scholarly journals Development and Identification of Working Parameters for a Lychee Peeling Machine Combining Rollers and a Pressing Belt

2019 ◽  
Vol 1 (4) ◽  
pp. 550-566 ◽  
Author(s):  
Le ◽  
Nguyen ◽  
Pham ◽  
Ly ◽  
Le ◽  
...  
Keyword(s):  
Experimental Data ◽  
Rotation Speed ◽  
Tangential Force ◽  
Static Friction ◽  
Gap Size ◽  
Operational Parameters ◽  
Length Width ◽  
Working Principle ◽  
Post Harvesting ◽  
Working Parameters

This work describes the development, design, and parameter identification of a lychee peeling machine. The working principle of the machine combines two rollers with a pressing belt to separate the peel from the fruits. It was designed and its operational parameters identified on the basis of experimental data on the Thieu lychee, which currently covers about 80% of the plantation area in Vietnam. To this end, the first step was to measure the physical characteristics of the fruits, such as size, shape, and density. Moreover, the coefficient of static friction between lychees and rubber rollers, and the critical peeling force, were identified, with a view to optimizing the operational parameters later on. Results showed that a minimum tangential force of 10.5 N is needed to break the peel and separate it from the pulp. Based on the balanced force principle, various optimal machine parameters such as roller rotation speed, roller diameter, roller length, gap size between the two rollers, belt velocity, and minimum pressure of the belt were calibrated. In addition, spiral grooves were created on the roller surface to facilitate the motion of the fruits. The optimal results were roller size 900 × 100 mm (length × diameter), rotation speed 159 RPM, gap size between rollers 4 mm, belt size 850 × 60 mm (length × width), belt pressure 13.5 N, and belt velocity 140 mm/s. Using the design and operational parameters mentioned above, the machine was able to perform regularly at a throughput of 100 kg/h, as demanded by the current market. Moreover, it would be easily feasible to combine multiple pairs of rollers and pressing belts in order to increase throughput. The methodology for the design of this peeling machine and identification of working parameters with respect to experimental data could be applied in many other post-harvesting configurations.

Simulation on Extrusion Comminution Model of Roller Press

2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Field Experiments ◽  
Size Ratio ◽  
Optimum Operating ◽  
Extrusion Force ◽  
Particle Size Ratio ◽  
Small Constant ◽  
Working Parameters ◽  
The Relationship

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.

scholarly journals The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component

10.14311/450 ◽  
2003 ◽  
Vol 43 (4) ◽  
Author(s):  
P. Hasal ◽  
I. Fořt ◽  
J. Kratěna
Keyword(s):  
Experimental Data ◽  
Spectral Analysis ◽  
Tangential Force ◽  
Low Frequency ◽  
Frequency Component ◽  
Relative Magnitude ◽  
Tangential Component ◽  
Vertical Position ◽  
Total Force ◽  
Rushton Turbine

Experimental data obtained by measuring the tangential component of the force affecting radial baffles in a flat-bottomed cylindrical mixing vessel stirred with a Rushton turbine impeller is analysed. Spectral analysis of the experimental data demonstrated the presence of its macro-instability (MI) related low-frequency component embedded in the total force. Two distinct dimensionless frequencies (both directly proportional to the impeller speed of rotation N) of the occurence of the MI component were detected: a lower frequency of approximately 0.025N and a higher frequency of about 0.085N. The relative magnitude QMI of the MI-related component of the total tangential force was evaluated by a combination of proper orthogonal decomposition (POD) and spectral analysis. The values of magnitude QMI varied in the interval [rom approximately 0.05 to 0.30. The magnitude QMI takes maximum values at low Reynolds number values (in laminar and transitional regions). In the turbulent region (ReM >20000) the QMI value is low and practically constant. The dependence oj the QMI values on vertical position in the vessel is only marginal. The results suggest that the magnitude of the MI component of the force is significantly influenced by the liquid viscosity and density.

scholarly journals DETERMINATION OF PHYSICAL AND ENGINEERING PROPERTIES OF TIGER NUT (Cyperus esculentus) RELEVANT TO ITS MECHANIZATION

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Tega A Emurigho ◽  
Canice O.O Kabuo ◽  
Arinze N Ifegbo
Keyword(s):  
Moisture Content ◽  
Static Friction ◽  
Major Axis ◽  
Angle Of Repose ◽  
Engineering Properties ◽  
Cyperus Esculentus ◽  
Mean Values ◽  
Principal Axes ◽  
Length Width ◽  
The Mean

