CN201844667U - Belt type conveying and drying system and device using solar energy to dehydrate and improve quality of brown coal - Google Patents

Abstract

The utility model relates to the field of high-efficiency utilization of coal and aims at providing a belt type conveying and drying system and a method using solar energy to dehydrate and improve the quality of brown coal. The system comprises a feed preheating chamber, a dryer and a discharge cooling chamber which are connected by belt type conveying equipment in sequence; the dryer is divided into an air preheating chamber and a drying chamber by a vertical partition wall; a through hole is arranged on the partition wall; the air preheating chamber is provided with an air inlet; the drying chamber is provided with an air outlet; the discharge cooling chamber is provided with a fresh air inlet; an air outlet of the discharge cooling chamber is connected with the air inlet of the air preheating chamber by an air pipe; an air outlet of the drying camber is simultaneously connected with an air inlet of the feed preheating chamber and the air inlet of the air preheating chamber by the air pipe; and an air outlet of the feed preheating chamber is connected with a coal powder separating system. The utility model has the advantages of obvious effects of energy saving and emission reduction, simple drying technique, small initial investment, low running cost, low consumption of conventional energy and low pollutant emission. Moreover, the management and application of the whole device are easier to be accepted by users.

Description

Belt transfer drying system and device for dehydration and upgrading of lignite by using solar energy

technical field

The utility model belongs to the field of high-efficiency utilization of coal, and in particular relates to a belt-type transfer drying system for realizing lignite dehydration and upgrading by utilizing solar energy. the

Background technique

my country's lignite reserves are very rich, and the proven reserves are more than 100 billion tons, accounting for about 13% of the total coal reserves. With economic development and the decline of recoverable reserves of high-quality coal resources, it is of great significance to effectively utilize lignite. However, lignite is a mineral coal with the lowest degree of coalification, which has high moisture content (generally 25wt%-50wt%), low calorific value (generally 1500kcal/kg-3500kcal/kg), and poor long-distance transportation economy. These disadvantages of lignite increase the utilization cost of lignite, reduce its market competitiveness, and limit the efficient and large-scale use of lignite. Therefore, reducing the moisture content of lignite and increasing energy density has become the key technology for lignite pretreatment. the

Research on lignite dehydration and upgrading technology has begun to become a hot spot at home and abroad, and a lot of research has been done abroad. There are many lignite dehydration and upgrading technologies, which can be roughly divided into three categories: mechanical dehydration, evaporative dehydration and non-evaporative dehydration. Law. Mechanical dehydration has been widely used in coal preparation plants, but its processing capacity and dehydration efficiency are still difficult to meet the requirements. The evaporative dehydration method uses hot oil, hot air, superheated steam and other media to directly or indirectly heat the lignite to remove the moisture in the lignite in gaseous form. The evaporative dehydration process requires a lot of energy to evaporate water, which consumes a lot of energy. The non-evaporative dehydration method is mainly divided into hydrothermal treatment method and mechanical hot pressing dehydration method, which removes the moisture in lignite in liquid form. The non-evaporative dehydration method has complicated process and high cost, and has not been put into industrial application at present. In addition, the non-evaporative dehydration method also brings problems such as wastewater and waste gas treatment. the

There are relatively few domestic studies on lignite dehydration and upgrading, and there are few reports. Domestic lignite dehydration and upgrading processes mainly include flue gas drying method and superheated steam drying method. Due to the high volatile content of lignite, the former is easily ignited and burned due to the influence of the air inlet temperature, and the drying efficiency is low, and the equipment is huge and the investment cost is high. The latter uses high-grade energy superheated steam as a heat source, which is expensive and consumes a lot of energy, which is not suitable for my country's national conditions. the

Therefore, it is of great significance to develop a green lignite dehydration technology with low energy consumption, low emission, low cost, safety and reliability. At present, there is no process and technology for dehydrating and upgrading lignite by using solar energy resources at home and abroad. The utility model fully utilizes the characteristics that the areas rich in lignite resources and the most abundant solar energy resources in my country fill the blank of solar lignite dehydration and upgrading. the

