CN108679963A - A kind of coal using flue gas dries dedusting and feed system - Google Patents

Abstract

The invention discloses a coal drying, dust removal and feeding system heated by flue gas, which includes a transmission storage system, a drying system, a dust removal and desulfurization system and a sealed feeding system. The drying system includes a Drum, the inlet end of the drum is provided with a feed seal box, and the outlet end is provided with a discharge seal box; the drum is at least one level; the dust removal and desulfurization system includes a dust collector, an induced draft fan, and a desulfurization device connected in sequence , the dust remover communicates with the hot air outlet end of the drying system; the sealed feeding system includes a second storage tank, which is connected to the second screw device, the feeding cylinder, and the reaction kettle in sequence, The ash removal device is arranged on the feeding cylinder, and the cross-section of the spiral blade in the feeding cylinder is not greater than 3/4 of the cross-section in the cylinder.

Description

A Coal Drying Dust Removal and Feeding System Utilizing Flue Gas Heating

technical field

The invention relates to the technical fields of coal clean pretreatment, comprehensive utilization, energy saving and emission reduction, in particular to a coal drying, dust removal and feeding system heated by flue gas.

Background technique

China is a country with "more coal, less oil, and less gas". Among my country's proven petrochemical energy reserves, oil and natural gas account for only 6%, and the remaining 94% are coal substances. Such resource characteristics determine that China should build an energy structure based on coal.

my country's coal use and reserves are dominated by low-rank coal, and coal contributes more than two-thirds of the total atmospheric emissions such as sulfur dioxide and nitrogen oxides. The clean and efficient use of coal has become a national strategy and an inevitable choice. There are two main directions for clean and efficient utilization, one is end treatment, ultra-low emissions after coal combustion, and the other is clean utilization at the source. Clean and pretreated coal can be used as raw material or high-quality fuel, changing the traditional utilization path, and will greatly change the existing utilization mode from the perspective of economy and environmental protection.

Coal material composition includes organic matter (carbon, hydrogen, oxygen, nitrogen, sulfur, etc.) and inorganic matter (moisture and minerals). Among them, the heat generated by the combustion of organic matter is its energy value, while the water absorbs heat and turns into water vapor when coal is burned, which not only affects the calorific value and market value of coal, but also brings potential safety hazards of unstable furnace pressure.

Therefore, the removal of water is of great significance to the comprehensive utilization of coal. At present, there are many drying equipment for single coal material, but less complete system equipment. The invention patent with the publication number CN107504789A discloses a clean briquette drying device, which includes a drying furnace. The top of the drying furnace is provided with a feed port, and the bottom is provided with a discharge port. There is a heat dissipation air supply pipe in the drying furnace, which is spirally rising, and the heat dissipation air supply pipe is connected with the hot air pipe. There are several ventilation holes on the heat dissipation air supply pipe; there is an umbrella in the feeding port of the drying furnace. Shape distribution tray; the drying furnace is connected to the suction fan through the dust removal pipe, and the exhaust end of the suction fan is connected to the recovery device. The above-mentioned vertical drying device is produced on one side and continuously discharged on the other side, and at the same time, it cannot ensure uniform coal distribution, sufficient medium exchange, and complete water evaporation. The moisture content of the dried coal often fails to meet the expected standard. In addition, the front transmission system of the vertical drying device has a large slope, and the energy consumption of the equipment is relatively high.

The publication number is CN101985558, which discloses a kind of coal decomposition equipment, which includes a closed kiln body with a feed port and a discharge port. The coal substance propelling and decomposing channel is formed between the walls of the body, and the coal decomposition gas collection pipe communicated with the coal propelling and decomposing channel is arranged on the kiln body. The equipment can decompose pulverized coal into gas, tar gas and coal with high calorific value, but the processing capacity is small and it is difficult to be applied industrially.

At the same time, pulverized coal can be continuously produced while efficiently removing high-temperature dust at the same time. There are almost no integrated equipment for continuous large-scale production in China, and some of them have to stop production for half a month for dust treatment.

Contents of the invention

In order to solve the deficiencies in the prior art, the present invention provides a simple structure, high drying efficiency, dust removal and desulfurization meet the requirements of environmental protection, continuous feeding, high-efficiency high-temperature dust removal, continuous gas production, and continuous industrialized large-scale production using smoke Gas-heated coal drying dust removal and feeding system. Under the conditions of low temperature, no oxygen, and no external water, the high-value oil, natural gas and water in coal are separated through clean pretreatment to obtain high-calorie anthracite, and the anthracite can also be further processed to obtain high value-added coal-based new material.

