A method and device for self-feedback drying of total material moisture content

Abstract

The application discloses a kind of for all material moisture content self-feedback drying method and device, the moisture content of material in feed hopper is monitored in real time by moisture content monitoring device, and different feed lines are selected according to moisture content: 90-98% moisture content material enters boiling bed filter and is preliminarily dewatered, and filter medium-material mixture enters next step with pulsating hot carrier gas;65-90% moisture content material is stirred into dispersion medium, and the obtained dispersion medium-material mixture enters next step with pulsating hot carrier gas;30-65% moisture content material is granulated by pelletizer and is cut into strip by hot carrier gas, and is brought into next step;10-30% moisture content material is crushed by crusher, and enters next step with hot carrier gas;Then by cyclone drying, sorting and gas-solid separation, 10%-98% moisture content material is realized continuous automatic feeding and efficient drying treatment, and the kind of material that can be handled is greatly widened, and has the characteristics of continuous, automation and stabilization.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of material drying, and particularly relates to a method and device for self-feedback drying of the moisture content of full material. BACKGROUND

[0002] With the progress of social economy and the increasing demand of people for a better life, social productivity has developed rapidly, but a large amount of pollutants generated in the production process have also caused environmental problems. The separation of pollutants in the process of environmental protection is at the cost of energy or material consumption. The energy consumed by global industry accounts for 32% of the total global energy consumption, of which the energy consumed by the separation process accounts for 45%-55% of the total energy consumption in industry. The energy consumed by thermal separation (including distillation, drying and evaporation, etc.) in the separation process accounts for 80% of the total energy consumption in the separation process, and the energy consumed by non-thermal separation accounts for only 20% of the total energy consumption in the separation process. The energy consumed by thermal separation accounts for 36%-44% of the total energy consumption in industry, and the energy consumed by non-thermal separation accounts for only 9%-11% of the total energy consumption in industry. Therefore, replacing thermal separation in industry with feasible non-thermal separation will save a large amount of energy and reduce the generation of environmental pollutants, which will help to solve the problems of energy shortage and environmental pollution.

[0003] When industrial sludge, vinasse, coal, crop products and waste residues, waste catalysts and other materials that need to be dewatered are dried, thermal separation is often used. Because the latent heat of vaporization of water is large, the energy consumption for phase change drying is large, which does not meet the goal of energy saving and emission reduction and pollution reduction and carbon reduction, and non-phase change drying meets the main theme of the "double carbon era". At the same time, the drying device for different types of materials and different moisture contents needs to be normalized to achieve the effect of one machine for multiple purposes, which is the only way to realize the systematization, large-scale and automation of industrial devices, which has great significance for reducing energy consumption and carbon emissions.

[0004] CN110257089A discloses a vinasse drying and resource treatment method, which uses pulsating gas as a carrier to induce water to migrate out of the particles while the vinasse particles are revolving in the cyclone field. After drying, the vinasse enters the shock drying column, and the pulsating drying gas stream will make the particles vibrate to speed up the drying speed. The vinasse particles after shock drying enter the secondary cyclone self-rotation dewatering separator for further drying, and finally the dried vinasse is subjected to anaerobic pyrolysis gasification. The moisture content of the dried vinasse particles obtained by this method is below 10%, but it does not consider that part of the wet vinasse particles are deposited at the bottom of the shock drying column and need to be returned for reprocessing.

[0005] CN110183089A discloses a method and device for dewatering and drying residual sludge, which concentrates high-moisture residual sludge through a granular bed with an internal cyclone, and then the concentrated sludge enters a cyclone self-rotation dewatering device and an acceleration airflow separation column in sequence for deep dewatering and separation of sludge and filtering medium. The dried residual sludge enters a cyclone trap from the top of the separation column, and the separated filtering medium is discharged from the bottom of the separation column and recycled. The method and device have good dewatering effect, but the fluidized bed in the device has slow filtering speed, complex operation when refilling the filtering medium, long running cycle, and cannot support continuous large-scale feeding. There is a phenomenon that sludge accumulates on the surface of the bed layer, causing the lower filtering medium not to be fully utilized.

[0006] CN110269094A discloses a method and device for drying and sorting grain, which dries and sorts wet grain by a one-stage cyclone, a separator, a two-stage cyclone, and a three-stage cyclone. The method can simultaneously realize drying and sorting of wet grain and dry grain with different specific gravities, and has good application prospect. However, the method uses electric heating carrier gas, which has high energy consumption. At the same time, the wet grain stays in the one-stage cyclone for a very short time, which may cause unstable drying effect of the wet grain. After entering the separator, large-particle wet grain may be discharged from the bottom of the separator and mixed with the dry grain.

[0007] CN113636737A discloses a method and device for dewatering and drying residual sludge, which concentrates residual sludge by centrifugal dewatering, mixes the concentrated sludge with a dispersing medium in a mixer, dries and sorts the sludge-dispersing medium mixture in a cyclone and a separation column, and then traps the dry sludge from a mixture of dry sludge and water-containing air in a cyclone trap. The method has good drying effect on residual sludge, and recovers low-grade heat energy from sewage by using a sewage source heat pump to transfer the heat energy to the inlet gas. However, the invention only deals with residual sludge, and cannot simultaneously deal with different moisture content sludge and different materials.

