Fluidized bed granulation system and method capable of improving granulation efficiency

Abstract

The invention relates to the technical field of fertilizer processing, in particular to a fluidized bed granulation system and method capable of improving granulation efficiency, the fluidized bed granulation system comprises fluidized bed granulation equipment, and a granulation section and a cooling section are respectively formed in the fluidized bed granulation equipment; the granulation section is provided with at least one sorting extractor, and the sorting extractor is used for sorting the large-particle fertilizer in the granulation section and outputting the large-particle fertilizer out of the fluidized bed granulation equipment. Small-particle fertilizer seed crystals are supplemented into the granulation section, then a fertilizer melt liquid is sprayed to the granulation section, the small-particle fertilizer seed crystals are converted into large-particle fertilizer, and the large-particle fertilizer flows to the cooling section of the fluidized bed granulation equipment. In the process, the granules reaching the standard are sorted out through the sorting extractor, so that the fertilizer melt sprayed on the small-granule fertilizer in unit area is increased, the efficiency of converting the small-granule fertilizer into the large-granule fertilizer is improved, more large-granule fertilizer can be output finally, and the efficiency of producing the large granules by the fluidized bed is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizer processing, and in particular to a fluidized bed granulation system and method capable of improving granulation efficiency. Background Art

[0002] Fertilizer, as one of the main indispensable factors for plant growth, has multiple functions and effects in agricultural production. The main form of fertilizer in agricultural production is granular fertilizer, which is divided into small particles (particle size less than 2mm) and large particles (particle size between 2 and 4mm). Since small granular fertilizer sticks to plant leaves and causes "seedling burn", the demand for large granular fertilizer is higher under the market mechanism. In the processing and production of granular fertilizer, the commonly used large granular fertilizer granulation production is carried out through a fluidized bed.

[0003] Fluidized bed granulation is to put the materials into a closed container at one time, mix the materials evenly and make them flow in the container to form granules.

[0004] In the traditional fluidized bed granulation production process, when the material forms particles and flows in the fluidized bed, there are both large particles and small particles. The small particles need to continue to be sprayed and granulated to form large particles, while the large particles that meet the standards will still be mixed with the small particles until they are output from the outlet. In this process, the large particles that have already met the standards will not only continue to grow, wasting materials, but also affect the growth of small particles due to occupying space, affecting the particle size compliance rate of the final output granular fertilizer, and reducing the granulation efficiency of the fluidized bed. Summary of the invention

[0005] The present invention provides a fluidized bed granulation system and method capable of improving granulation efficiency, so as to solve the defect in the prior art that large-particle fertilizers that meet the standards early in the fluidized bed granulation process will affect the fluidized bed granulation efficiency.

[0006] The present invention provides a fluidized bed granulation system capable of improving granulation efficiency, comprising a fluidized bed granulation device, wherein the fluidized bed granulation device comprises a fluidized bed granulator and a fluidized bed cooler, wherein the fluidized bed granulator and the fluidized bed cooler respectively form a granulation section and a cooling section in the fluidized bed granulation device; the granulation section is used for converting small-particle fertilizer seeds into large-particle fertilizer, and the cooling section is connected to the granulation section to receive and cool the granular fertilizer converted by the granulation section; the granulation section is provided with at least one sorting extractor, and the sorting extractor is used for sorting the large-particle fertilizer in the granulation section and outputting the large-particle fertilizer from the fluidized bed granulation device.

[0007] According to a fluidized bed granulation system capable of improving granulation efficiency provided by the present invention, a seed inlet is arranged at a position of the granulation section away from the cooling section, for adding small-particle fertilizer seeds to the granulation section; the granulation section is provided with a plurality of the sorting extractors, and the plurality of the sorting extractors are evenly spaced and arranged between the seed inlet and the cooling section.

[0008] According to a fluidized bed granulation system capable of improving granulation efficiency provided by the present invention, the granulation section is provided with a granulation nozzle, the granulation nozzle is externally connected to a fertilizer melt source through a pipeline, and the fertilizer melt source sprays the fertilizer melt toward the granulation section through the granulation nozzle to transform the small-particle fertilizer seeds in the granulation section into large-particle fertilizer.

[0009] According to a fluidized bed granulation system capable of improving granulation efficiency provided by the present invention, the fertilizer molten liquid source is a liquid tank containing fertilizer molten liquid, the liquid tank is connected to a delivery pump through a pipeline, and the delivery pump is connected to the granulation section through a pipeline.

