A Novel Coal Water Content Measurement Method on Conveyor Belt

2012 ◽  
Vol 503-504 ◽  
pp. 1292-1297
Author(s):  
Xue Zhen Cheng ◽  
Ji Ming Li ◽  
Qi Li ◽  
Mao Yong Cao ◽  
Laxmisha Rai

The coal dust storms create great harm to the environment and human health. The main source of coal dust is the low coal moisture on various types of coal conveying belt. The intensity of coal dust is heavy, especially in the coal-fired power plant, coal transportation coal conveyor belt and in areas, where various reprint point was heavy. In this paper, a measurement method on moisture content of coal conveying belt was proposed. The local group based on the probability can eliminate the factors affecting measuring accuracy such as the big piece of coal, the thickness of coal seam, and coal rock. The rationality behind the measurement was verified by simulation experiments. The proposed method gives an effective method to measure the moisture content of coal on the conveyer belt and provides technical support to prevent the spontaneous combustion and explosion of coal when the moisture content of coal is too low.

2020 ◽  
pp. 341-350
Author(s):  
Di Wang ◽  
Changbin He ◽  
Haiqing Tian ◽  
Liu Fei ◽  
Zhang Tao ◽  
...  

Low productivity and high electricity consumption are considered problems of the hammer mill, which is widely used in current feed production. In this paper, the mechanical properties of corn grain ground by a hammer mill were analysed, and the key factors affecting the performance of the hammer mill were determined. The single-factor experiment and three-factor, three-level quadratic regression orthogonal experiment were carried out with the spindle speed, corn grain moisture content and number of hammers as experimental factors and the productivity and electricity consumption per ton as evaluation indexes. The results showed that the order of influence on the productivity was spindle speed > corn grain moisture content > number of hammers and that the order of influence on the electricity consumption per ton was corn grain moisture content > spindle speed > number of hammers. The parameters were optimized based on the response surface method with the following results: the spindle speed was 4306 r/min, the corn grain moisture content was 10%, and the number of hammers was 24. The validation experiment was carried out with the optimal parameters’ combination. The productivity and electricity consumption per ton were 988.12 kg/h and 5.37 kW·h/t, respectively, which were consistent with the predicted results of the model.


1997 ◽  
Vol 36 (6-7) ◽  
pp. 493-500 ◽  
Author(s):  
J. J. Lay ◽  
Y. Y. Li ◽  
T. Noike ◽  
J. Endo ◽  
S. Ishimoto

A simple model developed from the Gompertz equation was used to describe the cumulative methane production curve in the batch culture. By using this model, three key parameters, namely methane production rate, potential and lagphase time, in a cumulative methane production curve were exactly estimated based on the experimental data. The results indicate that each gram of dry organic waste of a sludge cake, meat, carrot, rice, potato and cabbage had a methane production potential of 450, 424, 269, 214, 203 and 96 mL, respectively. The methanogenic activity of these digesters decreased with a decrease in the moisture content. The moisture content threshold limit, at which the methanogenic activity dropped to zero, was found to be 56.6% for the sludge cake, but greater than 80% for meat, carrot and cabbage. In the high-solids sludge digestion, the relative methanogenic activity dropped from 100% to 53% when the moisture content decreased from 96% to 90%. The rate of methane production at moisture contents of 90% to 96% functioned in a pH range between 6.6 and 7.8, but optimally at pH 6.8, and the process may fail if the pH was lower than 6.1 or higher than 8.3. On the other hand, the methanogenic activity was dependent on the level of ammonium, NH4+, but not free ammonia, NH3, indicating that the NH4+ was the more significant factor rather than the NH3 in affecting the methanogenic activity of a well-acclimatized bacterial system. In the wide pH range of 6.5 to 8.5, the methanogenic activity decreased with the increase in the NH4+; dropped 10% at the NH4+-N concentration of 1670-3720 mg·L−1, 50% at 4090-5550 mg·L−1 and dropped to zero at 5880-6600 mg·L−1. However, the lagphase time was dependent on the NH3 level, but not on NH4+, and when NH3-N was higher than 500 mg·L−1, a notable shock was observed. This suggests that the NH3 level was the more sensitive factor than the NH4+ level for an unacclimatized bacterial system.