[0008] In summary, the existing material drying methods and devices have the following problems: the existing drying technology and device only deal with a single material or a material with a certain moisture content, and are not universal for other materials. They cannot simultaneously deal with different materials and the same material with different moisture contents, and require different devices, resulting in large one-time investment, low drying efficiency, and waste of space and resources. SUMMARY

[0009] In view of the above problems existing in the prior art, the present application provides a method and device for self-feedback drying of moisture content of all materials, which monitors the moisture content of the material in the feeding hopper in real time through a moisture content monitoring device, and selects different feeding lines according to the moisture content, and then realizes continuous automatic feeding and efficient drying treatment of the material with a moisture content of 10%-98% through cyclone drying, separation and gas-solid separation, greatly broadening the types of treatable materials, and having the characteristics of continuity, automation and stabilization.

[0010] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0011] The first aspect of the present application is to provide a method for self-feedback drying of moisture content of all materials, which comprises the following steps:

[0012] (1) Determination of moisture content: infrared light is generated by an infrared light source, and infrared light of a characteristic wavelength is obtained through a filter on a light splitting disc, which is reflected by the material after passing through the infrared-transparent glass arranged at the bottom of the feeding hopper, and the reflected light signal is converted into an electric signal by a photoelectric sensor, and the electric signal is processed by a processor to obtain the moisture content, and the feeding line is adjusted according to the self-feedback of the moisture content.

[0013] (2) Feeding line: (21) the material with a moisture content of 90-98% enters a boiling bed filter, and preliminary dewatering is performed by using the filled filter medium, the filter medium-material mixture enters a cyclone dryer with pulsating hot carrier gas, and the filter medium acts as a dispersion medium in the cyclone dryer; (22) the material with a moisture content of 65-90% is stirred and mixed into the dispersion medium, and the obtained dispersion medium-material mixture enters the cyclone dryer with pulsating hot carrier gas; (23) the material with a moisture content of 30-65% is granulated into material strips by a granulator and is cut into strips by hot carrier gas, and then is brought into the cyclone dryer; (24) the material with a moisture content of 10-30% is crushed by a crusher and enters the cyclone dryer with hot carrier gas;

[0014] (3) Cyclone drying: the wet material from steps (21) and (22) is subjected to cyclone drying and separation in the cyclone dryer, and the obtained dispersion medium-dried material enters a separation column with pulsating hot carrier gas for accelerated separation; the wet material from steps (23) and (24) is subjected to cyclone drying and separation in the cyclone dryer, and the obtained dried material enters a gas-solid cyclone separator with hot carrier gas through the separation column;

[0015] (4) Accelerated separation of mixed material: in the separation column, the cumulative acceleration of the dried material and the dispersion medium is different due to the pulsating hot carrier gas, and the dried material and the dispersion medium are separated

[0016] (5) the dried material is further dried in a cyclone and separated into a gas containing water.

[0017] The application further provides that the hot carrier gas is a continuous flow of high-temperature flue gas; and the pulsating hot carrier gas is a periodically oscillating flow of high-temperature flue gas.

[0018] The high-temperature flue gas has a temperature of 40-80℃.

[0019] The pulsating hot carrier gas is a periodically oscillating flow of high-temperature flue gas obtained by periodically closing a butterfly valve, and the periodically closing of the butterfly valve is controlled by a gas flow pulsation generator.

[0020] The application further provides that the method further comprises a step (6) of gas-liquid separation and heat energy recycling, in which the gas containing water separated in the step (5) is separated into hot waste water and hot waste gas by a gas-liquid separator.

[0021] When the flow of the high-temperature flue gas is low, the hot waste gas is reused as the high-temperature flue gas, and whether low-temperature heating is performed is determined according to the reuse of the hot waste gas.

[0022] The hot waste water is used to preheat the wet material in the step (2), which is conducive to improving the cyclone drying effect and realizing waste heat utilization.

[0023] The application further provides that the dispersion medium separated in the step (4) is reused in the steps (21) and (22).

[0024] The application further provides that the method is suitable for materials with a water content of 10-98%, and the materials include sludge, vinasse, coal, crop residues and waste catalysts.

[0025] The application further provides that the thickness of the boiling bed layer in the boiling bed filter is set to be 0.4-1m.

[0026] The filtering medium used in the boiling bed layer includes perlite, quartz sand and sea sand.

[0027] The particle size of the filtering medium is 0.5-2mm.

[0028] The application further provides that in the step (22), the mixing mass ratio of the material with a water content of 65-90% to the dispersion medium is controlled to be 1:1-1:3.

[0029] The dispersion medium includes coal cinder particles, quartz sand, perlite and sea sand.

[0030] The particle size of the dispersion medium is 2-4mm.

