Industrial furnace dry sludge powder co-processing device with pulverizing system

Abstract

The invention relates to the technical field of environmental protection, and discloses an industrial furnace dry sludge powder co-processing device with a pulverizing system, which comprises a coal mill, an inlet of the coal mill is connected with a coal feeder, an outlet of the coal mill is connected with a coarse powder separator through a powder conveying pipeline, and an outlet of the coarse powder separator is connected with a fine powder separator through a powder conveying pipeline. An outlet of the fine powder separator is connected with a powder exhauster through a powder conveying pipeline, the pneumatic conveying pipeline is provided with a flow limiting valve and an isolating valve, and an outlet of the pneumatic conveying pipeline is connected with the powder conveying pipeline. According to the industrial furnace dry sludge powder co-processing device with the pulverizing system, the problems that unorganized emission, dust explosion and deliquescence are prone to occurring in the processes of coal mixing, conveying and entering the pulverizing system, so that energy waste is caused, and the output and efficiency of the pulverizing system are reduced are solved.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and in particular to an industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system. Background Art

[0002] Co-incineration of sewage sludge in industrial furnaces is a common and mature technology. There are two common methods of treatment and incineration: direct mixing with coal and mixing with coal after pre-treatment and dehydration.

[0003] Since the water content of sludge is generally high (for example, the water content of industrial sludge is generally 40-60%; the water content of municipal sewage treatment plant water treatment sludge is generally around 60-80%; the water content of some biochemical sludge and medical sludge can even reach more than 90%), if the amount of sludge is too large when it is directly mixed with coal for combustion, it will lead to a series of problems such as increased smoke exhaust loss and belt material line blockage, affecting the safe and economic operation of the kiln. Therefore, the amount of sludge directly mixed with coal is generally not large, and the weight ratio does not exceed 6% of coal.

[0004] The existing processing methods have the following problems:

[0005] 1. The sludge is first dehydrated and dried after pretreatment and then mixed with coal for combustion. The sludge is mixed with coal as a mixed fuel and sent to the kiln as a mixed fuel after the moisture content is reduced after dehydration. Common pretreatment dehydration equipment includes disc dryers, paddle dryers, thin film evaporators, belt dryers, drum dryers, etc. It is generally required that after dehydration and drying, the sludge must still maintain a certain moisture content. For example, the moisture content of the water treatment sludge in the municipal sewage treatment plant after drying is required to be controlled between 35 and 45%. At this moisture content, the water treatment sludge can form a better particle size, which is convenient for later transportation and mixing; below this range, the sludge will be fully powdered. In fact, the dried water treatment sludge collides with each other during transportation, and powdering and falling off is more common. In addition, excessive drying during the pretreatment drying process and residual heat drying during shutdown will produce a large amount of dry sludge powder;

[0006] 2. Some industrial sludge, such as the bottom sludge of the circulating water station pool, is difficult to granulate during the pretreatment drying process. The water content range of the sludge from plastic state to large-area powder (still containing a large amount of granular solids) is very narrow, only 2-5%, which makes it more likely to produce dry sludge powder;

[0007] 3. Currently, there is no special treatment process for dry sludge powder. It is usually sent to the furnace coal yard together with dry sludge particles to mix with coal. The particle size of dry sludge powder is relatively small, generally 40 to 220 μm, which can easily cause environmental problems such as unorganized emissions during unloading and transportation. At the same time, there is also a risk of dust explosion when dry sludge powder containing combustible components such as organic matter is flying;

[0008] 4. Many types of dry sludge powders are deliquescent. For example, the most common municipal sewage treatment plant sludge, neutral sludge and gas sludge produced by water treatment systems of some steel plants, etc., which are currently co-processed by thermal power plants. These powders absorb moisture in the environment before entering the industrial coal mill, objectively offsetting part of the effect of drying pretreatment and resulting in energy waste.

[0009] The main process of the pulverizing system equipped in industrial furnaces is to connect the coal feeder, coal mill, separator, and powder exhaust fan in sequence through pipelines, with the powder exhauster providing suction power. The coal mill, as a crushing equipment, is used to crush and sort the coal into coal powder with the required particle size through the coal mill, separator, powder exhaust fan, etc. and output it. It has the functions of drying, crushing, separation, and transportation. While inputting coal, hot air is introduced into the inlet of the coal mill as a desiccant. The mixture of dried and crushed coal powder and wind is discharged through the outlet and enters the separator for sorting. The coarse coal powder returns to the coal mill for re-grinding, and the fine powder is taken out.

