slip coefficients, local gas (vapor) content, liquid film thickness, especially in the areas of triple phase contact, etc. Theoretical approaches are also considered wherein analytical and numerical methods are used to describe the stability of bubble and film flows, cavitation phenomena, acoustics, and the gas dynamics of two-phase flows, including gas + solid particles. A significant number of reports are devoted to the urgent problems of power engineering, chemical technologies, studies on heat-and-mass transfer in cooling towers, cryogenic equipment under regasification, absorbers, jet cooling systems for heat-transfer surfaces, snow generators, and ultra-modern and highly efficient capillary-type heat exchangers.

The surfactant used in this study is well known as an additive for drag reduction in straight (non-swirling) pipe flow. This paper deals with swirling flow characteristics of a surfactant solution. We investigated the effects of surfactant concentration and Reynolds number on flow characteristics. It is shown that the drag reducing effect is less than in straight pipe flow, and that the surfactant solution must be highly concentrated with great elasticity in order to produce a drag reduction. As the results of velocity measurement by LDV and wall pressure measurement in the axial direction, it is expected that the swirl intensity of the drag reducing swirling flow with a surfactant decays more quickly as the flow progresses downstream. And we propose that this mechanism helps create the drag reduction in swirling flow. For the velocity profiles of drag reducing swirling flow, only the forced-vortex type is observed in this experiment. This suggests that the velocity profiles of drag reducing swirling flow change more quickly to a forced-vortex type from a Rankin's combined vortex type. It is also reported that turbulence intensity of drag reducing swirling flow is smaller than turbulence intensity of a solvent.

در این پژوهش میکروکپسول جدیدی تحت عنوان میکروکپسول آلژینات- پروتئین آب پنیر حامل دی استیل تهیه و خصوصیات آن تعیین گردید. رهایش دی استیل در شرایط شبیه سازی شده دهانی در سطوح مختلف بزاق به میکروکپسول (0:1، 1:4 و 1:8) و نیروهای برشی متفاوت (0، 50 و 100 معکوس ثانیه) مورد بررسی قرار گرفت و ضریب نفوذ با کمک معادله فیک تخمین زده شد. هدف اصلی این پژوهش توسعه مدلی به منظور پیش بینی فرآیند رهایش و نیز تخمین ضریب نفوذ از میکروکپسول جدید ابداعی بوده تا بتوان به کمک آن رهایش کنترل شده عطر و طعم در شرایط دهانی ایجاد نمود. نتایج این تحقیق نشان داد که مدل حاصله می تواند با ضریب همبستگی بالای 95 درصد رفتار رهایش را پیش بینی نموده و علاوه بر این مدل مذکور به خوبی قادر به تخمین میزان ضریب نفوذ می باشد. نتایج همچنین نشان داد که اعمال نیروی برشی بطور معناداری سبب افزایش ضریب نفوذ شده درحالیکه تغییر میزان بزاق تاثیر معناداری بر آن ندارد.