[0031] The second aspect of the present application is to provide a device for self-feedback drying of the moisture content of all materials based on the above method, comprising a feeding hopper, a feeding system, a cyclone dryer, a separation column and a gas-solid cyclone separator connected in sequence in the direction of material flow, a moisture content monitoring system for real-time monitoring of the moisture content of the material, and a carrier gas generating unit, wherein:

[0032] The feeding hopper is used for material feeding, and the bottom thereof is provided with four parallel feeding valves;

[0033] The moisture content monitoring device comprises an infrared light source, a light splitting disc, an infrared transparent glass provided on the feeding hopper, and a photoelectric sensor arranged in sequence in the direction of the light path, and a processor for converting the electrical signal received from the photoelectric sensor into moisture content information, the processor being electrically connected with the feeding valves of the feeding hopper to transmit control signals to the feeding valves;

[0034] The feeding system comprises a first feeding line, a second feeding line, a third feeding line and a fourth feeding line connected with the four feeding valves respectively;

[0035] A bubbling bed filter is arranged on the first feeding line; a mixer is arranged on the second feeding line; a heat exchanger is arranged on the third feeding line; and a crusher is arranged on the fourth feeding line;

[0036] The cyclone dryer is used for cyclone drying of the wet material from the feeding system to obtain dried material or a dispersion medium-dried material mixture;

[0037] The separation column is used for separating the dried material and the dispersion medium in the dispersion medium-dried material mixture;

[0038] The gas-solid cyclone separator is used for cyclone drying of the dried material from the separation column again, while obtaining moisture-containing gas;

[0039] The carrier gas generating unit comprises a heater, a first butterfly valve, an airflow pulsation generator and a hot air pipeline connected in sequence, the airflow pulsation generator is used for controlling the periodic closing of the first butterfly valve, the front and back sides of the first butterfly valve are directly connected through a bypass pipeline, and a second butterfly valve is arranged on the bypass pipeline.

[0040] The present application further provides that a heat exchanger is arranged after the bubbling bed filter, the mixer and the crusher and before the granulator in the first feeding line, the second feeding line, the third feeding line and the fourth feeding line respectively;

[0041] The device also comprises a gas-liquid separator connected with the gas-solid cyclone separator, for separating the water-containing gas from the gas-solid cyclone separator into hot waste water and hot waste gas, and the water phase outlet and the gas phase outlet of the gas-liquid separator are connected with a heat exchanger and a heater respectively.

[0042] The application further provides that the outlet of the granulator is vertically connected with a hot air pipeline, and an extrusion plate is arranged at the outlet of the granulator, and a plurality of round holes are uniformly distributed on the extrusion plate.

[0043] The application has the following beneficial effects:

[0044] (1) Compared with the traditional material drying method and device which only processes a single kind of material with a single water content, the application introduces a water content monitoring device to monitor the water content of the material in the feeding hopper in real time, and four kinds of feeding lines are designed for different water contents, the feeding line is adjusted through water content information feedback, automatic feeding drying of the material with a water content of 10-98% is realized, the application range is wide, and the application is conducive to popularization and dissemination.

[0045] (2) Compared with the traditional phase change drying method, the non-phase change drying method of the application has higher dehydration efficiency and lower energy consumption, the centrifugal force generated by the self-coupling motion of the wet material particles in the cyclone dryer (the self-rotation rate is as high as 20000r / min-60000r / min) and the shear force acting on the particles in the cyclone field are used to remove the water in the particles, the dehydration efficiency is high, and a large amount of energy required for vaporization in the phase change drying method is saved.

[0046] (3) Compared with the traditional drying device, the device of the application is stable and efficient, the self-coupling motion time of the wet material particles in the cyclone field is effectively prolonged through the multi-stage series connection of the cyclone dryer, and the drying effect is improved, thereby solving the problem that the use of a single-stage cyclone dryer causes unstable material particle drying effect and affects the working efficiency of the drying device.

[0047] (4) The method and device of the application use high-temperature flue gas as the carrier gas, and use the hot waste water obtained by separation to preheat the wet material, and the hot waste gas is reused as the carrier gas according to the situation. Waste heat utilization and waste heat reuse are realized, energy consumption is saved, the operation cost of the drying process can be significantly reduced, and the concept of energy saving, emission reduction, pollution reduction, carbon reduction and efficiency increase is met. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 It is a process flow diagram for the water content self-feedback drying of all materials of the application.

[0049] Figure 2 It is a structural schematic diagram of the water content monitoring device.

[0050] Figure 3 is a schematic diagram of the principle of a granulator.

[0051] Figure 4 is a comparison chart of energy consumption of non-phase change drying and phase change drying.

[0052] In the figure:

[0053] 1 - feed hopper; 11 - feed valve;

[0054] 2 - feed system; 21 - fluidized bed filter; 22 - mixer; 23 - granulator; 24 - crusher; 25 - heat exchanger; 26 - extrusion plate;

[0055] 3 - cyclone dryer;

[0056] 4 - sorting column;

[0057] 5 - gas-solid cyclone separator;

[0058] 6 - moisture content monitoring device; 61 - infrared light source; 62 - light splitting disc; 63 - infrared transparent glass; 64 - photoelectric sensor; 65 - processor;

[0059] 71 - heater; 72 - first butterfly valve; 73 - gas flow pulsation generator; 74 - hot air pipeline; 75 - second butterfly valve; 76 - fan;

[0060] 8 - gas-liquid separator. DETAILED DESCRIPTION

[0061] The technical solutions of the present application will be described in detail below in combination with specific embodiments. It should be understood that the following embodiments are only a part of the embodiments of the present application and are not used to limit the protection scope of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0062] The test methods in the following embodiments without specific conditions are usually according to the conventional conditions or according to the conditions suggested by the manufacturers. All percentages and fractions are by weight unless otherwise specified.

