Showing papers on "Countercurrent exchange published in 2018"
TL;DR: The staged diafiltration process not only provides for continuous buffer exchange, it could also provide significant reductions in the number of pump passes while providing opportunities for reduced buffer requirements.
Abstract: A number of groups have studied the application of continuous bioreactors and continuous chromatographic systems as part of efforts to develop an integrated continuous biomanufacturing process. The objective of this study was to examine the feasibility of using a countercurrent staged diafiltration process for continuous protein formulation with reduced buffer requirements. Experiments were performed using a polyclonal immunoglobulin (IgG) with Cadence™ Inline Concentrators. Model equations were developed for the product yield, impurity removal, and buffer requirements as a function of the number of stages and the stage conversion (ratio of permeate to feed flow rate). Data from a countercurrent two-stage system were in excellent agreement with model calculations, demonstrating the potential of using countercurrent staged diafiltration for protein formulation. Model simulations demonstrated the importance of the countercurrent staging on both the extent of buffer exchange and the amount of buffer required per kg of formulated product. The staged diafiltration process not only provides for continuous buffer exchange, it could also provide significant reductions in the number of pump passes while providing opportunities for reduced buffer requirements.
34 citations
TL;DR: In this article, the effect of nanoparticles on the absorption of vapor into a liquid film of lithium bromide aqueous solution flowing down over a cooled vertical channel was examined.
Abstract: This paper examined the effect of nanoparticles on the absorption of vapor into a liquid film of lithium bromide aqueous solution flowing down over a cooled vertical channel. For this, we realized a two-dimensional code which solves the governing equations using Comsol Multiphysics. In this model, the cooling water flows countercurrent to a solution of concentrated lithium bromide mixed with the copper nanoparticles. After the validation of the model, the effects of parameters such as Reynolds number, solid volume fraction of copper nanoparticles, inlet concentration and inlet temperature of solution on the performance of the absorption are presented and discussed. The important results indicate that the mass and heat transfer in binary nanofluids are enhanced more than that in base fluid and the efficiency of the nanofluid becomes higher to that of the base fluid for a lower Reynolds number and the inlet concentration and for a higher inlet temperature of solution.
27 citations
10 Dec 2018
TL;DR: In this paper, a physical and mathematical model of the absorber with countercurrent flow of dispersed gas phase was proposed and the model considered ideal displacement regime and uniform liquid phase with the diffusion flow structure.
Abstract: In this study, physical and mathematical model of the absorber with countercurrent flow of dispersed gas phase was proposed. The model considered ideal displacement regime and uniform liquid phase with the diffusion flow structure. The calculation algorithm was proposed. The technological and geometrical parameters of absorbers were compared with considered in the study flow structures as well as with flow structures of ideal displacement for both phases. The calculation algorithm for the phases is described in previous studies. The variation observed between the absorber flow structure and ideal displacement requires the increase in the column packing height.
21 citations
TL;DR: In this paper, two-phase countercurrent flow dynamics and simultaneous CO2 and H2S removal performance were studied in countercurrent randomly packed-bed columns with fourth generation Raschig super-Rings exposed to static inclination and heaving motion via an unsteady-state comprehensive three-dimensional model.
21 citations
TL;DR: In this article, the effect of coil pitch, coil diameter, and coiled tube diameter on heat transfer phenomena of helical coils was discussed and a new set of correlation of heat transfer data was created and it could be found that the results from the correlation agreed well with the experimental data.
19 citations
12 citations
TL;DR: In this paper, a methodology for predicting the gas holdup for both the homogeneous and heterogeneous regimes and the transition gas velocity and holdup is developed by extending existing models for homogeneous, heterogeneous and non-homogeneous regime.
11 citations
7 citations
16 Sep 2018
TL;DR: In this article, the hydrodynamics of the foam layer with the stabilizer on counteracting contact elements have been investigated and the structural parameters of the phases of foam layer as a whole medium are considered.