[0010] The fertilizer melt in the liquid tank is at least one of urea melt, ammonium nitrate melt, calcium ammonium nitrate melt, and compound fertilizer melt, and the weight percentage of the fertilizer melt is in the range of 92% to 99.7wt%.

[0011] According to a fluidized bed granulation system capable of improving granulation efficiency provided by the present invention, the outlet of the cooling section and the outlet of the sorting extractor are both connected to a dividing screen through a pipeline, the dividing screen comprises a small particle outlet and a large particle outlet, the small particle outlet is connected to the granulation section through a pipeline, and the large particle outlet outputs a granular fertilizer product.

[0012] According to a fluidized bed granulation system capable of improving granulation efficiency provided by the present invention, an intermediate cooler is arranged on the pipeline connecting the outlet of the cooling section and / or the outlet of the sorting extractor to the material separation screen.

[0013] According to a fluidized bed granulation system capable of improving granulation efficiency provided by the present invention, a bucket elevator is arranged on the pipeline connecting the small particle discharge port of the material dividing screen and the granulation section.

[0014] The large particle discharge port is connected to a product cooler so as to output the granular fertilizer product through the product cooler output port.

[0015] According to the present invention, a fluidized bed granulation system capable of improving granulation efficiency is provided, and the fluidized bed granulation system capable of improving granulation efficiency also includes an atomizing fan, the atomizing fan is connected to an atomizing air preheater through a pipeline, and the atomizing air preheater is connected to the fluidized bed granulation equipment through a pipeline.

[0016] The fluidized bed granulation system capable of improving granulation efficiency further comprises a fluidizing fan, the fluidizing fan is connected to a fluidizing air preheater via a pipeline, and the fluidizing air preheater is connected to the fluidized bed granulation equipment via a pipeline.

[0017] The tail gas outlet of the fluidized bed granulation equipment is connected to a dust collector, and the dust collector is connected to an induced draft fan, so that the tail gas of the fluidized bed granulation equipment is discharged through the dust collector and the induced draft fan.

[0018] The present invention also provides a fluidized bed granulation method capable of improving granulation efficiency, which is applicable to any of the fluidized bed granulation systems capable of improving granulation efficiency described above, and the fluidized bed granulation method capable of improving granulation efficiency comprises: adding small-particle fertilizer seeds to the granulation section of the fluidized bed granulation equipment; spraying fertilizer melt to the granulation section based on a fertilizer melt source, converting the small-particle fertilizer seeds into large-particle fertilizer, and flowing the large-particle fertilizer to the cooling section of the fluidized bed granulation equipment; sorting the granular fertilizers with particle sizes meeting the standards among the granular fertilizers flowing in the granulation section based on a sorting extractor; and outputting the granular fertilizers with particle sizes meeting the standards sorted by the sorting extractor and the granular fertilizers output by the cooling section.

[0019] A fluidized bed granulation method for improving granulation efficiency provided by the present invention also includes: screening the granular fertilizer output by the sorting extractor and the cooling section based on a classifying screen, conveying the small granular fertilizer screened by the classifying screen to the granulation section as small granular fertilizer seeds, and outputting the large granular fertilizer screened by the classifying screen as a granular fertilizer product.

[0020] The atomizing air is outputted into the fluidized bed granulation device by an atomizing fan and an atomizing air preheater, so as to form uniform droplets of the fertilizer melt sprayed in the fluidized bed granulation device.

[0021] The fluidizing air is outputted into the fluidized bed granulation equipment by a fluidizing fan and a fluidizing air preheater, so as to keep the granular fertilizer in the fluidized bed granulation equipment in a fluidized suspension state.

[0022] The fluidized bed granulation system and method provided by the present invention can improve the granulation efficiency. Small-particle fertilizer seeds are added into the granulation section of the fluidized bed granulation equipment, and then the fertilizer melt is sprayed on the granulation section to transform the small-particle fertilizer seeds into large-particle fertilizer, which flows to the cooling section of the fluidized bed granulation equipment. In the process of converting small-particle fertilizer seeds into large-particle fertilizers, the conversion rates of various small-particle fertilizer seeds are different. The particles that are successfully converted earlier in this process are sorted out and output through the sorting extractor, so that they do not participate in the later particle flow process. Only small-particle fertilizers that do not meet the standards are retained to flow in the granulation section, and are further sprayed and granulated to be converted into large particles. In this way, in the subsequent granulation section, since there is no large-particle fertilizer participating in the flow, the fertilizer molten liquid sprayed on the small-particle fertilizer per unit area increases, which improves the efficiency of converting small-particle fertilizers into large-particle fertilizers, so that more large-particle fertilizers can be output in the end. The large-particle fertilizers sorted by the sorting extractor and the granular fertilizers output by the cooling section are output together, which increases the proportion of large-particle fertilizers output by the fluidized bed and improves the efficiency of the fluidized bed in making large particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a schematic diagram of the flow of a fluidized bed granulation system provided by the present invention that can improve granulation efficiency.

