Separate Towers Research Articles

Heat and mass transfer performance of multi-solute electroplating wastewater in spray evaporation separation process

Electroplating wastewater is complex in composition and contains many harmful substances. Based on the single droplet heat and mass transfer method, a one-dimensional mathematical model for the evaporation separation heat and mass transfer process of multi-solute electroplating wastewater is established. In order to validate the model, the experimental system of evaporation separation tower is established, and Nusselt numbers corresponding to metal ion solutions are fitted, reliabilities of models are also verified. The maximum relative errors of mathematical models are within 10.0 %. In addition, effects of the type and concentration of metal ions and air inlet temperature on heat and mass transfer characteristics of spray separation tower are investigated. Experimental results show that when the wastewater inlet concentration is the same, the improvement effects of increasing air inlet temperature on evaporation and separation performance from high to low are ZnCl2, CuCl2, and NiCl2 solutions. When the air inlet temperature increases from 90 °C to 130 °C, the evaporation speed of ZnCl2, CuCl2 and NiCl2 solutions increase by 90.3 %, 84.3 % and 45.7 %, respectively. When the air inlet temperature is the same, with the increase of wastewater inlet concentration, the evaporation separation performance of electroplating wastewater in descending order is ZnCl2, CuCl2, and NiCl2 solutions.

Detection of Disease in Calves using Artificial Intelligence

Background: Livestock farming is experiencing a digital transformation and is becoming more information-driven. However, this type of data is often kept in separate storage towers, making it incapable of practicing its potential to boost animal welfare. Lumpy Skin Disease (LSD) is a serious threat to the health of cattle worldwide and has caused financial problems for many cattle farming enterprises. It has been shown that combining machine learning (ML) and artificial intelligence (AI) with biosensor data and conventional visual inspections can improve the identification and diagnosis of this serious condition. Methods: This study presents an extremely precise livestock farming framework that combines data streams from a wide array of disciplines of dairy cattle to see if ever wider/vast data sources enhance the overall projections for diseases and if using the more complicated prediction models can reimburse for less diverse data to some extent. Using images from the farming landscape, this study highlights the utility of convolutional neural networks (CNNs) in the identification of the Lumpy Skin Disease Virus (LSDV) in animals. Result: An analysis of the relative weight given to individual factors in predicting accuracy shows that disease in dairy cattle results from the intricate interactions between many life domains/parameters, such as housing, nutrition and climate; that prediction performance is enhanced by incorporating a wider range of data sources; and that current information can be repurposed to produce useful information for vaccine development. The study highlights the potential of data-driven dairy interventions, focusing on artificial intelligence for disease prediction in cattle, to improve animal welfare and reduce the risk of disease. A Convolutional Neural Network (CNN) based model effectively classified skin conditions with an overall accuracy of 73.89% after 27 training epochs. This study demonstrates CNN’s useful applications in the field of veterinary medicine by highlighting its potential for early detection of Lumpy Skin Disease (LSD).

Pole skipping in holographic theories with gauge and fermionic fields

Using covariant expansions, recent work showed that pole skipping happens in general holographic theories with bosonic fields at frequencies i(lb − s)2πT, where lb is the highest integer spin in the theory and s takes all positive integer values. We revisit this formalism in theories with gauge symmetry and upgrade the pole-skipping condition so that it works without having to remove the gauge redundancy. We also extend the formalism by incorporating fermions with general spins and interactions and show that their presence generally leads to a separate tower of pole-skipping points at frequencies i(lf − s)2πT, lf being the highest half-integer spin in the theory and s again taking all positive integer values. We also demonstrate the practical value of this formalism using a selection of examples with spins 0,12\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\frac{1}{2} $$\\end{document}, 1,32\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\frac{3}{2} $$\\end{document}, 2.