Abstract: Industrial implementation of the stabilization method of the gas-liquid layer can significantly expand the field of foaming devices and opens up new opportunities for intensifying technological processes with the simultaneous for creation of lowwaste technologies. The article reveals the basic regularities of the hydrodynamics of the foam layer with the stabilizer on counteracting contact elements. The structural parameters of the phases of the foam layer as a whole medium are considered. Take into account the mutual influence of two phases. The laws of gas content and parameters of the contact area of phases have been studied. The functional dependences of the main parameters of the process are established. The conducted analysis of a number of studies has shown that a promising direction of intensification of the mass transfer process is the development of apparatuses with a three-phase fluidized bed of an irrigated nozzle of complex forms made of porous materials. Consequently, it is necessary to carry out special investigations of the hydrodynamic modes of the apparatus with a foam layer, which stabilizes with the definition of parameters that affect the transition speed of the contact element from one mode to another. In today's conditions, a significant human-induced environmental impact on time is the search for the most effective and economical methods for the purification of industrial emissions. Methods of cleaning and equipment being developed should take into account the possibility of work in a wide range of working conditions. In order to reduce energy consumption in systems for catching harmful and toxic substances, it is necessary to provide a reduction of hydraulic resistance while maintaining the high efficiency of gas streams cleaning. Given the controversial requirements for equipment and despite the large number of existing machines for mass transfer processes, the development of new high-intensity and efficient equipment is of considerable interest for environmental technologies in many industries.
6 citations
TL;DR: In this article, the hydrodynamics and retention of 2D countercurrent chromatographic systems were investigated for ionic liquid based biphasic solvents using high-speed imaging.
6 citations
TL;DR: In this article, the authors studied the vertical countercurrent fire spread of XPS with different widths in the space and wall adhesion conditions, and found that the spread rate and the average flame height of the XPS decrease first and then increase with the increasing of the width under the two working conditions.
TL;DR: In this paper, an experimental measurement system was established to examine the heat and water transfer process for a porous plate in the self-humidifying system of a fuel cell, and the physical parameters of the fluid flow and porous plates were evaluated for their effects on the heat transfer characteristics of the porous plates.
TL;DR: The solubility of Antarctic krill proteins after multi- step dissolution was explored firstly; multi-step extraction was investigated; and then multi-stage countercurrent system for protein extraction was carried out.
Abstract: To systematically study multi-stage countercurrent process for Antarctic krill protein extracting and to optimize the multi-stage countercurrent technology, the solubility of Antarctic krill proteins after multi-step dissolution was explored firstly; multi-step extraction was investigated; and then multi-stage countercurrent system for protein extraction was carried out In single step extraction, krill-to-water ratio and pH were chosen as 1:10 and 125 respectively, in order to extract more protein In the multi-step dissolution process, the protein solubility of aqueous solution at pH 125 was 330 ± 08 mg/mL Multi-step cross-flow processing testified the feasibility of multi-stage countercurrent assumption Three-stage countercurrent method using krill-to-water ratio 1:10 extracted, 951 ± 06% protein from krill, where almost the same water as previous works The total recovery yield of 679 ± 16% was achieved after precipitation at pH 45
TL;DR: The liquid flow pattern of the countercurrent phase water isotope exchange process used for the removal of tritiated water vapor from gases has been studied via the pulse injection of a tracer into a liquid flow as discussed by the authors.
Abstract: The liquid flow pattern of the countercurrent phase water isotope exchange process used for the removal of tritiated water vapor from gases has been studied via the pulse injection of a tracer into a liquid flow. A specific feature of this process is an extremely low water irrigation density in a column. Based on the performed experiments, the liquid holdups have been calculated and the liquid flow pattern has been determined. It has been demonstrated that the standard estimation of the longitudinal mixing effect on the masstransfer characteristics of this process has a limited character and may result in incorrect conclusions at a low irrigation density on packings.
TL;DR: In this paper, the isotope separation in a high-frequency plasma circulating centrifuge operating with a product flow was analyzed and the optimal characteristics of the separation unit have been determined.