The specific technical scheme adopted in the present invention is as follows: including a transmission storage system, a drying system, a dust removal and desulfurization system and a sealed feeding system,

The transmission storage system includes a first transmission device for transporting raw coal, the first transmission device is connected to the first storage tank, the outlet end of the first storage tank is connected to the second transmission device, and the second transmission device is connected to the oven dry system;

The drying system includes a drum with a driving device, the inlet end of the drum is provided with a feed sealing box, and the outlet end is provided with a discharge sealing box; the drum has at least one stage;

The dust removal and desulfurization system includes a dust collector, an induced draft fan, and a desulfurization device connected in sequence, and the dust collector is connected to the hot air outlet end of the drying system;

The sealed feeding system includes a second storage tank, the second storage tank is connected to the second screw device, the feeding cylinder, and the reaction kettle in sequence, the ash removal device is arranged on the feeding cylinder, and the feeding The cross-section of the helical blade in the barrel is not greater than 3/4 of the cross-section in the barrel.

The conveying device includes screw conveying, scraper conveying, bucket elevator, roller conveying and so on.

The adjacent middle groove of the scraper conveyor can be bent to a limited extent in the horizontal and vertical planes, which is called a bendable scraper conveyor. Among them, the working face conveyor whose fuselage is bent at 90 degrees at the intersection of the working face and the transportation roadway is called "corner scraper conveyor". In the current coal mining face, the role of the scraper conveyor is not only to transport coal and materials, but also the running track of the coal mining machine, so it has become an indispensable main equipment in the modern coal mining process. The scraper conveyor can keep running continuously, and the production can go on normally. Otherwise, the entire coal mining face will show a shutdown state, so that the entire production is interrupted. The scraper conveyor is pulled by a scraper chain to transport bulk materials in the trough. The scraper conveyor can be used for horizontal transportation and can also be used for inclined transportation. It has the advantages of solid structure, simple structure, feeding or unloading at any point along the conveying length, and airtight casing, which can prevent dust from flying and pollute the environment when conveying materials.

Screw conveyor, commonly known as auger, is suitable for horizontal conveying, inclined conveying, vertical conveying and other forms of granular or powdery materials. The conveying distance varies according to the deformity, generally from 2 meters to 70 meters, and is used for material transfer between two adjacent rollers. The screw conveyor includes a shaftless screw and a shaft screw, and can also be set as a multi-stage screw propeller; Which conveyor to choose depends on the amount of material conveyed, the composition of the material, the inclination, and the aesthetics of the drying device.

Preferably, the first conveying device, the second conveying device, and the third conveying device can be scraper conveyors.

Preferably, the first screw device can be a screw with a shaft.

The main function of the first storage tank is to store materials and play a storage and buffer role, including cuboid and cylinder structures. Generally, a cylindrical structure is adopted, and the bottom adopts an inverted conical structure. This allows for maximum material storage with minimum material. The size of the storage tank and the number of tanks are determined according to the actual processing capacity and demand.

Preferably, the first storage tank may adopt a cylindrical structure.

The drum can be set as a single-stage or multi-stage device according to the production requirements, and the sequence can be selected in series or parallel, or mixed in series and parallel, depending on the production requirements and site layout. In order to ensure that the pulverized coal is not blown back by the high-pressure hot air from the inlet of the feed inlet, it can be fed by a screw propeller. Material drying can be divided into indirect drying and direct drying, direct hot air contact with pulverized coal is the highest drying efficiency. A hot air inlet and a hot air outlet are respectively arranged at both ends of the drum, which are used to transmit hot air to realize drying of pulverized coal.

Preferably, the drying system uses direct hot air to dry in contact with pulverized coal.

In order to ensure the tightness between the two ends of the drum and the hot air inlet and hot air outlet, an inlet sealing box and an outlet sealing box are respectively installed at both ends of the drum, and the outlet sealing box and the inlet sealing box are respectively connected to the drum through a dynamic and static sealing device. Prevent air leakage at the connection between the discharge sealing box and the feeding sealing box and the drum. If there is air leakage, it is easy to accumulate materials, store heat, and easily cause fires and other safety accidents due to spontaneous combustion. The hot air inlet is arranged on the side or in front of the feed sealing box, and the hot air outlet is arranged on the top or side of the outlet sealing box. The setting of the feed sealing box and the discharge sealing box ensures that the hot air inlet and outlet and the drum are independent of each other and do not interfere with each other; The cushioning effect ensures that the hot air passes through the inner cavity of the drum evenly.

The feed seal box includes a feed inlet and a hot air inlet, and the feed inlet is on the top or side upper part of the feed seal box; the discharge seal box includes a feed outlet and a hot air outlet, and the The discharge port is at the bottom or side lower part of the discharge sealing box.

There are two guide plates arranged at a certain angle at the outlet of the discharge sealing box, which are conducive to the materials in the drum entering the third conveying device; Sealed fit, pulverized coal enters the drum through the inlet of the feed seal box, and then discharges out of the drum from the outlet at the bottom of the discharge seal box.

The first screw device is sealed and connected with the feed inlet. In addition to automatic feeding, the first screw device also plays a sealing role to prevent hot air with a certain pressure in the drum from escaping from here, preferably with a shaft screw. And the sealing performance is good.