2018 ◽  
Vol 36 (9-10) ◽  
pp. 1744-1754 ◽  
Author(s):  
Fei Gao ◽  
Cun-Bao Deng ◽  
Xue-Feng Wang ◽  
Xue-Ming Li ◽  
Feng-Wei Dai

We propose an experimental adsorption device, imitating the environment of a coal-mine goaf and the composition of the flue gas in Tashan Mine Power Plant. The characteristics of the coal adsorbing flue gas were studied with the atmospheric volumetric method. The factors affecting the seal of CO2 were analyzed and the effect of power plant flue gas on fire prevention in the goaf was investigated at normal temperature and pressure. It can be inferred from the experiment that N2, SO2, and H2O can also reduce CO2 adsorption capacity. The increase or decrease in pH can increase the adsorption capacity of CO2, which is apparently larger when the pH is decreasing than when the pH is increasing. The O2 adsorption capacity can evidently be reduced when the power plant flue gas is injected into the goaf. The activation energy of coal burned in air is greater than that of coal burned in flue gas, indicating that the use of power plant flue gas, with N2 and CO2 as the main components, to replace the traditional inert gas can not only save N2 generation cost, but also reduce the emission of greenhouse gases, while the power plant flue gas can be adsorbed by coal.


2006 ◽  
Vol 3 (3) ◽  
pp. 987-1019 ◽  
Author(s):  
C. Fallico ◽  
E. Migliari ◽  
S. Troisi

Abstract. After pointing out the importance of the saturated hydraulic conductivity (ks) measurements and the difficulties and uncertainties that are present, and after recalling salient aspects of three well-known measurement methods of this parameter (i.e. constant-head tension infiltrometer (TI) method, constant-head pressure infiltrometer (PI) method and soil core (SC) estimates method), the results of an investigation on data which were obtained during a measurement campaign on an area of 800 m2, on a sandy loam hillslope, located in Southern Italy, were carried out again here. Three sets of values of ks, obtained with these measurement methods, were analyzed statistically, verifying that the log-normal distribution describes these better than the normal one; moreover, the more significant statistical parameters of each set were compared (average value , amplitude A, coefficient of variation CV and standard deviation SD), individualizing the more significant differences. The greatest value of hydraulic conductivity was found with method (PI), while the smallest with (SC) and the intermediate with (TI); these differences were translated into macroporosity and into the influence of the single measurement method. Moreover, referring to the possible factors affecting the results, the importance can be noted of the structure, the texture and the soil events, in terms of utilization, which can affect the measure of ks leading often to very different values even for similar soils, but with a different history, independently of the coincidence of the measurement points and they can be determining to explain the differences affecting the results obtained in analogous investigations by other researchers. Having confirmed that generalization is not possible, the need was emphasized to adopt the necessary devices relating to the specific measurement method, case by case, and to carefully explain the obtained results, in the light of the peculiarities and the limits of each situation. Finally, the results of similar statistical analysis carried out on a greater number of ks values, measured through the (TI) and (PI) methods are shown in this paper, with some statistical considerations on the increasing of the measurements number.


SINERGI ◽  
2019 ◽  
Vol 23 (3) ◽  
pp. 223
Author(s):  
Akhyar Zuniawan ◽  
Iphov Kumala Sriwana

