Hot Coal Research Articles

Workplace induced heat-related-illness and kidney disorders amongst coal cutters of underground mines

Workers in hot underground coal mines could develop heat-related illnesses, (especially skin, digestion and kidney problems), as compared to workers in non-hot mines. This study found severity of this situation by comparing heat illness symptoms, core body and skin temperature and kidney malfunctioning amongst workers of both types of mines. Ingestible thermometric pills (sending readings to Sensor Electronic Module every 15 s), skin temperature probes (connected to various body parts and sending readings to loggers) and laboratory analysis of pre- and post-shift samples of blood and urine, US-NIOSH-HETA-2012 sheet to survey symptoms, were used to collect data from 50 workers (25 from five hot mines (G1) and 25 from five non-hot mines (G2)). Two mine groups showed significant differences ( p-value <.001) regarding wet-bulb globe temperature, dry-bulb temperature and relative humidity. The highest core body temperature was 38.8°C in G1 and 37.9°C in G2. In intra-group comparison for kidney functioning, post-shift samples showed haematocrit (%) was reduced to 43.6 ± 2.1 from 45.4 ± 1.4 in G1 and to 44.0 ± 2.9 from 45.0 ± 0.75 in G2, and estimated glomerular filtration rate was reduced from 100 ± 19 to 94 ± 0 mL/min/1.72 m2in G1 and to 113 ± 15 from 115 ± 19ain G2 workers. The comparison showed hot mines could induce heat-related illnesses which would necessitate intervention to reduce exposure.

Effect of cobalt (nickel) oxide on the properties of zinc\u2013titanium sorbents for high temperature desulphurization of model coal gas

Zn–Ti–Co(Ni) sorbents for H2S removal from model hot coal were prepared and characterized. Effects of cobalt (Co) and nickel (Ni) on the sorbents texture, structure, H2S sorption capacity and regeneration properties were determined. TiO2 formed mixed metal oxides with CoO and NiO in the fresh sorbents, while TiO2 and nanocrystalline sulfides of Zn, Co, Ni were found in sulphided ones. The oxidative regeneration of sulphided sorbents re-formed mixed oxides. Sorption capacity of studied materials increased along with an increase of the amount of added Co (Ni) and also with the number of work cycles. Co-doped Zn–Ti materials adsorbed up to 244% more sulfur than these of Zn–Ti, while Ni-doped materials adsorbed ca. twice more H2S than the corresponding Co-doped sorbents. The addition of Co (Ni) decreased the temperature of ZnS oxidation. The catalytic effect of the Co (Ni) oxides on the oxidation of ZnS was suggested.

Влияние режимов термической обработки на закалочные напряжения и свойства сплава Д16

The investigation results of the impact of thermal treatment including water hardening, ascending hardening (hardened alloy cooling in liquid nitrogen, aging and heating in hot coal oil), and also natural or artificial aging upon properties of the bars of D16 deformed aluminum alloy are shown. Through the method of hole drilling there is defined a mode impact of this thermal treatment upon residual stresses.

Pyrolysis and gasification modelling of underground coal gasification and the optimisation of CO2 as a gasification agent

In the underground coal gasification (UCG) process, a feasible method for the reduction of CO2 emissions is to capture the CO2 present in syngas and reinject it as one of the gasification agents, which is called CO2 recycling. In this process, CO2 partially replaces steam as a gasification agent, which is of particular importance in areas lacking sufficient water. To obtain a more accurate and generally applicable means of calculation, a modified equilibrium calculation method, which calculates UCG parameters in the presence of CO2 in the gasification agent over two stages and then merges the resulting data, has been established. In addition, a suitable method for establishing optimal gasification agent parameters is proposed. Corresponding MATLAB™ routines were then compiled and applied to UCG gasification agent parameters optimisation simulations using data of Ankou coal. Calculation results indicated that CO2 partially replaced steam, and that an increase in CO2 concentration in the gasification agent enhanced the reduction reaction between CO2 and hot coal. In addition, the reaction equilibrium temperature is a key factor in the process, with the temperature being influenced by the ratio of (steam+CO2) to O2. Indeed, CO2 is more efficient than steam at reducing the gasifier temperature. Finally, the composition of the gasification agents was optimised by simulations using pure O2-steam-CO2 and air-steam-CO2 mixture as the gasification agents.

