Detection of flow of seeds in the seed delivery tube and choking of boot of a seed drill

2018 ◽  
Vol 153 ◽  
pp. 266-277 ◽  
Author(s):  
Rajeev Kumar ◽  
Hifjur Raheman
Keyword(s):  
Delivery Tube

scholarly journals Properties of PTFE tape as a semipermeable membrane in fluorous reactions

2015 ◽  
Vol 11 ◽  
pp. 980-993 ◽  
Author(s):  
Brendon A Parsons ◽  
Olivia Lin Smith ◽  
Myeong Chae ◽  
Veljko Dragojlovic
Keyword(s):  
Surface Tension ◽  
Organic Compounds ◽  
Polymer Films ◽  
Semipermeable Membrane ◽  
Reaction Vessel ◽  
Dimethyl Phthalate ◽  
Delivery Tube ◽  
Selective Permeability ◽  
Solvent Uptake ◽  
Solvent Adsorption

In a PTFE tape phase-vanishing reaction (PV-PTFE), a delivery tube sealed with PTFE tape is inserted into a vessel which contains the substrate. The reagent diffuses across the PTFE tape barrier into the reaction vessel. PTFE co-polymer films have been found to exhibit selective permeability towards organic compounds, which was affected by the presence of solvents. In this study, we attempted to establish general trends of permeability of PTFE tape to different compounds and to better describe the process of solvent transport in PV-PTFE bromination reactions. Though PTFE tape has been reported as impermeable to some compounds, such as dimethyl phthalate, solvent adsorption to the tape altered its permeability and allowed diffusion through channels of solvent within the PTFE tape. In this case, the solvent-filled pores of the PTFE tape are chemically more akin to the adsorbed solvent rather than to the PTFE fluorous structure. The solvent uptake effect, which was frequently observed in the course of PV-PTFE reactions, can be related to the surface tension of the solvent and the polarity of the solvent relative to the reagent. The lack of pores in bulk PTFE prevents solvents from altering its permeability and, therefore, bulk PTFE is impermeable to most solvents and reagents. However, bromine, which is soluble in liquid fluorous media, diffused through the bulk PTFE. A better understanding of the PTFE phase barrier will make it possible to further optimize the PV-PTFE reaction design.

Modeling of Flow Fields of Different Delivery Chamfers in Spray Forming Process

2014 ◽  
Vol 789 ◽  
pp. 554-559
Author(s):  
Yang Liu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Wen Yong Xu
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Metal Flow ◽  
Spray Forming ◽  
Operating Pressure ◽  
Delivery Tube ◽  
Forming Process ◽  
Atomization Process ◽  
Sharp Point

The computational fluid dynamic (CFD) software was used to calculate the velocity field in atomization chamber of spray forming equipment. The relationship between melt flow rates, gas aspiration of the atomizer and operating pressure are complex, and the above mentioned parameters are closely related to the atomization process. The influences of different delivery chamfers on gas flow field, which is determined by atomizer structure, were analyzed. Using K-epsilon model with a symmetrical domain, the gas dynamic of different delivery chamfer conditions were investigated. The results indicate that the sharp point of delivery tube causes detachment of flow field, and 56°, 45° and 34° chamfer conditions have same diffusion angle. Gas was aspirated from delivery tube when chamfer was 0°, which is beneficial to liquid metal flow in atomization process.

scholarly journals A Comparison of Two Heated Water-Bath Humidifiers

1975 ◽  
Vol 3 (1) ◽  
pp. 41-47 ◽  
Author(s):  
C. A. Shanks ◽  
J. M. Gibbs
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Absolute Humidity ◽  
Water Bath ◽  
Delivery Tube ◽  
Artificial Airway ◽  
Heated Water ◽  
Heating Wire ◽  
Selection Of ◽  
Independent Heat

The performance of two heated water-bath humidifiers was examined in terms of airway temperatures and humidities. These were the simple heated tank [Marshall and Spalding, 1953) and the Fisher and Paykel No. 328 (Spence and Melville, 1972), both of which had the potential to deliver gases at temperatures above 40°C, and with a moisture content in excess of 50 mg/litre. The major advantage of the No. 328 was its heating wire in the delivery tube. This lessened or prevented condensation within the tube, and allowed the water bath to be maintained at lower temperatures. Independent heat controls for the water bath and the delivery tubing allow precision of humidities in the gases provided for inspiration through an artificial airway. When condensation is prevented, the temperature of the saturated gases leaving the humidifier limits the absolute humidity supplied. Monitoring and adjustment of airway temperature of the patient then allows selection of temperature and relative humidity in the inspired gas.

scholarly journals Pressure Distribution around the Melt Delivery Tube for a Confined-type Gas Atomization Nozzle