[0025] Figure numerals: 1. fluidized bed granulation equipment; 101. granulation section; 102. cooling section; 2. sorting extractor; 3. conveying pump; 4. material dividing screen; 5. intermediate cooler; 6. bucket elevator; 7. product cooler; 8. atomizing fan; 9. atomizing air preheater; 10. fluidizing fan; 11. fluidizing air preheater; 12. dust collector; 13. induced draft fan. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of 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.

[0028] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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 an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0029] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0031] Combine the following Figure 1The specific composition of the fluidized bed granulation system capable of improving granulation efficiency and the specific process of the fluidized bed granulation method capable of improving granulation efficiency of the present invention are described.

[0032] One embodiment of the present invention provides a fluidized bed granulation system that can improve granulation efficiency. Figure 1 As shown, a fluidized bed granulation system capable of improving granulation efficiency comprises a fluidized bed granulation device 1, wherein the fluidized bed granulation device 1 comprises a fluidized bed granulator and a fluidized bed cooler, wherein the fluidized bed granulator and the fluidized bed cooler respectively form a granulation section 101 and a cooling section 102 in the fluidized bed granulation device 1; the granulation section 101 is used for converting small-particle fertilizer seeds into large-particle fertilizer, and the cooling section 102 is connected to the granulation section 101 to receive and cool the granular fertilizer converted by the granulation section 101; the granulation section 101 is provided with at least one sorting extractor 2, and the sorting extractor 2 is used for sorting the large-particle fertilizer in the granulation section 101 and outputting the fluidized bed granulation device 1.

[0033] It can be understood that the fluidized bed granulation system of the present invention which can improve the granulation efficiency adds small-particle fertilizer seeds into the granulation section 101 of the fluidized bed granulation equipment 1, and then sprays the fertilizer melt into the granulation section 101 to transform the small-particle fertilizer seeds into large-particle fertilizer, which then flows into the cooling section 102 of the fluidized bed granulation equipment 1. In the process of converting small-particle fertilizer seeds into large-particle fertilizers, the conversion rates of various small-particle fertilizer seeds are not the same. The particles that are successfully converted earlier in the process are sorted out and output through the sorting extractor 2, so that they do not participate in the later particle flow process. Only small-particle fertilizers that do not meet the standards are retained to flow in the granulation section 101, and are further sprayed and granulated to be converted into large particles. In this way, in the subsequent granulation section, since there is no large-particle fertilizer participating in the flow, the fertilizer melt sprayed onto the small-particle fertilizer per unit area increases, which improves the efficiency of converting small-particle fertilizers into large-particle fertilizers, so that more large-particle fertilizers can be output in the end. The large-particle fertilizers sorted by the sorting extractor 2 and the granular fertilizers output by the cooling section 102 are output together, which increases the proportion of large-particle fertilizers output by the fluidized bed and improves the efficiency of the fluidized bed in making large particles.

[0034] In some embodiments of the fluidized bed granulation system of the present invention that can improve granulation efficiency, a seed inlet is provided in the granulation section 101 away from the cooling section 102 for adding small-particle fertilizer seeds to the granulation section 101; the granulation section 101 is provided with a plurality of sorting extractors 2, and the plurality of sorting extractors 2 are evenly spaced between the seed inlet and the cooling section 102.

[0035] It is understandable that the small-particle fertilizer seeds added from the seed inlet to the granulation section 101 can be small-particle fertilizers screened out by the fluidized bed granulation system of the present embodiment, or small particles crushed by a conventional fluidized bed crusher, or small-particle seeds produced by a special seed production device. In the granulation section 101, multiple sorting extractors 2 are evenly spaced and arranged, and in the process of the small-particle fertilizers flowing from the seed inlet to the cooling section 102, the granular fertilizers that meet the standards can be sorted out in stages, thereby ensuring the flow space of the small-particle fertilizers that do not meet the standards, increasing the probability of the small-particle fertilizers being sprayed by the fertilizer melt, and improving the conversion rate into large-particle fertilizers. It should be understood that the sorting extractor 2 is a device for sorting particles, which can be air selection, or can be adjusted on a porous plate, or existing sorting equipment can be used to sort out granular fertilizers with standard particle sizes.