Abstract: We have analyzed the isotope separation in a high-frequency plasma circulating centrifuge operating with a product flow. The rotation of a weakly ionized plasma is ensured by a rotating magnetic field, while the countercurrent flow (circulation) is produced by a traveling magnetic field. We have calculated the dependences of the enrichment factor and the separative power of the centrifuge on a product flow. The optimal characteristics of the separation unit have been determined.
Patent•
18 Dec 2018
TL;DR: In this article, a method for measuring energy efficiency of a natural ventilation countercurrent wet cooling tower was proposed, which comprises the following steps: obtaining structural parameters of the thenatural ventilation counter-current liquid cooling tower, measuring operating parameters during an operation process, and measuring circulating water pump operating parameters, and calculating an energy efficiency evaluation index Eta of the naturalventilation countercurrent WET cooling tower.
Abstract: The invention discloses a method for measuring energy efficiency of a natural ventilation countercurrent wet cooling tower, which comprises the following steps: obtaining structural parameters of thenatural ventilation countercurrent wet cooling tower; measuring operating parameters during an operation process of the natural ventilation countercurrent wet cooling tower, and measuring circulatingwater pump operating parameters during the operation process of the natural ventilation countercurrent wet cooling tower, wherein the circulating water pump operating parameters comprise circulating water pump working voltage U and working current I, and obtaining consumed pump power W (pump power) of the matching circulating water pump of the natural ventilation countercurrent wet cooling tower based on the consumed pump power of the matching circulating water pump of the natural ventilation countercurrent wet cooling tower; calculating an energy efficiency evaluation index Eta of the naturalventilation countercurrent wet cooling tower; when the energy efficiency evaluation index Eta is smaller than a, determining that the energy efficiency of the natural ventilation countercurrent wet cooling tower is evaluated as low energy efficiency; when the energy efficiency evaluation index Eta is not smaller than a and smaller than b, determining that the energy efficiency of the natural ventilation countercurrent wet cooling tower is evaluated as intermediate energy efficiency; when the energy efficiency evaluation index Eta is not smaller than b, determining that the energy efficiency of the natural ventilation countercurrent wet cooling tower is evaluated as high energy efficiency.
01 Sep 2018
TL;DR: In this article, the authors investigated the characteristic of slug countercurrent flow pattern in a vertical small diameter pipe and found that the two-phase flow was always preceded by the instability of flow rate and bubbles appearance.
Abstract: Two-phase flow is widely encountered in several engineering and industrial facilities. The purpose of this study is to investigate the characteristic of slug countercurrent flow pattern in a vertical small diameter pipe. An experimental investigation in this study has been performed toward a transparent tube of 19 mm diameter (outside diameter 22 mm, length 200 mm), water and air as the liquid and gas fluid in the vertical pipe followed by taking a picture of flow pattern in the transparent pipe using the high-speed camera. Two differential pressure sensors were set in transparent tube in order to receive slug countercurrent flow rate associated with the acquisition data as media to record data and then displayed on the screen. The two-phase flow was always preceded by the instability of flow rate and bubbles appearance. It occurred after the steady flow data acquisition rate was turned on for recording the differential pressure. The result showed that the flow pattern characteristic of two-phase flow (air-water) in the vertical pipe caused by the superficial velocity of air.
Patent•
08 May 2018
TL;DR: In this article, a system for improving dryness of steam is described, which consists of steam generation equipment, a heat exchanger and process equipment, including a pressure reducing valve and a steam-water separator.
Abstract: The invention discloses a system for improving dryness of steam. The system comprises steam generation equipment, a heat exchanger and process equipment; the steam generation equipment and a cold fluid inlet of the heat exchanger are connected through a low-pressure steam pipe; a pressure reducing valve and a steam-water separator are arranged on the low-pressure steam pipe in a steam flowing direction in sequence; a cold fluid outlet of the heat exchanger and the process equipment are connected through a high-temperature steam pipe; a hot fluid inlet of the heat exchanger is connected with the low-pressure steam pipe at the upstream of the steam-water separator through the high-pressure steam pipe; a hot fluid outlet of the heat exchanger is connected with a condensed water reflux pipe leaded to the steam generation equipment; the flowing direction of a cold fluid in the heat exchanger is opposite to the flowing direction of a hot fluid; and the heat exchange mode is countercurrent heat exchange. The countercurrent heat exchange mode is adopted; low-pressure and low-temperature steam is heated by high-pressure and high-temperature steam; and part of water remained in the low-pressure steam is heated for vaporization as the steam, so that the dryness of the steam is improved.