The inner wall of the drum is provided with L-shaped lifting plates, and the L-shaped lifting plates are distributed around the inner wall of the drum. The lifting plate ensures that the material is heated evenly, and improves the drying efficiency and separation efficiency of the whole device; the number of lifting plates can be determined according to actual needs. The lifting plate arranged on the inner wall of the drum ensures that the pulverized coal is continuously tumbling when passing through the drum, the material is heated evenly, the drying speed is accelerated, and the agglomeration of the pulverized coal is reduced.

The rollers can be arranged horizontally or inclined. When arranged horizontally, the overall device is beautiful, neat and tidy, and has a small friction coefficient against the driving mechanism and the limit device, which is beneficial to improve the production life of the rollers and other conveying devices. In addition to the driving force brought by the forward movement of the hot air, the material is driven forward mainly by the L-shaped lifting plate in the drum, which is mainly realized by the L-shaped lifting plate having a certain angle of inclination. In addition to driving the turning of the material, the material plate can also drive the material to move forward slowly. The forward speed of the material is not only dependent on the rotating speed of the drum, but also has a great relationship with the inclination angle of the L-shaped lifting plate, which is specifically determined by the processing capacity of the pulverized coal upgrading and drying system.

When the rollers are arranged obliquely, the installation heights are the same, and the end of the rollers provided with the discharge port is at a low position. The inner and outer diameters and length of the drum can be determined according to the actual processing capacity of the actual pulverized coal upgrading system. The drum and the horizontal plane are set at a certain slope to ensure that the height of the front end of the drum is higher than that of the rear end of the drum. Materials such as pulverized coal are automatically transported under the action of their own gravity and hot air, which ensures continuous automatic operation of the entire device and reduces energy consumption. consumption.

The above-mentioned driving device of the drum includes a gear ring on the outer peripheral surface of the drum, a supporting wheel engaged with the gear ring, and a motor for driving.

As preferably, in order to prevent the roller from sliding down, a limit device can be provided at the support roller. The limiting device of the present invention can be selected to protrude from the annular steps at both ends of the supporting wheel, set a limiting groove on the outer peripheral surface of the supporting wheel to match the outer ring, set a groove on the outer ring, and set a concave groove on the outer peripheral surface of the supporting wheel. Groove matching limit protrusions and other forms.

The rollers include multiple stages, which are sequentially connected in series, parallel or mixed in series and parallel. For flat arrangement or inclined arrangement.

The second screw device is a shaftless screw or a shafted screw.

The materials between the rollers are conveyed by the third conveying device.

Inspection ports are respectively installed on the discharge sealing box and the feeding sealing box; an insulation layer is installed on the outside of the drum.

The feed cylinder and the reaction kettle are connected through a metal compensator and a dynamic and static sealing device.

A second valve and a third valve are respectively installed at the inlet and outlet of the second storage tank; a fourth valve is installed at the inlet of the feeding cylinder.

In order to ensure the drying effect of pulverized coal, the present invention sets up a multi-stage drying device. When the effect of the first-stage drying device is poor, a second-stage drying device is set up. The principle is the same as that of the first-stage drying device. If the effect of the secondary drying device still cannot meet the requirements of the subsequent high-temperature coal utilization system, and the moisture content is high, a third-stage drying device can be set up. And the multi-stage drying devices are independent of each other and can be operated independently, depending on the moisture content of pulverized coal, weather temperature, humidity, and four seasons.

The dust collectors include bag dust collectors and electric dust collectors. Set up a dust collection hood at each place where the dust is emitted, and transport the dust-laden gas to the dust removal device through the pipeline gas path, where the gas-solid separation is performed, and the dust is collected in the dust removal device, and the clean gas is introduced into the main pipe or The whole set of equipment that is directly discharged into the atmosphere is the dust removal system, and the dust collector is an important part of the system. From the perspective of ventilation and dust removal, dust is all small solid particles that can exist in the air in a floating state for a long time. It is a dispersed system called aerosol, in which air is the dispersion medium and solid particles are the dispersed phase. The dust collector is a device that separates this small solid particle from the aerosol.

The working principle of the dust collector is as follows: the dusty gas enters the filter chamber from the lower open flange, the coarser particles fall directly into the ash bin, the dusty gas is filtered through the filter bag, the dust is retained on the bag surface, and the clean gas passes through the bag mouth The clean air chamber is exhausted into the atmosphere by the fan. When the dust on the surface of the filter bag continues to increase, the program-controlled instrument starts to work, and the pulse valves are opened one by one, so that the compressed air can be blown to the filter bag through the nozzle to remove the dust, so that the filter bag suddenly expands, and under the action of the reverse air flow, the bag surface is given The dust quickly leaves the filter bag and falls into the ash bin, and the dust is discharged by the ash discharge valve. The dust collector is mainly composed of an upper box, a middle box, an ash hopper, an air inlet equalizing pipe, a support filter bag, an injection device, and an ash unloading device. The application of bag dust collector has a history of more than 100 years. Its biggest advantage is that the dust removal efficiency is high, reaching more than 99.99%, the emission concentration can reach below 10mg/ ^m3 , and the classification efficiency is also very high. Fine particles also have good capture efficiency, so they are widely used.