[0063] The present inventor has found through extensive and in-depth research that the existing material drying method and device can only dry a single material with a certain moisture content and does not have universality for drying other materials. When drying different materials, different devices need to be replaced, resulting in excessive one-time investment and waste of space and resources.

[0064] Therefore, this invention develops a method and apparatus for self-feedback drying of all materials based on moisture content. A moisture content monitoring device monitors the moisture content of the material in the feed hopper, and four different feed routes are designed to achieve continuous and stable feeding of materials with varying moisture contents, taking into account processing efficiency and energy consumption. The material is then subjected to cyclone drying, sorting, and gas-solid separation to achieve efficient drying.

[0065] Example 1

[0066] like Figure 1 As shown, a device for self-feedback drying of moisture content in all materials includes a feed hopper 1, a feeding system 2, a cyclone dryer 3, a sorting column 4, and a gas-solid cyclone separator 5 connected sequentially in the material flow direction; a moisture content monitoring system 6 for real-time monitoring of material moisture content; and a carrier gas generating unit, wherein:

[0067] The feeding hopper 1 is used for material feeding, and four parallel feeding valves 11 are provided at its bottom;

[0068] Combination Figure 2 As shown, the moisture content monitoring device 6 includes an infrared light source 61, a split disc 62, an infrared-transmitting glass 63 and a photoelectric sensor 64 arranged sequentially in the direction of the light path, and a processor 65 for converting the electrical signal received from the photoelectric sensor 64 into moisture content information. The processor 65 is electrically connected to the feed valve 11 of the feed hopper 1 to transmit control signals to the feed valve 11.

[0069] The feeding system 2 includes a first feeding line, a second feeding line, a third feeding line, and a fourth feeding line, which are respectively connected to four feeding valves 11;

[0070] A fluidized bed filter 21 is installed on the first feeding line. The fluidized bed filter 21 is used to perform preliminary dehydration on materials with a moisture content of 90-98%. It uses the filter medium to intercept and adsorb the material, so that the material remains in the fluidized bed and the filtered water is discharged.

[0071] The second feeding line is equipped with a mixer 22, which is used to stir materials with a moisture content of 65-90% and added dispersion medium to improve the dispersibility of materials and the effect of cyclone drying.

[0072] The third feeding line is equipped with a granulator 23, which is used to granulate materials with a moisture content of 30-65% to form material strips and feed them directly, maintaining a closed feeding environment and reducing air volume loss.

[0073] The fourth feeding line is equipped with a crusher 24, which is used to crush materials with a moisture content of 10-30%.

[0074] The cyclone dryer 3 is used for cyclone drying of the material from the feeding system 2 to obtain dried material or dispersion medium-dried material mixture;

[0075] The sorting column 4 is used for separating the dried material and the dispersion medium in the dispersion medium-dried material mixture;

[0076] The gas-solid cyclone separator 5 is used for cyclone drying of the dried material from the sorting column 4 again, while obtaining water-containing gas;

[0077] The carrier gas generating unit comprises a heater 71, a first butterfly valve 72, a gas flow pulsation generator 73 and a hot air pipeline 74 connected in sequence, the gas flow pulsation generator 73 is used for controlling the periodic closing of the first butterfly valve 72, the front and back sides of the first butterfly valve 72 are directly connected through a bypass pipeline, and the bypass pipeline is provided with a second butterfly valve 75;

[0078] The hot air pipeline 74 is communicated with the outlets of the first feeding line, the second feeding line, the third feeding line and the fourth feeding line and the inlet of the cyclone dryer 3 respectively, and is used for sending the wet material into the cyclone dryer 3.

[0079] When the wet material enters the cyclone dryer 3 through the first feeding line or the second feeding line, the second butterfly valve 75 is closed, the gas flow pulsation generator 73 controls the periodic closing of the first butterfly valve 72, and then periodic oscillation gas flow (i.e. pulsating hot carrier gas) is generated, which is used for separating the dried material and the dispersion medium in the sorting column 4;

[0080] When the wet material enters the cyclone dryer 3 through the third feeding line or the fourth feeding line, the first butterfly valve 72 is closed, and the second butterfly valve 75 is opened, at this time, continuous gas flow (i.e. hot carrier gas) is generated, and the sorting column 4 is equivalent to a straight channel.

[0081] In the application, heat exchangers 25 are arranged after the fluidized bed filter 21, the mixer 22 and the crusher 24 and before the granulator 23 in the first feeding line, the second feeding line, the third feeding line and the fourth feeding line respectively;

[0082] The device further comprises a gas-liquid separator 8 connected with the gas-solid cyclone separator 5, which is used for separating the water-containing gas from the gas-solid cyclone separator 5 into hot waste water and hot waste gas, the water phase outlet of the gas-liquid separator 8 is connected with the heat exchanger 25, and the hot waste water can be reused for preheating of the wet material; the gas phase outlet of the gas-liquid separator 8 is connected with the heater 71, and the hot waste gas can be reused as high-temperature flue gas, so that energy recycling is realized.

