A Study of Factors Affecting the Performance of Screw Conveyers and Feeders

Carleton, A. J.; Miles, J. E. P.; Valentin, Finn

doi:10.1115/1.3591565

Cited by 23 publications

(13 citation statements)

References 2 publications

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“…It means that the further increase of rotational speed causes a smaller increase in efficiency. Paper [3] shows the results of the experiments on the power demand of a screw conveyor. It was observed that in the case of not aerated materials (sand and gravel), the power demand increases proportionally to the rotational speed of the screw.…”

Section: Verification Of Theoretical Design Methods With •mentioning

confidence: 99%

Optimization of a screw conveyor's exploitation parameters

Karwat¹,

Rubacha²,

Stańczyk³

2021

Eksploatacja i Niezawodność – Maintenance and Reliability

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The paper describes the problem of designing screw conveyors in terms of determining their exploitation characteristics. Based on the actual values of mass efficiency and power demand obtained in a laboratory experiment, the theoretical design methods and the numerical discrete element method model results were verified. The obtained results have shown that the currently used theoretical methods underestimate the mass efficiency and power demand compared to experiments when typical values of filling rate coefficient and progress resistance coefficient are used. It was also shown that the results of DEM simulations are in good agreement with the experiments in terms of mass efficiency and power demand. Based on the exploitation characteristics determined in DEM simulations for different constructions of the screw and different rotational speeds, multi-objective optimization of the exploitation parameters of the screw was performed in order to minimize the power demand of a screw conveyor and simultaneously maximize its mass efficiency. The optimization results showed that it is possible to find such construction and the rotational speed that will maximize the mass efficiency of the conveyor and keep the power demand low, reducing the exploitation costs of the device.

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Section: Verification Of Theoretical Design Methods With •mentioning

confidence: 99%

Optimization of a screw conveyor's exploitation parameters

Karwat¹,

Rubacha²,

Stańczyk³

2021

Eksploatacja i Niezawodność – Maintenance and Reliability

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“…The use of augers in drilling is well known, though there is still a lot of empiricism in their design (Carleton et al, 1969). Augers generally work well when conveying dry, loose granular material over short distances and at high rpm; in turn, they do not work well at low rotational speeds and for small-diameter drills (ϳa few cm) (Mellor, 1981), i.e., parameters that are considered for extraterrestrial drilling.…”

Section: Removal Of Drilled Cuttingsmentioning

confidence: 99%

Drilling Systems for Extraterrestrial Subsurface Exploration

et al. 2008

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Drilling consists of 2 processes: breaking the formation with a bit and removing the drilled cuttings. In rotary drilling, rotational speed and weight on bit are used to control drilling, and the optimization of these parameters can markedly improve drilling performance. Although fluids are used for cuttings removal in terrestrial drilling, most planetary drilling systems conduct dry drilling with an auger. Chip removal via water-ice sublimation (when excavating water-ice-bound formations at pressure below the triple point of water) and pneumatic systems are also possible. Pneumatic systems use the gas or vaporization products of a high-density liquid brought from Earth, gas provided by an in situ compressor, or combustion products of a monopropellant. Drill bits can be divided into coring bits, which excavate an annular shaped hole, and full-faced bits. While cylindrical cores are generally superior as scientific samples, and coring drills have better performance characteristics, full-faced bits are simpler systems because the handling of a core requires a very complex robotic mechanism. The greatest constraints to extraterrestrial drilling are (1) the extreme environmental conditions, such as temperature, dust, and pressure; (2) the light-time communications delay, which necessitates highly autonomous systems; and (3) the mission and science constraints, such as mass and power budgets and the types of drilled samples needed for scientific analysis. A classification scheme based on drilling depth is proposed. Each of the 4 depth categories (surface drills, 1-meter class drills, 10-meter class drills, and deep drills) has distinct technological profiles and scientific ramifications.

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“…Total solid weight of 352 g/defecation (Including tissue paper) [24] Wet wt.% 110-170 g/cap/day [25] 250 and 111.3 g/ stool for men and women respectively were specified as 1 since it has been commonly found optimum in industrial practices [30].…”

Section: Refmentioning

confidence: 99%