RU2092757C1 - Thermal module for preparation of carbon sorbents - Google Patents

Abstract

FIELD: equipment for thermochemical processes of treatment of grain materials; carbonization and activation in production of active carbons. SUBSTANCE: module includes rotary carbonization and activation furnaces technologically connected by material and gas flows into single complex which is additionally provided with activation gas afterburning furnace mounted near activation furnace. This additional furnace is connected with unloading chamber. Firebox of carbonization furnace mounted separately is provided with heating chamber where heat-transfer agent superheating recuperator is mounted (air is used as heat-transfer agent). Recuperator is connected with heat-transfer supply and discharge chambers. Besides that, firebox is connected with unloading chamber of carbonization furnace. EFFECT: enhanced reliability. 2 dwg

Description

 The invention relates to the hardware design of thermochemical processes for processing granular materials, in particular carbonization and activation processes in the production of activated carbons.

 Known commercially available industry for the production of activated carbons apparatus with rotating drums containing a furnace, a rotating drum (housing), a loading device (estrus), loading (with countercurrent) and unloading (with forward flow) chamber.

The disadvantages of the known designs are:
low quality of the resulting product, as flue gases in the process of carbonization are in direct contact with the processed material;
unregulated temperature in the furnace, as the furnace does not have a dilution chamber, which also reduces the quality of the processed material;
the inability to use thermolysis gases as a coolant, which increases fuel consumption and, in the final result, the cost of products, rather than the complete combustion of thermolysis gases, leads to significant environmental pollution.

 Closest to the claimed invention is a plant for the thermal decomposition of carbon-containing materials (ed. St. USSR N 397729, class F 27 B 7/04, C 10 D 9/04, 1971), including a rotating drum with an internal retort, paired with a furnace ring diaphragm, loading and unloading devices.

 The known design does not allow you to adjust the temperature, because the afterburning of carbonization gases occurs unregulated in the annulus, which leads to a rapid failure of the furnace and retort. In addition, the design does not allow working in countercurrent mode, which reduces the quality of the resulting product, and also does not provide complete combustion of carbonization gases, which leads to significant environmental pollution.

 The task of the invention is to remedy these disadvantages.

 The subject of the application is a thermal module for producing carbon sorbents, containing rotary carbonization and activation furnaces, technologically connected by material and gas flows into a single complex, in which an activation gas post-combustion furnace connected to a load chamber is additionally installed in the activation furnace, as well as a carbonization furnace freestanding and equipped with a heating chamber, in which a heat carrier overheat recuperator (which uses air) is mounted, connected to the chambers th input and return the coolant; in addition, the furnace is connected to the discharge chamber of the carbonization furnace.

 The difference of the claimed module from the prototype is that: the activation and carbonization furnaces are technologically connected in a single complex for material and gas flows; the activation furnace additionally has an activation gas afterburner, which is connected to the discharge chamber; the carbonization furnace is equipped with an additionally installed coolant input chamber; the furnace of the carbonization furnace is made freestanding and equipped with a heating chamber, in which a heat carrier overheat recuperator is mounted, connected to the heat input and return chambers, in addition, the furnace is connected to the discharge chamber of the carbonization furnace.

 In FIG. 1 shows a carbonization unit; in FIG. 2 nodes activation and disposal.

 The carbonization unit contains a freestanding furnace 1 with a burner 2 and a heating chamber 3 with a recuperator 4 installed in it, a rotating drum 5 of the carbonization furnace with an internal retort 6, equipped with a loading device 7, an input chamber for a heated coolant 8, a return chamber for a cooled coolant 9, an unloading chamber finished carbonizate 10, exhaust fan 11 and flue 12.

 The activation unit includes a firebox 13 with a burner 14 and a dilution chamber 15, inside which a feed chute 16 is mounted, a rotating drum 17 of the activation furnace with steam-air supply pipes 18, on which a steam-air distributor 19 is fixed, an unloading chamber 20, an afterburner 21 with a burner 22 and a gas duct 23.

 The heat recovery unit consists of a recovery boiler 24 and a smoke exhauster 25.

 The term thermal module should be understood as a unified functional complex of sequentially located units of equipment for the production of activated carbon from various types of carbon-containing raw materials. At the same time, the equipment nodes are interconnected both in material and in gas flows.

 By installing nodes of various sizes, you can change the performance of the module as a whole. For example, an activation furnace with a diameter of 1.6 m and a length of 12 m gives an annual output of 500 t / year of finished AC, and a length of 16 m is 700 t / year (the dimensions of the rest of the equipment also change).

