Drum Speed Research Articles

DEVELOPMENT OF A FODDER BALES CHOPPER

The aim of the present study is to develop, construction and to evaluate the performance a fodder-bales chopper. The developed fodder-bales chopper consists of frame, chopper drum (cutting knives - hammers mills - cutting knives and hammers mills), feeding platform and feeding housing. Theoretical analysis was conducted to estimate the chopper shaft diameters so as to save it from over loads and high stresses. The studied performance factors are chopping-knives drum speeds 560, 750, 850 and 1040 rpm, number of knives is 84 for cutting knives and 77 for hammers and bale types (wheat and rice). The performance of the developed fodder bales chopper was evaluated in terms of average and percentage of cutting length, chopping efficiency, required power, energy requirements and operational cost. The main results can be summarized in the following points. The maximum machine productivity values were (785.5 and 830.7 kg/h), the maximum required power values were (20.86 and 22.64 kW), the maximum chopping efficiency values were (96.8 and 97.4%), the minimum average length of cut values were (2.6 and 1.54 cm). Mminimum operating cost values were 19.1 and 21.5 L.E/ton at wheat straw bale and rice straw bale, respectively by using combined knives with hammers at drum speed of 1040rpm.

Screening efficiency and rolling effects of a rotating screen drum used to process wet soft agglomerates

The rotating screen drums are largely used in most powder handling and processing industries. They are commonly used for size separation of granular materials. Objectives of the present work are to better understand both roles, screening efficiency and shaping effects and to investigate and model which process parameters are relevant when using an inclined rotating screen drum for processing wet couscous agglomerates. Durum wheat semolina was used as raw material to produce the wet agglomerates. The pilot rotating screen drum equipment was composed of two sieves to separate three fractions: fine, medium, and large agglomerates. The shaping effects of the rotating screen drum were evaluated from the measurements of the physico-chemical characteristics (size distribution, water content, compactness, and circularity) on wet soft agglomerates. To describe the screening efficiency parameters of a rotary screen drum, a specific method was developed by using a matrix analysis of the different measured weights of the collected products. The impacts of rotating screen drum parameters (angle of inclination, rotating speed, and product flow rate) on the sieving efficiency and on the shaping effects were investigated. The present results demonstrate high apparent screening efficiency of the rotating screen drum when used with wet agglomerates of durum wheat, ranging between 89 and 96% depending on the process conditions Finally, using dimensional analysis, two correlations were proposed on the circularity and the apparent screening efficiency whatever the operating conditions used (drum speed, angle of inclination and feed rate).

A new corrected formula to predict mean residence time of flexible filamentous particles in rotary dryers

The mean residence time of granular particles is one of the most crucial indexes in drying processes. In this paper, a new formula for correction of the mean residence time (MRT) is proposed, which includes the correlation among the MRT and the slope, number of flights and moisture content of particle. As a consequence, the results obtained by the new corrected formula agree well with the experimental. Then, a series of experiments is presented to describe the mean residence time and motion performance of flexible filamentous granular particles under different operating conditions. In order to meet the requirements of description properly on the residence time of granular particles, slope and rotational speed of drum, moisture content of particle at the inlet, mass flow rate of particles, and velocity of air flow are taken into account. Experimental results on flexible filamentous particles demonstrate that the mean residence time is significantly influenced by those parameters mentioned above. Moreover, the decrease of drum slope makes the mean residence time rise, and the increase of rotational speed results in the dropping of mean residence time. The reduction of mean residence time becomes slower with the faster increase of rotational speed. Moreover, the mean residence time climbs following the increase of moisture content and mass flow rate of particles at the inlet while experiences a slightly drop with the increase of air flow velocity.