Currently, many coal-fired powers plants are built to supply electrical energy needs in Indonesia due to relatively inexpensive raw materials and abundant in Indonesia. Handling of coal is mostly done at the power plant using coal handling facilities consisting of ship unloaders, conveyor belts, stock piles, silos or bunkers. The problem that arises in the coal handling facility is dust from coal that fells or hovers in the air so that it can interfere with the environment and health both for workers in the Coal Power and residents around the Coal Power. The purpose of writing this paper is to eliminate the spread of coal dust that arises due to coal handling equipment that is not precise and imperfect. The method used is the Soft System Methodology (SSM), which is a systematic approach used to analyze and solve problems in complex and messy situations. This paper examines the benefits of applying SSM to knowledge management issues in handling coal dust at a power plant. Improvement is done by upgrading coal handling equipment (ship unloader, conveyor belt, stock pile) with the addition of dust suppression, proper sealing system, dust bag, and training to operators on the impact and handling of coal dust and coal handling equipment maintenance, so resulting in a significant decrease in the spread of coal dust, creating a working environment and the environment becomes clean, healthy and safe.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Naifu Cao ◽  
Gang Wang ◽  
Yuntao Liang

In this article, a series of experiments have been carried out to study the spontaneous combustion and oxidation mechanism of coal after water immersion and investigate its tendency to spontaneous combustion, analyze the difficulty of spontaneous combustion of coal samples under different water immersion conditions, and establish a kinetic model of water immersion coal oxidation (taking the Bulianta 12# coal as a case study). They rely on physical oxidation adsorption, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetry, and oil bath heating. SEM has been used to analyze the characteristics of coal pore structure under different water immersion conditions (water-saturated coal samples under different water loss conditions until the coal samples are completely dried); FTIR served to investigate the characteristics of the molecular chemical structure of the coal surface before and after the coal is immersed in water. Through programmed temperature oxidation experiments combined with FTIR analyses and gas chromatographic (GC) analysis of gaseous products, it has been possible to study the changes of molecular structure and gas products on the surface of coal samples at different temperatures and water immersion conditions. The oxidation reaction rate of the 12# coal samples of Shendong Mine’s Bulianta Mine under different water content conditions during the spontaneous combustion process has been quantitatively studied. The difficulty of spontaneous combustion of coal samples has been correspondingly addressed. A kinetic model from the perspective of oxygen consumption has been proposed. Thermogravimetry-differential scanning calorimetry (TG-DSC) has been used to analyze and study the exothermal oxidation process before and after coal immersion. From the perspective of the exothermic intensity of the coal-oxygen reaction, an oxidation kinetic model for immersed coal samples has been developed to qualitatively determine its spontaneous combustion tendency. Results have shown that the increase in the specific surface area increases the risk of spontaneous combustion, and coal samples after soaking and drying have a stronger tendency to spontaneous combustion than raw coal. The moisture content of the coal sample leading to the easiest ignition conditions is 16.05%. Regardless of the moisture content, the critical temperature is maintained at 65–75°C, and the temperature of the left coal in the goaf should be prevented from exceeding this critical value.


2021 ◽  
Vol 37 (4) ◽  
pp. 615-621
Author(s):  
Jing Bai ◽  
Shaochun Ma ◽  
Jiwei Hu ◽  
Yi Wei ◽  
Fenglei Wang ◽  
...  

Highlights This article focuses on the tensile properties of sugarcane leaves. The moisture content and sheath diameter were selected as test factors, and the test index was the stalk-leaf connecting force. The load-displacement curves of stalks and leaves were plotted. Two-way ANOVA was also discussed. Abstract . The tensile properties of sugarcane leaves are critical factors affecting the harvesting quality of sugarcane harvesters. Thus, it is important to investigate the tensile properties of sugarcane stalks and leaves. The selected test factors were leaf moisture content and sheath diameter, and the stalk-leaf connecting force was selected as test index. The tests were conducted with two moisture content levels of 15% and 20%, and three sheath diameters of 22, 26, and 30 mm. The stress-strain curves of stalks and leaves were plotted to show how the tensile force varied during the tensile test. The results showed that there was a strong linear correlation between the stalk-leaf connecting force and diameter of leaf sheath, and the connecting force also increased with the increasing moisture content. In addition, leaf tensile forces in longitudinal direction were much larger than in transverse direction. Two-way ANOVA revealed that both of the moisture contents (A) and sheath diameters (B) had significant effects on the stalk-leaf connecting force (p < 0.01), however, the interaction between A and B was not significant (p > 0.1). This study provides a theoretical reference for the design and improvement of crop dividers of sugarcane harvester. Keywords: Moisture content, Sheath diameter, Stalk-leaf connecting force, Sugarcane leaves, Universal testing machine, Tensile properties.