 The module works as follows. At the time of ignition, the fuel (liquid or gaseous) supplied through the burner 2 to the furnace 1 burns out and the resulting flue gases enter the heating chamber 3, heating the heat exchanger installed in it 4. The heat transfer medium heated to the heat exchanger 4 (which is used as air) is fed into the chamber 8. Moving along the annulus between the rotating drum 5 and the inner retort 6, the coolant heats the latter and enters the return chamber of the cooled coolant 9 and the smoke exhauster 11 is supplied to the recuperator 4 for heating. Flue gases from the heating chamber 3 are supplied to the boiler 24 to recover the remaining heat.

 After warming the retort 6, the carbon-containing material is fed into the reaction space by the loading screw 7. The processed material (carbonizate) from the retort 6 enters the discharge chamber 10 and through its lower pipe enters the activation furnace.

 During the heat treatment of carbonization in the reaction space of the retort 6, gaseous products of thermal decomposition are formed. The latter through the end pipe of the chamber for unloading the finished carbonizate 10 through the duct 12 are fed to the combustion chamber 1.

 In the steady-state operating mode, carbonization gases are completely burnt due to the high temperature in the furnace 1, while releasing the heat necessary for the carbonization process. Therefore, the consumption of fuel supplied through burner 2 is significantly reduced (80-90%).

 Simultaneously with the ignition of the carbonization furnace, the activation furnace is ignited.

 The fuel (liquid or gaseous) supplied through the burner 14 to the furnace 13 burns out and the resulting flue gases (coolant) enter the dilution chamber 15, where they are cooled to the technologically necessary temperature by supplying steam (in no case air) and fed into the rotating drum 17, moving on which he warms it up.

 After warming up the activation furnace, carbonate is fed from the carbonization furnace through the feed chute 16.

 When the drum 17 is rotated through a steam and air distributor 19, an activating agent (water vapor) is supplied through the perforated pipes 18 under the carbonizate layer, which penetrates the carbonizate layer. Through the pipes 18 located in the upper part of the drum 17, the air necessary for the combustion of the generated activation gases is supplied.

 With the steady-state operation of the activation furnace, part of the burned activation gases emit the heat necessary for the activation process, thereby reducing by 70-80% the fuel consumption supplied through the burner 14.

 Since the combustion of activation gases occurs along the entire length of the drum 17, thereby maintaining the same temperature regime along the entire length of the furnace, which is difficult to withstand during operation of one furnace 13.

 Received activated carbon through the lower pipe of the discharge chamber 20 is fed for cooling to a rotary drum refrigerator (not shown).

 The gas phase of activation (flue gas and unburned part of the activation gas) through the gas duct 23 enters the afterburning in the furnace 21.

 The flue gases of the afterburning furnace 21 and the heating chamber 3 of the furnace 1 are fed to heat recovery to the boiler 24 and then by the fan 25 into a chimney (not shown). In the waste heat boiler 24, it is possible to obtain superheated steam (supplied through a steam and air distributor 19) necessary for the activation process.

Using the inventive module allows you to improve the quality of the resulting material due to:
use of the principle of counterflow of the heat carrier and the processed material in the carbonization furnace;
controlling the temperature of the coolant supplied to the annulus of the carbonization furnace and the reaction space of the activation furnace.

 The thermal module provides complete combustion of carbonization and activation gases with utilization of the generated heat and is an environmentally friendly object, since gas emissions do not contain harmful impurities, and superheated air is used as a heat carrier in the annulus of the furnace. In addition, the claimed module is energy-saving, because at the established operating mode, it works at 80-90% on the heat obtained from the combustion of carbonization and activation gases.

 Using an additionally installed inlet chamber for the heat transfer medium of the carbonization furnace allows us to process the material both according to the principle of counterflow and direct flow, changing the place of entry in the supply and return chambers of the heat transfer medium.

Claims (1)

 A thermal module for producing carbon sorbents, containing rotary carbonization and activation furnaces with furnaces, loading and unloading chambers, characterized in that the carbonization and activation furnaces are technologically combined through material and gas channels into a single complex that includes an activation gas post-combustion furnace installed in the activation furnace, connected to the discharge chamber, the input chamber of the heated coolant and the return chamber of the cooled coolant, while the furnace of the carbonization furnace is autonomous and has a a baking chamber with a heat carrier heating recuperator mounted therein, connected to a heated coolant inlet chamber and a cooled coolant return chamber, wherein the carbonization furnace is connected to the discharge chamber of the carbonization furnace.

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