Patent•
08 May 2018
TL;DR: In this article, a spiral plug-flow channel plate type heat exchanger is proposed, which is composed of a heat exchanging core, an inlet flow guiding section, an outlet flow guiding sections, a hot fluid inlet and outlet, and a cold fluid inlets and outlet.
Abstract: The invention relates to a spiral plug-flow channel plate type heat exchanger. The spiral plug-flow channel plate type heat exchanger is composed of a heat exchanging core, an inlet flow guiding section, an outlet flow guiding section, a hot fluid inlet and outlet and a cold fluid inlet and outlet. The heat exchanging core of the heat exchanger adopts a flowing channel where heat exchanging is conducted through spiral parallel countercurrent flow, and thus more sufficient heat exchanging of fluid in the heat exchanger is facilitated. The inlet flow guiding section and the outlet flow guiding section adopt direct in-out and side in-out staggered structures, and thus more even distribution of the fluid in the heat exchanger is facilitated. The cold fluid inlet and outlet and the hot fluid inlet and outlet adopt a square-round transition structure, and thus a more compact structure of the heat exchanger is facilitated. The spiral plug-flow channel plate type heat exchanger can achieve solid two-dimensional heat conduction, the heat conduction resistance is reduced, the heat transmission capacity between the fluid on the two sides is increased, the heat transmission area of the heat exchanger is enlarged, the compactness of the heat exchanger is improved, the comprehensive efficiency of the heat exchanger is improved, deformation caused by concentrated distribution of thermal stress is improved, the safety property of the heat exchanger is improved, and the service life is prolonged.
TL;DR: In this paper, the maximum efficiency of a system consisting of a heat recovery burner connected to an ideal Carnot heat engine was investigated. But the authors focused on the recovery of the heat of the combustible mixture through the heat-conducting wall of a countercurrent heat exchanger, in which the combustion products and the combustion mixture move toward each other in the channels connected by a heatconducting partition.
Abstract: Estimates are obtained for the maximum efficiency of a system consisting of a heat recovery burner connected to an ideal Carnot heat engine. The burner serves as a heater of the ideal heat engine, and the cold side is at the ambient temperature. Combustion products heat the hot wall of the ideal engine and then transfer heat to the combustible mixture supplied to the combustion chamber. Recovery of the heat of the combustible mixture occurs through the heat-conducting wall of a countercurrent heat exchanger, in which the combustion products and the combustible mixture move toward each other in the channels connected by a heat-conducting partition. An estimate is obtained for the total efficiency of the system, which is defined as the ratio of the net power of the ideal engine to the chemical energy flux reaching the burner device. It is shown that the total efficiency of the system can approach the Carnot-cycle efficiency with the maximum possible temperature of the hot side of the ideal heat engine.
Patent•
13 Jul 2018
TL;DR: In this paper, an ultrasonic wave enzyme is assisted low temperature continuous countercurrent and is leached extraction element, and the extraction element includes that feeder hopper, quantitative enzyme add device and setup in continuous counter-current extraction tube section, screw propulsion, ultrasonator and electric heater unit, and other end socket joint is covered in the bearing seal outerwall.