[0036] In some specific examples of the fluidized bed granulation system of the present invention that can improve granulation efficiency, the granulation section 101 is provided with a granulation nozzle, and the granulation nozzle is externally connected to a fertilizer melt source through a pipeline, and the fertilizer melt source sprays the fertilizer melt to the granulation section 101 through the granulation nozzle to convert the small-particle fertilizer seed crystals in the granulation section 101 into large-particle fertilizer. The fertilizer melt source is a liquid tank containing fertilizer melt, and the liquid tank is connected to the delivery pump 3 through a pipeline, and the delivery pump 3 is connected to the granulation section 101 through a pipeline. The fertilizer melt in the liquid tank is at least one of urea melt, ammonium nitrate melt, calcium ammonium nitrate melt, and compound fertilizer melt, and the weight percentage of the fertilizer melt ranges from 92% to 99.7wt%.

[0037] It can be understood that in order to improve the granulation efficiency, a granulation nozzle is provided in the granulation section 101, and the granulation nozzle is connected to the fertilizer melt source through a pipeline, so that the fertilizer melt can be accurately sprayed onto the small-particle fertilizer seeds in the granulation section 101 through the granulation nozzle. In this process, the delivery pump 3 plays a key role. It extracts and pressurizes the fertilizer melt contained in the liquid tank through the pipeline, and then delivers it to the granulation nozzle. In this way, the granulation nozzle can effectively spray the fertilizer melt onto the small-particle fertilizer seeds inside the granulation section 101, thereby promoting these small particles to gradually grow into large-particle fertilizers.

[0038] In the fluidized bed granulation system of the present invention, the fertilizer molten liquid source can specifically be one or more liquid tanks containing fertilizer molten liquid, which are connected to the delivery pump 3 through pipelines, and then the delivery pump 3 is connected to the granulation nozzle in the granulation section 101 through another set of pipelines, ensuring that the molten liquid can be stably and continuously sprayed onto the small-particle fertilizer seed crystals inside the granulation section 101 to support an efficient particle formation process.

[0039] The weight percentage (wt%) of the fertilizer melt in the liquid tank is controlled between 92% and 99.7wt%. This high concentration range helps to ensure that the melt has appropriate physical properties (such as viscosity and fluidity), which is conducive to the formation of high-quality granular fertilizers, and can reduce moisture content and reduce drying energy consumption. The fertilizer melt can be urea melt, ammonium nitrate melt, calcium ammonium nitrate melt or compound fertilizer melt prepared as needed. According to the selection of fertilizer melts, fertilizer products such as large-granular urea, large-granular ammonium nitrate, large-granular calcium ammonium nitrate, and large-granular compound fertilizer can be produced.

[0040] In some embodiments of the fluidized bed granulation system of the present invention that can improve granulation efficiency, continue to refer to Figure 1 As shown, the outlet of the cooling section 102 and the outlet of the sorting extractor 2 are both connected to the classifying screen 4 through pipelines. The classifying screen 4 includes a small particle outlet and a large particle outlet. The small particle outlet is connected to the granulation section 101 through a pipeline, and the large particle outlet outputs granular fertilizer products.

[0041] In order to ensure that the particle size of the final product meets the standards and effectively recover the particles that do not meet the standards to optimize resource utilization, the fluidized bed granulation system of this embodiment introduces a classifying screen 4. The outlet of the cooling section 102 and the outlet of the sorting extractor 2 are both connected to the classifying screen 4 through a pipeline. The granular fertilizer output from the outlet of the cooling section 102 and the outlet of the sorting extractor 2 is screened by the classifying screen 4. The classifying screen 4 can distinguish between small granular fertilizers that fail to reach the predetermined size and large granular fertilizers that meet the requirements.

[0042] The small-particle fertilizers screened out by the material-separating screen 4 are transported back to the granulation section 101 through a specific pipeline as small-particle fertilizer seeds, and these small-particle fertilizers can be further grown into qualified large-particle fertilizers in the granulation section 101, thereby avoiding material waste and improving overall production efficiency. The large-particle fertilizers that meet the preset specifications screened out by the material-separating screen 4 are directly output as finished products through the large-particle discharge port, ready to enter the market or the next stage of processing.