The physical and engineering properties of fresh and dried tiger nut (Cyperus esculentus) were determined at moisture content of 41.20% and 16.40% on wet basis respectively. The mean values for the three principal axes (length, width and thickness) were 9.52mm, 8.16mm, and 8.16mm for fresh tiger nut and 9.14mm, 7.72mm and 8.03mm for dried tiger nut respectively, showing a decrease with decrease in moisture content and was significantly different at p?0.05. The mean values of the bulk density, true density and porosity of both fresh and dried tiger nut were 0.59g/cm3 , 0.97g/cm3 , 40.61 and 0.58g/cm3, 0.94g/cm3 , 40.35 respectively and were not significantly different at p?0.05. The mean angle of repose and coefficient of static friction over formica, stainless steel, glass and plywood surfaces of fresh tiger nut were 50.11o , 2.73, 2.45, 2.22 and 1.77 while that of dried tiger nut were 48.23o , 2.41, 2.03, 2.11 and 2.00 respectively. The mean rupture force increased with compression force of 90.08N on the major axis to 116.88N for fresh tiger nut and from 120.55N to 161.10N for dried tiger nut and were significantly different at p?0.05. These properties determined are necessary in the design and fabrication of hoppers, conveyor equipment and the force tiger nut can withstand before it is ruptured.

On the Static-Kinetic Friction Transition in Dry Contact of Rough Surfaces

2011 ◽  
Author(s):  
K. Farhang ◽  
D. Segalman ◽  
M. Starr
Keyword(s):  
Large Scale ◽  
Rough Surfaces ◽  
Tangential Force ◽  
Static Friction ◽  
Partial Slip ◽  
Small Scale ◽  
Asperity Contact ◽  
Kinetic Friction ◽  
Tangential Load ◽  
Asperity Contacts

This paper shows that the Mindlin problem involving two spheres in contact under the action of oscillating tangential force can lead to the account of static-kinetic friction transition. In Mindlin’s problem two spheres experience partial slip as a result of application of oscillating tangential load. When the problem is extended to multi-sphere contact, i.e. two rough surfaces, the application of tangential oscillating load results in partial slip for some asperity contacts while others experience full slip. Increase in the amplitude of the oscillating tangential force results in more contacts experiencing full slip, thereby decreasing the number of contacts in parial slip. Constitutive relation proposed by Mindlin at small scale, governing asperity interaction, is used to obtain the large scale slip function through a statistical summation of asperity scale events. The slip function establishes the fraction of asperity contact in full slip. The complement of the slip parameter is a fraction of asperities in partial slip. Through slip function it is shown that it is possible to define a slip condition for the entire surface. The derivation of the slip function allows the account of transition between static friction and kinetic friction.

ROTATION OF THE AXISIMMETRIC DIELECTRIC BODIES (DEB) IN ELECTRORHEOLOGICAL SUSPENSIONS (ERS)

1996 ◽  
Vol 10 (23n24) ◽  
pp. 2903-2915 ◽  
Author(s):  
ZINOVIY P. SHULMAN ◽  
VALERIY NOSOV
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Rotation Speed ◽  
Electrophysical Properties ◽  
Engineering Applications ◽  
Dielectric Bodies ◽  
Electrorheological Suspensions

Consideration is given to rotation of nonconducting bodies in electrorheological suspensions. Experimental data are presented describing the effect of an electric field on the rotation speed as well as on rheological and electrophysical properties of ERS. The dependence of speed on temperature and the rotor geometry is considered in some detail. Two examples of engineering applications are presented.

scholarly journals Study on some engineering attributes of pine nut (Pinus pinea) to the design of processing equipment

2010 ◽  
Vol 56 (No. 3) ◽  
pp. 99-106 ◽  
Author(s):  
S.M.T. Gharibzahedi ◽  
V. Etemad ◽  
J. Mirarab-Razi ◽  
M. Fos hat
Keyword(s):  
Moisture Content ◽  
Geometric Mean ◽  
Seed Mass ◽  
Static Friction ◽  
Terminal Velocity ◽  
Angle Of Repose ◽  
Engineering Properties ◽  
Pine Nut ◽  
Length Width ◽  
Glass Surfaces