Utility model content

The technical problem to be solved by the utility model is to overcome the deficiencies in the prior art and provide a belt-type transfer drying system which uses solar energy to realize lignite dehydration and quality improvement in the original coal conveying system of the factory. the

In order to solve the technical problems, the utility model is achieved through the following technical solutions:

Provided is a belt transfer drying system that utilizes solar energy to realize dehydration and upgrading of lignite, comprising a feed preheating chamber, a drier, and a discharge cooling chamber sequentially connected by belt conveying equipment, characterized in that the drier is composed of a The vertical partition is divided into two parts: the air preheating chamber and the drying chamber. The partition is provided with a through hole, the air preheating chamber is provided with an air inlet, and the drying chamber is provided with an air outlet; the belt conveyor traverses the feed preheating chamber, Drying chamber and discharge cooling chamber; the discharge cooling chamber is provided with a fresh air inlet, the air outlet of the discharge cooling chamber is connected to the air inlet of the air preheating chamber through the air pipe, and the air outlet of the drying chamber is simultaneously connected to the feed air inlet through the air pipe. The air inlet of the preheating chamber and the air inlet of the air preheating chamber, and the air outlet of the feed preheating chamber are connected to the pulverized coal separation system. the

In the utility model, the cross-section of the dryer is a right-angled trapezoid, the drying chamber is on the side of the longer straight side, and the air preheating chamber is on the side of the shorter straight side; the shorter straight side and the hypotenuse of the dryer are transparent The glass cover plate, the bottom of the air preheating chamber and the side of the partition are provided with corrugated absorbing plates; the side of the drying chamber opposite to the partition is provided with a reflective plate, and the reflective plate extends beyond the glass cover plate. the

In the utility model, the loading part of the belt conveying equipment is a belt-type barbed wire. the

In the utility model, the upper part of the drying chamber is provided with an air curtain connected to the dust remover for blowing out the air curtain for cleaning dust. the

In the utility model, a fan is provided at the through hole on the partition of the dryer, and the through hole communicates with the lower air chamber of the belt conveying equipment, so that the hot air passes through the belt conveying equipment vertically after flowing through the lower channel. the

In the utility model, a one-way valve or blower is arranged on the air duct according to the transmission direction of the hot air. the

Further, the utility model also provides a device for realizing lignite dehydration and upgrading by using solar energy based on the aforementioned belt-type transfer drying system, including a coal bunker, a crushing device and a product coal bunker, and the coal bunker is connected to the A crushing device, the crushing device is connected to the feed preheating chamber through a belt conveyor, and the pulverized coal separation system is connected to the product coal bunker through a pulverized coal conveying device. the

In the utility model, the method for utilizing solar energy to realize lignite dehydration and upgrading based on the aforementioned device comprises the following steps:

(1) Send the lignite block of the coal bunker into the crushing device, so that the lignite is broken into coal particles whose particle size is below 6mm;

(2) Use the belt conveying equipment to first send the crushed coal particles into the feed preheating chamber, and exchange heat with part of the hot air from the drying chamber to preheat the coal particles;

(3) Send the preheated coal particles into the drying chamber, receive the solar radiation and the heat and mass transfer of the hot air from the air preheating chamber, the final temperature of the coal particles rises, the water evaporates and is taken out by the hot air for drying room, the coal particles are dried;

(4) Put the dried coal particles into the discharge cooling chamber to contact with the fresh air, cool the coal particles, and preheat the fresh air at the same time;

(5) Collect the product lignite coal particles from the discharge cooling chamber. the

In this method, also include:

(1) The hot air coming out of the drying chamber is divided into two parts, the first part of the hot air is recycled, mixed with the fresh air preheated in the coal unloading cooling room, heated by the air preheating room, and sent into the drying room; the second part is heated Air is sent into the feed preheating chamber to preheat the coal particles to be dried;

(2) The air discharged from the feed preheating chamber is separated from the air and the coal powder carried in the air through the pulverized coal separation system;

(3) The separated pulverized coal enters the product coal bunker, and the separated air is discharged into the atmosphere. the

