A spray fluidized bed drying device

Abstract

This utility model discloses a spray fluidized bed drying device, including a spray fluidized bed with atomizing nozzles inside. The raw material liquid is transported to the feed end of the spray fluidized bed via a liquid pipeline from a raw material liquid storage tank and a feed pump. Compressed air is mixed with the raw material liquid at the atomizing nozzles via a gas pipeline to form a spray. External air is sequentially processed by a blower and a heater before entering the lower air chamber of the spray fluidized bed to provide hot air. The exhaust gas from the top of the spray fluidized bed sequentially passes through a cyclone separator and a bag filter before being discharged by an induced draft fan. A premixer is installed on the liquid pipeline between the feed pump and the spray fluidized bed to premix and pre-disperse the raw material liquid; a pressure stabilizing chamber is installed on the gas pipeline between the bag filter and the induced draft fan to buffer and homogenize the exhaust gas pressure. This structure makes the atomization of the raw material liquid more uniform, improves the stability of the exhaust gas flow, and enhances the stability and reliability of the spray fluidized bed drying process.

Description

Technical Field

[0001] This invention relates to the field of fluidized bed equipment technology, and more particularly to a spray fluidized bed drying device. Background Technology

[0002] Spray fluidized bed dryers are a type of equipment that combines spray drying and fluidized bed drying, and are commonly used for the rapid drying of liquid materials. Existing spray fluidized bed devices typically include atomizing nozzles, a hot air system, and an exhaust gas dust removal system. The material undergoes atomization, drying, and classification within the spray fluidized bed.

[0003] In existing technologies, the raw material liquid is directly fed into the atomizing nozzle of the spray fluidized bed through a conveying pipeline. Due to issues such as viscosity fluctuations, uneven concentrations, or localized agglomeration in some raw material liquids, uneven atomization can easily occur, or even nozzle blockage can result, affecting drying efficiency and continuous equipment operation.

[0004] Furthermore, the exhaust gas from a spray fluidized bed typically passes through a cyclone separator and a bag filter for dust removal. During the online cleaning process of the bag filter, its resistance changes periodically, causing fluctuations in the pressure in the exhaust gas pipeline and the airflow at the induced draft fan inlet. These airflow variations affect the fluidization effect, leading to instability in the drying process and even causing problems such as product moisture fluctuations and dust spillage.

[0005] Therefore, in the existing technology, the key to improving the operating effect and stability of the spray fluidized bed drying device is to make the raw material liquid more uniform and stable before entering the spray fluidized bed, and at the same time keep the pressure and air volume of the exhaust gas stable before it is introduced into the induced draft fan. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides a spray fluidized bed drying device, which adopts the following technical solution: A spray fluidized bed drying device includes a spray fluidized bed with atomizing nozzles inside. The atomizing nozzles are connected to the feed end of the spray fluidized bed to receive compressed air and raw material liquid to be dried. The compressed air is connected to the feed end of the spray fluidized bed via a gas pipeline. The raw material liquid enters the feed end of the spray fluidized bed through a raw material liquid storage tank and a feed pump connected in sequence via a liquid pipeline. The device also includes a blower and a heater. External air enters the lower air chamber of the spray fluidized bed through the blower and heater connected in sequence via a gas pipeline. The top exhaust outlet of the spray fluidized bed is connected in sequence via a gas pipeline to a cyclone dust collector, a bag filter, and an induced draft fan. A premixing device is installed on the liquid pipeline between the feed pump and the feed end of the spray fluidized bed to homogenize and pre-disperse the raw material liquid before it enters the spray fluidized bed. A pressure stabilizing chamber is installed on the gas pipeline between the bag filter and the induced draft fan to buffer and homogenize the exhaust gas pressure.

[0007] Furthermore, the premixing device is a spiral static mixer.

[0008] Furthermore, the main body of the pressure stabilizing chamber is a cylindrical structure, including a trumpet-shaped diffuser section, a perforated plate, and a honeycomb rectifying section arranged sequentially along the exhaust gas flow direction. The trumpet-shaped diffuser section is a conical or trumpet-shaped diffuser structure with a cross-section that gradually increases from small to large. The perforated plate is arranged vertically at the cross-sectional position of the airflow channel and is welded to the inner wall of the pressure stabilizing chamber. Multiple through holes are uniformly opened on the perforated plate. The honeycomb rectifying section is composed of multiple parallel honeycomb channel units.