Preferably, the dust collector of the present invention can be a bag filter.

The induced draft fan is a device that generates negative pressure through the rotation of the impeller, and then extracts air from the system. It is generally installed at the end of the system and is used to extract the hot flue gas in the device. The invention is installed at the rear end of the dust collector, and the hot flue gas in the drum and the gas in the dust collector are driven by the negative pressure of the induced draft fan.

As preferably, the induced draft fan can be selected from a commercially available conventional induced draft fan, as long as it meets the production capacity.

The desulfurization device should be a small desulfurization and dust removal device, often called a desulfurization and dust removal device. In the desulfurization tower and desulfurization dust collector, the flue gas containing SO ₂ should be used to chemically absorb the SO ₂ in the flue gas. The SO ₂ absorption and purification process deals with low-concentration SO ₂ flue gas, and the amount of flue gas is considerable, requiring continuous and efficient flue gas purification in an instant. Therefore, the chemical reaction that _SO2 participates in should be an extremely fast reaction. Their conversion coefficient in the membrane is relatively large, and the reaction takes place in the membrane. Therefore, an absorption tower with a continuous gas phase, a high degree of turbulence, and a large phase interface is selected as the desulfurization tower. Towers and desulfurization dust collectors are more suitable. Generally, spray towers, packed towers, spray towers, plate towers, Venturi absorption towers, etc. can meet these requirements. Among them, the spray tower is one of the most widely used desulfurization tower types. The spray tower has the advantages of simple structure, mature and reliable technology, and is widely used in large power plants, small and medium-sized low-sulfur flue gas treatment; for high-sulfur flue gas treatment, The non-ferrous industry mainly uses pneumatic emulsification desulfurization towers and multi-layer spray towers.

As a preference, the desulfurization device can choose the mode of spray desulfurization.

The second screw device is mainly used for transporting the pulverized coal in the storage tank to the rear end, and needs to be transported in a sealed manner, including a shaftless screw and a shaft screw.

The end of the spiral conveying is appropriately extended for a certain distance, and the length of the extension distance can be determined according to the actual effect such as the size of the second storage tank and the amount of material produced. Bottom discharge spiral conveying can be conveyed in parallel or at a certain inclined angle. The inclined angle conveying can make the material easier to concentrate at one point, and the dead angle generated is only at the end of the conveying. The on-site personnel only need to open the end blind plate regularly to clean it. Blockage or dead angle can be solved Accumulated impurities such as pulverized coal particles.

As a preference, you can choose the shaftless spiral because the center of the shaftless spiral is a concentric circle; secondly, the use of the shaftless spiral is faster than the shafted spiral at a certain flow rate per unit area and at a low temperature. The material to be conveyed is large, thereby saving the material of the circular pipe.

The valves are mainly used to open or close pulverized coal transportation, including ball valves, gate valves and butterfly valves. The ball valve has the action of rotating 90 degrees. The cock body is a sphere with a circular through hole or channel passing through its axis. The ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. It only needs to be rotated 90 degrees and a small rotational torque can be closed tightly. Ball valves are most suitable for on-off and shut-off valves. The gate valve of the gate valve moves in a straight line with the valve stem, which is called a lifting stem gate valve, also known as a rising stem gate valve. Usually there is a trapezoidal thread on the lifter, and through the nut at the top of the valve and the guide groove on the valve body, the rotating motion is changed into a straight line motion, that is to say, the operating torque is changed into the operation thrust. The opening and closing part of the butterfly valve is a disc-shaped butterfly plate that rotates around its own axis in the valve body to achieve opening and closing or adjustment. The valve is called a butterfly valve. Which valve to choose can be determined according to the site and production needs.

Preferably, the first valve and the second valve may be ball valves with high practicability and low cost, and the third valve and the fourth valve may be pneumatic gate valves.

The front end of the feeding cylinder is connected with the second storage tank and the second screw device, which are respectively connected with the third valve and the fourth valve. The valve has two functions, one is to open or close the material; the other is to lock Gas, to prevent the high-temperature gas in the reactor from countercurrently flowing upward under pressure.

The middle part of the feeding cylinder communicates with the bottom of an ash removal device, and the end of the feeding cylinder is connected with the reaction kettle through a metal compensator and a dynamic and static sealing device.

The quantity and size of the second storage can be determined according to the daily processing capacity of the reactor, the purpose is to reserve and buffer the feed for the feed cylinder, when the second screw device is activated, the third valve is automatically opened, and the second storage The material in the reactor has a certain height, mainly because the compaction height of the material can block the pressure of the gas in the reactor to prevent leakage, and at the same time the second storage cannot be completely empty, otherwise the high-temperature oil and gas in the reactor will pass through the opened third valve It goes out countercurrently, so the second storage is generally equipped with a material level alarm. When it is lower than a certain value, it will automatically alarm and automatically add material.