[0010] The pulverizing system is divided into two types: direct blowing type and intermediate storage type. The qualified fine coal powder separated is directly sent to the kiln for combustion, which is called direct blowing type. The one that falls into the powder bin for storage and then is sent to the kiln through the powder feeding equipment is called intermediate storage type. The direct blowing type pulverizing system generally has only one-stage separator, called coarse powder separator, which is used to separate coarse and fine powders; the intermediate storage type pulverizing system is equipped with two-stage separators. In addition to the coarse powder separator separating coarse and fine powders, a fine powder separator is also installed after the coarse powder separator to separate fine powder and air carrying fine powder. Regardless of the type of pulverizing system, the inlet of the coal mill to the inlet of the powder exhaust fan is in a negative pressure state that gradually increases with the process. The working pressure of the drying, crushing and separation links is lower than the atmospheric pressure. The position with the lowest negative pressure is at the inlet of the coal mill, and the pressure difference with the atmospheric pressure is generally between tens to hundreds of Pascals; the negative pressure at the inlet of the powder exhauster can reach nearly 10,000 Pascals.

[0011] The material grinding capacity and efficiency of the pulverizing system are positively correlated with the drying capacity of the desiccant (known in the industry as the "drying output" of the pulverizing system). Low-temperature powder materials such as dry sludge powder do not actually need to be ground. After entering the coal mill, they will absorb part of the heat of the desiccant, reducing the drying capacity of the pulverizing system and causing a decrease in the efficiency of the pulverizing system.

[0012] Due to the low heat capacity of air, the powder making system needs to achieve sufficient drying output. First, the flow rate must be large enough, and second, the temperature must be high enough. For example, a powder making system equipped with DTW380 / 720-Ⅲ steel ball mill and with a maximum output of 48t / h, the inlet hot air design temperature is 340 degrees, and the ventilation flow rate reaches 140,000m 3 / h. With such a high inlet temperature, there is a risk of dust explosion when dry sludge powder containing combustible components with low ignition points enters the coal mill. The temperature of the air-powder mixture at the outlet of the coal mill is relatively low. According to DL / T466 "Guidelines for the Selection of Coal Mills and Pulverizing Systems in Power Plants", the maximum allowable outlet temperature of the coal mill of the fan mill direct-blowing pulverizing system for grinding lean coal is not more than 180°C, while the allowable outlet temperature of the coal mill of the ball mill pulverizing system for grinding lignite is 60-70°C. DB13 / T 5210 "Safety Specifications for Explosion-Proof Coal Powder Preparation and Injection Systems in Metallurgy and Cement Industries" stipulates that the outlet temperature of the coal mill should not be greater than 70°C.

[0013] Very few industrial furnaces for the coordinated disposal of sludge are equipped with high-temperature pre-carbonization integrated machines. The high-temperature pre-carbonization integrated machine is essentially a steel ball mill pulverizing system that is connected in parallel with the original pulverizing system and is specifically used for drying and crushing solid wastes such as sludge. The high-temperature pre-carbonization integrated machine has good adaptability to a variety of materials, and the use of high-temperature flue gas as a desiccant can also suppress the dust explosion problem of dry sludge powder, but the investment is large and the power consumption is relatively high (according to DL / T466 "Guidelines for the Selection of Coal Mills and Pulverizing Systems for Power Plants", the power consumption of a pulverizing system equipped with a steel ball mill is 22 to 40 kWh per ton of material, and the high-temperature pre-carbonization integrated machine can reach up to 90 kWh), and the layout requires a suitable site, and the system is also relatively complex.

[0014] In summary, in the prior art, in the process of dry sludge powder being mixed with coal, transported and entering the pulverizing system, it is easy to have problems such as unorganized emissions, dust explosions, deliquescence leading to energy waste, and reduced output and efficiency of the pulverizing system. Although the use of a pre-carbonization integrated machine can prevent problems such as unorganized emissions and dust explosions, it has problems such as complex system, large investment, land occupation, and high energy consumption. Summary of the invention

[0015] The purpose of the present invention is to address the deficiencies of the above-mentioned technologies and to provide an industrial furnace kiln dry sludge powder coordinated disposal device with a pulverizing system to avoid the problems of unorganized emissions, dust explosions, deliquescence leading to energy waste, and reduced output and efficiency of the pulverizing system during the process of coal mixing, transportation and entering the pulverizing system.

[0016] To achieve the above-mentioned purpose, the industrial furnace kiln dry sludge powder coordinated disposal device with a powder making system designed in the present invention includes a coal mill, the inlet of the coal mill is connected to a coal feeder, the outlet of the coal mill is connected to a coarse powder separator through a powder conveying pipeline, the outlet of the coarse powder separator is connected to a fine powder separator through a powder conveying pipeline, the outlet of the fine powder separator is connected to a powder discharger through a powder conveying pipeline, and also includes a pneumatic conveying pipeline, the pneumatic conveying pipeline is provided with a flow limiting valve and a shut-off valve, and the outlet of the pneumatic conveying pipeline is connected to the powder conveying pipeline.

[0017] Preferably, the inlet of the pneumatic conveying pipeline is connected to a silo pump, the bottom of the silo pump is provided with a compressed air pipeline connected to the compressed air network in the factory, and the outlet of the pneumatic conveying pipeline is connected to the vertical straight pipe section of the powder conveying pipeline arranged at the outlet of the coarse powder separator.