[0043] This embodiment can ensure that all granular fertilizers output as final products meet specific size requirements through effective screening by the material dividing screen 4, which helps to improve the consistency of product quality. The small granular fertilizers that do not meet the size requirements are reintroduced into the granulation process, which not only reduces the generation of waste, but also maximizes the utilization of resources and reduces production costs. It is understandable that according to the changes in actual production and market demand, the proportion of granular fertilizers of different sizes can be flexibly controlled by adjusting the working parameters of the material dividing screen 4, thereby adjusting the production capacity.

[0044] Furthermore, in addition to the small particle discharge port and the large particle discharge port of the classifying screen 4, an extra-large particle discharge port can also be set. For example, extra-large particles with a particle size greater than 4 mm can be screened out from the extra-large particle discharge port. The screened extra-large particle fertilizer can be crushed by a crusher and then added to the granulation section 101 as small particle seeds, or it can be dissolved by a dissolving device and enter the fertilizer melt source as a fertilizer melt.

[0045] In some embodiments of the fluidized bed granulation system of the present invention that can improve granulation efficiency, an intermediate cooler 5 is provided on the pipeline connecting the outlet of the cooling section 102 and / or the outlet of the sorting extractor 2 to the dividing screen 4. The main function of the intermediate cooler 5 is to perform additional cooling treatment on the materials coming out of the cooling section 102 and the sorting extractor 2, so as to ensure that the large-particle fertilizer has been fully cooled before entering the dividing screen 4, avoiding product quality problems caused by excessive temperature or blockages in the sorting process. Through the cooling treatment of the intermediate cooler 5, the difference between particles of different sizes can be made more obvious, thereby improving the sorting accuracy of the dividing screen 4 between qualified products and small particles that need to be returned for further granulation. At the same time, lowering the material temperature can also reduce the damage that high temperature may cause to the dividing screen 4 and its back-end equipment, extend the service life of the equipment, and also help maintain the stable operation of the entire system. It should be understood that the intermediate cooler 5 is an optional device and can be set or not set as needed; the intermediate cooler 5 can cool the materials coming out of the cooling section 102 and the sorting extractor 2 at the same time, and can also be used alone to cool the materials coming out of the cooling section 102 or alone to cool the materials coming out of the sorting extractor 2. The specific connection and installation can be based on actual needs.

[0046] A bucket elevator 6 is provided on the pipeline connecting the small particle discharge port of the material separation screen 4 and the granulation section 101. The bucket elevator 6 vertically lifts the small particle fertilizer screened by the material separation screen 4 and transports it to the granulation section 101. This design solves the space limitation problem that may be encountered in horizontal transportation and ensures that the small particle fertilizer can be smoothly returned to the starting stage of the granulation process. The bucket elevator 6 can realize continuous material transportation, ensure the smooth operation of the entire system, and improve production efficiency. Since the bucket elevator 6 has good material handling performance, it can effectively prevent pipeline blockage and maintain the stability and reliability of the system.

[0047] The large particle discharge port is connected to a product cooler 7 to output the granular fertilizer product through the output port of the product cooler 7. The product cooler 7 provides an additional cooling environment for the large granular fertilizer that has been initially cooled, ensuring that they reach a suitable storage and transportation temperature, and avoiding quality degradation or safety hazards caused by excessive temperature. The granular fertilizer treated by the product cooler 7 can be directly output as a finished product, ready to enter the market or be packaged, etc. This step helps to improve the appearance quality and physical properties of the product, such as hardness and roundness.

[0048] In some specific embodiments of the fluidized bed granulation system capable of improving granulation efficiency of the present invention, the fluidized bed granulation system capable of improving granulation efficiency further comprises an atomizing fan 8, the atomizing fan 8 is connected to an atomizing air preheater 9 via a pipeline, and the atomizing air preheater 9 is connected to the fluidized bed granulation equipment 1 via a pipeline.

[0049] The atomizing fan 8 can provide the required air flow pressure to break the fertilizer melt into fine droplets, thereby promoting particle formation. The atomizing air preheater 9 is used to heat the atomizing air from the atomizing fan 8 to ensure that it reaches an appropriate temperature so as to better contact the fertilizer melt, help form uniform small particle seeds, and accelerate the drying process. Specifically, the airflow generated by the atomizing fan 8 is transported to the atomizing air preheater 9 through a pipeline, where it is preheated and then enters the granulation section 101 of the fluidized bed granulation equipment 1 through a pipeline. The preheated atomizing air acts on the fertilizer melt sprayed from the granulation nozzle in the granulation section 101 to break it into fine droplets, and also helps to control the temperature of the granulation environment to prevent the particles from sticking due to excessive temperature.