Abstract: The utility model belongs to the chemical industry equipment field discloses an ultrasonic wave enzyme is assisted low temperature continuous countercurrent and is leached extraction element. The extraction element includes that feeder hopper, quantitative enzyme add device, continuous countercurrent extraction tube section, screw propulsion, ultrasonator and electric heater unit, continuous countercurrent extraction tube section feed end sets up takes socket joint seat drive shaft, and the discharge end sets up the bearing seal lid, feeder hopper and quantitative enzyme add the device and setup in continuous countercurrent extraction tube section front end, screw propulsion sets up in the continuous countercurrent extraction tube section, and the one of which end support is inserted on taking socket joint seat drive shaft, and other end socket joint is covered in the bearing seal, ultrasonator and electric heater unit set up in continuous countercurrent extraction tube section outerwall. The device can realize that the ultrasonic wave supplementary draws, the enzyme process supplementary draw with the integration of countercurrent extraction technique, realize extraction efficiency maximize, solvent quantity minimizing.
TL;DR: In this paper, a novel countercurrent flowing liquid bath collector was combined with a multi-needle electrospinning device to improve the properties of polyacrylonitrile nanofiber filaments.
Abstract: Wet electrospinning is a simple and efficient method to manufacture continuous nanofiber filaments. However, polyacrylonitrile nanofiber filaments collected using a static water bath are limited for application in certain areas due to their low degree of alignment and breaking stress values. To improve these properties, a novel countercurrent flowing liquid bath collector was combined with a multi-needle electrospinning device. The morphologies, crystalline structures, thermal behaviors and mechanical properties of filaments fabricated under different countercurrent bath liquid motion conditions were investigated. In addition, the forces acting on the nanofibers in the bundling triangular zone under countercurrent liquid bath motion were analyzed. The results showed that the average nanofiber diameter of the filaments decreased with an increase in bath solution motion forces. The maximum alignment degree and breaking stress of the nanofibers were 85 % and 0.63 cN/dtex, respectively, achieved using a liquid flow rate of 80 ml/min and water inlet diameter of 6 mm. The alignment degree of the assembled nanofibers in the bundling triangular zone could be increased by 57 % when using a countercurrent flowing liquid compared with a static liquid bath.
Patent•
26 Nov 2018
TL;DR: In this article, a method for reducing accumulation of liquid and freezing in plate type countercurrent heat exchanger (100) comprising stack of heat transfer plates (102) was proposed.
Abstract: FIELD: heat exchangeSUBSTANCE: present invention relates to a method for reducing accumulation of liquid and freezing in plate type countercurrent heat exchanger (100) comprising stack of heat transfer plates (102) Present invention also relates to plate type countercurrent heat exchanger (100) comprising stack of heat transfer plates (102) forming a primary flow channels for first flow (116) of heat exchange gas and a secondary flow channels for second flow (118) of heat exchange gas Stack of heat transfer plates comprise channelling section (138) in which the primary flow channels and the secondary flow channels are located Channelling section (138) of heat transfer plates (102) comprises formations which form ridges and grooves the direction of which is at an angle with respect to the direction of flows (116, 118) of the heat exchange gases in the primary flow channels and the secondary flow channels In some embodiments the direction of ridges and grooves is perpendicular to the direction of flows In some embodiments the distance between two adjacent plates in the stack is substantially constant at channelling section (138)EFFECT: structure of the heat exchanger plates according to the present invention reduces the risk of liquid building up inside the heat exchanger and hence reduces the risk of forming ice on the surfaces of the heat exchanger plates; therefore, flowing of gases (for example, air) inside the heat exchanger is also improved15 cl, 12 dwg
TL;DR: In this article, a mathematical model of the countercurrent extractor based on differential equations has been presented, which makes it possible to determine average concentrations of components and the extractor height.
Abstract: Mathematical model of the countercurrent extractor based on differential equations has been presented. The model makes it possible to determine average concentrations of components and the extractor height.
Patent•
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12 Apr 2018
TL;DR: In this paper, a total heat exchanger with a single motor was proposed to discharge indoor air and suction outdoor air simultaneously with the help of a single blower fan, capable of being installed in a duct, high in heat exchange performance because air does not directly passing through the exchanger.
