STRENGTH ANALYSIS OF SCREW CONVEYOR DRIVE

The present paper deals with research of strength characteristics in manufacturing engineering. The introduction of the work describes findings about the importance of the given subject. The publication is divided into two basic parts, namely the theoretical and the practical part. The theoretical part provides a detailed description of theoretical assumptions on solutions in the field of research, and it also describes optimization of structural units in manufacturing engineering, while the practical part analyses strength characteristics of the selected structural unit which is the drive of a manufacturing machine. The conclusion of the work presents the obtained results.

Consume Power Torque and Conveyor energy efficiency for a Horizontal Screw Conveyor with three different Screw Flight –A Comparison

Material handling cost plays crucial role in any manufacturing industries. A judicious selection of material handling system or equipment can only help to enhance productivity and thereby increasing profitability of an industry. Extensive studies require for establishing cost effective solution related to selection of right handling system. The objective of work is to find out running cost associated with screw type horizontal conveyor through experimental investigation of consume power and associated torque against three different types of screw flight(Continuous, Ribbon and Cut Flight) of same nominal diameter and pitch while keeping conveying distance as constant with same material at different screw speed. The experiment was conducted against two different trough heights for finding out mass flow rate. The consume power, torque and conveying energy efficiency calculated with three different screw flight and the results were compared for analysis. Hence on the basis of experimental results, conclusion was drawn. Present work confirming experimentally that the consume power at conveyor shaft and torque in case of ribbon flight was found to be 10 percent less than that of the continuous screw type of same nominal diameter, pitch and helix angle with same range of speed against single conveying material type in case of both the trough height(112 mm and 180 mm), which was in line with the statement made earlier[6]. In addition to that a trial has been made to establish a comparison in terms of consume power in between ribbon and cut flight against a constant trough height, which was not reported earlier. This comparative study may be helpful for taking decision in selecting material handling equipment type for specific application area. Now a day overall energy consumption becomes serious concern for different industries.

Study on the Mechanical Characteristics of the Screw Driving Torque during the Emptying of the Shield Soil Bin

This article studies the changing law of the driving torque of the screw conveyor during the emptying process of the earth pressure balance shield chamber. First, the discrete element method of discrete medium theory and 3D software SolidWorks were used to create the research object and the screw conveyor model, and then the model parameters were determined and calibrated through numerical calculations and indoor experiments. The final numerical calculation results show that: 1) the screw torque will drop in waves with the increase of the calculation time. When the screw conveyor rotates at 360 deg/s, the calculated screw torque fluctuation amplitude is small; 2) when the number of particles in the soil bin is reduced to a certain extent, the use of a higher screw speed to improve the “dumping soil effect” is of little significance; 3) the negative exponential function can be used to better fit the decrease of screw torque with time; 4) for the bulk medium, for a given particle size and screw structure, there is a suitable speed, so that the effect of “machine-soil collision” is small, and the torque change of the screw is relatively stable.

Effect of bentonite slurry on the function of foam for changing the permeability characteristics of sand under high hydraulic gradients

During earth pressure balance (EPB) shield tunnelling in sandy ground, not only foam but also other conditioning agents need to be injected to reduce the permeability of muck and avoid water spewing out of the screw conveyor. Permeability tests were carried out to study the permeability characteristics of conditioned sand under high hydraulic gradients. A low bentonite slurry injection ratio (BIR) enhanced the workability of foam-conditioned sand. As the hydraulic gradient increased, the initial permeability coefficient of conditioned sand increased, and the initial stable period became shorter or disappeared. The BIR had a more significant effect on the permeability of conditioned sand than the foam injection ratio (FIR), and this effect gradually weakened as the hydraulic gradient increased. The initial permeability coefficient of the foam-bentonite slurry-conditioned sand decreased by approximately an order of magnitude compared with that of the foam-conditioned sand. With the addition of bentonite slurry, suitable sand conditioning can accept a higher water content (w) and lower FIR, resulting in suitable ranges of w and FIR that are more flexible. Finally, the mechanism of stabilizing foam under the action of bentonite slurry was discussed by considering the interaction between foam bubbles and fine particles.

Perancangan Alat Pembuangan Abu Pada Gasifier Sistem Kontinu Berbahan Bakar Tongkol Jagung

Abstrak Indonesia membutuhkan energi alternatif yang berpeluang besar untuk dikembangkan pemanfaatannya, salah satunya adalah energi biomassa yang berasal dari jagung. Pada penelitian sebelumnya sudah dirancang dan dibuat sistem gasifikasi kontinu, tetapi masih terdapat kekurangan pada pemisahan abu setelah pembakaran. Tujuan dari penelitian ini adalah untuk merancang sistem pemisah abu pada sistem gasifikasi kontinu sehingga didapatkan spesifikasi dari sistem pemisah abu tersebut. Sistem pemisah abu yang dirancang adalah screw conveyor untuk memisahkan bottom ash dan siklon untuk memisahkan fly ash. Hasil perancangan diperoleh spesifikasi yang dibutuhkan yaitu diameter screw sebesar 6 inci, motor listrik yang digunakan memiliki daya 1 HP, putaran screw sebesar 0,31 rpm dan poros screw conveyor sebesar 2 inci. Dengan standar yang sudah diberikan, dengan mengasumsikan diameter body siklon sebesar 0,1 m maka diperoleh seluruh dimensi siklon. Dengan diameter sebesar 0,1 m secara perhitungan didapat efisiensi siklon sebesar 78% dan secara simulasi menggunakan software ANSYS didapat efisiensi sebesar 80%. Kata kunci: tongkol jagung, gasifikasi, screw conveyor, siklon, ANSYS Abstract Indonesia needs alternative energy that has a great opportunity to be developed its utilization, one of which is biomass energy derived from corn. In previous studies, a continuous gasification system has been designed and built, but there are still deficiencies in the separation of ash after combustion. The purpose of this research is to design an ash separator system in a continuous gasification system so that the specifications of the ash separator system can be obtained. The ash separator system designed is a screw conveyor for separating bottom ash and cyclones for separating fly ash. The design results obtained the required specifications, the screw diameter is 6 inches, the electric motor used has a power of 1 HP, the screw rotation is 0.31 rpm and the screw conveyor shaft is 2 inches. With the standards that have been given, assuming the diameter of the cyclone body is 0.1 m, all the dimensions of the cyclone are obtained. With a diameter of 0.1 m, the calculation is that the cyclone efficiency is 78% and by simulation using the ANSYS software, the efficiency is 80%. Key words: corn cobs, gasification, screw conveyor, cyclone, ANSYS