Re-Boiler Simulation of Separation Tower of Methanol to Propylene Conversion Unit

Re-Boiler Simulation of Separation Tower of Methanol to Propylene Conversion Unit

Experimental and simulation investigation on the characteristics and performance of the spray separation tower for evaporation crystallization of saline wastewater

Experimental and simulation investigation on the characteristics and performance of the spray separation tower for evaporation crystallization of saline wastewater

Purification Process Design of Vinyl Acetate Based on Aspen Plus

Based on Aspen Plus process simulation, the purification stage of the production of vinyl acetate by 450000 tons of calcium carbide acetylene process was optimized.The main equipment involved in the process are degassing tower, deacetaldehyde tower, crude separation tower, vinyl acetate refining tower, acetic acid distillation column and so on. The unit operation involved mainly includes general distillation, azeotropic distillation, distillation with side line extraction, absorption, extraction and so on. Aspen Plus sensitivity analysis function is used to analyze and optimize tower parameters such as reflux ratio, the number of theoretical plates, distillate feed ratio, feed position, side line extraction position. The results will provide reference for improving the problems of low purity and energy waste of products.

Study on the heat and mass transfer characteristics of spray separation tower at low temperature and normal pressure

A one-dimensional mathematical model for the drying process of calcium chloride solution in a co-current spray separation tower based on the four-stage drying model of single droplet is proposed. A corresponding pilot system is set up and the reliability of the model is validated by a series of experiments. The maximum relative errors of the mathematical model are within 10% and 15% while the average relative errors are 4.0% and 7.0% when predicting the outlet air temperature and humidity, respectively. The effects of inlet parameters on the heat and mass transfer characteristics of the spray separation tower at low temperature and normal pressure are evaluated as well. Simulation results show that air mass flow rate, inlet solution concentration and solution mass flow rate have greater effect on the thermal efficiency than other inlet parameters while the inlet solution concentration plays a pivotal role on the drying strength. The most significant factor on the volumetric heat transfer coefficient is the inlet solution concentration. Besides, the back propagation (BP) neural network model of the spray separation tower is also established on the basis of experimental data, and the comparison between the one-dimensional mathematical model and the BP neural network model is conducted in detail.

WATER AND OIL AUTOMATIC SEPARATION SYSTEM USING FUZZY CONTROL

This paper presents the design of a water and oil separation system as a contribution to reduce the problem of contamination of water in domestic and industrial sewage. The project consists of improvements in level detection in an automatic separation tower and in the use of the Fuzzy control. The main objective is to design a controller based on the values of the levels and increase the reliability in the process of separation of the fluids. The validation of the controller is obtained through simulation in MATLAB engineering software and the improvements applied are corroborated according to the results observed in the separation process. Satisfactory results show increased reliability in the fluid separation process, leaving the minimum fluid within the reservoir.

Theoretical investigation and experimental verification of a mathematical model for counter-flow spray separation tower

Despite the fact that the conventional one-dimensional model for counter-flow spray separation tower is advanced in reasonable accuracy as well as time and computational resources saving, it fails to describe the physical processes in details. In this paper, the concept of supersaturated state of the moist air was introduced, then a new sectional one-dimensional model was developed with a detailed derivation. A prototypic apparatus was set up and the reliability of the model was validated by the experimental study. When predicting the outlet solution temperature and outlet moist air wet bulb temperature, the relative errors would be more pronounced with a bigger heat and mass transfer driving potential, but they would not exceed 3.59% and 9.54% respectively under the experimental conditions. The simplifying assumptions, the ignored heat and mass transfer at cyclone region and the measuring errors are mainly blamed for the predicted errors. An in-depth heat and mass transfer investigation was conducted with the help of the validated model by studying the profiles of humidity ratio and moist air dry bulb temperature. The proposed model succeeded in capturing the state transformation of the air flow along the axis of the tower and the effects of the operating parameters on the process profiles are discussed.

Recirculation over complex terrain

AbstractThis study generated eddy covariance data to investigate atmospheric dynamics leeward of a small, forested hillside in upstate New York. The causes and effects of recirculation eddies were examined to support the larger goal of improving measurement of the exchange of energy, moisture, and trace gases between the terrestrial biosphere and the atmosphere over complex terrain. Sensors operated at five different altitudes on two separate towers—one at the top of the hill and one down the slope to the east—for approximately 8 weeks in the spring of 2013. During the experiment, the vertical potential temperature gradient was found to be the primary factor for determining whether winds interacting with the terrain features caused a recirculating eddy leeward of the hill. The study found evidence that the recirculation influenced carbon dioxide flux and caused the air column to be vertically well mixed.