Shaftless helical blades are installed inside the feed cylinder, and the cross section of the blade must not be greater than 3/4 of the cross section of the inner diameter of the cylinder. This is the important innovation point of the present invention, obtained on the basis of a large number of experiments. A more reasonable diameter comes out. The internal pipeline of the feeding cylinder is not only the outlet path of high-temperature oil and gas, but also the feeding path of pulverized coal. Therefore, the degree of internal heat exchange also determines the energy loss of the reactor. Generally, it is 5-20 meters, and at the same time, the outside of the feeding cylinder can be kept warm with insulation cotton, so that the pulverized coal and high-temperature oil and gas can fully exchange heat.

Shaftless screw and shafted screw can be used for the conveying screw. Shaftless screw is recommended, because the screw has no shaft, the material is not easy to block, and the discharge port is not blocked, so it can run at a lower speed, drive smoothly, and reduce energy consumption; the conveying capacity is It is 1.5 times that of the traditional shaft screw conveyor with the same diameter; it can discharge from the bottom and the end; it adopts a special liner, and the machine can work under high temperature.

Preferably, the shaftless screw of the feeding cylinder has a certain length, preferably 10 to 15 meters, too short is not conducive to heat exchange and sealing, and too long is easy to deform or even break when transporting at high temperature.

The inner diameter, thickness and length of the feeding cylinder can be determined according to the actual processing capacity of the reactor; in actual use, the shaftless screw is connected with the drive motor.

The invention utilizes the air outlet gap between the upper part of the conveying screw and the inner wall of the feeding cylinder, and the high-temperature oil and gas in the reactor are discharged from the feed end. If necessary, reduce the temperature in the reactor to realize continuous large-scale production without shutting down the reactor.

The main function of the ash removal device is to block or capture the dust-containing high-temperature oil gas from the reactor under the action of the device, and the high-temperature oil gas passes through to the next cooling and separation equipment. Dedusting devices include gravity dust removal, inertial dust removal, cyclone dust removal, electric dust removal, etc.

The mechanism of the cyclone dust collector is to make the dust-laden air flow rotate, and the dust particles are separated from the air flow by centrifugal force and collected on the wall of the device, and then the dust particles fall into the ash hopper by gravity. Each component of the cyclone dust collector has a certain size ratio. The change of each proportional relationship can affect the efficiency and pressure loss of the cyclone dust collector. Among them, the diameter of the dust collector, the size of the air inlet, and the diameter of the exhaust pipe are the main influencing factors. . When using it, it should be noted that when a certain limit is exceeded, favorable factors can also be transformed into unfavorable factors. In addition, some factors are beneficial to improving the dust removal efficiency, but they will increase the pressure loss, so the adjustment of various factors must be taken into account. But the biggest problem of cyclone dust removal is that the air volume must be stable, and the high-temperature oil and gas contain water vapor, asphalt, hydrophilic and sticky dust, the composition is complex, and it is not easy to fall off when it adheres to the wall. Unless it is regularly blown with oil and gas, otherwise it is not very suitable.

Electrostatic dust removal is a kind of gas dust removal method. The dust-containing gas is electrically separated when it passes through the high-voltage electrostatic field, and the dust particles and negative ions are combined with negative charges, and tend to discharge and deposit on the surface of the anode. The types of electrostatic precipitators can be roughly divided into the following categories: vertical and horizontal according to the airflow direction, plate and tube according to the sedimentation pole type, and dry and wet according to the dust removal method on the sedimentation pole plate. Wait. The advantages are high purification efficiency, small resistance loss, high allowable operating temperature, large processing gas range, and fully automatic operation control. The disadvantage is that the equipment is more complicated, requiring high levels of equipment transportation, installation and maintenance management. There are certain requirements for the specific resistance of dust, so there is a certain selectivity for dust, and it is not possible to obtain high purification efficiency for all dust. It is greatly affected by the operating conditions such as gas temperature and temperature. If the same kind of dust is operated at different temperatures and humidity, the effect will be different. Due to the change of dust resistance under temperature and humidity, it is almost impossible to use the electrostatic precipitator.

Gravity dedusting uses the principle of different specific gravity between dust and gas, so that the dust will naturally settle down from the gas by its own gravity. It is a relatively primitive purification equipment with simple structure, large volume, small resistance, easy maintenance and low efficiency, and can only be used for rough purification.

Inertial dust collectors are also called inert dust collectors. Its principle is to separate the dust from the gas by using the difference in inertial force between the dust and the gas in motion. Generally, some form of obstacle is set in front of the dusty airflow to change the direction of the airflow sharply. At this time, because the inertial force of the dust is much greater than that of the gas, the dust particles are separated from the airflow and separated, and the purified gas is discharged after a sharp change of direction. This kind of dust collector has simple structure, small resistance, and low purification efficiency (40-80%). It is mostly used in the first stage of multi-stage purification, concentration equipment in purification or used in conjunction with other purification equipment.

