Energetic and exergetic investigation of a mixed flow dryer: A case study of maize grain drying

In this paper the resource-constrained flow shop (RCF) problem is addressed. A number of realistic extensions are incorporated, including non-serial precedence requirements, mixed flow shop situations, and the distribution of the human workforce among a number of pre-determined groups. The RCF is then solved by meta-heuristics, primarily of the evolutionary type. An extensive numerical investigation, including a case study of a particular industrial situation, details the implementation and execution of the heuristics, and the efficiency of the proposed algorithms.

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Case Study of Multi-Stage Impeller with Guidevane

Volume 2: Fora ◽

10.1115/fedsm2005-77294 ◽

2005 ◽

Author(s):

Takuji Tsugawa

Keyword(s):

Velocity Ratio ◽

Optimum Shape ◽

Hydraulic Efficiency ◽

Mixed Flow ◽

Shape Factors ◽

Flow Angle ◽

Multi Stage ◽

Absolute Flow ◽

Specific Speed

In the previous paper, the optimum meridian profile of impeller was obtained for various specific speed by means of eight shape factors, that is, inlet relative flow angle β1, turning angle Δβ, axial velocity ratio kc = Cm2/Cm1, impeller diameter ratio kd = D1c/D2c, outlet hub-tip ratio ν2, tip solidity σtimp, mid span solidity σcimp and hub solidity σhimp. In this paper, the optimum meridian profile of multi-stage impeller with guidevane was obtained by means of twelve shape factors. The additional four shape factors are guidevane tip solidity σtgv, mid span solidity σcgv, hub solidity σhgv and coefficient of peripheral velocity at impeller inlet or guidevane outlet kCu1c. In the optimum method, the hydraulic efficiency and suction specific speed are calculated by diffusion factor. In the optimum condition, the best hydraulic efficiency or the best suction specific speed is obtained. In the cyclic flow condition of multi-stage impeller with guidevane, the absolute flow velocity of guidevane outlet is equal to that of impeller inlet, and the diameter of guidevane outlet is equal to that of impeller inlet. In this calculation, the diameter of impeller outlet is equal to that of guidevane inlet. The total calculation number of case study is very large, so the number of each parameter is about between four and seven. The best 1000 optimum meridian profiles and the best design parameter are selected for few kinds of specific speed using twelve dimensional optimum method. As the result of this calculation, the optimum meridian profile of multi-stage impeller and guidevane. The more detailed optimum multi-stage mixed flow impeller and guidevane profile is drawn. For, example, the 1000 specific speed is selected for case study of multi-stage mixed flow impeller. At first, the approximate optimum shape factors are present shape factors. And the optimum shape factors which have better efficiency are tried to find near the present shape factors. Then the study of shape factor changes is the objective of this paper.

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Case Study of Impeller Profile Considering Additional Parameters

Volume 3 ◽

10.1115/ht-fed2004-56059 ◽

2004 ◽

Author(s):

Takuji Tsugawa

Keyword(s):

Velocity Ratio ◽

Stream Line ◽

Mixed Flow ◽

Shape Factors ◽

Flow Angle ◽

Turning Angle ◽

Calculation Time ◽

Specific Speed ◽

Stream Lines

In the previous paper, the optimum meridian profile of impeller was obtained for various specific speed by means of five shape factors. In this paper, the optimum meridian profile of impeller is obtained by means of eight shape factors. The basic five shape factors are inlet relative flow angle β1, turning angle Δβ, axial velocity ratio kc = Cm2/Cm1 impeller diameter ratio kd = D1c/D2c and outlet hub-tip ratio ν2 (β1 and Δβ are in mid span stream surface). The additional three parameters are three stream lines solidity (tip solidity σt, mid span solidity σc, and hub solidity σh). The blade length of impeller meridian profile is able to obtain by additional three parameters. The method of optimization is the calculation of hydraulic efficiency and suction specific speed in all combinations of eight shape parameters. The number of five shape factors are expressed by Nβ1, NΔβ, Nkc, Nkd, Nν2. The number of calculations is expressed by Nβ1 × NΔβ × Nkc × Nkd × Nν2. For example, Nβ1 = NΔβ = Nkc = Nkd = Nν2 = 40, the number of calculations is about 100000000. The calculation time is about 2 hours. The best parameters are selected in 100000000 cases. In case of eight shape factors, the number of calculation is Nβ1 × NΔβ × Nkc × Nkd × Nν2 × Nσt × Nσc × Nσh. Nβ1 = NΔβ = Nkc = Nkd = Nν2 = Nσt = Nσc = Nσh = 10, the number of calculation is 100000000. In this case, the calculation time of eight shape factors is as same as that of five shape factors. By means of this method, the more detailed optimum mixed flow impeller meridian shape is obtained. In case study, the best 1000 optimum meridian profiles and the best design parameter are selected for few kinds of specific speed using eight dimensional optimum method. In the previous paper, the mixed flow angle on tip meridian stream line isn’t able to be decided by this optimization using diffusion factor. But, in this paper, the mixed flow angle is able to be decided by the number of blade and optimum solidity. As the best solidity of three stream lines is obtained, the axial coordinates of impeller inlet and outlet are obtained. The more detailed optimum mixed flow impeller meridian shape is drawn.