Downtown Nellmapius: The Vacant Plot Patient

No abstract available.

The Soul Craft of K’dushah B’tzibbur

The Soul Craft of K’dushah B’tzibbur Lilly Kaufman (bio) They Are So Different They are so different, Isaiah, Ezekiel, and the Psalmist. Isaiah wanted to join the heavenly choir (Isaiah 6:1–6); Ezekiel wanted to locate God (Ezekiel 3:12); the Psalmist wanted to crown God who attends to the disadvantaged (Psalm 146:10). They want different things, and yet they are joined together in k’dushah b’tzibbur, the communal cantata of holiness, chanted whenever we repeat the Amidah in a minyan. The question is: why bring these three different voices together? Isaiah aspires to be one of the angels who gather around God’s throne, singing “Holy, holy, holy, Adonai of Hosts, the whole world is filled with God’s Presence” (Isaiah 6:3). The only obstacle is his unclean lips. An angel rushes over with a hot coal and purifies his lips, and he can then sing their pure song about God’s Presence on earth, with an orderly and magnificent group of devoted singers. Ezekiel is caught up in turmoil, both natural and supernatural. The wind lifts him up, and he hears behind him, “Blessed is the Presence of Adonai from God’s place.” Why mi-m’komo, “from [God’s] place’? It appears to be a milah y’teirah, a superfluous word, which emphasizes, in an atmosphere of wind and noise (powerful elements that have neither beginning nor end), that God’s place can be located. Through and despite chaos, God can be found. Isaiah and Ezekiel serve as intentional foils in the spiritual masterpiece of the Kedushah liturgy. As a corrective to Isaiah’s vision of an orderly choir where solutions are prompt and clear-cut, the inclusion of Ezekiel’s vision [End Page 135] of heaven signals that truth-seeking can at times be paradoxical, impassioned, and disorderly. Conversely, as a counterpoint to the disorder of Ezekiel’s heaven, Isaiah’s vision provides the promise of stability, of an exalted home we might wish to travel to one day and whose radiant transcendence we glimpse at rare moments in life. These two prophetic visions are about the inner life. For those whose spiritual energy is directed outward, we have the verse from Psalms. The Psalmist wants to enthrone on earth the God who lifts up the downtrodden, secures justice for those who are wronged, gives food to the hungry, sets prisoners free, restores sight to the blind, makes those who are bent stand straight, loves the righteous, watches over the stranger, gives courage to the orphan and widow, but makes the path of the wicked tortuous. It is these actions of God that the Psalmist wants to enthrone forever among the people of Israel. Three different scenarios, three different yearnings, three different aspects of k’dushah (holiness). Why? These are three different yet equally central human aspirations toward holiness and toward God. Three Central Human Aspirations Toward God Isaiah seeks to join a community that exists to serve God and which is characterized by purity. He wishes to be part of something larger than himself: something of great beauty, serenity, and power. Self-perfection is closely associated with this yearning, because heaven is an environment of purity. This religious personality is the eager servant for whom order and purity are evidence of holiness.The Isaiah text itself models succinctness, a stylistic purity, conveying its powerful vision in a mere six verses. After Isaiah sees this vision, God appoints him to be a prophet. Ezekiel seeks to locate God through heavenly turmoil, in which natural phenomena occur in magnified, supernatural proportions. He hears rather than sees God, in a setting that threatens to confuse and harm him. His redemptive hearing pierces the noise and wind, finding God in a desperate situation. Ezekiel’s chaotic heavenly vision is expressed over whole chapters, in which each word clarifies less. After Ezekiel’s visions, God appoints him to be a prophet. In Psalm 146, we find a catalog of human needs that God attends to personally and with compassion. This list of God’s acts of hashgaḥah p’ratit [End Page 136] (individualized attentiveness) forms the basis of our morning blessings. As we...