[0083] In the application, as Figure 3As shown, the outlet of the granulator 23 is connected with the hot air pipeline 74 vertically, and an extrusion plate 26 is arranged at the outlet of the granulator 23, and a plurality of round holes are uniformly distributed on the extrusion plate 26, and the diameter D of the round holes is preferably 6 mm.

[0084] The granulator 23 can continuously form strip-shaped material by the extrusion of the screw, and at the same time, the continuous airflow in the hot air pipeline 74 can cut off the strip-shaped material and carry it into the cyclone dryer 3; and the feeding rate can be controlled by controlling the extrusion rate of the granulator 23.

[0085] Since the drying time of the material particles in the first-stage cyclone dryer 3 is short, a lot of water in the material particles with high water content has not been completely migrated from the inside to the surface for removal, resulting in that the material with high water content is deposited at the lower end of the sorting column 4, and further resulting in that the material needs to be returned for reprocessing, so it is necessary to ensure that the material particles reach a low water content before entering the sorting column 4 to improve the sorting efficiency.

[0086] Therefore, according to the actual processing situation, a plurality of cyclone dryers 3 can be connected in series to improve the drying effect of the wet material particles and reduce the amount of material that needs to be returned for reprocessing, thereby greatly improving the processing efficiency of the material drying device.

[0087] The device further comprises a material storage tank (not shown in the figure) arranged between the feeding hopper 1 and the feeding system 2, which is used for temporarily storing the input wet material and stabilizing the feeding amount of the pipeline; and a fan 76 arranged before the heater 71, which is used for providing power for the movement of the high-temperature flue gas.

[0088] The method for self-feedback drying of the water content of the whole material based on the above device comprises the following steps:

[0089] (1) Measurement of water content: infrared light is generated by the infrared light source 61, and infrared light of a characteristic wavelength is obtained through the filter on the light splitting disc 62, which is reflected by the material after passing through the infrared-transparent glass 63 arranged at the bottom of the feeding hopper 1, and the reflected light signal is converted into an electrical signal by the photoelectric sensor 64, and the electrical signal is processed by the processor 65 to obtain the water content, and the feeding line is adjusted according to the self-feedback of the water content to give different materials appropriate feeding modes, and to realize high automation of continuous feeding.

[0090] (2) Feeding line:

[0091] (21) The material with a water content of 90-98% enters the boiling bed filter 21 for preliminary dehydration, the filter medium filled in the boiling bed filter 21 filters the material to remove water, realizes drying reduction, and the filter medium-material mixture enters the cyclone dryer 3 with the pulsating hot carrier gas, and the filter medium acts as a dispersion medium in the cyclone dryer 3;

[0092] The high water content material is preliminarily dewatered by the boiling bed filter 21, the water content of the material is reduced, the feeding and conveying problems of the high water content material caused by stickiness and bridging can be solved, and the final drying treatment effect can be improved.

[0093] (22) The material with 65-90% water content is stirred and mixed into the dispersion medium, and the obtained dispersion medium-material mixture enters the cyclone dryer 3 with the pulsating hot carrier gas;

[0094] The addition of the dispersion medium can improve the dispersibility of the material and solve the feeding problem caused by strong stickiness of the material;

[0095] (23) The material with 30-65% water content is granulated into material strips by the granulator 23 and is cut into strips by the hot carrier gas, and then is brought into the cyclone dryer 3;

[0096] The granulation by the granulator 23 is beneficial to the subsequent cyclone drying process, realizes direct feeding, maintains a closed feeding environment, reduces the air volume loss, and solves the problem of incoherent feeding.

[0097] (24) The material with 10-30% water content is crushed by the crusher 24 and then enters the cyclone dryer 3 with the hot carrier gas;

[0098] In view of the characteristics of the material with 10-30% water content, such as low water content and high hardness, the material is fed after crushing, the feeding problem is solved, and the gas-liquid exchange area in the subsequent cyclone drying process is increased.

[0099] (3) Cyclone drying:

[0100] (31) The wet material from steps (21) and (22) is subjected to cyclone drying and separation in the cyclone dryer 3, and the obtained dispersion medium-dried material enters the sorting column 4 with the pulsating hot carrier gas for accelerated sorting;

[0101] (32) The wet material from steps (23) and (24) is subjected to cyclone drying and separation in the cyclone dryer 3, and the obtained dried material enters the gas-solid cyclone separator 5 through the sorting column 4 (which can be regarded as a straight passage) with the hot carrier gas;

[0102] (4) Accelerated sorting of mixed material:

[0103] In the sorting column 4, due to the mass difference between the dried material and the dispersion medium, the cumulative acceleration of the pulsating hot carrier gas to the two is different, the total displacement direction of the dispersion medium is downward, and the total displacement direction of the dried material is upward, so that the dispersion medium is discharged from the bottom of the sorting column 4, and the dried material is discharged from the top of the sorting column 4 and then enters the gas-solid cyclone separator 5;

[0104] (5) the dried material is further dried in a cyclone dryer and separated into a gas containing water.

