UA20328U - Use of vat evaporator (toaster-dissolventizer) as mechanism for distillation of solvent from solid mineral wealth (brown coal) after extraction thereof. - Google Patents

Abstract

Use of vat evaporator for distillation of solvent from solid mineral wealth (brown coal) after extraction thereof.

Description

Description of the invention

The useful model refers to the field of organic chemistry, namely to methods of processing solid fuel 2 fossils, coal and peat, by extraction with hydrocarbon solvents, in order to obtain lignite wax, which is widely used in precision casting, chemical, leather, paper, electrical engineering and other industries .

A known method of obtaining lignite wax by extracting lignite with a hydrocarbon solvent - extraction gasoline with (up 70-1202С, at a temperature 2-59 below the boiling point of the solvent in a 70 bucket extractor of the Griess system with subsequent distillation in a screw evaporator, which is used at the Semenivsk plant mountain wax. (The description appears in the book I. E. Svyatets, A. A. Agroskin. Brown coal as a technological raw material. M., "Nadra", 1976, 223 p. UDC 622.7321-622.813; A. A. Krychko, V. Lebedev. V., Farberov

I.L. Non-fuel use of coal. M., "Nadra", 1978, 215 p. UDC 622.7).

The disadvantages of the specified equipment are that due to the design of the screw evaporator, the small heating surface, more than 6095 heat in the form of steam, from the total required for removing the solvent from the coal, must be supplied in the form of open steam, due to which only a small part of the heat is usefully used, and "waste" steam condenses in refrigerators.

The remaining material after the extraction of lignite - extracted (bituminous) coal - is a valuable product and its physical and chemical characteristics practically do not differ from the original coal. 720 It contains a large amount of humic substances, has a high calorific value, etc. valuable consumer properties. However, up to 25...4595 of solvent and water are contained in the corner leaving the extractor. If this solvent is not returned to production, its losses will be significant and the cost price of lignite wax will increase. In addition, the solvent in the corner gradually evaporates and can create an explosive concentration in the air. Also, coal with a solvent cannot be used in further processing. Therefore, the solvent is removed by heat treatment with blunt and sharp steam. The purpose of heat treatment is to remove the maximum amount of solvent from the material.

In the process of distillation, the weakly bound solvent first evaporates from the surface of the material particles, and then the strongly bound solvent is separated, that is, the solvent molecules move from the inside of the particle to its surface. 09

Complete evaporation of the solvent is achieved by increasing the temperature of the process. At the same time, the influence of high temperatures in combination with oxygen leads to oxidation of coal and a decrease in fuel characteristics, which impairs the value of coal, as well as the possibility of spontaneous combustion. Therefore, the process of distilling off the solvent should be carried out in compliance with the conditions that ensure optimal wet-heat treatment. av)

It is possible to reduce the temperature of the solvent distillation process and shorten its duration by using it

From sharp steam, rarefaction inside the devices and mixing of the material. high school

The use of sharp steam ensures rapid heating of the material to the required temperature, a decrease in the concentration of solvent vapors above the surface (which accelerates the process of its removal), and the creation of a directed flow of solvent vapors from the devices. "

Rarefaction inside the devices in the process of distillation reduces the partial pressure of solvent vapors above the surface of coal, which intensifies the process of their removal. c Mixing of the material in the distillation process accelerates the heating of its particles and increases the rate of evaporation

Of" them the solvent. Coal processed in this way should have the following quality indicators: temperature should not exceed 1002C, humidity - 8...2595, solvent content in the material should be less than or equal to 0.196. 7 but the Channy evaporator (toaster desolventizer) (Fig. 1, 2) of Schumacher design, refers to the type of devices in which the solvent is distilled from the material in a moving layer (The description is reflected in the book Kaloshyn Yu. (av) A. Technology and equipment of oil and fat enterprises M., "Akademiya" Publishing Center, 2002, 36 p. The toaster is a column-type device (vertical cylinder) consisting of several (up to ten or more) vats, installed one above the other, which are divided into: ko 50 - one or more departments of preliminary desolventization, со - several departments of desolventization and toasting, Y - one department of desolventization by instantaneous evaporation and - one or more cooling departments.

In the departments of preliminary desolventization, the solvent is evaporated by introducing steam into the steam jacket, that is, by heating without direct contact of the steam with the material. The purpose of preliminary desolventization is to reduce the content of the solvent in the material to a level acceptable for subsequent calcination, in order to increase the economy of the process.