Author(s):  
Z.G. Ufatova

The mining factors of ore fire hazard during mining of the lower horizons of the Oktyabrskiy and Talnakhskiy northern deposits are considered. It is noted that the probability of self-heating of sulfide ores and the sulfide dust’s tendency to spontaneous combustion and explosiveness in certain sections of rich sulfide copper-nickel ores are quite high. The oxidation of sulfide ores occurs continuously due to the absorption of oxygen from the mine atmosphere and is accompanied by the release of heat. The oxidation can be accompanied by intense heating of the ore in mining conditions, with the accumulation of large volumes of broken rock mass for a long time in treatment and preparation workings and with free access of air to the bulk of the ore mass. The processes of ore and rock oxidation are especially intense when their moisture content is 1–4%. When the ore is heated above 35 °C, sulfurous gas (SO2) may be released. The main signs of the above-mentioned oxidative processes’ development and signs of the initial phase of a possible underground endogenous fire are indicated along with a constant increase in the temperature of the air coming from the bottom of the face. It is noted that in case of detecting at least one of the signs of a possible underground endogenous fire’s initial phase, urgent measures are taken to improve the ventilation of this working face, to ensure maximum intensity of shipped ore from the fresh stream and the content of sulfurous gas and hydrogen sulfide and mine air temperature are determined every 4 hours. If after two days on the outgoing stream there is no decrease in the content of sulfur dioxide and air temperature, then it should be considered that an endogenous fire has occurred. Measures for the prevention, localization and elimination of foci of spontaneous combustion are given. As an additional safety measure, it is recommended to moisten the dust, since sulfide dust becomes non-explosive at a moisture content of 9–9,5%, and at a humidity of 10% the dust does not transmit an explosive impulse.


Author(s):  
Jeff D. Craven ◽  
Andrew W. Muscha ◽  
R. Chase Harrison ◽  
Markus A. R. Kreitzer ◽  
Robert N. Dean ◽  
...  

The spontaneous combustion of curing hay bales poses serious safety and financial issues to farmers and ranchers across the United States and abroad. The primary cause of this spontaneous combustion is the baling of hay before it has adequately dried and reached a sufficiently low moisture content level. This inadequate drying is primarily due to the farmer allowing the hay to dry in the field after cutting for a given period of time. But unfortunately, this does not always ensure that the hay has sufficiently dried before baling. Spontaneous combustion of hay bales is due to a proliferation of thermophilic bacteria that thrive in a moist and hot environment. If the moisture content of hay is greater than 20%, it provides a suitable environment for mesophilic bacteria, which can heat the hay to as a high as 140°F. Although this is not problematic in and of itself, a 140°F hay bale is a suitable environment for the proliferation of thermophilic bacteria, which can further heat the hay to 170oF. At this temperature, the hay can spontaneous combust, destroying the hay and risking the loss of buildings, equipment, livestock and agricultural workers. To combat this problem, a low-cost, low-power, wireless hay bale status sensor suite has been developed so that the farmer can easily and safely monitor the conditions inside a curing hay bale, to give the farmer time to take action before the bale spontaneously combusts. The battery operated sensor suite has two sensors in contact with the hay inside the bale, a printed circuit board (PCB) moisture content sensor and a discrete temperature sensor. The extremely low-cost of the PCB moisture content sensor is what enables the practicality of the sensor suite. WiFi is used to transmit moisture content and temperature data to the farmer's smartphone when it comes within range. The sensor suite is placed inside the bale at the time of baling. After the bale has fully cured, in four to six weeks, the reusable sensor suite can be removed and used in a new bale.


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