Using DCS to Realize Ball Mill Fuzzy Control System

By way of summarizes operation experience, using fuzzy control method to realize the decoupling control of coal mill cold air damper, hot air damper and coal feeder, by using cascade control of fuzzy control look up table and PI controller in DCS, it’s convenient to realized the automatic control of ball mill. Practice proves that this method is easy to achieve and good control effect could be achieved.

Eulerian–Lagrangian method for three-dimensional thermal reacting flow with application to coal gasifiers

Energy transport and chemistry are modeled in an extension of the Eulerian–Lagrangian computational particle fluid dynamics (CPFD) methodology. The CPFD methodology is based on the MP-PIC method, which uses a stochastic particle method for the particle phase and an Eulerian method for the fluid phase, to solve equations for dense particle flow. In our extension of CPFD, an enthalpy equation describes energy transport for fluid, and provides for transfer of sensible and chemical energy between phases and within the fluid mixture. Homogenous and heterogeneous chemistry are described by reduced-chemistry, and the reaction rates are implicitly solved numerically on the Eulerian grid. Inter-phase momentum and energy transfer are also implicitly calculated, giving a robust numerical solution from the dilute flow to close-pack limits. A three-dimensional example of a hot fluidized bed coal gasifier is presented with homogeneous and heterogeneous chemistry. The inter-dependencies of fluidization, thermal, and chemistry behaviors in this complex three-dimensional calculation are described.

Effect of processing and preservation method on the organoleptic and shelf life of meat products

Two meat products (Beef and Mutton) were subjected to four processing methods-frying, boiling, roasting and oven-drying to investigate the effects of processing and preservation methods on the organoleptic and shelf-life of meat products. The results obtained revealed fried Mutton to have the highest rating scores (better taste) of 91% while boiled beef had the lowest rating of 42%. Preserving the meat at room temperature (25°C average) had a significant (P<0.01) effect on the taste and microbial load of the meat products. Processing methods however, had no significant effect on the microbial count of product. Boiled meat (at 100°C for 30 minutes) had the shortest shelf, while fried meat (at 180°C for 10 minutes) stored at refrigerated temperature (4°C) had the highest shelf life of 14 days. Oven-dried meat (200°C for 24 hours) and roasted meat (on open hot coal for 12 hours) had shelf life of 7 days each at 4°C. Lower shelf-life was recorded for meat stored at 25°C all the processing methods. Keywords: Meat products, processing, preservation, qualities

Minimization of Moisture Readsorption in Dried Coal Samples

Low-rank coals csonstitute a major energy source for the future as reserves of such high-moisture coals around the world are vast. Currently they are considered undesirable since high moisture content entails high transportation costs, potential safety hazards in transportation and storage, and the low thermal efficiency obtained in combustion of such coals. Furthermore, low-moisture-content coal is needed for the various coal pyrolysis, gasification developed. Hence, various upgrading processes have been developed to reduce the moisture content. Moisture readsorption and spontaneous combustion are important issues in coal upgrading processes. This article discusses results of laboratory experiments conducted to study the options for minimization of readsorption of moisture after drying of selected coal samples. Results suggest that there is little benefit in drying low-rank coal at high temperatures. It was found that the higher the amount of bitumen used for coating, the lower is the readsorption of moisture by dried coal. Also, mixing high-temperature-dried coal with wet coal in appropriate proportion can yield reduced moisture content as the sensible heat in the hot coal is utilized for evaporation.