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Evaluation of the Properties and Usefulness of Ashes from the Corn Grain Drying Process Biomass

Energies ◽

10.3390/en13051290 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1290 ◽

Cited By ~ 1

Author(s):

Grzegorz Zając ◽

Grzegorz Maj ◽

Joanna Szyszlak-Bargłowicz ◽

Tomasz Słowik ◽

Paweł Krzaczek ◽

...

Keyword(s):

Toxic Elements ◽

The Other ◽

Waste Biomass ◽

Drying Process ◽

Corn Cobs ◽

Corn Husk ◽

Grain Drying ◽

Maize Grain ◽

Corn Grain ◽

Corn Grains

The paper presents the results of a study on chemical composition of ashes from three types of waste biomass in terms of fertilizer usefulness. Waste from the process of corn grain drying, including corn cobs, corn grains and corn husk and their mixtures in the ratio 4:1 (v/v) were examined. The study proved that corn grain was the material with the highest concentration of macroelements among those studied (P—21,452 ppm, K—25,970 ppm, S—5911 ppm) and the mixture of corn cobs with corn grains (Ca—81,521 ppm). When microelements were considered, the highest concentration was recorded for corn cobs (Cu—207 ppm, Mn—844 ppm, Zn—857 ppm) and corn husk (Fe—15,100 ppm). The analysis of toxic elements in the ashes of the biomass studied showed their highest concentration in corn husk ash (Ni—494 ppm, Cr—301 ppm, Pb—42.7 ppm, As—4.62 ppm). The analysis showed that regardless of the type of biomass studied, all ashes were strongly enriched (in relation to the average soil content) with phosphorus and corn husk ash with calcium in particular. A slight enrichment in copper and lead was recorded for all ashes, and moderate or low for the other elements. It was found that the examined ashes from biomass, which is a residue from the drying of maize grain, have a high fertilizer usefulness.

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Relation between surface temperature and dryer operation

Research in Agricultural Engineering ◽

10.17221/14/2008-rae ◽

2008 ◽

Vol 54 (No. 4) ◽

pp. 176-182

Author(s):

I. Vitázek ◽

J. Tirol

Keyword(s):

Surface Temperature ◽

Production Process ◽

Technological Process ◽

The State ◽

Quick Response ◽

Vertical Layer ◽

Unfavourable Effect ◽

Grain Drying ◽

Medium Flow ◽

Maize Grain

The most significant way of grains conservation is heat drying. This technological process is regarded as a part of the production process with such commodities as grain maize, grain sunflower, rape, and other oil plants. The paper presents partial results of a check measurement on MC 3180 dryer with descending vertical layer in drying grain maize. On the basis of the evaluation of the measured parameters of the drying medium and the analysis of thermovision camera screenshots together with applying the knowledge of the mechanics of wet air, insufficiencies in the dryer operation were revealed and specified. Significant diferences in surface temperatures of the dryer casing were caused by its silting up, which had an unfavourable effect on the drying medium flow throug the layer of the dried material. The analysis of the state of the drying medium was done using i-x diagram of wet air. The presented knowledge allows for a quick response to an improper operation of the dryer and ensuring the efficiency of grain drying.

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Evaluating the Options in Urban Areas with Financial Constraints

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198196151800110 ◽

1996 ◽

Vol 1518 (1) ◽

pp. 48-56

Author(s):

Patrick Decorla-Souza ◽

Jerry Everett ◽

Brian Gardner ◽

Michael Culp

Keyword(s):

Urban Areas ◽

Financial Constraints ◽

General Purpose ◽

Highway Capacity ◽

Mixed Flow ◽

Policy Makers ◽

Infrastructure Investments ◽

New Infrastructure

Logic is devised for a needs test for new general-purpose lane (GPL) highway capacity in urban areas that have limited funding available for new infrastructure investments. GPL capacity is defined as mixed-flow lanes on which both single-occupant and high-occupancy vehicles are permitted. Methodologies to apply the needs test and to evaluate the options in urban areas facing limitations on new GPL capacity are developed. A case study is used to demonstrate the methodologies to evaluate the air quality and cost-effectiveness impacts of transportation system alternatives, illustrating how planners may develop the type of information that policy makers will need to help them make informed decisions about long-term options.

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