WO2017133029A1 - Device for drying brown coal or low-metamorphic long-flame coal, and method therefor - Google Patents

Abstract

A device for drying brown coal or low-metamorphic long-flame coal comprises a tank body (1). The tank body (1) sequentially consists of a preheating section (1A), a heating section (1B) and a cooling section (1C) from top to bottom. The tank body (1) is provided with a feeding hole (2), a discharging hole (5), an exhaust gas outlet (4), and a high-temperature gas inlet (3). The feeding hole (2) is formed in the top of the tank body (1), and the discharging hole (5) is disposed in the bottom the tank body (1). The exhaust gas outlet (4) is formed in the preheating section (1A) of the tank body (1), and the high-temperature gas inlet (3) is formed in the heating section (1B) or the cooling section (1C) of the tank body or is formed at the joint of the heating section (1B) and the cooling section (1C). An air inducing device (8) is connected to the exhaust gas outlet (4), and the high-temperature gas inlet (3) is connected to a high-temperature gas source device (3A, 3B). The drying device can control stopping time of coal in parts of the tank body by changing a feeding speed and a discharging speed or changing the shape and the volume of the tank body at preheating, heating and cooling stages, so as to control the drying effect, and can also change the drying effect by changing the temperature and the amount of fed steam or a mixed gas of the steam and other gases.

Description

 Drying device for lignite or low metamorphism long flame coal and method thereof Technical field

The invention relates to the field of processing and utilization of lignite or low metamorphic long flame coal, in particular to a device and a method for drying lignite or low metamorphosed long flame coal.

Background technique

As we all know, lignite or low metamorphic long flame coal is very large on the earth, but the water is high, the unit heat value is low, it is easy to absorb the water in the environment and the temperature rises to cause spontaneous combustion, easy to powder, low mechanical strength and thermal stability. It is not conducive to direct transportation and utilization. Over the years, countries around the world have done a lot of research on reducing the moisture of lignite or low-temperature long-flame coal, thereby increasing the unit heat value and improving the coal quality. However, there are still no mature technical processes and many drawbacks. The main ones are as follows: 1. The hot air energy consumption is high, and the heat energy of the large amount of water in the evaporated coal is too high, and the large amount of energy released by the lignite or low metamorphic long flame coal is not utilized; 2. The coal temperature during the drying process Below 105 °C, it fails to cause the lignite or low metamorphism long flame coal to change its own properties, the internal water is difficult to reduce, the product re-sucks the water in the drying process environment seriously; 3, the product is severely pulverized, mechanical strength, low thermal stability It is not conducive to transportation; 4, the equipment is complex, the cost is high, the production cost is high, and it is difficult to use in large-scale industrialization.

Summary of the invention

In view of the problems of the prior art, the present invention provides a device for drying lignite or low metamorphosed long flame coal and a method therefor. The moisture of the lignite dried by the device and method is significantly reduced, the unit heat value is increased, the particle volume is reduced, the water absorption is less, the mechanical hardness and thermal stability are well maintained, and the powdering and weathering are greatly reduced. During the drying process, the bulk heat of the lignite or low metamorphic long flame coal is released and the latent heat of vaporization is mostly recycled, the added energy consumption is low, the equipment cost is low, the production cost is low, the environmental protection is easy to control, and it is easy to mass production.

To achieve the above object, the technical solution of the present invention is:

A drying device for lignite or low metamorphism long flame coal, comprising a tank body; the tank body is composed of a preheating section, a heating section and a cooling section from top to bottom; the feeding port and the discharging body of the tank body The mouths respectively correspond to the top and bottom of the tank; the tank body further comprises one or more tail gas outlets and one or more high temperature steam inlets, and the tail steam outlets are arranged in the preheating section of the tank body The high temperature inlet port is disposed at a heating section, a cooling section of the tank body or at a junction of the heating section and the cooling section; the tail steam outlet is connected with a drafting device, and the high temperature inlet port One or more high temperature vapor source devices are connected.

A drying apparatus for lignite or low-grade long-flame coal as described above, wherein the feed port and the discharge port are provided with a gas shutoff device.

A drying apparatus for lignite or low metamorphosed long flame coal as described above is further provided with one or more air inlets in the preheating section of the tank.