[0009] Furthermore, the cellular channel unit can be any of hexagonal channels, square channels, and circular channels.

[0010] Furthermore, the pressure stabilizing chamber is provided with flange interfaces at both ends that match the gas pipeline, wherein the inlet flange of the pressure stabilizing chamber is sealed to the outlet flange of the bag filter, and the outlet flange is sealed to the inlet flange of the induced draft fan.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model premixes, homogenizes, and pre-disperses the raw material liquid by installing a static mixer between the feed pump and the spray fluidized bed. The fixed mixing unit inside the static mixer can shear and divide the raw material liquid during the liquid flow process, achieving homogenization without additional power. This makes the raw material liquid more uniform and stable before entering the spray fluidized bed, thereby improving the droplet formation quality, reducing nozzle clogging, and enhancing the stability of spray drying.

[0012] 2. This utility model achieves buffering and homogenization of exhaust gas pressure by setting a pressure stabilizing chamber between the bag filter and the induced draft fan. The pressure stabilizing chamber is sequentially equipped with a trumpet-shaped diffuser section, a perforated plate, and a honeycomb rectifier, which can effectively reduce the exhaust gas velocity, uniformly distribute the airflow, and stabilize the flow direction, making the airflow at the inlet of the induced draft fan more stable. This reduces the impact of airflow fluctuations on the operation of the spray fluidized bed and improves the operational stability and reliability of the entire drying system. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the system flow of the spray fluidized bed drying device of this utility model; Figure 2 This is a cross-sectional structural diagram of the voltage stabilizing cavity of this utility model.

[0014] The components include: 1. Spray fluidized bed; 2. Cyclone separator; 4. Bag filter; 5. Exhaust fan; 6. Raw material liquid storage tank; 7. Feed pump; 8. Blower; 9. Heater; 10. Premixer; 11. Pressure stabilizing chamber; 12. Horn-shaped diffuser section; 13. Perforated plate; 14. Through hole; 15. Honeycomb rectifier section; 16. Honeycomb channel unit; 17. Flange. Detailed Implementation

[0015] The following will describe the technology of the embodiments of the present utility model clearly and completely with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present utility model. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present utility model can be combined with each other.

[0016] Example 1: Reference Figures 1-2 A spray fluidized bed drying device includes a spray fluidized bed 1. The spray fluidized bed 1 is equipped with atomizing nozzles connected to the feed end of the spray fluidized bed. These nozzles receive compressed air and the raw material liquid to be dried, forming droplets inside the bed. The raw material liquid is transported to the feed end of the spray fluidized bed 1 via a raw material liquid storage tank 6 and a feed pump 7, which are connected in sequence by liquid pipelines. The compressed air required for atomization is transported to the feed end of the spray fluidized bed via a separate gas pipeline, mixing with the raw material liquid at the atomizing nozzles to form a spray. External air is pressurized by a blower 8 and enters a heater 9 through a gas pipeline. After being heated to a set temperature, it is sent to the lower air chamber of the spray fluidized bed 1 to provide a stable hot air fluidization flow for the bed. The exhaust gas from the top of the spray fluidized bed 1 enters a cyclone separator 2 and a bag filter 4 in sequence via gas pipelines for dust removal, and is finally discharged by an induced draft fan 5.

[0017] The above structure constitutes the basic workflow of the spray fluidized bed drying system: the raw material liquid and compressed air are mixed at the atomizing nozzle to form droplets and come into contact with the hot air below, and are rapidly dried in a fluidized state; the generated exhaust gas passes through a cyclone separator and a bag filter in sequence to complete the graded dust removal and is then discharged by an induced draft fan.