[0050] Furthermore, the fluidized bed granulation system that can improve the granulation efficiency also includes a fluidizing fan 10, and the fluidizing fan 10 is connected to the fluidizing air preheater 11 through a pipeline, and the fluidizing air preheater 11 is connected to the fluidized bed granulation equipment 1 through a pipeline. The fluidizing fan 10 can provide sufficient airflow to support the particles and put them in a suspended state, which is the so-called "fluidization" to facilitate mass transfer and heat transfer. The fluidizing air preheater 11 preheats the fluidizing air from the fluidizing fan 10 and adjusts it to a temperature suitable for the granulation process to ensure that the particles can grow under optimal conditions. Specifically, the airflow provided by the fluidizing fan 10 is also connected to the fluidizing air preheater 11 through a pipeline. After preheating, it is sent to the granulation section 101 and the cooling section 102 of the fluidized bed granulation equipment 1 through another set of pipelines. In the granulation section 101, the preheated fluidizing air helps to maintain the fluidized state of the material and ensure the uniform distribution and growth of the particles, while in the cooling section 102, it is mainly used to take away heat and help cool the large-particle fertilizer.

[0051] In some specific examples, the tail gas outlet of the fluidized bed granulation equipment 1 is connected to the dust collector 12, and the dust collector 12 is connected to the induced draft fan 13, so that the tail gas of the fluidized bed granulation equipment 1 is discharged through the dust collector 12 and the induced draft fan 13. It can be understood that in order to ensure environmental protection and operational safety during the production process, this example specially designs a tail gas treatment system, which is composed of a dust collector 12 and an induced draft fan 13, and is used to treat the tail gas discharged from the fluidized bed granulation equipment 1. Specifically, during the fluidized bed granulation process, due to the heating and evaporation of the material, tail gas containing dust and other pollutants will be generated. These tail gases are first discharged from the tail gas outlet of the fluidized bed granulation equipment 1, and then directly enter the dust collector 12 through the pipeline. In the dust collector 12, the tail gas is subjected to efficient dust removal treatment, and most of the dust and particulate matter are effectively captured, reducing the impact on the environment. According to the specific application scenario, the dust collector can use different types of equipment, such as bag dust collectors, electrostatic dust collectors or wet scrubbers. The tail gas purified by the dust collector 12 is safely discharged to the atmosphere through the pipeline system under the action of the induced draft fan 13. The suction force provided by the induced draft fan 13 ensures the smooth flow of the tail gas during the entire treatment process. At the same time, the induced draft fan 13 is an optional equipment, and the air volume can be adjusted according to actual needs. It is selected whether the induced draft fan 13 is needed to ensure the best treatment effect.

[0052] The fluidized bed granulation method capable of improving granulation efficiency provided by the present invention is described below. The fluidized bed granulation method capable of improving granulation efficiency described below and the fluidized bed granulation system capable of improving granulation efficiency described above can be referred to each other.

[0053] In some embodiments of the fluidized bed granulation method that can improve the granulation efficiency of the present invention, the fluidized bed granulation method that can improve the granulation efficiency includes: adding small-particle fertilizer seeds into the granulation section 101 of the fluidized bed granulation equipment 1; spraying fertilizer melt to the granulation section 101 based on the fertilizer melt source, converting the small-particle fertilizer seeds into large-particle fertilizer, and flowing to the cooling section 102 of the fluidized bed granulation equipment 1; sorting the granular fertilizers with particle sizes that meet the standards among the granular fertilizers flowing in the granulation section 101 based on the sorting extractor 2; and outputting the granular fertilizers with particle sizes that meet the standards sorted by the sorting extractor 2 and the granular fertilizers output by the cooling section 102.

