Continuous Generation of Millimeter-Sized Glycine Crystals in Non-Seeded Millifluidic Slug Flow

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 412 ◽  
Author(s):  
Mingyao Mou ◽  
Huayu Li ◽  
Bing-Shiou Yang ◽  
Mo Jiang
Keyword(s):  
Slug Flow ◽  
Crystallization Process ◽  
Secondary Nucleation ◽  
Flow Rates ◽  
Aspect Ratios ◽  
Cooling Crystallization ◽  
Primary Nucleation ◽  
Continuous Generation ◽  
Inner Diameter ◽  
Air Streams

Millimeter-sized α-glycine crystals were generated from continuous non-seeded cooling crystallization in slug flow. The crystallization process is composed of three steps in sequence: slug formation, crash-cooling nucleation, and growth. Stable uniform slugs of three different aspect ratios (slug length/tubing inner diameter) were formed, by adjusting the flow rates of both the solution and air streams. Besides supersaturation, the slug aspect ratio can also affect primary nucleation outcome. Stable slug flow can accommodate a relative supersaturation (C/C*) of up to 1.5 without secondary nucleation. Large glycine crystals can grow to millimeter size within 10 min, inside millimeter-sized slugs without reducing the slug quality.

A Novel Design of Heat Exchanger for Epsom Salt Cooling Crystallization

2014 ◽  
Vol 881-883 ◽  
pp. 1505-1508
Author(s):  
Ai Qun Zhang ◽  
Yan Fei Wang
Keyword(s):  
Heat Exchanger ◽  
Crystallization Process ◽  
Salt Lake ◽  
Secondary Nucleation ◽  
Primary Nucleation ◽  
Metastable Zone ◽  
Cooling Media ◽  
Novel Design ◽  
Salt Lake Brine ◽  
Epsom Salt

We introduced a design of a novel cooling heat exchanger for crystallization process of MgSO4.7H2O, and described the concepts of primary nucleation and secondary nucleation. To avoid the primary nucleation during crystallization process, the super-cooling degree limit of the salt lake brine was measured to define the supersaturation limit to MgSO4.7H2O, and the result is 1.32°C at-1°C. In this design, a primary circulation of solution is employed with a large enough flow rate to control the super-cooling degree of solution not to exceed 0.7 °C. A secondary circulation of cooling media is designed to add to this system, instead of the coldest cooling media being fed to shell directly, it is fed to the circulation pipe of the shell. It will help to prevent the supersaturation of solution exceeding the metastable zone width, thus to gurantee no primary nucleation during the Epsom salt crysatllization process.

scholarly journals Differential Sorting of Microparticles Using Spiral Microchannels with Elliptic Configurations

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 412
Author(s):  
Kaan Erdem ◽  
Vahid Ebrahimpour Ahmadi ◽  
Ali Kosar ◽  
Lütfullah Kuddusi
Keyword(s):  
Cell Sorting ◽  
Microfluidic Channel ◽  
Major Axis ◽  
Label Free ◽  
Flow Rates ◽  
Inertial Focusing ◽  
Size Dependent ◽  
Curved Channels ◽  
Aspect Ratios ◽  
Dependent Cell

Label-free, size-dependent cell-sorting applications based on inertial focusing phenomena have attracted much interest during the last decade. The separation capability heavily depends on the precision of microparticle focusing. In this study, five-loop spiral microchannels with a height of 90 µm and a width of 500 µm are introduced. Unlike their original spiral counterparts, these channels have elliptic configurations of varying initial aspect ratios, namely major axis to minor axis ratios of 3:2, 11:9, 9:11, and 2:3. Accordingly, the curvature of these configurations increases in a curvilinear manner through the channel. The effects of the alternating curvature and channel Reynolds number on the focusing of fluorescent microparticles with sizes of 10 and 20 µm in the prepared suspensions were investigated. At volumetric flow rates between 0.5 and 3.5 mL/min (allowing separation), each channel was tested to collect samples at the designated outlets. Then, these samples were analyzed by counting the particles. These curved channels were capable of separating 20 and 10 µm particles with total yields up to approximately 95% and 90%, respectively. The results exhibited that the level of enrichment and the focusing behavior of the proposed configurations are promising compared to the existing microfluidic channel configurations.

The Varieties of Scrubbers, Tubing, and Tubing Connectors

2018 ◽  
pp. 221-231
Author(s):  
John R. B. Lighton
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Correct Selection ◽  
Flow Rates ◽  
Intended Application ◽  
Metabolic Measurement ◽  
Air Streams ◽  
Selection Of ◽  
Selective Membranes

This chapter discusses several often-neglected areas of respirometry infrastructure. These include the correct selection of scrubber chemicals for removing water vapor and/or carbon dioxide from air streams, without undesirable interactions; chemical-free scrubbing techniques such as selective membranes, thermal condensing systems, and mathematical correction for water vapor dilution; selecting tubing for metabolic measurement; evaluating the different tubing chemistries in light of the intended application; selecting appropriate tubing diameters for the flow rates that will be used; selecting tubing connectors; maintaining connector gender conventions to minimize plumbing confusion; and other related topics.

scholarly journals Erosion–Corrosion of 30°, 60°, and 90° Carbon Steel Elbows in a Multiphase Flow Containing Sand Particles