Mathematical model of oriented planting of bulbs with bulb stem pointing downwards

Theoretical studies are carried out on the substantiation of design and technological parameters of vibration and pneumatic planting unit of a bulb-planting machine, and of a disc coverer with soil deflectors. The subject of research is the process of oriented planting and embedding of seed onion bulbs into soil. The article considers the process of bulbs orienting during planting and their orientation maintaining during interaction with the soil, taking into account the regularities of bulbs motion by means of vibrating chute and pneumatic drum, as well as the work of coverers during covering of bulbs with soil. The research is done on the basis of laws of classical mechanics and Lagrange's equations of the second kind. Theoretical studies of the working process of vibration and pneumatic planting unit of a bulb-planting machine are carried out. As a result, analytical dependences are obtained for determination of its design and operational parameters: the groove radius, the distance between chute and groove bottom, the diameter of suction opening, the rotation speed of pneumatic drum, the height of planting unit installation above the soil level. The studies allowed to determine: the condition of oriented embedding of bulbs into furrow with bulb stem pointing downwards; the analytical dependences for determining the trajectory of soil particles motion on the working surface of deflector of a disc coverer; the equation of soil particles motion after detachment from deflector’s surface, during covering with soil of bulbs oriented in furrow with bulb stem pointing downwards; the equations of relative, transfer and absolute velocities of soil particles. The expressions are obtained that allow to determine the technological parameters of disc coverer with soil deflectors: the forward velocity of disc coverer, the angle of attack, the center distance between discs.

Wpływ prędkości obrotowej bębna sitowego na proces wydzielania mas ziarna jęczmienia w urządzeniu rotacyjnym

Wpływ prędkości obrotowej bębna sitowego na proces wydzielania mas ziarna jęczmienia w urządzeniu rotacyjnym

MANUFACTURED AND EVALUATION OF CORN SHELLER SUITABLE FOR EGYPTIAN FARMER

A power-operated corn sheller was manufactured to investigate the effect of corn moisture content, drum rotary speed on the percentage of damaged kernels, undamaged kernels, losses of kernels as well as shelling efficiency and machine productivity. The experiments were conducted at four levels of kernels moisture content of 12,2, 13.3, 14.5and 16 % and four drum rotary speeds of 220 , 280, 340 and 400 rpm ( 23.02, 29.31, 35.9 and 41.9 m/s). The results indicated that, increasing drum speed lead to increase each of damaged kernels, losses kernels and machine productivity. On the other side, increasing drum speed tends to decrease the undamaged kernels and machine efficiency. The least value of damaged kernels (1.5%) and the highest values of undamaged kernels (98.5%) and machine efficiency (96.3%) were obtained at moisture content of 13.3%. While increasing moisture content lead to increase the losses kernels and decrease machine productivity.

Performance Evaluation of New Sugarcane Peeling Machine Prototype

The present investigation was carried out to develop and evaluate the performance of a new small-scale sugarcane peeler machine. The developed machine prototype was tested through real experiments carried out at a sugarcane private store in Kafrelsheikh province during 2014/2015 season. The experiments illustrated the effects of the main design and operating parameters, on the machinery performance and finished product quality. The investigated parameters included three different peeling drum brush types namely: zigzag, straight and spiral, four peeling drum speeds of 3.53, 5.30, 7.47 and 9.18m/s, three peeling drum clearances of 1.0, 1.5 and 2.0cm and three feeding rates of 3, 6 and 9 canes/min. The developed machine performance were evaluated in terms of: machine production efficiency, cane stalks peeling efficiency, peel retention on peeled stalks, cane stalks weight losses, machine power consumption and machine unit cost. The gained results revealed in general that using the zigzag peeling drum brush type tends to improve the peeling performance of the developed machine, compared to straight and spiral brush types. In addition, the obtained results indicated that, the maximum machine production efficiency (88.85%) and the minimum electrical power consumption (5.56kW), were achieved at peeling drum speeds of 9.18 and 3.53m/s, peeling drum clearance of 2cm and No. of feeding canes per minute of 3 canes, respectively. Moreover, the maximum peeling efficiency, the minimum cane stalks losses and the lowest percentage of the peel retention on peeled stalks were 91.40%, 3.02% and 2.46%, respectively. These percentages were recorded at peeling drum speed of 9.18m/s, peeling drum clearance of 1cm and 3 canes/min feeding rate. Also, the minimum machinery unit cost was 67.49LE/Mg at peeling drum speed of 3.53m/s, drum clearance of 1.5cm and 9 cans/min feeding rate.