[0105] In the present application, the hot carrier gas is a continuous flow of high-temperature flue gas; the pulsating hot carrier gas is a periodic oscillation flow of high-temperature flue gas; the temperature of the high-temperature flue gas is 40-80℃, which can reduce the adhesion resistance of water and further improve the dehydration effect.

[0106] The pulsating hot carrier gas is a periodic oscillation flow of high-temperature flue gas obtained by periodic closure of a butterfly valve, and the periodic closure of the butterfly valve is controlled by the gas flow pulsation generator 73.

[0107] In the present application, the method further comprises step (6) gas-liquid separation and heat energy recycling: the water-containing gas separated in step (5) passes through a gas-liquid separator 8 to separate hot waste water and hot waste gas;

[0108] When the flow of high-temperature flue gas is low, the hot waste gas can be reused as high-temperature flue gas, and whether low-temperature heating is performed is determined according to the reuse of the hot waste gas.

[0109] The hot waste water can be used to preheat the wet material in step (2), which is beneficial to improve the cyclone drying effect and realize waste heat utilization.

[0110] In the present application, the dispersion medium separated in step (4) can also be reused in steps (21) and (22) to realize resource recycling.

[0111] In the present application, the method can be applied to the drying of materials with a full water content, and since the drying of materials with a water content below 10% is less required in actual application, the method is preferably applied to the continuous and automatic drying of all materials with a water content of 10-98%, including but not limited to sludge, vinasse, coal, crop waste and waste catalysts, etc.

[0112] In step (21), the thickness of the boiling bed layer in the boiling bed filter 21 is set to 0.4-1m.

[0113] The filtering medium used in the boiling bed layer is preferably a granular substance with high mechanical strength and large density, such as perlite, quartz sand and sea sand, etc.

[0114] The particle size of the filtering medium is 0.5-2mm, which plays a role of dispersion medium in the subsequent cyclone drying process and can be recycled.

[0115] In the present application, the dispersion medium in step (22) comprises coal cinder particles, quartz sand, perlite, sea sand and other particle substances with high mechanical strength and density difference from the dried material;

[0116] The particle size of the dispersion medium is 2-4 mm;

[0117] The mixing mass ratio of the material with 65-90% moisture content and the dispersion medium is controlled at 1:1-1:3.

[0118] In the present application, the material particles perform high-speed rotation and revolution motion in the cyclone dryer 3. The high-speed rotation motion of the material particles in the cyclone field induces non-phase change drying. The huge centrifugal force generated by the high-speed rotation motion of the material particles makes the internal gap water of the material overcome the viscous resistance and be removed. Meanwhile, the self-revolution coupling motion accelerates the mass transfer update rate on the surface of the material particles, thereby strengthening the removal of water in the material.

[0119] Figure 4 is a comparison chart of energy consumption of non-phase change drying and phase change drying. As shown in the chart, the temperature required by the normal pressure phase change drying process is higher than the boiling point of water. The water undergoes phase change in the evaporation process, and the phase change energy consumption (latent heat of vaporization) is higher than 2000 kJ / kg.

[0120] The temperature required by the vacuum phase change drying process is lower than the boiling point of water. The water undergoes phase change in the evaporation process, and the phase change energy consumption is also higher than 2000 kJ / kg, but the energy consumption is lower than that of the normal pressure phase change drying process.

[0121] The temperature required by the normal pressure non-phase change drying process is 60-90℃. The water does not undergo phase change in the drying process. The energy consumption is only 378 kJ / kg when the normal pressure non-phase change drying is performed at 90℃.

[0122] Therefore, the energy consumption required by the normal pressure non-phase change drying is one order of magnitude lower than that of the normal pressure phase change drying and the vacuum phase change drying, which has a significant energy saving advantage. The cyclone drying is realized by cyclone self-revolution revolution coupling oscillation. The water does not undergo phase change, and the energy consumption is 378 kJ / kg at 90℃, which greatly reduces the drying energy consumption (the energy consumption of the normal pressure and vacuum phase change drying is higher than 2600 kJ / kg).

[0123] Application Example

[0124] The drying of residual sludge and dewatered sludge is performed by using the method and device of Example 1. The specific operation process and effect are described as follows:

[0125] 1. Sludge source and properties

[0126] The residual sludge used in the present example is taken from the secondary sedimentation tank of Shanghai Minhang Wastewater Treatment Plant. The dewatered sludge 1 and the dewatered sludge 2 are taken from Shanghai Fuzheng Environmental Protection Technology Co., Ltd. Table 1 shows the properties of the three kinds of sludge.

[0127] Table 1 Three kinds of sludge properties

[0128]

[0129] 2. Implementation process

[0130] The method of the above-mentioned Example 1 was implemented, specifically as follows:

[0131] The materials used in this example were residual sludge and dewatered sludge, and the gas carrying the sludge was high-temperature flue gas. Perlite with a particle size of 0.5-1 mm was selected as the filter medium of the fluidized bed filter, and the bed thickness was set at 0.8 m; the mixing ratio of dewatered sludge 1 and the dispersion medium was set at 1:2, the particle size of the dispersion medium was selected to be 2-3 mm, and the dispersion medium was quartz sand; the feed rate of the granulator was set at 30 kg / h.