An Experimental and Numerical Analysis of Puff Hydrodynamics

Abstract The permeability of a tobacco rod in a cigarette increases as it converts into char and ash in the coal. The hot coal introduces a significant resistance to the air flow when air passes through. Through a series of experiments, the cigarette burn line and burn rate, the centerline temperature, and the pressure drop were measured for continuous puffing conditions. The gas viscosity was calculated from the temperature distribution inside the cigarette and applying Sutherland's law. Then, the experimental setup was mathematically modeled from a commercially available CFD (Computational Fluid Dynamics) code and, by matching the numerical and experimental results, the changes in coal and filter permeability during puffing were estimated. The numerical simulation successfully reproduced the results of experiments on the air flow through the coal, ventilation holes and paper wrapper.

Direct determination of Ge in hot spring waters and coal fly ash samples by hydride generation-ETAAS

A method for Ge determination in hot spring water and acid extracts from coal fly ash samples involving hydride generation, trapping and atomisation of the hydride generated from Ir-treated graphite tubes (GTs) has been developed. Hydride was generated from hydrochloric acid medium using sodium tetrahydroborate. Several factors affecting the hydride generation, transport, trapping and atomisation efficiency were studied by using a Plackett-Burman design. Results obtained from Plackett-Burman designs suggest that trapping and atomisation temperatures are the significant factors involved on the procedure. The accuracy was studied using NIST-1633a (coal fly ash) reference material. The detection limit of the proposed method was 2.4 μg l −1 and the characteristic mass of 233 pg was achieved. The Ge concentrations in fly ash and hot spring samples were between 6.25–132 μg g −1 and 12.84–36.2 μg l −1.

State >Legitimacy and the (In)significance of Democracy in Post‐Communist Russia

A few apocalyptic predictions of a post‐communist ‘maelstrom’ notwithstanding,1 the break‐up of the USSR was initially greeted by optimistic assessments of the prospects for democracy in the ‘new R...

Direct determination of Ge in hot spring waters and coal fly ash samples by hydride generation-ETAAS

A method for Ge determination in hot spring water and acid extracts from coal fly ash samples involving hydride generation, trapping and atomisation of the hydride generated from Ir-treated graphite tubes (GTs) has been developed. Hydride was generated from hydrochloric acid medium using sodium tetrahydroborate. Several factors affecting the hydride generation, transport, trapping and atomisation efficiency were studied by using a Plackett-Burman design. Results obtained from Plackett-Burman designs suggest that trapping and atomisation temperatures are the significant factors involved on the procedure. The accuracy was studied using NIST-1633a (coal fly ash) reference material. The detection limit of the proposed method was 2.4 μg l−1 and the characteristic mass of 233 pg was achieved. The Ge concentrations in fly ash and hot spring samples were between 6.25–132 μg g−1 and 12.84–36.2 μg l−1.

Stephen Crowley, Hot Coal, Cold Steel: Russian and Ukrainian Workers From the End of the Soviet Union to the Post-Communist Transformations. Ann Arbor: University of Michigan Press, 1997. x + 277 pp. $42.50 cloth.

Stephen Crowley, Hot Coal, Cold Steel: Russian and Ukrainian Workers From the End of the Soviet Union to the Post-Communist Transformations. Ann Arbor: University of Michigan Press, 1997. x + 277 pp. $42.50 cloth.

Hot Coal, Cold Steel: Russian and Ukrainian Workers from the End of the Soviet Union to the Post-Communist Transformations. By Stephen Crowley. Ann Arbor: University of Michigan Press. 277p. $42.50.

Hot Coal, Cold Steel: Russian and Ukrainian Workers from the End of the Soviet Union to the Post-Communist Transformations. By Stephen Crowley. Ann Arbor: University of Michigan Press. 277p. $42.50.