[0018] Preferably, the inlet of the pneumatic conveying pipeline is connected to a silo pump, the bottom of the silo pump is provided with a compressed air pipeline connected to the compressed air network in the factory, and the outlet of the pneumatic conveying pipeline is connected to the vertical straight pipe section of the powder conveying pipeline arranged at the outlet of the coal mill.

[0019] Preferably, the inlet of the pneumatic conveying pipeline is connected to a silo pump, and a compressed air pipeline connected to the compressed air network in the factory is provided at the bottom of the silo pump. The powder conveying pipeline at the inlet of the powder discharger is a horizontal straight pipe section, and the end of the pneumatic conveying pipeline is horizontally inserted into the horizontal straight pipe section, and the center of the inserted pneumatic conveying pipeline coincides with the center of the horizontal straight pipe section.

[0020] Preferably, the inlet of the pneumatic conveying pipeline is connected to the on-board material discharge pipe of the suction and discharge tank truck through a pipe joint, and the outlet of the pneumatic conveying pipeline is connected to the vertical straight pipe section of the powder conveying pipeline arranged at the outlet of the coal mill.

[0021] Preferably, the outlet of the pneumatic conveying pipeline is obliquely connected to the powder conveying pipeline from bottom to top, and the angle between its center and the horizontal line is 100-110 degrees, so that the coal powder airflow connected to the powder conveying pipeline flows from bottom to top.

[0022] Preferably, the outlet of the pneumatic conveying pipeline is located at the access point on the powder conveying pipeline, and the inner wall of the powder conveying pipeline within 2 m is mounted with a wear-resistant ceramic sheet.

[0023] Preferably, the flow limiting valve is a butterfly valve, and the isolation valve is a gate valve.

[0024] Preferably, the powder return port of the coarse powder separator is connected to the inlet of the coal mill through a powder return pipe, and an air lock is provided on the powder return pipe.

[0025] Preferably, the pneumatic conveying pipeline is provided with grounding, and the grounding resistance is less than 6 ohms.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. The sealed disposal of dry sludge powder is realized, which avoids the occurrence of unorganized emission. The pneumatic conveying process of dry sludge powder is less affected by external environmental factors such as rainfall, air humidity, etc., which avoids the deliquescence of dry sludge powder;

[0028] 2. The powder material is connected to the low temperature area of ​​the powder making system, and anti-static measures are taken to avoid the risk of dust explosion caused by high temperature and static electricity;

[0029] 3. The dry sludge powder is directly fed into the powder making system by pneumatic conveying pipeline, which omits the process of coal mixing and adding warehouse, with short process and simple system.

[0030] 4. After the dry sludge powder is connected to the coal mill of the pulverizing system, it avoids the crowding out of the drying output of the pulverizing system and the reduction of the efficiency of the pulverizing system;

[0031] 5. Flexible layout, the location of access points can be flexibly adjusted according to site conditions;

[0032] 6. No new equipment is required, the investment is small, the construction period is short, no new energy consumption is required, and no new land is required;

[0033] 7. It is suitable for a variety of sludge powders, and can also be used to dispose of and utilize other powdered materials, such as dust, coal dust, coal powder discharged from adjacent furnaces, etc., or to add tracers in field tests, etc., with strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic structural diagram of Example 1 of an industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system of the present invention;

[0035] Figure 2 It is a schematic structural diagram of Embodiment 2 of the industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system of the present invention;

[0036] Figure 3 It is a schematic structural diagram of Embodiment 3 of the industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system of the present invention;

[0037] Figure 4 It is a structural schematic diagram of Example 4 of the industrial furnace kiln dry sludge powder coordinated disposal device with a powder making system of the present invention.

[0038] The components in the figure are numbered as follows:

[0039] Coal mill 1, coal feeder 2, powder conveying pipeline 3, coarse powder separator 4, fine powder separator 5, powder discharger 6, pneumatic conveying pipeline 7, flow limiting valve 8, isolation valve 9, silo pump 10, compressed air pipeline 11, pipe joint 12, suction and discharge tank truck 13, vehicle-mounted material discharge pipe 14, wear-resistant ceramic sheet 15, powder return pipe 16, grounding 17, air lock 18, angle a. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] A certain factory is equipped with two 670t / h boilers, each boiler is equipped with two sets of intermediate storage type pulverizing systems, and the pulverizing system is equipped with two DTW380 / 720-Ⅲ steel ball coal mills. The maximum output of each coal mill is designed to be 48t / h. The exhaust gas at the outlet of the pulverizing fan is introduced into the upper part of the furnace as tertiary air. The pulverizing system uses hot air heated by the boiler air preheater as a desiccant, and the designed inlet air temperature is 341℃. A wood block separator, a coarse powder separator, and a fine powder separator are installed in sequence between the pulverizer outlet and the pulverizer. After the coal blocks are dried and crushed in the pulverizer, they are discharged together with the air. After being sorted by the coarse powder separator, the coarse powder with unqualified particle size returns to the pulverizer through the powder return pipe installed at the bottom of the coarse powder separator for re-grinding, and the qualified fine powder is separated from the air in the fine separator and falls into the powder bin below the fine separator. To ensure safety, the plant requires that if the furnace is shut down for more than three days, the coal powder in the powder bin must be burned out to avoid spontaneous combustion. In practice, this is difficult to achieve completely, and the powder must be released manually after the furnace is shut down.