The utility model utilizes a semi-closed air system through cold and hot air circulation and fresh air supplementation, and has a built-in air preheating dryer; the coal particle conveying equipment passes through the middle part of the feeding preheating chamber, drying chamber and unloading cooling chamber in sequence, and The front and rear process equipment connected to the drying chamber realize the preheating, drying and cooling process in sequence according to the requirements of the heat exchange principle; the air circulation semi-closed system refers to the fresh air passing through the discharge cooling chamber to cool the hot coal particles, and after preheating itself, Part of the dried hot air enters the built-in air preheating chamber of the drying chamber, and uses solar light to increase the air temperature for recycling, while the other part of the hot air enters the feed preheating chamber to preheat coal particles, which reduces the humidity in the air , and recycle hot air to form a semi-closed air system. the

Compared with traditional desiccators, this device realizes the purpose of one room and two uses, and makes the structure more compact. The glass cover plates of the air preheating chamber or the drying chamber are arranged obliquely, and share one facing the direction where the sunlight is sufficient. the

In the utility model, the temperature of lignite, the drying medium entering the discharge cooling chamber, can reach up to 100°C, and the temperature of the air entering the drying chamber can reach 50-70°C. The lignite with a moisture content (full water) of more than 30% can be dried to less than 5%. According to the measured results, the thermal efficiency of the drying device can reach up to 61% (the thermal efficiency of the traditional drying device is generally 40%). the

The beneficial effects of the utility model are:

Compared with the prior art, the utility model has the following advantages and outstanding effects:

The effect of energy saving and emission reduction is remarkable, and the lignite is dried on-site by using the abundant solar energy in Inner Mongolia, Yunnan, Xinjiang and other places rich in lignite production; the drying process is simple, the initial investment is small, the operation cost is low, the conventional energy consumption is small, and the pollutant discharge is small; However, the traditional heat treatment method not only consumes a lot of fossil energy, but also produces flue gas and increases _CO2 emissions. Therefore, solar drying of lignite has obvious energy-saving and emission-reducing effects.

Using solar non-focus dryer, the drying temperature of lignite is 90-100℃, the temperature is relatively low, and the heating is uniform, without local overheating and short-term high temperature, which will change the quality of coal, and also prevent spontaneous combustion and explosion. phenomenon, which effectively solves the potential safety hazards that may be caused by the traditional direct heating and drying of flammable lignite. the

There is no fluidized flow pattern control problem in the drying device, which makes the system operation simple and stable; according to the needs of drying speed and drying capacity, the coal input amount of the system is adjusted. the

The device and system of the utility model can be directly connected to the fuel system of the power plant, arranged online, and combined with the fuel system and equipment of the power plant, and even part of the equipment can be used. Therefore, the management and use of the entire device are easier to be accepted by users. the

The utility model can be used in a large-scale lignite drying and upgrading process to realize high-efficiency, low-pollution and low-cost utilization of lignite. the

Description of drawings

Fig. 1 is the schematic flow sheet that utilizes solar energy to realize lignite dehydration and upgrading system in the utility model;

Fig. 2 has shown the structural representation of belt type transfer drying device;

Fig. 3 is a cross-sectional view along A-A in Fig. 2 . the

Reference signs: 1 coal bunker, 2 crushing device, 3 feeding preheating chamber, 4 discharging cooling chamber, 5 product coal bunker, 6 dryer with built-in air preheating, 7 pulverized coal separation system, 8, coal seam, 9 chain barbed wire, 10 pulley, 11 air preheating chamber, 12 corrugated absorbing plate, 13 glass cover, 14 air inlet, 15 dust collector, 16 air curtain machine, 17 air outlet, 18 air curtain, 19 reflector, 20 drying room, 21 insulation layer, 22 fan. the

Detailed ways

Embodiments of the utility model are described in detail below in conjunction with the accompanying drawings. the