[0132] The residual sludge with a moisture content of 98.90% was fed into the fluidized bed separator with perlite as the filter medium for preliminary dewatering, and the sludge-perlite mixture was generated after concentration;

[0133] The dewatered sludge 1 with a moisture content of 81.3% was mixed with quartz sand particles to obtain a sludge-quartz sand mixture.

[0134] The dewatered sludge 2 with a moisture content of 53.4% was granulated by a granulator to obtain 6 mm long strip-shaped sludge.

[0135] (1) Drying process of the sludge-perlite mixture and the sludge-quartz sand mixture:

[0136] The high-temperature flue gas passed through the heater, the first butterfly valve, and the airflow pulse generator in turn to form a pulsating hot carrier gas, and the sludge-perlite mixture and the sludge-quartz sand mixture were fed into the cyclone dryer for drying; the heating temperature of the high-temperature flue gas in the experiment was 70°C.

[0137] In the cyclone dryer, the huge centrifugal force generated by the high-speed self-rotation movement of the particles in the cyclone field was used to remove the interstitial water and capillary water of the sludge, and the dewatered sludge-perlite mixture or sludge-quartz sand mixture entered the sorting column from the underflow port of the cyclone dryer.

[0138] The pulsating hot carrier gas discharged from the overflow port of the cyclone dryer entered from the lower end of the sorting column, and the density difference between the sludge and the perlite and quartz sand particles caused a difference in the total displacement direction of the particles in the pulsating airflow field, so that the sludge and the perlite and quartz sand particles were separated in the sorting column. The sorted perlite and quartz sand settled at the bottom of the sorting column and were discharged and recycled, while the sludge particles entered the gas-solid cyclone separator from the top of the sorting column.

[0139] In the gas-solid cyclone separator, the separation of sludge particles and gas is realized, the dried sludge is discharged from the underflow port and collected, and the gas carrying the water phase is discharged from the overflow port into the gas-liquid separator.

[0140] (2) Drying process of long strip sludge:

[0141] The high-temperature flue gas passes through the heater and the second butterfly valve in sequence to form a hot carrier gas, and the long strip sludge is sent into the cyclone dryer for drying; in the experiment, the heating temperature of the high-temperature flue gas is 70℃.

[0142] In the cyclone dryer, the huge centrifugal force generated by the high-speed self-rotation movement of the particles in the cyclone field is used to remove the interstitial water and capillary water of the sludge, and the dewatered sludge enters the separation column from the underflow port of the cyclone dryer. The hot carrier gas discharged from the overflow port of the cyclone dryer enters from the lower end of the separation column and sends the dewatered sludge into the gas-solid cyclone separator to realize the separation of sludge particles and gas.

[0143] In the gas-solid cyclone separator, the separation of sludge particles and gas is realized, the dried sludge is discharged from the underflow port and collected, and the gas carrying the water phase is discharged from the overflow port into the gas-liquid separator.

[0144] 3. Implementation effect

[0145] The comparison table of sludge moisture content before and after drying is shown in Table 2:

[0146] Table 2 Comparison table of sludge moisture content

[0147]

[0148] From the results in Table 2, it can be seen that the method and device of the present application can realize automatic feeding and drying of different moisture content of materials to be dried, and has the advantages of excellent drying effect, multiple types of materials to be treated, continuous, stable and efficient operation.

[0149] The above examples are only preferred embodiments of the present application, and are not intended to limit the scope of the present application. Any equivalent replacement, change or modification made according to the content of the present application should be within the scope of protection of the present application.

Claims

1. A method for self-feedback drying of the moisture content of all materials, characterized in that, Includes the following steps: (1) Moisture content determination: Infrared light is generated by an infrared light source, and infrared light of characteristic wavelength is obtained by passing through the filter on the disc disc. After passing through the infrared-transparent glass set at the bottom of the feed hopper, it is reflected by the material. The photoelectric sensor converts the light signal of the reflected light into an electrical signal, and the electrical signal is processed by the processor to obtain the moisture content. The feed line is adjusted according to the self-feedback of the moisture content. (2) Feeding line: (21) Materials with a moisture content of 90-98% enter the fluidized bed filter and are initially dehydrated using the filled filter medium. The filter medium-material mixture enters the cyclone dryer with the pulsating hot carrier gas. The filter medium acts as a dispersion medium in the cyclone dryer. (22) Materials with a moisture content of 65-90% are stirred and mixed into the dispersion medium. The resulting dispersion medium-material mixture enters the cyclone dryer with the pulsating hot carrier gas. (23) Materials with a moisture content of 30-65% are granulated by a granulator to form material strips and cut into strips by the hot carrier gas, and then carried into the cyclone dryer. (24) Materials with a moisture content of 10-30% are crushed by a crusher and enter the cyclone dryer with the hot carrier gas. (3) Cyclone drying: The wet materials from steps (21) and (22) are dried and separated in a cyclone dryer. The resulting dispersion medium-dried material enters the separation column with the pulsating hot carrier gas for accelerated separation. The wet materials from steps (23) and (24) are dried and separated in a cyclone dryer. The resulting dried material enters the gas-solid cyclone separator with the hot carrier gas through the separation column. (4) Accelerated separation of mixed materials: In the separation column, the dry material and the dispersion medium are separated by the difference in cumulative acceleration of the pulsed hot carrier gas. (5) The dried material is further dried by cyclone drying and gas-solid separation: The dried material enters the gas-solid cyclone separator for further cyclone drying and is discharged, while water-containing gas is separated.