[0054] The fluidized bed granulation method that can improve the granulation efficiency also includes: screening and sorting the granular fertilizer output from the extractor 2 and the cooling section 102 based on the material dividing screen 4, the small granular fertilizer screened by the material dividing screen 4 is transported to the granulation section 101 as a small granular fertilizer seed, and the large granular fertilizer screened by the material dividing screen 4 is output as a granular fertilizer product. The atomizing fan 8 and the atomizing air preheater 9 are used to output atomizing air into the fluidized bed granulation device 1 to form uniform droplets of the fertilizer melt sprayed in the fluidized bed granulation device 1. The fluidizing fan 10 and the fluidizing air preheater 11 are used to output fluidizing air into the fluidized bed granulation device 1 to keep the granular fertilizer in the fluidized bed granulation device 1 in a fluidized suspension state.

[0055] It can be understood that the fluidized bed granulation method of this embodiment is intended to provide a granulation method that can improve the granulation efficiency. In the process of converting small-particle fertilizer seeds into large-particle fertilizers, fertilizer particles with particle sizes that meet the standards are continuously output through the sorting extractor 2 to improve the contact between the granular fertilizers that do not meet the standards and the fertilizer melt, thereby improving the efficiency of converting small-particle fertilizers into large-particle fertilizers.

[0056] First, small-particle fertilizer seed crystals are added to the granulation section 101 of the fluidized bed granulation equipment 1, and the fertilizer melt is extracted from the fertilizer melt source by the delivery pump 3, and the melt is evenly sprayed into the granulation section 101 through the granulation nozzle. The fertilizer melt adheres to the small-particle fertilizer seed crystals and gradually forms large-particle fertilizer. As the granulation process proceeds, the granular fertilizer will move to the cooling section 102 of the fluidized bed granulation equipment 1. During this process, the granular fertilizer flowing in the granulation section 101 is sorted by the sorting extractor 2 to separate the granular fertilizer with a particle size that meets the standard. The granular fertilizer with a particle size that meets the standard sorted by the sorting extractor 2 and the granular fertilizer output from the cooling section 102 are transported out as the object of subsequent processing. The granular fertilizer output from the sorting extractor 2 and the cooling section 102 is screened by the material screening screen 4. The small granular fertilizer after screening is sent back to the granulation section 101 to continue the granulation process, while the large granular fertilizer after screening is output as the final product.

[0057] In the above process, since the sorting extractor 2 continuously sorts out granular fertilizers with particle size that meet the standard from the granulation section 101 of the fluidized bed granulation equipment 1, only small granular fertilizers that do not meet the standard are retained to flow in the granulation section 101, and are further sprayed and granulated to be converted into large particles. In this way, in the subsequent granulation section, since there is no large granular fertilizer participating in the flow, the fertilizer molten liquid sprayed onto the small granular fertilizer per unit area increases, thereby improving the efficiency of converting small granular fertilizers into large granular fertilizers, so that more large granular fertilizers can be output in the end. The large granular fertilizers sorted by the sorting extractor 2 and the granular fertilizers output by the cooling section 102 are output together, thereby increasing the proportion of large granular fertilizers output by the fluidized bed and improving the efficiency of the fluidized bed in making large particles.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fluidized bed granulation system capable of improving granulation efficiency, characterized in that: The invention comprises a fluidized bed granulation device (1), wherein the fluidized bed granulation device (1) comprises a fluidized bed granulator and a fluidized bed cooler, wherein the fluidized bed granulator and the fluidized bed cooler respectively form a granulation section (101) and a cooling section (102) in the fluidized bed granulation device (1); the granulation section (101) is used to convert small-granular fertilizer seeds into large-granular fertilizer, and the cooling section (102) is connected to the granulation section (101) to receive and cool the granular fertilizer converted by the granulation section (101); the granulation section (101) is provided with at least one sorting extractor (2), and the sorting extractor (2) is used to sort the large-granular fertilizer in the granulation section (101) and output the large-granular fertilizer to the fluidized bed granulation device (1).

2. The fluidized bed granulation system capable of improving granulation efficiency according to claim 1, characterized in that: The granulation section (101) is provided with a seed inlet at a position away from the cooling section (102), which is used to feed small-particle fertilizer seed crystals into the granulation section (101); the granulation section (101) is provided with a plurality of the sorting extractors (2), and the plurality of the sorting extractors (2) are evenly spaced and arranged between the seed inlet and the cooling section (102).

3. The fluidized bed granulation system capable of improving granulation efficiency according to claim 1, characterized in that: The granulation section (101) is provided with a granulation nozzle, the granulation nozzle is connected to an external fertilizer melt source via a pipeline, and the fertilizer melt source sprays the fertilizer melt onto the granulation section (101) via the granulation nozzle, so as to transform small-particle fertilizer seeds in the granulation section (101) into large-particle fertilizer.