Figure 1 is a schematic flow diagram of a system for dehydrating and upgrading lignite by using solar energy. The device includes a coal bunker 1, a crushing device 2, a product coal bunker 5, a pulverized coal separation system 7, a feed preheating chamber 3, a dryer with built-in air preheating 6, and a discharge cooling chamber 4; the coal bunker 1 passes through raw coal The conveying equipment is connected to the crushing device 2, and the crushing device 2 passes through the feeding preheating chamber 3, the dryer 6, and the discharging cooling chamber 4 in turn through the belt conveying device with holes, and then connects to the product coal bunker 5; the discharging cooling chamber 4 Set the fresh air inlet, the air outlet of the discharge cooling chamber 4 is connected to the air inlet of the preheating chamber 11 through the air pipe, and the air outlet of the drying chamber 20 is connected to the air inlet of the feeding preheating chamber 3 and the air preheating chamber through the air pipe The air inlet of 11 and the air outlet of the feed preheating chamber 3 are connected to the pulverized coal separation system 7, and the pulverized coal separation system 7 is also connected to the product coal bunker 5 through the pulverized coal conveying equipment. the

Fig. 2 is a structural schematic diagram of a belt transfer drying device, and Fig. 3 is a sectional view A-A of a dryer with built-in air preheating. It includes belt conveying equipment with holes for transporting coal particles. The loading part is a chain wire mesh 9, and the lignite is laid flat on the belt wire mesh. The movement of the lignite is driven by the transmission of the belt wire mesh. Material preheating chamber 3, dryer with built-in air preheating 6, unloading cooling chamber 4, enters the product coal bunker 5, and completes the entire dehydration process of preheating, drying, and cooling. The dryer 6 with built-in air preheating is divided into two parts: a built-in air preheating chamber 11 and a drying chamber 20. The air preheating chamber 11 is placed in the drying chamber 20, and the preheating chamber 11 is connected to the drying chamber through a tuyere. 21, a fan 22 is installed at the tuyere; a glass cover plate 13 is arranged on the top of the drier with built-in air preheating, and a corrugated absorbing plate 12 is laid on the bottom and north wall of the preheating chamber 11; It passes through the middle of the drying chamber 20 and connects the feed preheating chamber 3 and the discharging cooling chamber 4 of the front and rear process equipment of the dryer 6; the preheating chamber 11 is provided with an air inlet 14, and the drying chamber 20 is provided with an air outlet 17. the

The glass cover plate 13 of the drier 6 with built-in air preheating is arranged obliquely, and towards the direction that the sun shines enough, wherein the glass plate on the south side of the air preheating chamber is vertically arranged. On the north side inner wall of the drying chamber 20, a vertical reflector 19 is set (or the side wall is coated with reflective paint), which is used to reflect sunlight and penetrate the glass cover plate 13 to enter the desiccator 6 and absorb the sun. Light reflects off the coal surface. The top of the drying chamber 20 is provided with an air curtain machine 16 connected to the dust remover 15 for blowing an air curtain 18 for sweeping dust. the

Process flow and working principle of the present utility model are:

The lignite is sent out from the coal bunker 1, broken into coal particles by the crushing device 2, and evenly spread on the belt-type wire mesh 9, and transported to the feed preheating chamber 3 through the transmission of the chain, and heated by the exhaust gas of the drying chamber 20. , the temperature rises and preheats initially. The preheated coal particles are sent into the dryer 6 with built-in air preheating by the same conveying device, and receive the direct sunlight radiation passing through the glass cover plate 13 and the reflection of the sunlight radiation on the reflection plate 19 on the north wall of the drying chamber. Radiation, while the heated air in the preheating chamber 11 penetrates the coal seam, and heat and mass transfer occurs with the lignite coal particles, the temperature of the lignite rises, and the moisture is removed. The dried lignite coal particles are sent to the unloading cooling chamber 4 by the same conveying device, and the fresh air enters the unloading cooling chamber 4 to cool the lignite. The temperature of the dehydrated lignite is lowered and sent to the product coal bunker 5 . The belt conveying equipment is used to connect the feed preheating chamber, the dryer and the discharge cooling chamber to complete the dehydration process of lignite preheating, drying and cooling. the

