The article presents the problems of determining the mass efficiency of a rotary feeder depending on the selection of design parameters of the device, such as outer diameter, number of blades and ...rotational speed of the rotor. The hitherto theoretical methods of calculating the feeder efficiency were presented, as well as a new method of determining the device operation parameters was proposed. For this purpose, the numerical Discrete Element Method was used, which allowed simulating the transport of limestone powder in a cell feeder with various design variants. The results of the tests showed that the above design parameters affect the instantaneous efficiency of the feeder and thus impact the distribution of the dosed material during the operation of the device. Depending on the design solution, the simulation results gave information on the fill factor of the feeders. The study showed a significant potential of DEM simulation in the design of circular feeders intended for dosing bulk materials.
From year to year, the agricultural sector of the economy of the Russian Federation is faced two tasks: the first is harvesting grain crops at a short stated agrotechnical time, and the second – to ...preserve the quality of food and seed grains until the moment of product sale or sowing. One of the most effective ways to preserve the quality of food and seed grains is its cleaning and sorting. They are performed by pneumatic sorting tables of periodic and continuous operations type. In our country, the most common types of tables are PSS-0.2, PSS-2.5, PS-10, TDV 150. They have a classic scheme of pneumatic systems, vibration tables with decks and their drive mechanisms. Their disadvantages include the impossibility of uniform grain supply and increased threshing at the outlet due to the lack of grain supply devices in the hoppers, which reduces the quality of cleaning and sorting. To eliminate the identified shortcomings, we have developed, manufactured and tested a pneumatic sorting table with a rotary feeder. At first, the best type of rotary grain feeder was specified, which turned out to be a three-bladed rotary feeder with a grain supply of 0.45 kg/s and a non-uniformity of supply of 12.5%. Then, comparative studies were carried out for the chosen type of rotary feeder and the quality indicators of the technological process were determined. We compared the developed pneumatic sorting table, equipped with a three-blade rotary feeder, to the base table PSS-0.2. It was found that when cleaning the grain of winter soft wheat of "Lgovskaya 8" variety (thousand grain weight — 46.4 g, moisture content — 14.2%, and density — 1.6 g/cm3), the studied device reduces the grain crushing by 0.06 % and non-uniformity of supply (11.5%). Also, it increases the laboratory and field germination (2% and 5%, respectively), the content of the most valuable output groups III and IV by 21.2% with a slight decrease in supply by 0.01% and productivity per hour of main operating time 0.04 t/h Thus, the possibility of using the rotary feeder in pneumatic machines is proved.
The analysis of resource-saving technologies of cultivation and refinement of agricultural crops confirmed that the use of PSS pneumatic sorting tables allows to somewhat reduce the costs of cleaning ...and sorting. However, the imperfection of their designs and uneven grain supply reduces the effectiveness of their use. Therefore, the purpose of the research was to improve the quality of post-harvest processing of grain crops, the development of a rotary feeder. To achieve this goal, research methods and techniques have been developed. A pneumatic sorting table equipped with a three-blade rotary feeder with an outer diameter of 80 mm with straight blades located at an angle of 120 degrees has been developed. The process of grain flow motion in the hopper was studied and dependencies were established to determine grain motion in the hopper, the time of grain motion in the area under consideration and the speed of grain motion at the exit from the hopper, which was 1.167 m/s. The equations of motion of the blades for the outer and inner diameter of the rotary feeder are established, according to which the actual coordinates of their motion and displacement of the shaft axis of the rotary feeder from its original position are calculated. Calculations have determined that with an outer diameter of 0.08 m of the rotary feeder, grain velocity of 1.02 m/s, an angular velocity of 2.9 s-1, the displacement of the shaft axis of the rotary feeder from its original position at a 360 degree rotation angle will be 160 mm. This will reduce the unevenness of grain supply, and grain shattering, increase laboratory and field germination, improve the content of the output groups of full-fledged grain and, consequently, improve the quality of post-harvest processing of grain crops by a developed pneumatic sorting table equipped with a three-blade rotary feeder.