Hot Coal, Cold Steel: Russian and Ukrainian Workers from the End of the Soviet Union to the Post-Communist Transformations

Well after the disintegration of the Communist Party and the Soviet state--and through several years of economic collapse--industrial workers in almost every sector of the former Soviet Union have remained quiescent and the same ineffective and unpopular trade unions still hold a virtual monopoly on worker's representation. Why? While many argue that labor is a central variable in the development of economic and political systems, little is known about workers in the states of the former Soviet Union since the fall of Communism. In a comparative study of two groups of industrial workers--the coal miners and steelworkers--at the end of the Soviet era, Stephen Crowley sheds light on where these workers have been and where they are going. Coal miners in the final years of the Soviet Union effectively organized and led strikes which supported the end of Communism, even though their heavy subsidies would be threatened by capitalism. Steel workers, in contrast, did not effectively organize and strike. This pattern has continued under the new governments, with the coal miners effectively organized and seeking protection from the worst consequences of marketization, while the steel workers remain weakly organized despite deteriorating economic conditions. Based on extensive on-site research including interviews with miners and steelworkers, labor leaders and plant managers, Crowley develops a detailed picture of the conditions under which workers organize. His findings have application beyond the conditions of post-Communist Russia and Ukraine to other societies undergoing fundamental change. This book will be of interest to sociologists and political scientists interested in the role of labor in transitional societies, the patterns of organization of labor, as well as area specialists. Stephen Crowley is Associate Professor of Political Science, Oberlin College.

Hot Coal, Cold Steel: Russian and Ukrainian Workers from the End of the Soviet Union to the PostrCommunist Transformations. By Stephen Crowley. Ann Arbor: University of Michigan Press, 1997. x, 277 pp. Notes. Bibliography. Index. $42.50, hard bound.

Hot Coal, Cold Steel: Russian and Ukrainian Workers from the End of the Soviet Union to the PostrCommunist Transformations. By Stephen Crowley. Ann Arbor: University of Michigan Press, 1997. x, 277 pp. Notes. Bibliography. Index. $42.50, hard bound. - Volume 57 Issue 3

Preheating techniques to manufacture metallurgical coke.

Recently, reserves of good coking coals have become less available and comparatively more expensive. Resources are being extended by the use of coal blends with different coking properties and/or selective additive. Coal preheating technology emerged as a technique to overcome some of these problems. It has several advantages including: increases in coke oven productivity, improvements in quality of metallurgical coke, greater uniformity of charge, less air pollution by using a closed charging system, levelling of the charge, a saving in energy because dry coal is more efficient in the preheater than in a coke oven, and the possibility of using poorer and cheaper coking coals. The disadvantages of this technique are the handling of fine and hot coal, the carry-over and the preheater fines.Currently, the preheating process is being re-considered in combination with dry-cooling of coke in a European Research Project called Jumbo Coking Reactor, which is based on past and current experience of development of modern cokemaking technology.This study reviews preheating technology as a means to widen the range of coking coals including not only the high-volatile coals which are more abundant, but also semi-anthracite and petroleum coke. A 6 t Experimental Coke Oven and a 2 t/h Preheating Pilot Plant (Precarbon Process) were used.

Testing of novel sorbents for H2S removal from coal gas

AbstractApplication of zinc ferrite, a regenerable mixed metal oxide, for the removal of H2S from hot coal derived gas streams is limited to a maximum temperature of about 1,250°F (677°C) and to a minimum H2S concentration of about 5 ppmv in the cleaned gas. Four novel sorbents that have shown potential for overcoming the limitations of zinc ferrite [1, 4] were selected for development and bench‐scale testing. Several variations of these mixed metal oxides were prepared, using different amounts of binders. They were tested in the presence of simulated coal gas using a thermogravimetric reactor (TGR) for selection of preparations possessing an adequate combination of reactivity, regenerability, capacity, and strength. Limited bench‐scale tests were conducted in the presence of simulated fluidized‐bed coal gasifier product gases at pressures from 1 to 2 MPa, temperatures from 525°C to 625°C and space velocities from 1,000 to 3000 Nm3/(m3 · h).