Performance Evaluation of a Small-Scale Mechanical Fish Feeder

The performance evaluation of an existing mechanical fish feeder was carried out. Floating feeds of sizes 2 mm, 4 mm, and 6 mm at constant moisture content of 13 % were fed into the feeder. The feeder was powered by a 3-phase, 1.5 kW reducing gear electric motor at speed 40 rpm, 50 rpm, 60 rpm, 70 rpm and 80 rpm machine. It was observed that the horizontal screw conveyor effectively transported the material from the hopper to the discharged point. The results obtained from the tests showed an optimal performance of the machine at speed 50 rpm with dispensing efficiency of 93.1 % for 2 mm feed size, while the throughput was 75.76 kg/h at motor speed of 80 rpm also for the 2 mm fish feed size. The ANOVA at p ≤ 0.05 showed that machine speed has significant effect on its dispensing efficiency and the throughput capacity. The cost of production of the mechanical fish feeder was ₦262,300 which made it affordable for young entrepreneurs.

“Design and Development of Tractor Drawn Subsurface Manure and Seed Applicator”

Organic farming is now recognized as the best known alternative to the conventional agriculture, where cultivation and raising of crops and best quality of food is grown without any harm to the soil health, environmental and to the human being and microorganism present in the soil. Efficient organic nutrient supply to plant in adequate quantities to sustain most plant growth and yield while minimizing the environmental affected by the use of large quantities of inorganic fertilizers and pesticides which reduces the soil characteristics and productivity. Vermicom post is the major alternatives for organic farming with higher plant nutrients. Therefore, a tractor drawn subsurface manure and seed applicator was designed and developed in Farm Machinery and Power Engineering Department, G.B.P.U.A& T Pantnagar, Uttara khand for placement of vermicom post (organic manure) at a depth of 50 to 200 mm below the soil surface. Firstly the frame for vermicom post and seed hopper was fabricated according to the desired capacity of vermicom post manure hopper. Six rectangular orifices were provided for delivery of manure at the middle of the bottom surface of the manure hopper. A counter shaft was fixed on the frame which was driven by the ground wheel and rotated the horizontal screw conveyor shaft of the manure hopper as well as seed hopper shaft by means of chain - sprocket arrangement. The velocity ratios between the ground wheel and the manure and fluted roller shaft were 2:1. The manure hopper shaft and fluted roller shaft were rotated at 14, 35 and 41 rpm when tractor forward speed 2, 4 and 6 km/h, respectively. Two depth control side wheels were provided below the frame to adjust the depth of cut of machine in field operation. A furrow opener was designed to penetrate into the soil at the desired depth and placed the vermicom post and seed below the soil surface.

Design, Simulation and Experimentation of an Axial Flow Sunflower-Threshing Machine with an Attached Screw Conveyor

Sunflower threshing is one of the most interesting field processes for making the sunflower ready for seed handling, drying, cleaning and oil extraction. One of the biggest problems observed during the sunflower threshing process is the accumulation of threshed crop on the first third of the threshing roller and passing off some unthreshed parts of sunflower heads. To solve the aforementioned problem and optimize the efficiency of the sunflower threshing process, this research was focused on devising and testing a sunflower threshing machine with a close threshing box system equipped with a screw conveyor that evenly distributed the feedstock of sunflower heads on the entire length of the threshing roller. The machine was tested to assess the seed damage rate, unthreshed seed percentage, threshing efficiency, machine productivity, power requirements and specific energy consumption. The evaluation was done under different roller rotational speeds (150, 200, 250 and 300 rpm) and feeding rates (600, 700, 800 and 900 kg/h). The obtained results revealed that the threshing evaluation parameters were affected significantly by the roller rotational speed and feeding rate. The threshing efficiency was observed to rise with the rise in the roller rotational speed, and it also rose with the increasing feed rate up to 800 kg/h and then started to descend. The unthreshed seed percentage decreased with the increase in the roller rotational speed for all feed rates, and it decreased with the increasing feed rate up to 800 kg/h and then started to increase at the higher feed rates. The damaged seed percentage, power requirement and machine productivity increased with the increase of the roller speed and feed rate. The Buckingham π theorem was followed to find an equation to predict the threshing efficiency, resulting in an equation with an R2 value of 0.9309. With elimination of the blockage problem and better threshing efficiency, this machine could be a good choice for small- to medium-sized sunflower farms.