Optimization Studies on a Multi-Gravity Separator Treating Ultrafine Coal

ABSTRACTThe present article outlines the tests carried out on an ultrafine coal sample collected from an operating washery using a multi-gravity separator (MGS) for its beneficiation. Influence of the most significant operational parameters of MGS, such as drum speed, tilt angle, and shaking amplitude, were varied for modelling and optimization purposes during the study to generate empirical correlations for prediction of yield and ash content with the help of a three-level Box-Behnken factorial design combined with response surface methodology (RSM). Equations of the second order were developed from response functions expressed as functions of these three operating parameters of MGS. The influence of the process variables of MGS on yield and ash content of the coal were presented as three-dimensional response surface graphs. Taking advantage of the mathematical-software-optimized levels of the process variables that have been determined as optimum levels to achieve the maximum yield of 61.3% and minimum ash of 17.5% product was predicted (from a feed ash of 33.5%). Further optimization test was carried out by targeting the minimum ash and yield product of above 60% and found a yield of 63.48% with an ash content of 17.25%.

Granular dynamics of cohesive powders in a rotating drum as revealed by speckle visibility spectroscopy and synchronous measurement of forces due to avalanching

We have used speckle visibility spectroscopy (SVS) and synchronized force measurements to compare the granular dynamics of two cohesive lactose powders, with Sauter mean diameters of ~29 and ~151μm, in a rotating drum. A load cell (LC) was used to measure forces on the drum mounting frame and enable monitoring of bulk powder motion; SVS is a dynamic light scattering technique particularly suited for studying dynamics in dense, non-ergodic granular systems. Our results reveal that surface slumping and intermittent collisional dynamics in the bulk of the bed are correlated, especially for the fine more cohesive particles (Geldart group C/A boundary), but not as much for the less cohesive larger particles (Geldart group A/B boundary). The specific dissipation energy of the particles in the drum is similar for both powders, and increases linearly with increasing drum speed. However, the dependencies of the load cell and SVS signals on rotation speed have opposing trends for these two powders, indicating different dissipation mechanisms for the different Geldart Groups; collisional dissipation is more important for the Geldart C/A powder, while for the Geldart A/B powder avalanche dissipation is dominant.

Estimation of retorted phosphor powder from spent fluorescent lamps by thermal process

The degree of thermal stabilization of phosphor powder from spent fluorescent lamps (SFLs) manufactured by three companies (A, B, C) was estimated by examining mercury content in phosphor powder with retorting time, retorting temperature and rotational speed of drum. Mercury content of phosphor powders from spent fluorescent lamps manufactured by A, B and C companies as samples in thermal experiments was 4031mg/kg, 3522mg/kg and 3172mg/kg, respectively. In the thermal experiments, the optimal conditions for retorting time, retorting temperature, and rotational speed were determined at 6h, 400°C, and 2.0rpm, respectively. With thermal processing at the optimal conditions, mercury content of all samples for retorted phosphor powder was less than 3.0mg/kg, while efficiency of thermal process to control mercury content was higher than 99.9%. Leaching tests such as Toxicity Characteristic Leaching Procedure (TCLP) and Korea Extraction Test (KET) were subsequently carried out to verify if retorted phosphor powder is hazardous waste. Leaching concentrations of mercury for all samples of retorted phosphor powder were satisfied with regulatory levels in both leaching tests. Hence, retorted phosphor powders at the optimal conditions are considered to be non-hazardous wastes.