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3898 ◽  
Author(s):  
Rehan Khan ◽  
Hamdan H. Ya ◽  
William Pao ◽  
Armaghan Khan
Keyword(s):  
Carbon Steel ◽  
Slug Flow ◽  
Surface Characterization ◽  
Corrosion Mechanism ◽  
Surface Imaging ◽  
Flow Loop ◽  
Erosion Corrosion ◽  
Inner Diameter ◽  
Corrosion Pits ◽  
Microscopic Surface

Erosion–corrosion in flow changing devices as a result of sand transportation is a serious concern in the hydrocarbon and mineral processing industry. In this work, the flow accelerated erosion–corrosion mechanism of 90°, 60°, and 30° long radius horizontal–horizontal (H–H) carbon steel elbows with an inner diameter of 50.8 mm were investigated in an experimental closed-flow loop. For these geometrical configurations, erosion–corrosion was elucidated for erosive slug flow regimes and the extent of material degradation is reported in detail. Qualitative techniques such as multilayer paint modeling and microscopic surface imaging were used to scrutinize the flow accelerated erosion–corrosion mechanism. The 3D roughness characterization of the surface indicates that maximum roughness appears in downstream adjacent to the outlet of the 90° elbow. Microscopic surface imaging of eroded elbow surfaces disseminates the presence of corrosion pits on the exit regions of the 90° and 60° elbows, but erosion scars were formed on the entry regions of the 30° elbow. Surface characterization and mass loss results indicated that changing the elbow geometrical configuration from a small angle to wide angle significantly changed the mechanical wear mechanism of the tested elbows. Moreover, the maximum erosive location was identified at the top of the horizontally-oriented elbow for slug flow.

Controlling the Size of Taurine Crystals in the Cooling Crystallization Process

2013 ◽  
Vol 52 (37) ◽  
pp. 13449-13458 ◽  
Author(s):  
Ruohui Lin ◽  
Meng W. Woo ◽  
Cordelia Selomulya ◽  
Jianping Lu ◽  
Xiao Dong Chen
Keyword(s):  
Crystallization Process ◽  
Cooling Crystallization

scholarly journals The Metastability and Nucleation Thresholds of Ibuprofen in Ethanol and Water-Ethanol Mixtures

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Abdur Rashid ◽  
Edward T. White ◽  
Tony Howes ◽  
James D. Litster ◽  
Ivan Marziano
Keyword(s):  
Water Content ◽  
Propanoic Acid ◽  
Secondary Nucleation ◽  
Metastable Zone Width ◽  
Zone Width ◽  
Primary Nucleation ◽  
Metastable Zone ◽  
The Times ◽  
Induction Times ◽  
Supersaturated Solutions

To investigate the crystallization of ibuprofen [((RS)-2-(4-(2-methylpropyl) phenyl) propanoic acid)] from ethanol and water-ethanol mixtures it is necessary to know the nucleation limits of its solutions. In the absence of crystals, nucleation will seldom occur below the PNT (primary nucleation threshold). If crystals are present, nucleation will seldom occur until below the lower SNT (secondary nucleation threshold). Below the SNT, crystals will still grow with negligible nucleation. PNT and SNT values (expressed as relative supersaturationσ) have been measured at 10, 25, and 40°C for ibuprofen in ethanol and in a range of mixtures of different ethanol (E)/water (W) ratios. The induction times were determined from observing the times to nucleate for a range of different supersaturated solutions at a given temperature andE/Wratio. As expected, lowering the supersaturation leads to longer induction times. In ethanol, the SNT values are small and thus the secondary metastable zone width (MSZW) is relatively narrow with a 1 h SNT relative supersaturation typically aboutσ~ 0.05. The 1 h PNT values are much larger with values forσaround 0.3. In aqueous ethanolic mixtures at 25°C, both the PNT and SNT decrease as the water content increases.

Sensitivity of Slug Flow Mechanistic Models on Slug Length

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Cem Sarica ◽  
Hong-Quan Zhang ◽  
Robert J. Wilkens
Keyword(s):  
Slug Flow ◽  
Gas Flow ◽  
Model Development ◽  
Unified Model ◽  
Mechanistic Models ◽  
Flow Rates ◽  
Fluid Properties ◽  
The Common ◽  
Pipe Geometry ◽  
Probabilistic Nature

Slug flow is one of the common flow patterns in gas and oil production and transportation. One of the closure relationships required by the multiphase flow mechanistic models is slug length correlation. There are several closure relationships proposed in the literature as function of pipe geometry, pipe diameter, and inclination angle, and to a lesser extent to the flow rates and fluid properties. In this paper, we show that most of the frequently used mechanistic models are insensitive to slug length information. The only exception to this is identified as the Zhang et al. (2003, “Unified Model for Gas-Liquid Pipe Flow via Slug Dynamics—Part 1: Model Development,” ASME J. Energy Resour. Technol., 125, pp. 266–272). The unified model shows sensitivity at high gas flow rates, while displaying a negligible sensitivity at low gas flow rates. In conclusion, the slug length closure relationship is not crucial for pressure loss and holdup calculations. It can be speculated that the success of the unit cell slug flow modeling approach could be attributed to insensitivity of the models to slug length considering the highly probabilistic nature of the slug length.

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