Study on Electrostatic Preparation High-Ash Coal from China Using Roll-Type Electrostatic Separator and the Combustion Characteristics of the Cleaned Coal

The dry roll-type electrostatic coal beneficiation technology under high voltage is used to study the beneficiation of low-grade and high-ash coal in Inner Mongolia, northern China. The optimal coal beneficiation conditions are determined by adjusting three parameters: the electrode voltage, the distance between the electrode and the drum, and the angle θ of the electrode. The best quality clean coal is obtained under the condition of voltage of 30 kV, angle θ of 75°, and electrode distance of 7 cm. Moreover, after separation, the quality of clean coal accounted for 48.41% of the raw coal mass, while the ash ratio decreased from 38.6% of the raw coal to 18.71% of the clean coal, which significantly improves the coal usability. Finally, through the methods of combustion characteristics analysis, infrared spectrum analysis, and combustion exhaust gas analysis of raw and clean coal, it is proven that the roll-type electrostatic separation technology has a high coal beneficiation effect on the high-ash, low-grade coal in Inner Mongolia.

Development of the design and method of calculating the strength of the roll-type electric baromembrane apparatus

The design of the roll-type electric baromembrane apparatus is developed. High quality separation of solutions is achieved by combining electric baromembrane separation with electrode cooling using collectors for the flow of cooling water with an independent arrangement of drainage channels of the near-cathode and near-anode permeate. A method is proposed for calculating the strength of the body of an electric baromembrane apparatus with the determination of the required thickness of the body wall and fiberglass flanges. Keywords: electric baromembrane apparatus, separation, membrane, strength calculation. [email protected]

Innovative Measurement Of Stress Superposed Steel Strip For Straightening Machines

Higher quality requirements by customers demand higher precision and accuracy from manufacturing processes. Application oriented preparation of semi-finished materials is key for subsequent forming operations, therefore, straightening machines are employed. Straightening strengthens the material by increasing plastic deformation by means of strain hardening, resulting in undesirable reduction in formability when processing high strength materials, in particular. Conventional roll-type straightening machines process either bars or strips. This is achieved upon passing material between rolls arranged in two staggered rows. However, conventional straightening processes do not adapt to the local varying distortion of coiled strips. Innovative, self-correcting process control techniques, which adapt to the initial geometric characteristics of the strip, present a promising approach to fix this issue through optimization of the leveling process. Here, an innovative strategy to improve straightening of high strength steel materials (1.4310) is presented. This implements optimized leveling, adding minimal plastic deformation and, thus, strain hardening. To operate an intelligent straightening machine, a reliable online measurement of the surface defects is fundamentally essential. The MagnaTest, which is developed for material testing, is made feasible for such purposes after calibrating for curvature measurement. Preliminary results are promising in regards to measuring the curvature online, so that the following straightening process can be close loop controlled. The bending measurement is linked to open/closed loop control, therefore providing an optimal straightening result in regards to formability, leveling, and reduced strain hardening.

Technical, Field, Economic and Energy Comparison of Cutter Bar Maize Header With Snap Roll Maize Header

In India, most of the maize combine harvester currently being used employs snap roll type header. This type of header is costly, dependent on row spacing of maize crop and causes losses at headlands during turning. Moreover owing to its heavy weight its frequent lifting and downing during harvesting season causes hydraulic leakages in certain sections of combine. Therefore to overcome these problems a new light weight cutter bar Maize header is developed and evaluated for maize crop. The performance evaluation of the cutter bar type maize header is done in a dislodged and a partially lodged (30-40%) maize crop. For lodged crops, the header losses varied from 19.18-26.71% and for dislodged crops it was varied from 5.29-10.15% respectively. The cylinder losses for dislodged crop varied from 2.70-2.86% and for lodged crop it varied from 0.85-2.04%. The mean cleaning efficiency for lodged and dislodged maize crop was found as 88.87% and 90.58% respectively. The grain damage for lodged and dislodged crop was observed as 8.31% and 5.94% respectively. The trash content for lodged and dislodged crop was 2.75 and 3.45% respectively. The performance of snap roll and cutter bar was also done. Total losses with snap roll header were higher as 15.06% and lower for cutter bar as 10.85%. The brokens were higher for cutter bar as 5.94 and lower for snap roll as 3.45%. The trash content was 3.45% for cutter bar header and 2.24% for snap roll header. The total energy input in snap roll header, cutter bar maize header and maize dehusker cum sheller were 2360.05, 1970.90 and 3770.48 MJ/ha respectively.The cost of operatin with cutter bar maize header, snap roll maize header and maize dehusker cum sheller were 53.62 $/ha, 68.73$/ha 187.32 $/ha respectively.

Experimental study of fractional composition of pieces of brittle material during crushing in a single-roll crusher with block stop on the roll

Processing of bulk materials used in metallurgical industry to obtain necessary grades of size requires application of crushing machines, including a single-roll type. Indicators of crushing process are degree and efficiency of crushing. Degree of crushing is estimated by the ratio of size of initial crushed and resulting pieces, which depends on size of the gap between a roll and a fixed jaw. The Siberian State Industrial University has patented, designed and manufactured a pilot unit, which is a single-roll crusher with block stop on the roll to study crushing process. A series of experiments on different samples (in shape, size and strength) crushing was carried out on the developed unit. Technique of the experiment and the design of a single-roll crusher with block stop on the roll were described. Results of destruction of the samples of isotropic material made of sand-cement mixture of regular (spherical) shape are presented. Samples from isotropic material allow comparison of analytical conclusions of determining position of the plane of action of maximum tangential stresses with experimental data. Samples of anisotropic material (for example, ferroalloy) were also destroyed. It was experimentally determined that the larger is clearance between the roll and the fixed jaw, the larger is the size of fraction of finished product and over-grinding is less than after crushing the same piece with a smaller clearance. The degree of crushing in a single-roll crusher with block stop on the roll cannot be equal to 4 or more. It was proved that destruction of isotropic materials occurs along the plane of action of maximum tangential stresses. Anisotropic materials are destroyed, depending on size of clearance between a roll and a jaw, both on the plane of action of the maximum tangential stresses and on the planes of least resistance.