A drying apparatus for lignite or low-grade long-flame coal as described above, wherein the high-temperature inlet is connected to a vapor dispersion device.

a drying apparatus for lignite or low metamorphosed long flame coal as described above, wherein the feed port and the discharge port have a cross-sectional area smaller than a cross-sectional area of the can body; and the feed port has a certain length of communication Inside the tank body, the discharge port has a certain length and communicates with the inside of the tank body.

A drying apparatus for lignite or low-grade long-flame coal as described above, wherein the tail gas outlet is connected to the high-temperature steam inlet.

A drying device for lignite or low metamorphosed long flame coal as described above, the steam source that is introduced into the high temperature inlet port is steam, or a mixture of steam and other gases, said steam, or a mixture of steam and other gases. The temperature of the steam is higher than 180 ° C, and the steam required, or the vapor of the mixed vapor of steam and other gases, should be such that the temperature of the coal in the heating section of the tank rises to 105 ° C - 180 ° C.

A drying apparatus for lignite or low-grade long-flame coal as described above, wherein the mixed vapor of steam and other gases contains oil vapor which is insoluble or poorly soluble in water.

A drying apparatus for lignite or low-grade long-flame coal as described above, wherein the mixed vapor of steam and other gases contains a vapor which is volatile at room temperature.

The lignite or low metamorphic long flame coal processed by the drying device of the brown coal or the low metamorphic long flame coal of the invention and the drying method thereof have the following advantages:

First, it is believed that steam of more than 180 ° C, or a mixture of steam and other gases, passes through the tank, and the temperature of the coal in the heating section of the tank is raised to 105 ° C - 180 ° C, which helps Improve the unit heat value of lignite or low-grade long-flame coal, and increase economic value and application range. Due to the poor strength of lignite or low metamorphic long flame coal, it is easy to weather and pulverize. The invention adds insoluble or poorly soluble oil steam or steam which is volatile at room temperature to the mixed steam, so that the produced lignite or low metamorphic long flame Coal is reduced in water content, and the unit heat value is improved. The mechanical strength and thermal stability are well maintained. In addition to fuel, it can be used as raw coal in other fields such as steam making and coal chemical industry.

Second, energy saving. Because lignite or low-grade long-flame coal itself will release a large amount of heat energy when it absorbs water, and it is connected to the vapor dispersion device through the high-temperature inlet port, so that the steam or steam mixed with steam and other gases and vapor evaporated from the coal vaporize. Most of the heat is utilized, so the heat source steam used in the method and the invention is used in a small amount and consumes less energy. Moreover, in addition to the high-temperature steam source device, the steam tail gas recovery of the power plant or chemical plant can be utilized as a heat source, and the latent heat of vaporization can be recycled and utilized. The source of the steam source is wide, and the society can save energy and reduce emissions.

Thirdly, the coal to be processed according to the invention is preheated, heated and cooled from top to bottom in a tank body, and the process is simple, the production is safe, the equipment cost is low, the production cost is low, and the large-scale industrial production and promotion are easy.

DRAWINGS

The drawings described herein are intended to provide a further understanding of the invention, and are intended to be a part of the invention. In the drawing:

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of a drying apparatus for lignite or low-grade long-flame coal of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in order to make the present invention. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

A drying device for lignite or low metamorphosed long flame coal as shown in FIG. 1 includes a can body 1. The can body 1 is sequentially composed of a preheating section 1A, a heating section 1B, and a cooling section 1C from top to bottom. The shape of the can body 1 may be a vertical cuboid, a square or a gourd shape, and the shape of the can body 1 should be such that the coal is uniformly preheated and heated as much as possible.

The tank body 1 is provided with a feed port 2 and a discharge port 5, and the feed port 2 is provided at the top of the tank body 1, and may be connected from the top surface of the tank body 1 to the inside of the tank body, or from the tank The side of the body 1 communicates with the inside of the tank; the discharge opening 5 is provided at the bottom of the tank body 1, The inside of the can body is connected from the bottom surface of the can body 1.