Numerical analysis of mixing of particles in drum mixers using DEM

Mixing of particles in a rotating drum mixer with filling level greater than 50% has been analysed using Discrete Element Method (DEM). An attempt has been made to understand the mechanism of the dead zone formation and the degree of mixing by varying the mixing parameters. These include the size and packing of particles, speed and shape of the mixer, etc. While the formation of the dead zone is qualitatively analysed, the degree of mixing has been quantified with a suitable mixing index (ψ). It is found that packing arrangement and particle size significantly affect the formation of the dead zone, whereas, the drum speed and geometry has a relatively lesser effect. The effect of various parameters on the dead zone formation is explained on the basis of variation in energy distribution pattern from the wall towards the centre of the mixer. It has been found that the energy required for agitating the particles is transferred from the outer wall to the centre of the mixer. In the process of transfer, a significant amount of energy is expended before reaching the centre, which allows a compacted dead zone to form around the centre. A preliminary attempt has been also made to study mixing in a drum with baffles. The baffles act as the medium of efficient energy transfer by imparting their energy to the particles that come in contact with them thereby resulting in better mixing.

Application of artificial neural network to study the performance of multi-gravity separator (MGS) treating iron ore fines

ABSTRACTThe present article describes an attempt made to study the possibility of beneficiating low-grade iron ore fines of Barbil Area of Orissa state, India, using multi-gravity separator (MGS) after grinding the −10 mm fines to < 75 micron size and prepare a pellet feed of 65% Fe content. For the performance analysis, an artificial neural network (ANN) mathematical modeling approach was attempted. A three-layer feedforward neural network with a backpropagation method has been adopted, considering the three significant parameters of MGS, mainly drum inclination, drum speed, and shake amplitude, were varied and the results were evaluated for grade, recovery, and separation efficiency. The results of beneficiation studies showed that good recovery of hematite is possible with simultaneous increase in Fe(T) grade from 50.74% to 65.26% with 71.25% recovery. The predicted value obtained by ANN shows good agreement with the experimental values.

Effect of drying conditions on properties, pigments and antioxidant activity retentions of pretreated orange and purple-fleshed sweet potato flours.

Pigmented sweet potatoes (SPs) are outstanding sources of anthocyanin, β-carotene and other color-related phytonutrients. However, fresh SP roots are highly perishable and difficult to store. To reduce losses and extend their uses, fresh SP could be converted into flour. SP cultivars with deep purple (Phichit 65-3) and orange-fleshed (T101) colors newly developed in Thailand were studied. The influence of drying methods on physico-chemical properties, anthocyanin, β-carotene and antioxidant activity retentions of purple and orange-fleshed SP flours (SPFs) was investigated. Peeled purple and orange SPs were pretreated by blanching (100°C, 5sec) and soaking in 0.5% (w/v) sodium metabisulphite, then dried in either hot air oven at 50-80°C or steamed for 10min and placed to the drum dryer at 80-110°C and 3-7rpm drum speed. The drying processes significantly enhanced anthocyanin contents of SPFs by 1.8 to 3.8 times; however, there was a significant loss of β-carotene occurred during drying processes. Drum drying yielded SPFs with better color, higher total phenolic contents and antioxidant activity than the hot air drying. Pasting temperatures of hot air dried orange-fleshed SPFs (84-85°C) were slightly higher than those of purple-fleshed SPFs (80-83°C). Drum drying process produced pre-gelatinized (instant) SPFs as indicated by RVA and DSC results. The optimal conditions for drum dried and hot air dried SPF manufactured were 95°C at 5rpm and 70°C, respectively, based on anthocyanin, β-carotene, total phenolic, antioxidant activity, color retentions, and pasting properties.