[0044] The plant also burns sludge and is equipped with two 120t / d sludge drying production lines, involving 60% inlet sludge moisture content and 40% outlet sludge moisture content; the drying production line uses a disc dryer and uses low-pressure steam as a heat source for drying. The drying production line plant is a negative pressure plant, and a bag dust collector is installed at the exhaust port entrance of the plant, which regularly collects a certain amount of dry sludge powder.

[0045] The factory has carried out environmental protection transformation on the belt material line and slag removal device. The closed dust removal device of the belt material line and the dry slag machine unloading dust collector will collect a large amount of dust.

[0046] In addition, the plant also disposes of and utilizes some dust materials generated externally, such as carbonaceous sludge powder, blast furnace dust removal ash, waste carbon powder, etc. All of them are transported into the plant by sealed suction and discharge tank trucks. The suction and discharge tank trucks are equipped with on-board compressors with a working pressure of 1 to 3 kg / cm2.

[0047] Example 1

[0048] The particle size of dry sludge powder collected by the dust collector in the drying plant is generally less than 70 microns, and can be directly mixed into the finished coal powder. It adopts a fixed pipeline positive pressure pneumatic conveying and is connected to the 4 outlets of the coarse powder separator, such as Figure 1 As shown, an industrial furnace dry sludge powder coordinated disposal device with a powder making system includes a coal mill 1, the inlet of the coal mill 1 is connected to a coal feeder 2, the outlet of the coal mill 1 is connected to a coarse powder separator 4 through a powder conveying pipeline 3, the outlet of the coarse powder separator 4 is connected to a fine powder separator 5 through a powder conveying pipeline 3, the outlet of the fine powder separator 5 is connected to a powder discharger 6 through the powder conveying pipeline 3, and also includes a pneumatic conveying pipeline 7, the pneumatic conveying pipeline 7 is provided with a flow limiting valve 8 and a shut-off valve 9, and the outlet of the pneumatic conveying pipeline 7 is connected to the powder conveying pipeline 3.

[0049] Among them, the inlet of the pneumatic conveying pipeline 7 is connected to a silo pump 10, and a compressed air pipeline 11 connected to the compressed air network in the factory is provided at the bottom of the silo pump 10. The outlet of the pneumatic conveying pipeline 7 is connected to the vertical straight pipe section of the powder conveying pipeline 3 arranged at the outlet of the coarse powder separator 4.

[0050] In this embodiment, the outlet of the pneumatic conveying pipeline 7 is obliquely connected to the powder conveying pipeline 3 from bottom to top, and the angle a between its center and the horizontal line is 100 to 110 degrees, so that the coal powder airflow connected to the powder conveying pipeline 3 flows from bottom to top. The outlet of the pneumatic conveying pipeline 7 is located at the access point on the powder conveying pipeline 3, and the inner wall of the powder conveying pipeline 3 within 2m after the access point is installed with a wear-resistant ceramic sheet 15.

[0051] In this embodiment, the flow limiting valve 8 is a butterfly valve and the isolation valve 9 is a gate valve. When dry sludge is not being transported, the isolation valve 9 is closed to prevent air leakage into the pulverizing system. When the installation is completed and debugged, the opening of the flow limiting valve 8 is adjusted according to the normal working conditions of the pneumatic conveying device until the unloading speed meets the expectations and the negative pressure at the inlet and outlet of the coal mill 1 is not positive. The opening of the flow limiting valve 8 is determined and locked.

[0052] In this embodiment, the pneumatic conveying pipeline 7 is provided with a grounding 17, and the grounding resistance is less than 6 ohms. The pneumatic conveying pipeline 7 is a carbon steel pipe and is fully welded.

[0053] Example 2

[0054] The coal dust collected by the belt line dust collector contains about 15% large solid particles, which should not be directly mixed into the finished coal powder. It is equipped with a fixed pipeline positive pressure pneumatic conveying and connected to the outlet of the coal mill 1, such as Figure 2 As shown, an industrial furnace dry sludge powder coordinated disposal device with a powder making system includes a coal mill 1, the inlet of the coal mill 1 is connected to a coal feeder 2, the outlet of the coal mill 1 is connected to a coarse powder separator 4 through a powder conveying pipeline 3, the outlet of the coarse powder separator 4 is connected to a fine powder separator 5 through a powder conveying pipeline 3, the outlet of the fine powder separator 5 is connected to a powder discharger 6 through the powder conveying pipeline 3, and also includes a pneumatic conveying pipeline 7, the pneumatic conveying pipeline 7 is provided with a flow limiting valve 8 and a shut-off valve 9, and the outlet of the pneumatic conveying pipeline 7 is connected to the powder conveying pipeline 3.