The can body 1 further includes one or more tail gas outlets 4 and one or more high temperature inlet ports 3. The tail gas outlet 4 is provided in the preheating section 1A of the tank body 1. Specifically, the tail gas outlet 4 is located at the top of the tank body 1, and may be connected from the top surface or the side surface of the tank body 1 to the inside of the tank body. The high temperature steam inlet 3 is provided in the heating section 1B of the tank body, the cooling section 1C, or at the junction of the heating section 1B and the cooling section 1C.

The tail gas outlet 4 is connected with a drafting device 8, which may be a device such as an induced draft fan, an air pump, or the like that can form a negative pressure environment in the can body 1.

The high temperature steam inlet 3 is connected to one or more high temperature steam source devices. In the present embodiment, the high temperature steam source device is provided as front and rear high temperature steam source devices 3A, 3B as shown in FIG. The steam source that enters the high temperature inlet port is steam, or a mixture of steam and other vapors. The steam source is heated by the front high temperature steam source unit 3A and then heated by the reheating unit (post high temperature steam source unit 3B). After the vapor. The steam generated by the front high temperature steam source device 3A is preferably low pressure superheated steam or steam tail steam with thermal energy; the higher the proportion of steam in the mixed steam, the better, other steam bodies should not cause processing. The coal that is on fire. The high temperature steam source device may be a steam superheater, a heat carrier boiler or a heat exchanger and other devices capable of heating the steam.

In operation, the coal to be processed 7 is sent to the feed port 2 provided at the top of the tank, and the coal 7 to be processed can fall by gravity or enter the vertical tank 1 according to the set feeding device. The cross-sectional area of the feed port 2 should be smaller than the cross-sectional area of the can body 1, and the feed port 2 has a certain length to communicate with the inside of the can body. In the embodiment, the feed port 2 is With a certain length extending into the interior of the tank, the column of coal that satisfies the filling of the material can prevent a large amount of air from entering the inlet 2.

The feed port 2 is provided with a gas shutoff device 6. When the coal 7 enters the tank body 1, the preheating section 1A located at the upper portion of the tank body is preheated by steam or mixed steam rising from the middle or lower portion of the tank body. At the same time, the absorption steam and the condensed water themselves heat up, and the further generated tail gas is mostly discharged from the one or more tail gas outlets 4 provided at the top of the tank. The operation of the air guiding device 8 connected through the tail gas outlet 4 allows the whole of the tank body 1 (other than the inlet port 3 to be positive pressure or negative pressure) to be in a negative pressure environment. The tail gas outlet 4 is connected to the high temperature inlet port 3. The tail gas drawn from the air introducing device 8 can be partially reused as a component of the mixed steam from the high temperature inlet port 3. A small amount of tail gas or condensed water is accompanied by coal particles falling.

The invention also adds one or more air inlets 9 in the middle or lower portion of the preheating section 1A of the can body 1. The air inlet 9 is connected to a gas dispersing device so that the gas is uniformly diffused. Air enters the interior of the tank from the air inlet 9 and is extracted from the plurality of tail gas outlets 4 at the top of the tank. A large amount of condensed water and low temperature tail gas can be entrained from the surface of the coal particles and the tank body to reduce the condensed water accompanying the coal particles. It is heated repeatedly to reduce the total energy consumption of drying.

The steam source that is introduced into the high temperature inlet port 3 is steam or a mixture of steam and other gases. The higher the proportion of steam in the mixed steam, the better. The other vapors in the mixed steam may be exhaust gas with thermal energy extracted from the tail gas outlet 4 as described above, and may be air or air. Contains oil vapors that are insoluble or poorly soluble in water, or other beneficial vapors such as vapors that are volatile at room temperature. The high temperature steam inlet 3 is connected with a vapor dispersing device so that the steam or the mixed steam is uniformly diffused. The coal from the tank preheating section 1A continues to descend to the heating section 1B. The steam or steam mixed with the other gas entering from the high temperature inlet port 3 heats and dries the coal slowly descending from the upper portion, and the temperature of the steam, or the mixture of steam and other gases, should be higher than 180 ° C (steam is lower than steam) 180 ° C drying capacity is limited, drying speed is slow, steam consumption is large), and the required steam, or steam of steam and other gases, the steam should be able to increase the temperature of the coal in the heating section 1B of the tank To 105 ° C - 180 ° C (product coal below 105 ° C is easy to reabsorb moisture in the air, volatiles in the product coal above 180 ° C easily escape). During the drying process, the steam or the mixture of steam and other gases has its own temperature reduced or partially condensed, and the uncondensed tail gas and the vapor evaporated from the coal mostly rise, and further heat exchange with the coal and air above. A small part of the coal particles go down.