Investigation of β phase formation in piezoelectric response of electrospun polyvinylidene fluoride nanofibers: LiCl additive and increasing fibers tension

As a piezoelectric polymer, poly (vinylidene fluoride) (PVDF) is attractive in energy conversion applications between electrical and mechanical forms because of its low cost, high flexibility, and biocompatibility. The piezoelectricity of electrospun PVDF polymer is due to changes in the crystalline structure (e.g., creating the β‐phase) during the electrospinning process. This research focuses on two approaches for investigation of β Phase formation: (1) addition of LiCl in different concentrations (0.001, 0.00133, 0.002, 0.004 wt%) as inorganic salt to the polymer solution, (2) increasing tension along the fiber axis by increasing the collector drum speed during the aligning process. Performances of these structures were evaluated by using X‐ray diffraction (XRD), Fourier Transform Infrared (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). A one‐step nano‐generator and cost‐effective package based on electrospun nanofibers was presented to measure output voltages as a performance factor. Results show that the addition of LiCl leads to β Phase formation in the crystalline structure, decreasing fiber diameter to 65 nm, and increment in the work of rupture and piezoelectric output. Moreover, the results show that increasing collector drum speed causes the alignment of β‐crystallites along the fiber axis and subsequently no considerable effect on the formation of β‐phases and output voltage. POLYM. ENG. SCI., 56:61–70, 2016. © 2015 Society of Plastics Engineers

MODELING OF PROTOTYPE FOR GINNING SODOM APPLE PLANT

Ginning process plays an important role in separating fibers from seeds, efficient ginning process provides farmers with viable and undestroyed seeds for plant type preservation and good fibers for textile processing. Due the great divergence in characteristics between sodom apple fibers and seeds and those of cotton, preliminary experiments showed that cotton ginning machines is incompatible with that able to gin sodom apple. Experiments were carried out with four drum speed, 1.05, 2.10, 3.15 and 4.20 m/s (100, 200, 300 and 400 r.p.m), concave clearances (0.005, 0.010, 0.015 and 0.020 m) and number of drums (one drum and two drums).Results showed that the two drums prototype at 0.005 m clearance and 4.20 m/s drum rotational speed was the optimal performing system as the productivity is 1.85 times that of one drum, seed damage, fiber losses percentage, energy requirements and criterion costs is decreased by 6.98, 13.32%, 48.69 % and 45% than that of one drum at the same operating conditions respectively. The dimensional analysis was reasonably accepted for predicting the separation time with coefficient of determination 0.96, that helps in producing large scale ginning machines.

THE REQUIRED ENERGY FOR CUTTING OPERATION OF SOME FIELD CROP RESIDUES

The performance of an experimental crop residues cutting machine has been investigated in this work in order to evaluate the energy requirements for cutting operation of three different crop residues (cotton stalks, corn stalks, and rice straw). The effect of cutting drum speed, knife edge angle and clearance distance on the machine productivity, fuel consumption, required power, specific consumed energy, cutting efficiency and the economical costs at optimum machine operation were, also, studied. The machine evaluated at five cutting drum speeds 1200, 1300, 1400, 1500 and 1600 rpm (8.29,8.98,9.68,10.37 and 11.06m/s); five knife edge angles (20°, 25°, 30°, 35° and 40°); and five clearance distance (1, 2, 3, 4 and 5mm). The results showed that the maximum cutting efficiency for cotton stalks (20.56% Mcwb),corn stalks (25.64% Mcwb), and rice straw (14.8% Mcwb) were 67.7%, 47.59,% and 62.75%, respectively, at 1600 rpm cutting drum speed, 20°knife edge angle, and 1mm clearance distance.