1996 ◽  
Vol 82 (8) ◽  
pp. 665-670 ◽  
Author(s):  
Tadashi FUKUDA ◽  
Mutsuo NAKANISHI ◽  
Toshihiko KUBO
Keyword(s):  
Pressure Distribution ◽  
Gas Atomization ◽  
Delivery Tube ◽  
Atomization Nozzle

MORTALITY OF ADULT GRAIN BEETLES IN SAMPLE DELIVERY SYSTEMS USED IN TERMINAL GRAIN ELEVATORS

1977 ◽  
Vol 109 (2) ◽  
pp. 209-213 ◽  
Author(s):  
J. M. Bryan ◽  
J. Elvidge
Keyword(s):  
Delivery Systems ◽  
Tube Length ◽  
Cryptolestes Ferrugineus ◽  
Oryzaephilus Surinamensis ◽  
Insect Infestation ◽  
Delivery Tube ◽  
Mortality Pattern ◽  
Grain Elevators ◽  
Grain Beetles ◽  
L 22

AbstractThe detection of insect infestation by the Canadian Grain Commission is decreased in efficiency by the mortality of adult beetles in the pneumatic sample delivery systems used in terminal elevators in the Vancouver, B.C., area. Dead insects are difficult to see while grading the grain and cannot be extracted by Berlese funnels.The level of mortality varied with the species of beetle and the system tested, but not with the type of grain. In one system the following mortalities were found: Cryptolestes ferrugineus (Stephens), 73%; Oryzaephilus surinamensis (L.), 65%; Tribolium castaneum (Herbst), 65%; and Sitophilus granarius (L.), 22%. C. ferrugineus, the most important insect infesting Canadian grain, sustained an average mortality of 55% in the five systems tested. No consistent mortality pattern was found among the systems with respect to delivery tube length, number of turns, or approximate grain speed. Berlese funnel extraction was found to be inefficient for O. surinamensis and inconsistent for S. granarius.

Numerical Analyses of Fluid Dynamics of an Atomization Configuration

2002 ◽  
Vol 17 (1) ◽  
pp. 156-166 ◽  
Author(s):  
Q. Xu ◽  
D. Cheng ◽  
G. Trapaga ◽  
N. Yang ◽  
E.J. Lavernia
Keyword(s):  
Gas Flow ◽  
Fluid Dynamic ◽  
Flow Behavior ◽  
Ambient Pressure ◽  
Delivery Tube ◽  
Compression Waves ◽  
Pressure Region ◽  
High Kinetic Energy ◽  
Dynamic Techniques ◽  
Liquid Delivery

Computational fluid dynamic techniques were used to analyze the gas flow behavior of a typical atomization configuration. The calculated results are summarized as follows. The atomization gas flow at the atomizer's exit may be either subsonic at ambient pressure or sonic at an underexpanded condition, depending on the magnitude of the inlet gas pressure. When the atomization gas separates to become a free annular gas jet, a closed recirculating vortex region is formed between the liquid delivery tube and the annular jet's inner boundary. Upon entering the atomization chamber, an underexpanded sonic gas flow is further accelerated to supersonic velocity during expansion. This pressure adjustment establishes itself in repetitive expansion and compression waves. A certain protrusion of the liquid delivery tube is crucial to obtain a stable subatmospheric pressure region at its exit. The vortex flow under the liquid delivery tube tends to transport liquid metal to the high kinetic energy gas located outside the liquid delivery tube, thereby leading to an efficient atomization.

Confined Gas Atomization: The Role of the Melt Delivery Tube in Particle Size Control

1986 ◽  
Vol 80 ◽  
Author(s):  
R. V. Raman
Keyword(s):  
Unique Feature ◽  
Size Control ◽  
Lower Surface ◽  
Spherical Particles ◽  
Gas Atomization ◽  
Reactive Elements ◽  
Delivery Tube ◽  
Atomization Process ◽  
Rapidly Solidified

AbstractGas atomization is one of the key processes used for the production of rapidly solidified materials. The unique feature of the gas atomization process is its capability to form spherical powders of multicomponent alloys containing reactive elements. Spherically shaped powder is specified in the secondary processing operations used in a number of applications. This requirement has resulted from the higher flow rate, better packing density, and lower surface area obtained in spherical particles compared to irregularly shaped particles.

ODOR Artifacts of an Olfactometer Evoke a Cer in the Rat

1972 ◽  
Vol 35 (3) ◽  
pp. 931-936 ◽  
Author(s):  
Richard G. Davis ◽  
Jack T. Tapp
Keyword(s):  
Food Reward ◽  
Complete Suppression ◽  
Water Delivery ◽  
Delivery Tube ◽  
Unavoidable Shock

Rats were trained to lick for food reward on a water delivery tube. Odor stimuli which preceded an unavoidable shock produced complete suppression of the licking while the equivalent air stimulus without the odor present did not disrupt the licking. When the odor was removed from the olfactometer, the rats suppressed partially to the air stimuli delivered from the previously odorized olfactometer.

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