In the desolventization and toasting compartments, the material is exposed to hot steam, which is supplied through a number of holes in the bottom of the compartment. Hot vapor fractions rise from compartment to compartment towards the material, being evenly distributed over the entire volume of the material. The bottoms of all compartments are also heated by steam.

In the flash unit, a slight pressure drop is used to further reduce the solvent content in the material.

In the cooling compartment, cold air is supplied through holes in the bottom and passes through the material, as it cools it. The air leaving the cooling section is dedusted in appropriate cyclones before being released into the atmosphere.

Through all compartments (tanks) passes a vertical hollow shaft, which is rotated from below by an electric motor through a gearbox.

Knives are rigidly attached to the shaft and serve to evenly mix the material and move it from one tank to another. Hot steam is brought to the hollow shaft through a nozzle, which is then fed to the knives.

The movement of material from vat to vat is carried out through holes in the bottoms, which are closed by segmental passage valves (sluice gates), connected by means of a lever mechanism with regulators of the material filling level in the compartments or hydraulics. 70 In the bottom of each tank, except for the bottom one, there are holes for the passage of a mixture of solvent vapors and water from the lower tanks into the upper part of the toaster - the expander.

The material from the extractor is fed into the toaster through a nozzle with the help of a feeder. The removal of material with traces of solvent from the device is carried out from the bottom by a discharge auger with an individual drive through a nozzle. Sampling of material is carried out through a nozzle. Each vat is equipped with a peephole for inspection.

Pipes are provided for the installation of thermometers and pressure gauges.

Vapors of water and solvent, as well as dust captured by vapors from the desolventization-toasting unit, pass through the nozzle and are trapped in the wet trap (Fig. 1, 3), in which, thanks to the pump, hot water circulates in a closed circuit. Some installations use wet traps using a solvent.

Cyclonic wet trap (Fig. 1, 3) is included in the set of extraction lines, which include hot toasters. It is made in the form of a cyclone and consists of a cylindrical body with a conical bottom. An inlet for steam and solid particles is located tangentially to the cylindrical body.

Inside the device there is a central pipe for the release of purified vapors of the solvent and water.

Slotted nozzles are installed in the annular space between the outer cylinder and the central pipe for irrigating steam with hot water. An inspection window is located opposite each nozzle for monitoring their operation.

A pipe is provided for the exit of sludge water. In addition, in the conical part of the device there is a safety but hydraulic valve for the removal of steam when the pressure in the system increases.

On the branch (elbow) of the central pipe, there are nozzles and a hatch for cleaning settled dust particles of the material. со со Mixture of solvent vapors and water with particles of material (coal) enters tangentially into the annular space between the outer cylinder and the central pipe, where it is irrigated with hot water and begins a circular motion. Under the action of c centrifugal force, solid particles are thrown to the walls of the outer cylinder and washed away by a jet of hot c water.

Purified vapors of the solvent and water through the central pipe enter for condensation in the heat exchangers, where they give off their heat. Sludge waters are collected in the conical part and allocated through a nozzle for further processing.

Some extraction plants use wet traps using a solvent.

After cleaning the steam-gas mixture from small solid particles, it is subjected to regeneration in order to capture gasoline. "

A tank evaporator (toaster desolventizer) works in the following way. Coal from the extractor is fed into the upper part of the toaster - the expander through the sluice seam with the shutter and the feeder (if necessary, it is moistened with water in the screw feeder). From the upper tank, the processed material continuously passes through all the others, )" is kept for a certain time in each tank for uniform distribution of moisture and for more complete evaporation of the solvent and water. In the vats, the material is heated, steamed with hot steam and mixed with knives. The height of the layers in each tank is kept constant.

GI Vapors of the solvent and water from each tank through holes in the bottom of the tank and particles of the processed material are allocated to the expander, where they are first freed from solid particles. o The finished material with a temperature of no more than 1002C (depending on the solvent used), a moisture content of 8-2590 oz and a solvent content of no more than 0.195 is removed from the toaster through the auger and sluice gate.

The main advantages of the design of the toaster desolventizer are as follows: o - full use of the energy of bubbling steam, c - effective and uniform removal of the solvent from the material. The material, which is difficult to desolvent due to its physical properties, comes out of the installation with such a low solvent content that it is impossible to achieve with traditional equipment. - simplicity of design: a single installation instead of two separate units with their connecting conveyors in the traditional design. c - homogeneity of the material at the output due to the fact that each part of it is subjected to the same processing at each stage of the technological process. for

Claims (1)

The formula of the invention Application of a tank evaporator (toaster-desolventizer) as a device for distilling the solvent from a solid useful mineral (lignite) after its extraction in order to obtain lignite (mountain) wax. b5