Data mining and clustering in chemical process databases for monitoring and knowledge discovery

Modern chemical plants maintain large historical databases recording past sensor measurements which advanced process monitoring techniques analyze to help plant operators and engineers interpret the meaning of live trends in databases. However, many of the best process monitoring methods require data organized into groups before training is possible. In practice, such organization rarely exists and the time required to create classified training data is an obstacle to the use of advanced process monitoring strategies. Data mining and knowledge discovery techniques drawn from computer science literature can help engineers find fault states in historical databases and group them together with little detailed knowledge of the process. This study evaluates how several data clustering and feature extraction techniques work together to reveal useful trends in industrial chemical process data. Two studies on an industrial scale separation tower and the Tennessee Eastman process simulation demonstrate data clustering and feature extraction effectively revealing significant process trends from high dimensional, multivariate data. Process knowledge and supervised clustering metrics compare the cluster results against true labels in the data to compare performance of different combinations of dimensionality reduction and data clustering approaches.

Lightning protection of overhead transmission lines using external ground wires

In this paper, a new kind of overhead transmission line (OHL) lightning protection system based on external ground wires is analyzed. Instead of a standard ground wire, two ground wires placed at the top of separate external towers located at both sides of the protected line are used. This type of protection should be applied in specific circumstances for protection of short OHL sections which are highly endangered by lightning. The distance between external protection system and OHL is calculated by using EMTP-ATP. Calculations are performed in order to avoid flashovers from the point where lightning strikes the external protection system to the protected OHL. A rolling sphere method is used to calculate the height of external ground wires above OHL phase conductors to avoid shielding failures. An experiment in a high voltage laboratory is performed to verify the dimensions of the external protection system from the aspect of shielding failures. According to the results of simulation and experiment, the optimal dimensions of the external protection system are determined.

3D Modeling of the Tower Head Based on ObjectARX

Elliptical head is an important standard part of the separation tower equipment. It can not be generated by tensile method, rotation method, because the rotation axis can not pass region. This paper introduces the ObjectARX programming environment. It describes how to build the menu and the dialog box. ObjectARX is a secondary development tool of AutoCAD. With its function and its mechanical drawing once learned, four arcs of ellipse can be used to build 3d modeling of head.of tower equipment. The ObjectARX programming technology is applied to develop AutoCAD, making it more convenient to darw the professional 3d graphics.

Novel scrubbing system for post-combustion CO2 capture and recovery: Experimental studies

Power plant emissions of flue gas to the atmosphere releases considerable CO2 which is considered to be the main contributor to global warming. Several gas absorption techniques are being investigated to reduce the capital and operating costs for CO2 capture from post-combustion flue gas. Conventional method of CO2 capture by an aqueous solution of monoethanolamine (MEA) and its subsequent stripping in a separate tower with steam at 120°C is highly energy intensive. The low partial pressure of CO2 in the flue gas inhibits the application of CO2-selective membranes unless methods are employed to increase the CO2 partial pressure in the flue gas to be treated. An absorption–stripping technique to potentially bypass the shortcomings of many existing approaches is described here. Bench-scale CO2 capture and recovery from simulated flue gas with and without moisture was demonstrated using an advanced hollow fiber membrane contactor. This was achieved by the use of a novel non-volatile absorbent, consisting of the ionic liquid [bmim][DCA] containing 20wt% polyamidoamine (PAMAM) dendrimer Gen 0. We have employed a simulated humidified flue gas containing around 14% CO2 and demonstrated successful removal of bulk of the CO2 and its recovery in a CO2-concentrated stream; the CO2 concentration achieved in the stripper out stream was ~92vol%. An estimate of the overall volumetric mass transfer coefficient (Kla) for the current CO2-IL-PAMAM Gen 0 system has been obtained.