[0055] Among them, the inlet of the pneumatic conveying pipeline 7 is connected to a silo pump 10, and a compressed air pipeline 11 connected to the compressed air network in the factory is provided at the bottom of the silo pump 10. The outlet of the pneumatic conveying pipeline 7 is connected to the vertical straight pipe section of the powder conveying pipeline 3 arranged at the outlet of the coal mill 1.

[0056] In this embodiment, the outlet of the pneumatic conveying pipeline 7 is obliquely connected to the powder conveying pipeline 3 from bottom to top, and the angle a between its center and the horizontal line is 100 to 110 degrees, so that the coal powder airflow connected to the powder conveying pipeline 3 flows from bottom to top. The outlet of the pneumatic conveying pipeline 7 is located at the access point on the powder conveying pipeline 3, and the inner wall of the powder conveying pipeline 3 within 2m after the access point is installed with a wear-resistant ceramic sheet 15.

[0057] In this embodiment, the flow limiting valve 8 is a butterfly valve and the isolation valve 9 is a gate valve. When dry sludge is not being transported, the isolation valve 9 is closed to prevent air leakage into the pulverizing system. When the installation is completed and debugged, the opening of the flow limiting valve 8 is adjusted according to the normal working conditions of the pneumatic conveying device until the unloading speed meets the expectations and the negative pressure at the inlet and outlet of the coal mill 1 is not positive. The opening of the flow limiting valve 8 is determined and locked.

[0058] In this embodiment, the powder return port of the coarse powder separator 4 is connected to the inlet of the coal mill 1 through the powder return pipe 16, and the powder return pipe 16 is provided with an air lock 18. The large-particle coal powder is separated after passing through the coarse powder separator 4, and returns to the inlet of the coal mill 1 through the powder return pipe 16 equipped with the air lock 18 for grinding.

[0059] In this embodiment, the pneumatic conveying pipeline 7 is provided with a grounding 17, and the grounding resistance is less than 6 ohms. The pneumatic conveying pipeline 7 is a carbon steel pipe and is fully welded.

[0060] Example 3

[0061] The dust collected by the slag removal device has a low carbon content, no particle size requirements and explosion risks, and adopts a fixed pipeline positive pressure pneumatic conveying and is connected to the inlet of the dust removal machine 6, such as Figure 3 As shown, an industrial furnace dry sludge powder coordinated disposal device with a powder making system includes a coal mill 1, the inlet of the coal mill 1 is connected to a coal feeder 2, the outlet of the coal mill 1 is connected to a coarse powder separator 4 through a powder conveying pipeline 3, the outlet of the coarse powder separator 4 is connected to a fine powder separator 5 through a powder conveying pipeline 3, the outlet of the fine powder separator 5 is connected to a powder discharger 6 through the powder conveying pipeline 3, and also includes a pneumatic conveying pipeline 7, the pneumatic conveying pipeline 7 is provided with a flow limiting valve 8 and a shut-off valve 9, and the outlet of the pneumatic conveying pipeline 7 is connected to the powder conveying pipeline 3.

[0062] Among them, the inlet of the pneumatic conveying pipeline 7 is connected to a silo pump 10, and the bottom of the silo pump 10 is provided with a compressed air pipeline 11 connected to the compressed air network in the factory. The powder conveying pipeline 3 at the inlet position of the powder discharger 6 is a horizontal straight pipe section, and the end of the pneumatic conveying pipeline 7 is horizontally inserted into the horizontal straight pipe section, and the center of the inserted pneumatic conveying pipeline 7 coincides with the center of the horizontal straight pipe section.

[0063] In this embodiment, the flow limiting valve 8 is a butterfly valve and the isolation valve 9 is a gate valve. When dry sludge is not being transported, the isolation valve 9 is closed to prevent air leakage into the pulverizing system. When the installation is completed and debugged, the opening of the flow limiting valve 8 is adjusted according to the normal working conditions of the pneumatic conveying device until the unloading speed meets the expectations and the negative pressure at the inlet and outlet of the coal mill 1 is not positive. The opening of the flow limiting valve 8 is determined and locked.

[0064] In this embodiment, the powder return port of the coarse powder separator 4 is connected to the inlet of the coal mill 1 through the powder return pipe 16, and the powder return pipe 16 is provided with an air lock 18. The large-particle coal powder is separated after passing through the coarse powder separator 4, and returns to the inlet of the coal mill 1 through the powder return pipe 16 equipped with the air lock 18 for grinding.

[0065] In this embodiment, the pneumatic conveying pipeline 7 is provided with a grounding 17, and the grounding resistance is less than 6 ohms. The pneumatic conveying pipeline 7 is a carbon steel pipe and is fully welded.

[0066] In this embodiment, the inlet elbow of the powder discharger 6 and the wind shell of the powder discharger 6 are affixed with wear-resistant ceramic sheets 15, and no additional anti-wear measures are required. The bolt heads on the impeller connecting plate facing the airflow are treated with anti-wear paint.