The heated air in the preheating chamber 11 enters the drying chamber 20, penetrates the coal seam, and transfers heat and mass with the lignite. In the early stage of drying, the temperature of the lignite bottom layer is relatively low, and the air temperature is relatively high. On the one hand, the hot air passes through the coal seam, heats the coal seam thoroughly, reduces the temperature difference between the coal seams, and reduces the drying stress. Moisture escapes the drying chamber 20 . In the later stage of drying, the temperature of the lignite rises, and the temperature of the hot air is lower than that of the lignite, so the hot air mainly plays the role of carrying the evaporated moisture in the lignite. The hot and humid air coming out of the drying chamber 20 is divided into two parts, one part is sent into the feed preheating chamber 3 to preheat the lignite to be dried, and the other part of the air is re-sent into the preheating chamber 11 as return air. The fresh air passes through the coal unloading cooling chamber 4, on the one hand the dried lignite is cooled, and on the other hand the fresh air is preheated. The preheated fresh air is mixed with the return air in the drying chamber and sent into the preheating chamber 11. The corrugated absorbing plate 12 in the preheating chamber 11 receives the direct radiation of sunlight penetrating the glass, the temperature rises, and exchanges heat with the mixed air of the fresh air and return air flowing through the preheating chamber 11, heating the air, and the hot air again Enter the drying chamber 20. In this way, hot and cold air circulation and fresh air supplement are completed to form a semi-closed air system. the

The above is only a specific implementation case of the utility model, and does not limit the utility model in any form. Although the utility model has been disclosed as above with a preferred implementation example, it is not used to limit the utility model. Those skilled in the art may use the structure and technical content disclosed above to make some changes or modify them into equivalent implementation cases without departing from the scope of the technical solutions of the present utility model. However, any simple modifications, equivalent changes and modifications made to the above implementation cases according to the technical essence of the present invention are still within the scope of the technical solution of the present invention. the

Claims (7)

1. A belt transfer drying system utilizing solar energy to realize dehydration and upgrading of lignite, comprising a feed preheating chamber, a drier and a discharge cooling chamber connected successively by a belt conveyor, it is characterized in that the drier is composed of A vertical partition is divided into two parts: the air preheating chamber and the drying chamber. The partition is provided with a through hole, the air preheating chamber is provided with an air inlet, and the drying chamber is provided with an air outlet; the belt conveyor crosses the feed preheating chamber. , a drying chamber and a discharge cooling chamber; the discharge cooling chamber is provided with a fresh air inlet, the air outlet of the discharge cooling chamber is connected to the air inlet of the air preheating chamber through an air pipe, and the air outlet of the drying chamber is connected to the air inlet through an air pipe at the same time. The air inlet of the material preheating bin and the air inlet of the air preheating chamber, and the air outlet of the feed preheating chamber is connected to the pulverized coal separation system. 2. The belt transfer drying system according to claim 1, characterized in that, the cross-section of the dryer is a right-angled trapezoid, the drying chamber is on the side of the longer straight side, and the air preheating chamber is on the side of the shorter straight side. side; the short straight side and hypotenuse of the dryer are transparent glass cover plates, the bottom of the air preheating chamber and the side of the partition are provided with corrugated absorbing boards; the side of the drying chamber opposite to the partition is provided with a reflector, and extends beyond the glass cover. 3. The belt transfer drying system according to claim 1, characterized in that the loading portion of the belt conveying device is a belt wire mesh. 4. The belt transfer drying system according to claim 1, characterized in that an air curtain machine connected to a dust collector is provided on the upper part of the drying chamber for blowing out the air curtain for sweeping dust. 5. The belt transfer drying system according to claim 1, characterized in that a blower fan is arranged at the through hole on the partition of the dryer, and the through hole communicates with the lower air chamber of the belt conveying equipment, so that the hot air After flowing through the lower channel, it passes through the belt conveyor vertically. 6. The belt transfer drying system according to claim 1, characterized in that, on the air duct, a one-way valve or blower is set according to the direction of hot air transmission. 7. A device for utilizing solar energy to realize lignite dehydration and upgrading based on the belt transfer drying system described in any one of claims 1 to 6, characterized in that, it also includes a coal bunker, a crushing device and a product coal bunker, the The coal bunker is connected to the crushing device through raw coal conveying equipment, the crushing device is connected to the feed preheating chamber through belt conveying equipment, and the pulverized coal separation system is connected to the product coal bunker through pulverized coal conveying equipment. the

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