Moisture-dependent engineering properties of pine nut were studied at 6.3, 8.2, 10.8, 14.5, 18.9, and 20.1% moisture content (dry basis). The length, width, thickness, and geometric mean diameter increased significantly (P < 0.05) from 21.75 to 21.85 mm, 7.39 to 7.47 mm, 6.07 to 6.14 mm, and 9.89 to 9.98 mm, respectively, with an increase in moisture content from 6.3% to 20.1%, whereas the increase in sphericity from 45.49% to 45.69% was not significant. Similarly, thousand seed mass, true density, porosity, terminal velocity, and angle of repose increased (P < 0.05) from 0.85 to 0.93 kg, 1043.3 to 1071 kg/m3, 41.31% to 44.57%, 8.67 to 8.83 m/s, and 35.4° to 39°, respectively, with an increase in moisture content under the experimental condition. Moreover, the bulk density decreased significantly (P < 0.05) from 612.3 to 593.6 kg/m3. Coefficient of static friction increased (P < 0.05) from 0.251 to 0.292, 0.241 to 0.271, 0.227 to 0.262, and 0.218 to 0.247 on plywood, galvanized iron sheet, stainless steel, and glass surfaces, respectively, with an increase in moisture content from 6.3% to 20.1%.

The Variation of the Coefficient of Static Friction with the Rate of Application of the Tangential Force

1950 ◽  
Vol 163 (1) ◽  
pp. 176-184 ◽  
Author(s):  
R. C. Parker ◽  
W. Farnworth ◽  
R. Milne
Keyword(s):  
Hydraulic System ◽  
Normal Force ◽  
Tangential Force ◽  
Static Friction ◽  
Constant Rate ◽  
Dry Conditions ◽  
Mechanical Devices ◽  
Solid Bodies ◽  
Type Of Failure ◽  
Wire Resistance

The coefficient of static friction has been measured for a number of different materials under impact conditions. An analysis of the conditions of impact, derived from collision between solid bodies, and from a suitable hydraulic system, showed the latter to be the more convenient and equally effective method of applying tangential force. The method adopted consisted of feeding oil at a constant rate into an oil cylinder, the piston of which constituted the striking head. The friction members were so arranged that the struck member was in the form of a bar that was clamped between two massive plates. The normal force was applied hydraulically and the tangential force was measured by wire resistance strain-gauges. The static friction was measured for rates of application of the axial force up to 103 tons per sec. Under dry conditions the friction increased with the rate of applied force, an effect more pronounced between a non-metal and a metal than between metals. Lubrication with oil diminished the variation of friction with rate of application of force for all combinations of materials tested. The magnitude of this effect was sufficient to explain a type of failure commonly encountered with safety clutches, and similar mechanical devices.

On the Mechanics of Shear Spinning

1961 ◽  
Vol 83 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Serope Kalpakcioglu
Keyword(s):  
Experimental Data ◽  
Shear Strain ◽  
Specific Energy ◽  
Tangential Force ◽  
Metal Flow ◽  
Shear Strain Rate ◽  
Analytical Work ◽  
Spinning Process ◽  
Shearing Mechanism ◽  
Shear Spinning

With the use of an idealized model of the shear spinning process some of the basic quantities in the shearing mechanism have been defined and formulated, these being: shear strain, shear strain rate, specific energy, and tangential force (torque) in spinning. An experimental technique to study metal flow in shear spinning has been described. The results of analytical work have been compared with experimental data.

scholarly journals MODEL OF CALCULATIONS FOR EXPERIMENTALLY-OBTAINED GAS AND WATERPROOF SER-VICE LINE OPERATIONAL PARAMETERS

2020 ◽  
Vol 47 (1) ◽  
pp. 117-125
Author(s):  
О. I. Stepanov ◽  
Е. E. Zaitseva ◽  
S. A. Khudyakova
Keyword(s):  
Fire Departments ◽  
Calculation Methods ◽  
Operational Parameters ◽  
Return Trip ◽  
Air Supply ◽  
Complicating Factors ◽  
Experimental Justification ◽  
Limiting Parameters ◽  
Working Parameters ◽  
In Fire

Abstract. Aim. Modelling and calculations were were carried out to justify the tactical capabilities of gas and smoke protection units of the fire and rescue units as primary units carrying out fire reconnaissance and rescue of victim s of fires. A methodology for assessing actions of personnel of fire departments when rescuing victims was analysed.Method. An experimental justification is given for the need to adjust the calculation methods for determining the working parameters of gas and smoke protection units when organising mass rescue of victims of a fire. A model is proposed for considering the actions of the fireteam of a gas and smoke protection service based on graph theory. Various approaches to forecasting operational parameters of gas and smoke protection units in fire services are considered.Results. Factors determining the limiting parameters of the gas and smoke protection units are presented along with examples for calculating operational parameters during mass rescue of victims of a fire.Conclusion. A conclusion is formulated regarding complicating factors of the work of the personnel of the gas and smoke protection service in the coefficient, considering the necessary air supply for the return trip, unforeseen circumstances and average air flow.

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