[0067] Example 4

[0068] The sludge powder generated outside the factory is transported into the factory by a sealed suction and discharge tanker. The suction and discharge tanker 13 is equipped with an on-board compressor with a working pressure of 1 to 3 kg / cm 2 , using tank trucks for transportation and connecting to the outlet of coal mill 1, such as Figure 4 As shown, an industrial furnace dry sludge powder coordinated disposal device with a powder making system includes a coal mill 1, the inlet of the coal mill 1 is connected to a coal feeder 2, the outlet of the coal mill 1 is connected to a coarse powder separator 4 through a powder conveying pipeline 3, the outlet of the coarse powder separator 4 is connected to a fine powder separator 5 through a powder conveying pipeline 3, the outlet of the fine powder separator 5 is connected to a powder discharger 6 through the powder conveying pipeline 3, and also includes a pneumatic conveying pipeline 7, the pneumatic conveying pipeline 7 is provided with a flow limiting valve 8 and a shut-off valve 9, and the outlet of the pneumatic conveying pipeline 7 is connected to the powder conveying pipeline 3.

[0069] Among them, the inlet of the pneumatic conveying pipeline 7 is connected to the on-board material discharge pipe 14 on the suction and discharge tank truck 13 through a pipe joint 12, and the outlet of the pneumatic conveying pipeline 7 is connected to the vertical straight pipe section of the powder conveying pipeline 3 arranged at the outlet of the coal mill 1. In addition, the pneumatic conveying pipeline 7 is fixed, and the on-board material discharge pipe 14 of the suction and discharge tank truck 13 is firmly and reliably connected to the pneumatic conveying pipeline 7 through the pipe joint 12 each time feeding.

[0070] In this embodiment, the outlet of the pneumatic conveying pipeline 7 is obliquely connected to the powder conveying pipeline 3 from bottom to top, and the angle a between its center and the horizontal line is 100 to 110 degrees, so that the coal powder airflow connected to the powder conveying pipeline 3 flows from bottom to top. The outlet of the pneumatic conveying pipeline 7 is located at the access point on the powder conveying pipeline 3, and the inner wall of the powder conveying pipeline 3 within 2m after the access point is installed with a wear-resistant ceramic sheet 15.

[0071] In this embodiment, the flow limiting valve 8 is a butterfly valve and the isolation valve 9 is a gate valve. When dry sludge is not being transported, the isolation valve 9 is closed to prevent air leakage into the pulverizing system. When the installation is completed and debugged, the opening of the flow limiting valve 8 is adjusted according to the normal working conditions of the pneumatic conveying device until the unloading speed meets the expectations and the negative pressure at the inlet and outlet of the coal mill 1 is not positive. The opening of the flow limiting valve 8 is determined and locked.

[0072] In this embodiment, the powder return port of the coarse powder separator 4 is connected to the inlet of the coal mill 1 through the powder return pipe 16, and the powder return pipe 16 is provided with an air lock 18. The large-particle coal powder is separated after passing through the coarse powder separator 4, and returns to the inlet of the coal mill 1 through the powder return pipe 16 equipped with the air lock 18 for grinding.

[0073] In this embodiment, the pneumatic conveying pipeline 7 is provided with a grounding 17, and the grounding resistance is less than 6 ohms. The pneumatic conveying pipeline 7 is a carbon steel pipe and is fully welded.

[0074] In Embodiment 1, Embodiment 2 and Embodiment 4, a more preferred option is that the outlet of the pneumatic conveying pipeline 7 is obliquely connected to the powder conveying pipeline 3 from bottom to top, and the angle a between its center and the horizontal line is 105 degrees.

[0075] The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system of the present invention has the following characteristics:

[0076] 1) Collecting the dry sludge powder by negative pressure suction in a dry gas environment;

[0077] 2) connecting the collected dry sludge powder to the pneumatic conveying pipeline 7;

[0078] 3) Connect the outlet of the pneumatic conveying pipeline 7 to the negative pressure pipeline at the outlet section of the coal mill 1;

[0079] 4) The pneumatic conveying pipeline 7 is provided with measures for preventing air leakage in the powder making system and adjusting the feeding speed;

[0080] 5) The location and method of connecting the pneumatic conveying pipeline 7 to the outlet pipeline of the coal mill 1 should be such as to avoid the generation of large eddies and sediment blockage.

[0081] 6) The pneumatic conveying pipeline 7 adopts measures to generate static electricity by high-speed friction of dry sludge powder;

[0082] 7) Measures are taken to prevent the negative pressure pipe at the outlet section of the coal mill 1 from being aggravated by wear after the pneumatic conveying pipeline 7 is connected.