The past two decades have seen a surge in applications of concentrated solar power (CSP) technology. The generation of solar-fuels, such as hydrogen, via CSP-thermal receiver/reactor technology has ...progressed from large scale demonstration to preliminary commercial venture. Solar receiver/reactors vary widely, and one of the distinguishing characteristics between reactors is the way in which reactants are introduced into the high-temperature reaction environment. Here, we focus on gravity-driven feeding of solid-particle reactants via hoppers and metering splines which can be employed for solar-thermochemical dissociation of metal oxides during continuous or batch processing. This relatively simple method can provide consistent and uniform reactant flow with high durability and low maintenance. We present experiments and analysis of gravity feeding of solid particles for CSP applications, focusing on the case study of 1–5μm ZnO powder at mass flow rates of 0–2g/s. ZnO powder feeding is facilitated by adding vibration to the hopper followed by metering past a rotating spline, and delivered via gravity to an ultra-high temperature reaction cavity comprised of inclined alumina tile reaction surfaces. This paper will address hopper and spline design, feed rate characterization and modeling, particle residence time, and the effect of moisture and hopper vibration on the effective delivery of ZnO powder to the thermochemical reactor.
Display omitted
•A novel powder feeder was built and tested for a solar-thermochemical reactor.•The rotating-spline powder feeder delivers ZnO powder without clogging or stalling.•Precise feeding of 1–5μm ZnO particles was achieved in the range of 0–2g/s.•A correlation was obtained for feed-rate vs. the spline's rotational speed.•The non-linearity of feed-rate vs. RPM was described by a fourth-order polynomial.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
5.
Lithium technologies for edge plasma control Sergeev, Vladimir Yu; Kuteev, Boris V.; Bykov, Aleksey S. ...
Fusion engineering and design,
October 2012, 2012-10-00, 20121001, Volume:
87, Issue:
10
Journal Article
Peer reviewed
► We have investigated two new modes of operation been in T-10 limiter tokamak experiments with a novel rotary feeder of lithium dust. ► The observed decreases of bolometer and Dβ signals, with ...increase of the electron density during the lithium dust injection, reveal the effects of the first wall conditioning. ► The lithium technology may provide inherent safety mission for major disruption mitigation in a tokamak reactor, which requires demonstration in contemporary tokamak experiments.
We have investigated two new modes of operation been in T-10 limiter tokamak experiments with a novel rotary feeder of lithium dust. Quasi steady-state mode I and pulse mode II of dust delivery were realized in both OH and OH+ECRH disruption free plasmas at the lithium flow rate up to 2×1021atoms/s. A higher flow rate in mode II with injection rate of ∼5×1021atoms/s caused a series of minor disruptions, which was completed by discharge termination after the major disruption. The observed decreases of bolometer and Dβ signals, with increase of the electron density during the lithium dust injection, reveal the effects of the first wall conditioning. The lithium technology may provide inherent safety pathway for major disruption mitigation in a tokamak reactor, which requires demonstration in contemporary tokamak experiments.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper presents the fundamentals of designing and manufacturing a rotary feeder for feeding plastic moulded Tee 90°. This feeder consists of an inclined rotating disc and revolving bowl. The ...parts are metered from a prefeeder on this inclined rotating disc. The disc carries the parts to the rim of the rotating bowl in a single lane due to the centrifugal forces. Fixed mechanical qualifiers orient and qualify the parts. Improperly oriented parts are ejected from the rim to the disc for recirculation. Properly oriented parts moved out of the rim and out of the feeder. They are carried by a horizontal belt conveyor for coding by laser. The aims of the research is to design and manufacture a rotary feeder with the capacity up to 200 parts per minute. In addition, the feeder is capable of performing at very low noise levels, feeding parts reliable and efficient, and improving the work environment for the operator.
Abstract
Rotary feeders are one of the most widely used devices for regulating the flow of powdered and granular solid materials from storage facilities such as hoppers, silos, bins and bunkers. In ...this paper the performance characteristics of such feeders are examined, from both model and experimental standpoints, with a view to enhancing understanding of the operation of these devices. Through understanding the way in which materials flow through the inlet port and into the rotor pockets a model is developed that describes how the feed rate varies with the rotor speed. Experimental work confirms the general form of the characteristics predicted by the model studies. An approach is developed for predicting the feed rate characteristics when handling free-flowing materials having particle sizes greater than 5 mm. Further work is necessary to predict these characteristics when handling materials have particles smaller than this size.
This chapter concentrates on the feeding of solids arrangements for pneumatic conveying systems. Feeding is a crucial component of these systems and can be handled in a variety of ways. There are ...many unique feeders which makes classifying them difficult since each manufacture has modified feeders to make them uniquely theirs. One can use the term pressure, vacuum and pressure-vacuum to describe feeders as well as low, medium and high pressure operations. This chapter describes the operation and control of a wide spectrum of feeders employed in industry.
Full text
Available for:
FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