The ash removal device of the present invention is based on several commonly used devices, and a high temperature resistant, oil-repellent and water-repellent polymer material is installed inside the ash removal device. When the dust slowly accumulates to a certain extent, under the influence of its own gravity or external wind force, it will freely fall to the bottom and will not stick to the device, so that the device loses the function of ash removal. The molecular material is equipped with high-pressure oil guns in many places, and it is automatically purged, so that the dust will not wrap the polymer material and deactivate it. The invention of this technology greatly increases the difficulty of high-temperature oil and gas dust, and the dust that falls into the cylinder is fed It enters the reaction kettle again through screw conveying.

Preferably, a metal compensator is installed at the connection between the feed cylinder and the reactor, and a temperature sensor and a pressure sensor for remote control and on-site monitoring are respectively installed at the top.

As a flexible pressure-resistant pipe fitting, the metal compensator uses the effective expansion and contraction deformation of the bellows of its working body to absorb the dimensional changes of pipelines, conduits, containers, etc. due to thermal expansion and contraction, or to compensate for pipelines, conduits, containers, etc. Equal axial, lateral and angular displacement, absorbing vibration energy, can play the role of vibration reduction, noise reduction, etc., with good flexibility, light weight, corrosion resistance, fatigue resistance, high and low temperature resistance and many other characteristics.

The dynamic and static sealing device is mainly composed of a gland assembly, a reinforced flexible graphite disk, a sealing outer ring assembly, and a sealing inner retaining ring assembly.

The gland assembly is assembled and welded by flanges, seamless steel pipes and compression rings. Because the gas generated by the cracking furnace during the working process is not corrosive, and the temperature of the gas is about 200-400°C. Therefore, ordinary carbon structural steel can be used for the pressure ring assembly to meet the process requirements, and the tightness of the graphite packing seal can be adjusted by adjusting the length of the gland that penetrates into the outer ring of the seal.

Reinforced flexible graphite packing not only overcomes the shortcomings of pure graphite materials such as low tensile strength, softness, poor resilience, and low air tightness; it also has good temperature resistance, oxidation resistance, corrosion resistance and good compression performance. At the same time, it also has the excellent characteristics of graphite; therefore, it is used as an important seal in the structure of cracking furnace and spiral sealing device; it also uses its axial stretchability, radial lubricity and its comprehensive performance;

Preferably, the number of winding turns in this structure is 8-12 turns.

The sealed outer ring assembly is welded by flanges, pipes and pressure rings, and the sealed inner retaining ring is welded by steel pipes and rings; graphite packing is wound between the two, and is sealed by friction between the three. , and cooperate together to play a sealing role in the radial and axial directions.

The reaction kettle is a rotatable mechanism, which can make the materials in the reaction kettle evenly heated; a heating box is arranged outside the reaction kettle, and a heat conducting pipe passing through the reaction kettle is provided, and the heat conducting pipe communicates with the heating box; The heat conduction tubes are arranged vertically to the axis of the reactor, and two adjacent heat conduction tubes are vertically staggered.

The reaction kettle is equipped with a deflector arranged obliquely and in a spiral structure. The deflector is divided into a deflector steel plate and a deflector stainless steel plate. Diversion structure; during the rotation of the reactor, the obliquely arranged deflectors have a diversion effect on the materials in the reactor, and the materials in the reactor move to the discharge port under the action of the deflectors, speeding up the flow of the reactor. Discharge of internal materials.

The reaction kettle in this embodiment is a progressive circulation continuous production reaction device with 6 to 15 built-in wireless temperature controllers for monitoring the temperature in the interval. When the temperature of the equipment outlet has not reached the specified temperature (500 ° C ~ 800°C), the specific temperature is determined by different products, the temperature sensor transmits the signal to the computer and the alarm device, and reminds the staff that this means that the product has not yet reached the qualified requirements. At this time, the main measures to be taken are as follows. Rotate, so that the material that is about to exit enters the reactor again for full reaction, prolongs the residence time, and continues heating at the same time. Whether the temperature sensor alarms, if it alarms, the reaction kettle is reversed again, and so on, to ensure that the product is qualified and offline. If the temperature sensor shows that the temperature reaches the standard, the pulverized coal enters the discharge port and enters the next procedure.

For the convenience of maintenance, inspection ports can be provided on the inlet sealing box and the outlet sealing box respectively. The number, size and specific location of the inspection ports can be determined by the equipment and site space; the number of inspection ports is 1 to 5 , the inner diameter is between DN300 and 800. When the device breaks down, on-site operators can repair the components in the device through the inspection hole, and close the inspection door after the repair is completed. The location of the inspection hole can be determined according to the actual situation.

Preferably, the number of inspection ports for each device is 1 to 3, and the inner diameter is between DN400 and DN500.

In order to prevent manual work from being scalded, and make full use of heat and heat exchange, thermal insulation cotton can be used in the feed seal box, discharge seal box and the outer side of the drum. The thickness and heat preservation effect of the insulation cotton depend on the temperature inside the device and the device. requirements.

Preferably, the insulation layer has a thickness of 100 mm to 200 mm.