[0083] Regarding feature 1), since the dry sludge powder has good fluidity and some of it is deliquescent, it is not suitable to be exposed to the air for a long time. For dry sludge powder whose production location is relatively stable and close to the powder making system, special collection equipment can be set up, such as exhaust fan + dry sludge powder silo + bag dust collector. For dry sludge powder that is temporarily produced or needs to be transported to the powder making system over a long distance, it can be collected by a suction tank truck 13 to avoid the problem of unorganized emissions.

[0084] In view of feature 2), for dry sludge powder with special collection equipment, a fully sealed unloading and pneumatic conveying device such as a dome valve and a silo pump 10 can be connected under the collection equipment; for dry sludge powder collected by a suction and discharge tank truck 13, the suction and discharge tank truck 13 is equipped with a compressor, a discharge pipe, a pipe joint 12 and other pneumatic conveying devices.

[0085] In view of feature 3), for the pneumatic conveying pipeline 7 connected to the special collecting equipment, its outlet pipe is directly connected to the negative pressure pipe of the outlet section of the coal mill 1. For the dry sludge powder collected by the suction and discharge tank truck 13, a feed pipe is connected to the negative pressure pipe of the outlet section of the coal mill 1. The other end of the feed pipe is equipped with a hose and a pipe joint 12 that can be reliably connected to the suction and discharge tank truck 13.

[0086] In view of feature 4), a shut-off valve 9 and a flow limiting valve 8 can be installed before the pneumatic conveying pipeline 7 enters the negative pressure pipe of the outlet section of the coal mill 1. The shut-off valve 9 can be in the form of a gate valve, and the flow limiting valve 8 can be in the form of a butterfly valve. When dry sludge is not being conveyed, the shut-off valve 9 is closed to prevent air leakage into the pulverizing system. When the installation is completed and debugged, the opening of the flow limiting valve 8 is adjusted according to the normal working conditions of the pneumatic conveying pipeline 7 until the unloading speed meets the expectations and the negative pressure at the inlet and outlet of the coal mill 1 is not positive. The opening of the flow limiting valve 8 is determined and locked. The opening of the flow limiting valve 8 can also be adjusted to meet the demand in coordination with the output of the pneumatic conveying pipeline 7 each time the pneumatic conveying is fed.

[0087] In view of feature 5), the pneumatic conveying pipeline 7 should be connected from the pipeline between the outlet pipeline of the coal mill 1 and the inlet of the powder discharger 6. It cannot be connected from the coarse powder separator 4, the fine powder separator 5 and other possible equipment and accessories, auxiliary pipelines such as wood block separators, powder return pipes, and moisture absorption pipes to prevent changes in the internal flow field of the equipment and affect the function of the equipment. The pneumatic conveying pipeline 7 cannot be connected from the bottom of the elbow of the outlet pipeline of the coal mill 1, otherwise coal powder will be deposited at the pipe mouth, which may block the pipe mouth. It is also possible that the coal powder that falls into the pipe mouth when the pulverizing system is shut down cannot be blown away, and long-term accumulation will form a self-ignition point, causing safety risks. The direction in which the pneumatic conveying pipeline 7 is connected from the negative pressure pipe of the outlet section of the coal mill 1 should be as consistent as possible with the coal powder airflow, and reverse access should be avoided, and vertical access should be avoided as much as possible.

[0088] In view of feature 6), the pneumatic conveying pipeline 7 and the joint are made of metal and are well grounded. The pneumatic conveying pipeline 7 and the joint are connected by welding as much as possible. If a flange connection (such as a steel pipe + aluminum joint) is required, a wire jumper should be installed at both ends of the flange.

[0089] In view of feature 7), since the maximum wear of dust on metal is related to the material, impact rate, uniformity coefficient and flow rate, especially to the vertical velocity component of the dust particles impacting the metal, which is approximately proportional to the 3.3th power of the velocity component, the airflow conveying the dry sludge powder will form a dense phase flow when entering the negative pressure pipeline at the outlet of the coal mill 1, and the pneumatic conveying pressure is generally 2-4 kg / cm 2The pressure in the powder making system is within the range of 200°, which is much higher than the pressure in the powder making system. According to the heat and mass transfer equations, the airflow will expand rapidly and mix strongly after entering the powder conveying pipeline 3, and a large lateral component velocity will be generated downstream of the connection point, close to the connection point of the elbow. Airflow may also fall off the wall at the elbow, and a recirculation zone and a high-speed zone are formed near the inner and outer walls after the elbow, respectively. The above three situations will cause changes in the wear characteristics of the pipeline after the access point and accelerate the local wear rate. Therefore, different pipeline anti-wear reinforcement measures should be taken according to different access positions, such as installing wear-resistant ceramic sheets 15 on the affected areas.

[0090] By adopting the above technical scheme, dry sludge powder can be directly mixed with coal powder, reducing the intermediate link of dry sludge powder entering the furnace for combustion, avoiding the possibility of unorganized emissions and the risk of dust explosion, and reducing the impact of dry sludge powder on the output and efficiency of the powder making system. The conveying and mixing process is controllable, which helps to ensure that the process of coordinated disposal of dry sludge powder and other powdered materials by the furnace is economical, safe and environmentally friendly.

