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Date submitted2015-10-05
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Date accepted2015-12-14
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Date published2016-08-22
Coal-peat compositions for co-combustion in local boilers
- Authors:
- A. V. Mikhailov
In article results of experiments on creation of coal and peat fuel compositions for burning in solid-fuel boilers are described. The main objective of research consisted in development of combination of coal dust and natural peat without binding additives. The role of peat consists that it increases efficiency of process of granulation, being natural binding. The method of granulation allows to utilize waste of the coal industry. Joint burning of two types of fuel – coal dust and peat reduces emission of sulfur dioxides. The cost of peat raw materials is lower, than artificial binding, applied to briquetting of coal dust. The composition of mix of coal dust and peat varied in the ratio 2:1, 1:1 and 1:2 in volume ratio at humidity of mix before extrusion of 65 %. In the course of preparatory operations of coal raw materials its crushing and sifting through sieve of 24 mesh (0,707 mm) was carried out. Procedure of hashing of samples of coal and peat was carried out before receiving homogeneous mixture. After hashing mix was located in piston press for receiving granules. Coal dust and wet peat pass semifixed extrusion on piston press with formation of cylindrical granules with a diameter of 16 mm. After extrusion of granule are dried to operational humidity of 25 %. Coal and peat fuel granules showed sufficient mechanical strength for transportation and power feed in solid-fuel boilers. Burning of coal and peat fuel granules in vitro at temperature of 800 °C does not lead to ashes agglomeration. The conducted preliminary researches showed prospects of utilization of coal waste by granulation method in mix with natural peat.
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Date submitted2014-07-21
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Date accepted2014-09-19
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Date published2014-12-22
Preliminary preparation of oil for primary processing
Oil supplied for primary processing always undergoes preliminary preparation, the purpose of which is to eliminate the harmful effect of water and salt contained in the oil. It is thought that corrosion of the equipment is connected mainly with chlorides of magnesium and calcium, which are subjected to hydrolysis with the formation of hydrochloric acid. Under the influence of hydrochloric acid the destruction (corrosion) of metal equipment at technological plants occurs (especially refrigerating-condensing and heatexchange equipment, furnaces of rectification units etc.). The authors of the article, on the basis of thermodynamic calculations, provide their point of view on this process and give a methodology by which the process of preliminary oil dehydration and desalting can be controlled. The thermodynamic calculations executed for standard conditions on the basis of refer-enced data confirm a high probability of chemical interaction of iron with hydrogen ions, hy-drogen sulphide and especially with carbonic acid. This testifies to high activity of the carbon dioxide dissolved in water and the impossibility of hydrolysis of ions of magnesium, calcium and iron. The calculations show that only the hydrolysis of magnesium chloride is possible tak-ing into account the ionic composition of the water phase in the oil. It should be noted that the presence of ions of chlorine shifts the iron potential in a nega-tive direction and increases the speed of corrosion of petrochemical equipment. The solution of this problem is in the development of modern methods of crude oil dehydration and desalting. It is also, however, in an intensification of the processes of mixing water-oil emulsions with wash-ing water by using various physical fields (for example, ultrasound) and creating new effective mixing devices on the basis of them.
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Date submitted1951-08-29
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Date accepted1951-10-16
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Date published1952-04-24
Nomogram for determining the chemical composition of a mixture of waters
- Authors:
- P. I. Zheltov
The mixing of two waters with different concentrations and chemical compositions can be analyzed by the graph-analytical method proposed by A. N. Ogilvy. Having established the rectilinear law of mixing two waters, A. N. Ogilvy constructs a graph in a rectangular coordinate system, plotting the total mineralization of the mixed water along the x-axis, and the content of individual components in the mixing waters along the y-axis. Such a graph-nomogram does not make it possible to take into account the volumes of mixing waters. The nomogram we propose compensates for the shortcoming of A. N. Ogilvy's graph and can be used in cases where it is necessary to determine the quantities of mixing waters. The nomogram we constructed is based on the law of change of all components of mixing waters according to the equation of a straight line established by A. N. Ogilvy. The content of components in mg/l or g/l from 0 to any value limited by the data of chemical analysis is plotted along the y-axis in a certain scale. The divisions convenient for calculating the ratio of the volumes of mixing waters are plotted along the x-axis, let's put it from 0 to 10 or, more conveniently, from 0 to 100. The left column of the nomogram (y-axis) is allocated for the components of one of the mixing waters, the right one - for the components of the second water.