RU2611630C1 - Method for preparation of water-bearing fuel-coal slurry - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: invention relates to a method for preparation of water-bearing fuel and coal slurry comprising M40 mazut dispersion, containing 1 % wt of water, in an amount of 60 % wt, grinding the dry coal in an amount of 40 % wt or dropout of it in a grinder to fraction less than 10 mm, supply of water-mazut mixture and pulverized coal in a mixer, mixing them in a mixer, subsequent supply of mixture to the next stage of dispersion of coarse grind, regrinding of slurry in a fine grinder, after which the slurry becomes homogenity and stable flow characteristics because of humic acids and humates extracted from coal.

EFFECT: increased calorific efficiency of fuel in form of a slurry.

3 tbl, 1 dwg

Description

The invention relates to the field of fuel energy, in particular to methods for preparing liquid fuel based on coal, suitable for direct combustion in boilers, furnaces and various power plants; for pipeline transportation and long-term storage, designed to replace coal, fuel oil and gas at fuel processing facilities.

The prior art [patent RU 2178455 C1, publ. January 20, 2002] there is a known method for producing coal-water fuel, which makes it possible to obtain highly demineralized ecologically clean "ecowoot" coal-water fuel based on fossil coal, water and other chemical ingredients (if necessary), intended to replace gas and fuel oil at fuel-consuming facilities. The ecowoot preparation technology includes crushing coal, wet grinding it to obtain a water-coal suspension, stepwise demineralization, moreover, the ecowut solid phase water-coal fuel is crushed to a colloidal size (average size not more than 3 microns). Demineralization is carried out by flotation, then demineralized coal is dehydrated to the required moisture, and then the necessary chemical additives are introduced.

The disadvantages of the above method include: 1) high energy consumption for grinding the solid component up to 3 microns; 2) the complexity of conducting multi-stage demineralization in foam flotation apparatus; 3) the need for dehydration of the finely ground product; 4) the possible need for the use of various chemical additives.

The closest technological solution to the present invention is a method for the preparation of cavitation water-coal fuel (KaWUT) and a production line for its implementation [patent RU 2380399 C2, publ. 01/27/2010], which allows to obtain coal-water fuel using cavitation effects, including the preparation of alkaline water, grinding dry coal, mixing them in a mixer and directing the mixture into a cavitation coarse dispersant, with further passage through three cavitation finely divided dispersers.

The disadvantages of this method are the lack of an accurate mass concentration of substances, which is necessary for the preparation of a stable water-coal fuel, as well as the lack of consideration of the total specific calorific value, and as a result, the relatively small (relative to the proposed method) specific calorific value of the resulting fuel.

The technical result of the invention is to increase the calorific value of the fuel in the form of a suspension.

The technical result is achieved by a method of preparing an aqueous coal-fuel suspension, including dispersing fuel oil grade M40 containing 1 wt.% Water, grinding dry coal or screening it in a grinder to a fraction of less than 10 mm, feeding a mixture of water-fuel oil and ground coal into the mixer, mixing them in the mixer, with the subsequent direction of the mixture to the next stage of dispersion of coarse grinding, regrinding the suspension in a fine grinder, and which is characterized by the fact that fuel oil and coal are used in quantities 60 wt.% And 40 wt.%, Respectively.

That is, the technical result is achieved by the fact that the composition of the suspension includes fuel oil (with a water content of 1 wt.%) Having a high calorific value of 41.2 MJ / kg (according to the reference data of the engineering reference table tehtab.ru [http: // tehtab. ru /]) in combination with finely divided dry charcoal, whose calorific value is 29.6 MJ / kg (according to the reference data of the engineering reference table tehtab.ru [http://tehtab.ru/]), which can be dispersed as by means of cavitation dispersant, and by means of a disintegrator or a de-membrane ator.

Dry charcoal was selected based on the analysis of the maximum specific heat of combustion of various types of dry coal (the data are shown in Table 1 in accordance with the reference data of the engineering reference table tehtab.ru [http://tehtab.ru/]).

The mass concentration of the components of the proposed water-containing coal-coal suspension is selected based on the calculation of the maximum specific calorific value of the whole mixture, taking into account the cost of the components and the stability of the suspension depending on the amount of solid particles.

The proposed method is illustrated by the following examples.