The beneficial effects of the present invention are reflected in:

(1) The feeding cylinder and ash removal device of the present invention can continuously feed materials, automatically remove ash, make full use of the law of energy conservation, improve the utilization rate of heat exchange, and generally reduce the temperature of the reactor, thereby greatly saving energy consumption.

(2) Through the simple connection of the second storage tank, the second screw device and the valve, the present invention solves the problem that continuous feeding cannot automatically lock the air for decades. Through the automatic induction of the material level sensor of the second storage tank, the pneumatic The opening or closing of the gate valve, the material conveying of the screw conveying device, the fully sealed connection, the operation is simple, no need for large and complicated equipment, which greatly reduces the safety hazard for the workshop employees.

(3) The present invention adopts single-stage or multi-stage drums, connected in series or parallel, or even mixed in series and parallel, depending on the site production capacity and site layout. Such a drying system greatly improves the drying of pulverized coal. As a result, the energy consumption of the follow-up reactor is greatly reduced, and the volume of liquid water becomes thousands of times higher than that of high-temperature steam, and the reduction of water greatly improves the unit capacity of the follow-up cooling equipment.

(4) The equipment of conventional devices such as dust collector and desulfurization device of the present invention makes the sulfur content and dust content of the waste heat flue gas very consistent with the national emission standards, while improving the energy utilization rate and meeting the development of clean coal utilization.

Description of drawings

Fig. 1 is a schematic structural view of a coal drying, dedusting and feeding system utilizing flue gas heating according to the present invention.

Fig. 2 is a cross-sectional view along A-A in Fig. 1 .

Fig. 3 is a schematic structural diagram of the transport storage system in the present invention.

Detailed ways

A coal drying, dedusting and feeding system heated by flue gas according to the present invention will be further described in detail with reference to the accompanying drawings.

As shown in Figures 1-3, a coal drying, dust removal and feeding system heated by flue gas mainly includes a conveying storage system 1: a first conveying device 2, a first storage tank with a first valve 4 3. The second conveying device 5 and the first screw device 6; drying system 10: including a drum 11 with a driving device 14, a feed seal box 18 and a discharge seal box 19 connected with the front and back of the drum 11 in a dynamic and static seal ; Dust removal and desulfurization system 20: includes a dust collector 21 connected in sequence, an induced draft fan 22, and a desulfurization device 23; a sealed feed system 30: includes a second storage tank 31, a second screw device 32, a feed cylinder 33, and ash removal Apparatus 34 and reactor 37.

The feed seal box 18 includes a feed inlet 12 and a hot air inlet 13, and the feed inlet 2 is on the top or side upper part of the feed seal box 18; the discharge seal box 19 includes a discharge outlet 15 and The hot air outlet 16, the discharge port 5 is at the bottom of the discharge sealing box 15 or the lower part of the side.

The inner wall of the drum 11 is provided with an L-shaped lifting plate 17 . Mainly rely on the L-shaped lifting plate 17 in the drum 11 to drive forward. The L-shaped lifting plate 17 has a certain inclined arrangement. In addition to driving the turning of the material, it can also drive the material to move forward slowly.

Multi-stage drums 11 include sequential series or parallel connection, and more than three-stage drums 11 can also be mixed in series and parallel. Single-stage or multi-stage drums 11 include horizontal arrangement and inclined arrangement; specifically, it depends on the production capacity of pulverized coal and the local climate. It is determined by factors such as humidity, dryness, and site layout.

The selection of bag dust collector 21 greatly improves the dust removal efficiency of exhaust gas;

The first valve 4 and the second valve 26 may be ball valves with high practicability and low cost, and the third valve 27 and the fourth valve 28 may be pneumatic gate valves.

The middle part of the feeding cylinder 33 communicates with the bottom of a dust removal device 34 , and the end of the feeding cylinder 33 is connected with the reaction kettle through a metal compensator 35 and a dynamic and static sealing device 36 . Shaftless spiral blades are installed inside the feeding cylinder 33, and the cross section of the blades shall not be greater than 3/4 of the cross section of the inner diameter of the cylinder, generally 5 to 20 meters. Full heat exchange between pulverized coal and high temperature oil and gas.

Ash removal device 34 is equipped with high temperature resistant, lipophilic and hydrophobic polymer materials

The dynamic and static sealing device 36 is mainly composed of a gland assembly, a reinforced flexible graphite disk, a sealing outer ring assembly, and a sealing inner retaining ring assembly.

The reaction kettle 37 is a rotatable mechanism, which can make the materials in the reaction kettle 37 evenly heated; a heating box is arranged outside the reaction kettle 37, and a heat pipe running through the reaction kettle 37 is provided, and the heat pipe is communicated with the heating box ;

The working process of the above-mentioned coal drying dust removal and feeding system heated by flue gas is as follows:

1) Conveying and storage system 1: Under the action of the manual operation grab, the powdered coal and other materials in the raw coal yard enter the first storage tank 3 with storage, buffer and backup through the first conveying device 2, and pass through the first storage tank 3. The opening or closing of the first valve 4 at the lower end of the tank 3 conveys the material to the second conveying device 5. The second conveying device 5 can be composed of multi-stage conveying devices, including scraper conveyors, screw conveyors, etc., and then passes through the first screw device. 6. Transport the material to the feed port 12.

