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The combustion of coal mixtures is regarded both as a necessary step and as a technology which offers noticeable technical, economic, and ecological advantages. The choice of an optimal, or even acceptable, mixture requires knowledge of the characteristics and properties of the coals being blended and of how their behavior changes in a mixture. With mixing, all the indicators characterizing a coal undergo changes and an improvement in one may be accompanied by the deterioration of others. Based on experimental and published data, we have analyzed the major characteristics of mixtures that control the operation of coal-dust thermal power plants, first the ones which are not additive, and then those whose additivity is not evident without experimental study.The preparation and combustion of mixtures of coals with similar characteristics has long been done in worldwide practice, primarily to maintain the quality of the fuel in the market. In recent years European thermal power plants have customarily burnt mixtures of coals with different characteristics and properties that have been mined on different continents. The blends are prepared at coal depots in ports and at power plants. The permissible quality of the mixture is determined by the primary application intended for the mixture and by how much the characteristics of the coals differ from one another.Coal traditionally arrives at many Russian thermal power plants from several suppliers and is alternately fed "by rota" to the boiler bins in the form of a controlled mixture of the different coals from the depot. With rare exceptions, this does not yield an adequately uniform mixture, primarily because there is no operational control of the quality of the arriving coal or modern equipment for blending it at the coal depots. However, when there is a system for operational monitoring at the intake and for batching of the storage pile, or for separative storage of coals from different suppliers, high quality coal blending can be achieved in some cases even with available equipment.The combustion of coal mixtures is regarded both as a necessary step and as a technology which offers noticeable technical, economic, and ecological advantages. The use of coal blends for new technologies and thermal power plants makes it possible to standardize equipment, mass produce tested new designs, and provide high power thermal power plants with stable fuel.The advantages of using coal blends at operating power plants include the following: extending the range of acceptable coals and thereby reducing the dependence on a single (or monopoly) fuel supply; and, the possibility of burning coals which could not be burnt in their "pure" form at a given power plant, in particular coals that were not incorporated in the plant design, without substantial modification of equipment. The use of blends may be an optimum solution of the problem of reducing harmful emissions, such as sulfur oxides -by adding coal with a low sulfur or solid particulate content -through burning of a low-ash coal mi...

The development of protein ingredients based on the composites from secondary collagen-containing meat raw materials and obtained by the methods of deep processing attracts increasing attention of specialists.In the presented work, the composite and mass composition of the protein ingredient from hydrolysates of beef hide split, pork skin and blood plasma in a ratio of 45:45:10 was established. The improved amino acid composition of the protein ingredient due to addition of dry blood plasma suggests an increased biological and nutritional value of the developed product. Addition of up to 15 % of the protein ingredient instead of beef in the technology of minced semi-prepared products improves the rheological and organoleptic characteristics of the finished product.

It is shown that out-of-design coal should be used only after computational analysis of slagging of the boiler. The use of ash fusibility as a criterion for the analysis should be avoided because this property does not reflect the slagging properties of coal to an acceptable degree. Parameters characterizing the properties more appropriately are presented. It is shown that slagging of an actual furnace depends on many factors and the condition that "the thermal stresses should be lower than the limiting value" is insufficient. An algorithm for the analysis is suggested on the basis of the slagging conditions arising upon transition from one kind of fuel to another with allowance for the actual slagging situation.Keywords: out-of-design fuel, mixture of coals, joint firing, mineral part of coal, internal and external zones, slagging of a boiler, fouling based on active alkali, strength properties of deposits.Many thermal power plants fire out-of-design coals due to economic conditions or other factors or consider the possibility of using an alternative fuel in the future. Factors limiting the interchangeability of coals include the difference in their slagging properties. Neglect of this factor can lead not only to impermissible limitations in the operation of a boiler in the period when it fires out-of-design fuel but also to enhanced slagging and disturbed output of the boiler in subsequent operation on conventional or design coal. It is known that the range of coals applicable with respect to the slagging properties can be widened, if there is a possibility of replacing a part of the conventional coal by an out-of-design coal mixture, using the technology of joint firing [1], or operating at reduced loads in the period of firing the unconventional coal.It is obvious that in any situation the use of out-of-design coal should be preceded by a computational analysis of slagging of the boiler. When considering the possibility of the use of coal novel for the power industry the properties of the coal should be studied additionally. It is known that the fusibility of ash does not reflect appropriately the slagging properties of coal and cannot be recommended for analyzing the slagging capacity and ash tapping as is done, for example, in [2].The mineral part of coals. The slagging properties of coals depend primarily on the composition of their mineral part, which is represented by the set of mineral admixtures and mineral elements in the composition of the organic compounds. For low-ash coals like the Kansko-Achinskii ones the latter can exceed substantially half of the entire mineral part. In practice, the mineral part is frequently divided into internal and external ash. The external ash is understood as the fraction that separates easily from the coal substance during milling and contains particles of mineral admixtures and their concretions. The internal ash contains the mineral components of the organic compounds and fine mineral inclusions. As the particles of coal dust burn, the internal ash acquires their tem...

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