Dynamic Analysis of the Double Tower Connected Structure under Earthquake Action

The mechanical behavior research on double tower connected structure under earthquake action is more and more important gradually with wide application of high-rise building connected structures in the engineering field. Structure stress and deformation become extremely complicated due to connected structure, thereby the paper adopts two kinds of different analysis software for simulation of simplified model and system comparative analysis on a project example of one double tower connected structure, single tower separate calculation and double tower connected integral calculation are respectively conducted, structure dynamic features under the earthquake action is comparatively analyzed, the influence of connected structure on tower integral structure vibration mode, displacement and period is analyzed, thereby obtaining some conclusions beneficial for project design as references.

Experimental study on wind loading on a complicated group-tower

This paper studied how wind pressures and forces affect rigid sectional models of a complicated group-tower using experimental wind tunnel tests. The group-tower was composed of five separate sub-towers with different diameters and heights. The basic characteristics of the mean and fluctuating wind pressure distributions on typical parts of the sub-towers were analyzed along the heights of each sub-tower, and their distribution trends are discussed. Also, the mean base shear and moment coefficients and their characteristics are presented. The wind pressure and wind force results showed that because the group-tower structure consisted of five separate lofty towers, the mutual aerodynamic interferences were serious; thus, the mean and fluctuating wind pressure, wind force distributions and the mean base shear and moment coefficients were quite complicated.

Spin dynamics between two BECs of magnons in superfluid 3He-B coupled via a channel

We present the results of a study of the interaction between two Bose-Einstein condensates of magnons i.e. homogeneously precessing domains (HPDs) created simultaneously in two separate towers joined together by a channel. The interaction between these two HPDs was provided by a common domain wall established and placed in the channel. Preliminary results show that the spin precession waves excited on the domain wall in one HPD are dragged by spin supercurrents flowing through the channel towards to the second HPD; and the frequency of these incoming waves depends on the velocity of this spin flow. This seems to be a signature of an analogue of the Doppler effect on the spin precession waves, similar to that known in acoustics or hydromechanics.

The endogranitic tin zone, Mount Pleasant, New Brunswick, Canada and its metallogenesis

The Mount Pleasant Sn–W–Mo deposits occur within the margin of an eroded caldera underlain by a Devono–Mississippian intrusive-subvolcanic-eruptive complex of granitic, porphyritic and felsic pyroclastic rocks. The separate North and Fire Tower mineralised zones are centred in volcanic necks defined by hydrothermal breccias within this complex. The oldest of three successive granites in both Zones hosts W–Mo mineralisation, whereas the two younger granites in the North Zone contain various Sn deposits. One of these, the endogranitic tin zone, is an irregular but generally tabular body hosted within a distinctive, highly evolved phase of the third, and youngest granite.The endogranitic tin zone was formed by successive stages of sericitisation, chloritisation/topazification-silicification, brecciation, dense chloritisation-topazification and late replacement. It contains quartz, chlorite, topaz, fluorite, cassiterite, arsenopyrite, base metal sulphides, pyrite, stannite, wolframite, native bismuth, molybdenite, kaolinite and carbonates. The ore minerals occur about equally in veinlets and disseminations. Cassiterite was deposited in all stages, but more abundantly during brecciation and particularly during dense chloritisation-topazification where it accompanies a distinctive, avocado-green, Fe-rich chlorite. The host, endogranitic tin zone granite, has undergone significant depletions and enrichments in major and minor elements.Fluid inclusions indicate that the chloritised/topazified-silicified rock formed from early, low salinity dominantly meteoric fluids at ∼200–225°C. Later, saline, magmatic-hydrothermal fluids, probably differentiated in the upper part of the endogranitic tin zone granite, mineralised the brecciated and densely chloritised-topazified rocks at similar temperatures. Latest low salinity meteoric fluids formed the late replacement bodies at 175–185°C. Sn was deposited under acidic conditions at oxygen fugacity of 10−39–10−34 atm from dominant SnCl20 and SnF+ complexes due to fluid oxidation and neutralisation, and cooling.Endogranitic tin zone cassiterite has a trace element signature that is intermediate between that of cassiterite from deep-seated greisens and pegmatites, and shallower cassiterite–sulphide and Bolivian porphyry–tin ores. The late replacement cassiterite, however, is high in Nb, Ta, Ti and Fe, and thus has a pegmatitic signature. This, together with their size and distribution within the endogranitic tin zone and elsewhere in the complex, suggests that the late replacement bodies are aborted pegmatites formed when the magmatic-hydrothermal fluids became largely diluted by the late meteoric fluids. Wood tin and colloform cassiterite contain abundant Fe, resembling wood tin in the high-level topaz rhyolites and Russian subvolcanic tin deposits. Sphalerite contains abundant In, as do other high-level, stanniferous polymetallic ores. The endogranitic tin zone at Mount Pleasant appears to be unique, differing from both greisen– and porphyry–tin deposits and no close analogues are known elsewhere.