As described above, the present invention adds insoluble or poorly water-soluble oil vapor to the mixed steam which is introduced into the high temperature steam inlet, because the negative pressure environment operates, the oil vapor is easily absorbed by the coal particles, and the waterproof performance of the finished coal can be enhanced. .

As described above, the present invention adds a vapor which is easily volatilized at a normal temperature such as alcohol or industrial alcohol to the mixed steam which is introduced into the high temperature steam inlet, so that the coal can be further dehydrated during the heating process and the stacking process.

The coal heated and dried by the heating section 1B continues to descend, and the water itself is further evaporated, while gradually cooling itself, and finally discharged from the discharge port 5 at the bottom of the tank. The cross-sectional area of the discharge opening 5 is smaller than the cross-sectional area of the can body 1, and the discharge opening 5 has a certain length protruding out of the can body 1 to satisfy the coal column to prevent a large amount of air from the discharge opening. 5 Enter the tank. The discharge port 5 is provided with a gas shut-off device 6, and the coal discharged from the tank body can be cooled by natural cooling or further forced cooling (while itself will evaporate a part of water again), that is, the finished product.

The invention can control the residence time of the coal in various parts of the tank by changing the feed and discharge speed, or changing the shape and volume of the tank body in the preheating, heating and cooling stages, thereby controlling the drying effect, and also changing the supply. The steam or the temperature and vapor of the mixture of steam and other gases change the drying effect.

The above description shows and describes a preferred embodiment of the present invention. As described above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be construed as being Combinations, modifications, and environments are possible, and can be modified by the teachings of the above teachings or related art within the scope of the inventive concept described herein. All changes and modifications made by those skilled in the art are intended to be within the scope of the appended claims.

Claims (9)

A drying device for lignite or low metamorphism long flame coal, comprising a tank body; wherein: the tank body is composed of a preheating section, a heating section and a cooling section from top to bottom; the feeding of the tank body The mouth and the discharge port are respectively disposed at the top and the bottom of the tank; the tank body further includes one or more tail gas outlets and one or more high temperature steam inlets, and the tail steam outlet is disposed in the tank body The preheating section, the high temperature inlet port is disposed at a heating section, a cooling section of the tank body or at an interface of the heating section and the cooling section; the tail steam outlet is connected with a drafting device, The high temperature steam inlet is connected to one or more high temperature steam source devices. A drying apparatus for lignite or low-grade metamorphic long-flame coal according to claim 1, wherein said inlet port and the discharge port are provided with a gas shutoff device. A drying apparatus for lignite or low metamorphosed long flame coal according to claim 1, characterized in that one or more air inlets are provided in the preheating section of the tank. A drying apparatus for lignite or low metamorphosed long flame coal according to claim 1, wherein said high temperature inlet port is connected to a vapor dispersing device. A drying apparatus for lignite or low-grade metamorphic long-flame coal according to claim 1, wherein said feed port and the discharge port have a cross-sectional area smaller than a cross-sectional area of the can body; and The feed port has a certain length to communicate with the inside of the tank body, and the discharge port has a certain length to communicate with the inside of the tank body. A drying apparatus for lignite or low metamorphosed long flame coal according to claim 1, wherein said tail gas outlet is connected to said high temperature inlet port. A drying apparatus for lignite or low metamorphosed long flame coal according to claim 1, wherein the steam source that is introduced into the high temperature inlet port is steam, or a mixture of steam and other gases, said steam, Or the temperature of the mixture of steam and other gases is higher than 180 ° C, and the required steam, or the vapor of the mixture of steam and other gases, should increase the temperature of the coal in the heating section of the tank to 105 ° C - 180 °C. A drying apparatus for lignite or low metamorphosed long flame coal according to claim 7, wherein said mixed vapor of steam and other gases contains oil vapor which is insoluble or poorly soluble in water. A drying apparatus for lignite or low metamorphosed long flame coal according to claim 7, wherein said mixed vapor of steam and other gases contains a vapor which is volatile at room temperature.