The effect of MWNTs concentration and nanofiber orientation on mechanical properties of PAA nanocomposite nanofibrous web

In this research, nanocomposite nanofibrous webs of poly(acrylic acid) (PAA)/multi‐walled carbon nanotubes (MWNTs) were obtained via electrospinning. The effect of MWNTs concentration on the morphology and mechanical properties of PAA/MWNTs nanofibers was investigated by changing the MWNTs content from 0 to 5 wt%. The results showed that average diameter of nanofibers increased with increasing the MWNTs concentration and presence of MWNTs led to the enhancement of mechanical properties. Also, the results revealed that the strength, modulus, and elongation at break of samples increased 3.22, 2.70, and 4.27 fold, respectively, after adding 3 wt% of MWNTs. In addition, the effect of rotating speed of collector on the orientation of PAA nanofibers and its effect on mechanical properties was investigated. Scanning electron microscopy (SEM) studies demonstrated that the degree of nanofibers orientation increased with the augmentation of drum speed to 25 rps. Moreover, the average nanofibers diameter decreased with the increase of drum speed. Improvement of nanofiber orientation resulted in superior mechanical properties that is, higher strength and modulus of aligned nanofiber layers were obtained in comparison to nonaligned layers (12.6 and 26.6 fold, respectively). POLYM. COMPOS., 37:3149–3159, 2016. © 2015 Society of Plastics Engineers

STUDY ON THE MECHANIZATION OF BEAN (Phaseolus vulgaris) CROP UNDER EGYPTIAN CONDITIONS

This study aimed to select the proper system of bean crop mechanization to achieve high yield, low grain losses with high field efficiency. The experiments were carried out using pneumatic planter and seed drill in planting operations in addition to the manual method, and tractor mounted mower was used in harvesting operation under different forward speeds and moisture contents compared to the manual method. Also, a Turkish threshing machine was used for threshing the crop at different drum speeds and seed moisture contents. From the obtained data it was concluded that; the pneumatic planter followed by tractor mounted mower and threshing by Turkish machine was considered the proper system for producing dry bean under Egyptian conditions, where as required minimum cost compared to the others. The seed moisture content of 14.86% and forward speed of 2.9 km/h were the proper conditions for harvesting dry bean crop. The threshing drum speed of 10.47m/s and seed moisture content of 11.33 % considered the proper values for threshing bean.

Evaluation of poly-disperse solid particles mixing in a slant cone mixer using discrete element method

There is a lack of sufficient knowledge regarding mixing of poly-disperse particles. Thus, the main objective of this study was to investigate the mixing of the bi-disperse, tri-disperse, and poly-disperse particles in the slant cone using the discrete element method. DEM results were validated using experimental data obtained from both sampling and image analysis techniques. The effects of initial loading scenarios, particle size, drum and agitator speeds on the mixing efficiency were explored. The mixing metric was utilized to measure the mixing quality for the different mixtures. The mixing index increased to a maximum value and decreased slightly before reaching a plateau for bi-disperse particles for different loading methods and 15rpm drum speed as a direct result of the trajectory segregation of the particles with different sizes. The highest mixing index for bi-disperse particles was achieved for top–bottom smaller-to-larger initial loading and 45rpm drum speed. The mixing quality of the bi-disperse particles was improved by the rotation of the agitator compared to that achieved with the stationary agitator at the fill level of 100%. The highest mixing indices were achieved for the tri-disperse and poly-disperse particles under the top–bottom smaller-to-larger loading method at the drum speed of 15 and 55rpm, respectively.

DEVLOPMENT AND PERFORMANCE EVALUATION OF LOCAL SUNFLOWER THRESHER

The present study was conducted to develop a threshing unit for a sunflower thresher. Experiments were carried out to evaluate the developed thresher at drum speeds of 400, 500 and600 rpm (8.36, 10.79 and 12.54 m/sec) and four levels of moisture content 10.2, 12.5, 15 and 18.7 %. The performance was evaluated in terms of output seed damage, undamaged seeds, threshing losses, threshing efficiency and cleaning efficiency. The lowest seed damaged and threshing losses of 2.6 and 3.25 % were obtained at drum speed of 400 rpm (8.36 m/sec) and moisture content of 10.2 %. The highest undamaged seeds, threshing efficiency and machine productivity of 97.4, 94.15 % and 306.12 kg/h respectively were obtained at drum speed of 600 rpm and moisture content of 10.2 %.