Spatial and temporal variability in forest–atmosphere CO2 exchange

AbstractSeven years of carbon dioxide flux measurements indicate that a ∼90‐year‐old spruce dominated forest in Maine, USA, has been sequestering 174±46 g C m−2 yr−1 (mean±1 standard deviation, nocturnal friction velocity (u*) threshold >0.25 m s−1). An analysis of monthly flux anomalies showed that above‐average spring and fall temperatures were significantly correlated with greater monthly C uptake while above‐average summer temperatures were correlated with decreased net C uptake. Summer months with significantly drier or wetter soils than normal were also characterized by lower rates of C uptake. Years with above‐average C storage were thus typically characterized by warmer than average spring and fall temperatures and adequate summer soil moisture.Environmental and forest–atmosphere flux data recorded from a second tower surrounded by similar forest, but sufficiently distant that flux source regions (‘footprints’), did not overlap significantly showed almost identical temperature and solar radiation conditions, but some differences in energy partitioning could be seen. Half‐hourly as well as integrated (annual) C exchange values recorded at the separate towers were very similar, with average annual net C uptake differing between the two towers by <6%. Interannual variability in net C exchange was found to be much greater than between tower variability. Simultaneous measurements from two towers were used to estimate flux data uncertainty from a single tower. Carbon‐flux model parameters derived independently from each flux tower data set were not significantly different, demonstrating that flux towers can provide a robust method for establishing C exchange model parameters.

Computational Fluid Dynamics Investigation of the Hydraulic Behaviour of the Roman Inverted Siphon System at Aspendos, Turkey

The hydraulic characteristics of the 3rd century ce Roman inverted siphon system at Aspendos is subject to analysis using modern computational fluid dynamics methods. The 1·67 km long siphon consists of a header basin, two separate elevated tower open basins and a receiving basin all interconnected by long piping segments. The receiving basin distributes water to the fountains, baths and housing structures of the ancient city of Aspendos. Based upon the Roman text of Vitruvius, transient pressure wave phenomena occurring during siphon start-up, if not counteracted by hydraulic and structural defensive design measures, can lead to pipeline breakage. The present study examines the hydraulic behaviour of the Aspendos siphon during start-up and steady state conditions for both impulsive and slow-filling water supply conditions. By revealing the underlying hydraulic behaviour of the siphon, the meaning of Vitruvius' text statements concerning siphon operation, albeit in prescientific terminology, can be interpreted in light of the computed physical behaviour of the system. Analysis results indicate that impulsive siphon start-up is characterized by fluid column oscillations in all siphon branches downstream of the header basin. Depending upon the internal wall roughness of the piping and the filling rate, oscillations can vary in periodicity and amplitude before being damped by fluid friction effects. Slowing the siphon infilling rate (as Vitruvius advises) is shown to reduce start-up oscillatory behaviour and reduce forces on the piping. The presence of the elevated tower open basins is shown to limit oscillations from propagating into the downstream branches of the siphon, i.e., the tower basins act as accumulators to dampen the transmission of fluid column oscillations and pressure waves past the first leg of the siphon. Several suggestions as to the enigmatic meaning of the term colliquiaria with respect to siphon operation are investigated to attempt to recover Vitruvius' original meaning.