4. The fluidized bed granulation system capable of improving granulation efficiency according to claim 3, characterized in that: The fertilizer molten liquid source is a liquid tank containing fertilizer molten liquid, the liquid tank is connected to a delivery pump (3) via a pipeline, and the delivery pump (3) is connected to the granulation section (101) via a pipeline; The fertilizer melt in the liquid tank is at least one of urea melt, ammonium nitrate melt, calcium ammonium nitrate melt, and compound fertilizer melt, and the weight percentage of the fertilizer melt is in the range of 92% to 99.7wt%.

5. The fluidized bed granulation system capable of improving granulation efficiency according to claim 1, characterized in that: The outlet of the cooling section (102) and the outlet of the sorting extractor (2) are both connected to a sorting screen (4) via a pipeline. The sorting screen (4) comprises a small particle outlet and a large particle outlet. The small particle outlet is connected to the granulation section (101) via a pipeline, and the large particle outlet outputs a granular fertilizer product.

6. The fluidized bed granulation system capable of improving granulation efficiency according to claim 5, characterized in that: An intermediate cooler (5) is provided on the pipeline connecting the outlet of the cooling section (102) and / or the outlet of the sorting extractor (2) to the material separation screen (4).

7. The fluidized bed granulation system capable of improving granulation efficiency according to claim 6, characterized in that: A bucket elevator (6) is provided on the pipeline connecting the small particle discharge port of the material dividing screen (4) and the granulation section (101); and / or, The large particle discharge port is connected to a product cooler (7) so as to discharge the granular fertilizer product through the output port of the product cooler (7).

8. The fluidized bed granulation system capable of improving granulation efficiency according to any one of claims 1 to 7, characterized in that: The fluidized bed granulation system capable of improving granulation efficiency further comprises an atomizing fan (8), wherein the atomizing fan (8) is connected to an atomizing air preheater (9) via a pipeline, and the atomizing air preheater (9) is connected to the fluidized bed granulation equipment (1) via a pipeline; and / or, The fluidized bed granulation system capable of improving granulation efficiency further comprises a fluidizing fan (10), wherein the fluidizing fan (10) is connected to a fluidizing air preheater (11) via a pipeline, and the fluidizing air preheater (11) is connected to the fluidized bed granulation equipment (1) via a pipeline; and / or, The tail gas outlet of the fluidized bed granulation equipment (1) is connected to a dust collector (12), and the dust collector (12) is connected to an induced draft fan (13), so that the tail gas of the fluidized bed granulation equipment (1) is discharged to the outside through the dust collector (12) and the induced draft fan (13).

9. A fluidized bed granulation method capable of improving granulation efficiency, characterized in that: The fluidized bed granulation system capable of improving granulation efficiency according to any one of claims 1 to 8, wherein the fluidized bed granulation method capable of improving granulation efficiency comprises: Adding small-granular fertilizer seed crystals into the granulation section (101) of the fluidized bed granulation equipment (1); Based on a fertilizer molten liquid source, the fertilizer molten liquid is sprayed onto the granulation section (101), the small-particle fertilizer seed crystals are converted into large-particle fertilizer, and the large-particle fertilizer flows toward the cooling section (102) of the fluidized bed granulation device (1); Using a sorting extractor (2) to sort the granular fertilizers flowing in the granulation section (101) into granular fertilizers having particle sizes that meet the standards; The granular fertilizer with a particle size that meets the standard sorted by the sorting extractor (2) and the granular fertilizer output by the cooling section (102) are output.

10. The fluidized bed granulation method capable of improving granulation efficiency according to claim 9, characterized in that: Also includes: Based on the use of a classifying screen (4) to classify the granular fertilizer outputted from the classifying extractor (2) and the cooling section (102), the small granular fertilizer classified by the classifying screen (4) is conveyed to the granulation section (101) as small granular fertilizer seed crystals, and the large granular fertilizer classified by the classifying screen (4) is outputted as a granular fertilizer product; Outputting atomizing air into the fluidized bed granulation device (1) using an atomizing fan (8) and an atomizing air preheater (9) to form uniform droplets of the fertilizer melt sprayed in the fluidized bed granulation device (1); A fluidizing fan (10) and a fluidizing air preheater (11) are used to output fluidizing air into the fluidized bed granulation equipment (1) so as to keep the granulated fertilizer in the fluidized bed granulation equipment (1) in a fluidized suspension state.

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