Abstract: PROBLEM TO BE SOLVED: To provide a total heat exchanger configured to discharge indoor air and suction outdoor air simultaneously with a single motor, capable of being installed in a duct, high in heat exchange performance because air does not directly passing through the exchanger, and further dispensing with integrated control.SOLUTION: A total heat exchanger 1 includes a blower fan 40 including an outer peripheral fin 42 and an inner peripheral fin 44 facing reversely to the outer peripheral fin 42. The total heat exchanger is configured to rotate the blower fan 40 to simultaneously discharge indoor air 2 and suction outdoor air 3 through an element 60, thereby generating countercurrent in a coaxial direction with a single motor 48. Consequently, the total heat exchanger can reduce costs compared to a conventional case where countercurrent is generated with two motors, and also can save energy.SELECTED DRAWING: Figure 4
01 Apr 2018
TL;DR: In this paper, the authors investigated the process of asbestos-cement dust slippage past dust collectors with countercurrent swirling flows, taking into account the mass rate of dust getting to the working zone air, total gas flow rate, the length of the lower inlet branch duct, the conditional relative speed in the midsection of the apparatus, the ratio of the flow rates delivered to the upper and lower inlets, the distance between the axes of local exhausts, the relative concentration and particle size distribution of dust.
Abstract: The authors have investigated the process of asbestos-cement dust slippage past dust collectors with countercurrent swirling flows. They took into account the mass rate of dust getting to the working zone air, the total gas flow rate, the length of the lower inlet branch duct, the conditional relative speed in the midsection of the apparatus, the ratio of the flow rates delivered to the upper and lower inlets, the distance between the axes of local exhausts, the relative concentration and particle size distribution of dust. In the course of the investigation, the methods of mathematical statistics and probabilistic-stochastic approach were applied. The optimal ratio of the given parameters was determined, at which the maximum dust collection efficiency was observed. Keywords—dust collection efficiency, assessment of dust slippage, asbestos-cement dust, dust particle size distribution, dust collectors with countercurrent swirling flows
Patent•
09 Jan 2018
TL;DR: In this article, a heat exchange method of a fair current and countercurrent mode adjustable high-efficiency heat exchange system was presented. But the authors did not consider the effect of the fair current on the performance of the system.
Abstract: The invention discloses a heat exchange method of a fair current and countercurrent mode adjustable high-efficiency heat exchange system. The heat exchange method comprises the steps of established power, system flow and flow rate, detection of temperature, calculation of inlet temperature difference of cold fluid and hot fluid, small heat requirement of the system, fair current flowing, large heat requirement of the system, countercurrent flowing, moderate heat requirement of the system, and countercurrent flowing. The fair current flowing mode is adopted under the condition of the small heatrequirement of the system, so that the system resistance is small, the unnecessary energy consumption is reduced, and the system operates safely and stably. The countercurrent flowing mode is adopted under the condition of the large heat requirement of the system, so that the average temperature difference is large, the heat exchange efficiency of a heat exchanger is improved, and the heat requirement of the system is satisfied. The fair current and the countercurrent alternate according to the heat exchange method, thereby preventing high temperature from centralizing at one end of the heatexchanger and prolonging the service life of the heat exchanger. According to the change of practical situations, the flowing direction of heat exchanger fluid is flexibly changed; and the heat exchange method gives full play to the respective advantages of the fair current and the countercurrent and has an obvious energy saving effect and very good economic benefits and social benefits.
TL;DR: In this article, a countercurrent sublimation method is proposed to increase the efficiency of the separation and purification of substances such as iodine, the iodides of elements, the chlorides and fluorides of transition metals, and a number of organic compounds by sublimations.
Abstract: A countercurrent sublimation method is proposed in order to increase the efficiency of the separation and purification of substances such as iodine, the iodides of elements, the chlorides and fluorides of transition metals, and a number of organic compounds by sublimation methods. Ultrasound is used to break the crystal layer formed on a desublimator and shake off the finely dispersed crystal phase into the working zone of a column. The mathematical models of the purification of substances by countercurrent sublimation are proposed that take into account the longitudinal diffusion of an impurity and the change in the size of a crystal along the height of the column. The mathematical models of countercurrent sublimation are verified using the borneol–camphor system. It is shown that the enlargement of crystals substantially affects the degree of the purification of substances in a countercurrent sublimation column.