[0091] It should be noted that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solutions of the present invention are limited only by the scope of the claims.

[0092] The various aspects disclosed for describing the present specification and claims are merely examples, and therefore, the present specification and claims are not limited to the details shown. In the above description, when the detailed description of the related known functions or configurations is determined to be unnecessary to obscure the focus of the present specification and claims, the detailed description will be omitted.

[0093] In the case of using “including”, “having” and “comprising” described in the present specification, unless otherwise used, there may also be another part or other parts, and the terms used may generally be in the singular but may also represent the plural form.

[0094] Finally, it should be pointed out that the above content is a further detailed description of the invention in combination with specific implementation methods. It cannot be considered that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, simple replacements made without departing from the concept of the present invention should be regarded as belonging to the protection scope of the present invention. The above embodiments are only more representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments, and there can be many variations. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention should be considered to belong to the protection scope of the present invention.

[0095] At the same time, it should be noted that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be construed as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solutions of the present invention are limited only by the scope of the claims. The features of the various embodiments of the present invention may be partially or completely combined or spliced ​​with each other, and may be performed in various different configurations as those skilled in the art may fully understand. The embodiments of the present invention may be performed independently of each other, or may be performed together in a mutually dependent relationship.

[0096] For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, and the above structures should be regarded as belonging to the protection scope of the present invention.

Claims

1. An industrial furnace kiln dry sludge powder coordinated disposal device with a powder making system, comprising a coal mill (1), the inlet of the coal mill (1) is connected to a coal feeder (2), the outlet of the coal mill (1) is connected to a coarse powder separator (4) through a powder conveying pipeline (3), the outlet of the coarse powder separator (4) is connected to a fine powder separator (5) through a powder conveying pipeline (3), and the outlet of the fine powder separator (5) is connected to a powder discharger (6) through a powder conveying pipeline (3), characterized in that: It also comprises a pneumatic conveying pipeline (7), on which a flow limiting valve (8) and a cut-off valve (9) are provided, and the outlet of the pneumatic conveying pipeline (7) is connected to the powder conveying pipeline (3).

2. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 1 is characterized by: The inlet of the pneumatic conveying pipeline (7) is connected to a silo pump (10), and a compressed air pipeline (11) connected to the compressed air network in the factory is provided at the bottom of the silo pump (10). The outlet of the pneumatic conveying pipeline (7) is connected to a vertical straight pipe section of a powder conveying pipeline (3) provided at the outlet of the coarse powder separator (4).

3. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 1 is characterized by: The inlet of the pneumatic conveying pipeline (7) is connected to a silo pump (10), and the bottom of the silo pump (10) is provided with a compressed air pipeline (11) connected to the compressed air network in the factory, and the outlet of the pneumatic conveying pipeline (7) is connected to the vertical straight pipe section of the powder conveying pipeline (3) provided at the outlet of the coal mill (1).

4. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 1 is characterized by: The inlet of the pneumatic conveying pipeline (7) is connected to a silo pump (10), and the bottom of the silo pump (10) is provided with a compressed air pipeline (11) connected to the compressed air network in the factory. The powder conveying pipeline (3) at the inlet position of the powder discharger (6) is a horizontal straight pipe section, and the end of the pneumatic conveying pipeline (7) is horizontally inserted into the horizontal straight pipe section, and the center of the inserted pneumatic conveying pipeline (7) coincides with the center of the horizontal straight pipe section.

5. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 1 is characterized by: The inlet of the pneumatic conveying pipeline (7) is connected to a material discharge pipe (14) on a suction and discharge tanker (13) via a pipe joint (12), and the outlet of the pneumatic conveying pipeline (7) is connected to a vertical straight pipe section of a powder conveying pipeline (3) provided at the outlet of the coal mill (1).

6. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 2 or 3, characterized in that: The outlet of the pneumatic conveying pipeline (7) is obliquely connected to the powder conveying pipeline (3) from bottom to top, and the angle (a) between its center and the horizontal line is 100 to 110 degrees, so that the coal powder airflow connected to the powder conveying pipeline (3) flows from bottom to top.

7. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 2 or 3, characterized in that: The outlet of the pneumatic conveying pipeline (7) is located at the access point on the powder conveying pipeline (3), and a wear-resistant ceramic sheet (15) is attached to the inner wall of the powder conveying pipeline (3) within 2 m after the access point.

8. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 1 is characterized by: The flow limiting valve (8) is a butterfly valve, and the isolation valve (9) is a gate valve.

9. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 1 is characterized by: The powder return port of the coarse powder separator (4) is connected to the inlet of the coal mill (1) through a powder return pipe (16), and an air lock (18) is provided on the powder return pipe (16).

10. The industrial furnace kiln dried sludge powder coordinated disposal device with a powder making system according to claim 1, characterized in that: The pneumatic conveying pipeline (7) is provided with a grounding (17), and the grounding resistance is less than 6 ohms.

Images