Example 1. Fuel oil grade F5 (with a water content of 0.3 wt.% From fuel oil) is selected in an amount of 60 wt.% Through a volumetric dispenser and sent to a mixer, where it is thoroughly mixed with dry coal or its screening in an amount of 40 wt.% ( fraction less than 10 mm). Dry coal or its screening before mixing with fuel oil is first crushed to a fraction of less than 10 mm, then it is sent to a receiving hopper by a belt or other conveyor, after which it enters the mixer to the homogenization stage with a water-fuel oil mixture. The resulting suspension, which is a water-containing coal-coal mixture, is sent from the mixer to the dispersion stage (dispersion can be carried out either by means of a cavitation dispersant, or by means of a disintegrator or de-separator) of coarse grinding, during which grinding, homogenization, destruction of the solid component of the fuel, and separation of humic acids and the formation of salts of humates, etc. Next, the suspension is sent to the next mixer, and then to the stage of dispersion of the fine grinding, where it is further milled, homogenized, the destruction of the solid component, the release of humic acids and the formation of humates. Leaving the mixer, the suspension is sent to the receiving tank of the stage of dispersing the fine grinding of the first stage, then passing sequentially the stage of dispersing the fine grinding of the second and third stages. After processing at the last stage of dispersion, a finely divided homogeneous and starting to “thicken” water-containing coal-coal suspension is sent to the receiving tank, and then to the stage of fine grinding of the fourth stage, in which all technological operations of grinding, homogenization, heating, and the release of humic acids and humates are completed and direction to the storage tank.

Example 2. The method is carried out in accordance with example 1 with the difference that the fuel oil is selected in the amount of 70 wt.%, And the crushed dry coal before mixing with fuel oil is selected in the amount of 30 wt.%.

Example 3. The method is carried out in accordance with example 1 with the difference that the fuel oil is selected in the amount of 80 wt.%, And the crushed dry coal before mixing with water and fuel oil is selected in the amount of 20 wt.%.

Example 4. The method is carried out in accordance with example 1 with the difference that the fuel oil is selected in the amount of 90 wt.%, And the crushed dry coal before mixing with water and fuel oil is selected in the amount of 10 wt.%.

Example 5. The method is carried out in accordance with example 1 with the difference that the brand M40 fuel oil is used, where the water content in the fuel oil is 1.0 wt.%.

Example 6. The method is carried out in accordance with example 2 with the difference that the brand M40 fuel oil is used, where the water content in the fuel oil is 1.0 wt.%.

Example 7. The method is carried out in accordance with example 3 with the difference that the brand M40 fuel oil is used, where the water content in the fuel oil is 1.0 wt.%.

Example 8. The method is carried out in accordance with example 4 with the difference that the brand M40 fuel oil is used, where the water content in the fuel oil is 1.0 wt.%.

Example 9. The method is carried out in accordance with example 1 with the difference that the fuel oil brand Ml00 is used, where the water content in the fuel oil is 10 wt.%.

Example 10. The method is carried out in accordance with example 2 with the difference that the fuel oil brand Ml00 is used, where the water content in the fuel oil is 10 wt.%.

Example 11. The method is carried out in accordance with example 3 with the difference that the fuel oil brand Ml00 is used, where the water content in the fuel oil is 10 wt.%.

Example 12. The method is carried out in accordance with example 4 with the difference that the brand Ml00 fuel oil is used, where the water content in the fuel oil is 10 wt.%.

At different mass ratios of components with respect to the total mass of the mixture, suspensions are formed with different total specific calorific value and different and price (according to http://www.pulscen.ru/price/040112-mazut, http://velar.ru/ catalog) for the product received.

According to the data from table 3, a graphical dependence of the amount of calorific value for the suspension was calculated taking into account the cost of the components (q ^c _∑ ) from the amount of charcoal for different water contents in the fuel oil composition (Fig. 1).

From those shown in FIG. 1 of the data on the total calorific value of suspensions, taking into account the cost (described in examples 1-12), we can conclude that the methods described in examples 5-8 are the most beneficial from the point of view of achieving maximum calorific value and the cost of the whole suspension. Therefore, it is more advisable to use fuel oil of the M40 brand in an amount of 60 wt.% (With a water content of 1 wt.%) And charcoal in an amount of 40 wt.%, Which will give a maximum calorific value.

Claims (1)

A method of preparing a water-containing fuel-coal suspension, comprising dispersing fuel oil of brand M40 containing 1 wt.% Water, grinding dry coal or sieving it in a grinder to a fraction of less than 10 mm, feeding a mixture of water-fuel oil and ground coal into a mixer, mixing them in a mixer , in the subsequent direction of the mixture to the next stage of dispersion of coarse grinding, regrinding the suspension in a fine grinder, after which the suspension acquires homogeneity and stable rheological properties, thanks to I humic acids and humates, characterized in that fuel oil and coal are used in an amount of 60 wt.% and 40 wt.%, respectively.

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