2. The method for self-feedback drying of the moisture content of all materials according to claim 1, characterized in that, The heat carrier gas is a continuous flow of high-temperature flue gas; the pulsating heat carrier gas is a periodic oscillating flow of high-temperature flue gas. The temperature of the high-temperature flue gas is 40-80℃; The pulsating hot carrier gas is a periodic oscillating airflow obtained by the periodic closing of a butterfly valve through high-temperature flue gas. The periodic closing of the butterfly valve is controlled by an airflow pulsation generator.

3. The method for self-feedback drying of the moisture content of all materials according to claim 2, characterized in that, The method further includes step (6) gas-liquid separation and heat energy recovery: the water-containing gas obtained in step (5) is separated into hot wastewater and hot waste gas by a gas-liquid separator; When the flow rate of high-temperature flue gas is low, the heat-containing waste gas is reused as high-temperature flue gas, and a decision is made on whether to perform low-temperature heating based on the reuse status of the heat-containing waste gas. The heated wastewater is used to preheat the wet material in step (2).

4. The method for self-feedback drying of the moisture content of all materials according to claim 1, characterized in that, The dispersion medium separated in step (4) is reused in steps (21) and (22).

5. The method for self-feedback drying of the moisture content of all materials according to claim 1, characterized in that, The method is applicable to materials with a moisture content range of 10-98%, including sludge, distiller's grains, coal, agricultural waste, and spent catalysts.

6. The method for self-feedback drying of the moisture content of all materials according to claim 1, characterized in that, The thickness of the fluidized bed in the fluidized bed filter is set between 0.4 and 1 m; The fluidized bed uses perlite, quartz sand and sea sand as the filter media. The particle size of the filter medium is 0.5-2 mm.

7. The method for self-feedback drying of the moisture content of all materials according to claim 1, characterized in that, In step (22), the mixing mass ratio of the material with a moisture content of 65-90% to the dispersion medium is controlled at 1:1-1:

3. The dispersion medium includes coal slag particles, quartz sand, perlite, and sea sand; The particle size of the dispersion medium is 2-4 mm.

8. A device for self-feedback drying of moisture content in all materials, characterized in that, The method for self-feedback drying of the moisture content of all materials according to any one of claims 1-7 includes a feed hopper, a feeding system, a cyclone dryer, a sorting column, and a gas-solid cyclone separator connected sequentially in the material flow direction, a moisture content monitoring system for real-time monitoring of the material moisture content, and a carrier gas generating unit, wherein: The feeding hopper is used for material feeding, and its bottom is equipped with four parallel feeding valves; The moisture content monitoring device includes an infrared light source, a split disc, an infrared-transmitting glass disposed on the feed hopper, and a photoelectric sensor arranged sequentially in the direction of the light path, and a processor for converting the electrical signal received from the photoelectric sensor into moisture content information. The processor is electrically connected to the feed valve of the feed hopper to transmit control signals to the feed valve. The feeding system includes a first feeding line, a second feeding line, a third feeding line, and a fourth feeding line, which are respectively connected to four feeding valves; A fluidized bed filter is installed on the first feeding line; a mixer is installed on the second feeding line; a granulator is installed on the third feeding line; and a crusher is installed on the fourth feeding line. The cyclone dryer is used to cyclone dry wet materials from the feeding system to obtain dried materials or a mixture of dispersion medium and dried materials. The sorting column is used to separate the dried material and the dispersion medium in the dispersion medium-drying material mixture; The gas-solid cyclone separator is used to further dry the dried material from the separation column by cyclone drying, while simultaneously obtaining water-containing gas. The carrier gas generating unit includes a heater, a first butterfly valve, an airflow pulsation generator, and a hot air duct connected in sequence. The airflow pulsation generator is used to control the periodic closing of the first butterfly valve. The front and rear sides of the first butterfly valve are directly connected through a bypass pipe, and a second butterfly valve is provided on the bypass pipe.

9. The apparatus for self-feedback drying of moisture content in all materials according to claim 8, characterized in that, In the first, second, third, and fourth feed lines, heat exchangers are respectively installed after the fluidized bed filter, the mixer, and the crusher, and before the granulator. The device also includes a gas-liquid separator connected to the gas-solid cyclone separator, used to separate water-containing gas from the gas-solid cyclone separator into hot wastewater and hot waste gas. The water phase outlet and gas phase outlet of the gas-liquid separator are respectively connected to a heat exchanger and a heater.

10. The apparatus for self-feedback drying of moisture content in all materials according to claim 8, characterized in that, The outlet of the granulator is vertically connected to the hot air duct, and an extrusion plate is also provided at the outlet of the granulator, with several round holes evenly distributed on the extrusion plate; the cyclone dryer is a single-stage or multi-stage series.

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