2) Drying system 10: the driving device 14 drives the drum 11 to rotate, and materials such as pulverized coal enter in the feed port 12 of the feed sealing box 18, hot air such as waste heat flue gas enters from the hot air inlet 13, and the materials in the drum 11 are The L-shaped lifting plate 17 continuously rolls down, falls freely and moves forward slowly. After the material is fully contacted with the hot air and dried, the material is discharged from the discharge port 15 of the discharge sealing box 19. If necessary, it enters the third conveyor. Device 25, then enters the drum 11 of the next cycle, until the drying meets the requirements;

3) Dust removal and desulfurization system 20: the waste heat flue gas with a certain amount of dust comes out from the hot air outlet 16, enters the dust collector 21 under the action of the induced draft fan 22 to remove dust, and the desulfurization device 23 desulfurizes, and enters the atmosphere after reaching the standard.

4) Sealed feeding system 30: The dried and qualified materials are freely switched into the second storage tank 31 through the second valve 26 according to the demand under the action of the conveying device for storage and standby. The second screw device 32 is fed into the feed cylinder 33 from the fourth valve 28, and the feed cylinder 33 is connected with the rotating reactor 37 in the bedroom through the metal compensator 35 and the dynamic and static sealing device 36. The high temperature and dust in the reactor 37 The gas passes through the feeding cylinder 33 and enters the ash removal device 34 for ash removal, and the high-temperature oil gas after ash removal enters the next link.

The above descriptions are only examples of the preferred implementation of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention within.

Claims (10)

1. A coal drying, dedusting and feeding system utilizing flue gas heating, characterized in that it includes a transmission storage system (1), a drying system (10), a dust removal and desulfurization system (20) and a sealed feeding system (30) , The transmission storage system (1) includes a first transmission device (2) for transporting raw coal, the first transmission device (2) is connected to the first storage tank (3), and the outlet end of the first storage tank (3) Connect the second conveying device (5), and the described second conveying device (5) is connected to the drying system; The drying system (10) includes a drum (11) with a driving device (14), the inlet end of the drum (11) is provided with a feed sealing box (18), and the outlet end is provided with a discharge sealing box (19). ); said drum (11) is at least one level; The dust removal and desulfurization system (20) includes a dust remover (21), an induced draft fan (22), and a desulfurization device (23) connected in sequence, and the dust remover communicates with the hot air outlet port of the drying system (10) ; The sealed feeding system (30) includes a second storage tank (31), and the second storage tank (31) is sequentially connected to the second screw device (32), the feeding cylinder (33), and the reaction kettle (37) , the ash removal device (34) is arranged on the feeding cylinder (33), and the cross-section of the spiral blade in the feeding cylinder (33) is not greater than 3/4 of the cross-section in the cylinder. 2. coal drying dust removal and feeding system as claimed in claim 1, is characterized in that, described feed sealing box (18) comprises feed inlet (12) and hot air inlet (13), and described The feed inlet (2) is at the top or side top of the feed seal box (18); the discharge seal box (19) includes a discharge port (15) and a hot air outlet (16), and the discharge Mouth (5) is at the bottom or the side lower part of the discharge sealing box (15). 3. coal drying dust removal and feeding system as claimed in claim 1, is characterized in that, the inner wall of described drum (11) is provided with L-shaped lifting plate (17), and described L-shaped lifting plate ( 17) Distribute around the inner wall of the drum. 4. The coal drying dust removal and feeding system according to claim 1, characterized in that, the drum (11) includes multiple stages, which are sequentially connected in series, parallel or mixed in series and parallel. 5. The coal drying dust removal and feeding system according to claim 1, characterized in that, the drum (11) is arranged horizontally or inclined. 6. The coal drying dust removal and feeding system according to claim 1, characterized in that, the second screw device (8) is a shaftless screw or a shafted screw structure. 7. The coal drying, dust removal and feeding system according to claim 1, characterized in that, the materials between the drums (11) are conveyed by the third conveying device (25). 8. The coal drying and dedusting and feeding system according to claim 1, characterized in that, inspection ports (24) are respectively installed on the discharge sealing box (18) and the feeding sealing box (19); An insulation layer is installed on the outside of the described cylinder (11). 9. coal drying dust removal and feed system as claimed in claim 1, is characterized in that, described feed cylinder body (33) and reactor (37) pass metal compensator (35) and dynamic and static sealing device ( 36) Connect. 10. The coal drying dust removal and feeding system according to claim 1, characterized in that, the second valve (26) and the second valve (26) are installed at the inlet and outlet of the second storage tank (31) respectively. A third valve (27); a fourth valve (28) is installed at the feed inlet of the feed cylinder (33).