[0018] Specifically, the drying device proposed in this embodiment has a premixer 10 installed on the liquid pipeline between the feed pump 7 and the feed end of the spray fluidized bed 1. This premixer is used to premix, homogenize, and pre-disperse the raw material liquid before it enters the spray fluidized bed, making the concentration distribution of the raw material liquid more uniform, thereby improving the spray atomization quality and reducing the risk of nozzle clogging. At the same time, a pressure stabilizing chamber 11 is installed on the gas pipeline between the bag filter 4 and the induced draft fan 5. The pressure stabilizing chamber is used to buffer and homogenize the exhaust gas pressure, reduce the fluctuation of system airflow caused by changes in the resistance of the bag filter, and improve the stability of the airflow at the inlet of the induced draft fan.

[0019] Preferably, in this embodiment, the premixer is a static mixer. The static mixer 10 is a hollow tubular shell with multiple spiral or baffled mixing units fixedly arranged inside along the liquid flow direction. These mixing units are typically arranged in alternating left-right spiral twists. When the raw liquid flows through the mixer, it is sheared, divided, deflected, and recombinated by the mixing units at each stage, causing continuous tangential mixing and interlayer exchange within the pipe cross-section, thereby achieving homogenization and pre-dispersion under non-powered conditions. The static mixer 10 can effectively eliminate concentration stratification, agglomeration, or local high viscosity areas of the raw liquid during transportation, giving the raw liquid more stable rheological properties and uniformity before reaching the spray fluidized bed 1, which helps to improve droplet formation quality and enhance overall spray drying efficiency.

[0020] Specifically, the pressure stabilizing chamber 11 has a cylindrical structure, comprising a trumpet-shaped diffuser section 12, a perforated plate 13, and a honeycomb rectifier section 15 sequentially along the exhaust gas flow direction. The trumpet-shaped diffuser section 12 has a gradually expanding cross-section to reduce the exhaust gas velocity. The perforated plate 13 is vertically arranged at the channel cross-section, with uniformly distributed through holes 14 to divide the airflow into multiple smaller streams and achieve pressure equalization. The honeycomb rectifier section 15 contains honeycomb channel units 16 to ensure consistent airflow direction and uniform velocity distribution, thereby stabilizing the airflow entering the induced draft fan 5. Flanges 17 are provided at both the inlet and outlet of the pressure stabilizing chamber 11, sealingly connecting to the gas pipelines at the outlet of the bag filter 4 and the inlet of the induced draft fan 5, respectively.

[0021] The working process of the spray fluidized bed drying device described in this embodiment is as follows: The feed liquid is first stored in the feed liquid storage tank 6 and then transported through the liquid pipeline driven by the feed pump 7. During the transport process, the feed liquid flows sequentially through the premixer 10 located in the liquid pipeline. Because the premixer has multiple spiral or baffled mixing units, the feed liquid is subjected to continuous shearing, segmentation, reversal, and recombination as it passes through these units, resulting in sufficient lateral mixing within the pipeline, achieving concentration homogenization and micro-agglomeration pre-dispersion. The premixed feed liquid enters the feed end of the spray fluidized bed 1 in a more homogeneous and stable state.

[0022] Compressed air, supplied synchronously with the raw material liquid, enters the feed end of the spray fluidized bed 1 through a separate gas pipeline and mixes with the raw material liquid at the atomizing nozzle to form fine droplets. After entering the interior of the spray fluidized bed, the droplets come into full contact with the hot air from the lower air chamber, rapidly completing heat and mass exchange in a suspended and fluidized state, achieving instantaneous drying of the raw material liquid. The fluidized hot air is delivered by the blower 8 and heated to the predetermined temperature by the heater 9 before entering the lower air chamber of the spray fluidized bed, ensuring stable hot air volume and temperature during the drying process.

[0023] The exhaust gas generated during the spray drying process is discharged from the top of the spray fluidized bed and sequentially enters the cyclone separator 2 and the bag filter 4 through the gas pipeline. The cyclone separator 2 performs primary separation of large particles in the exhaust gas, while the bag filter 4 further captures fine dust, achieving efficient dust removal of the exhaust gas.

[0024] After being discharged from the bag filter, the exhaust gas enters the pressure stabilizing chamber 11 located before the inlet of the induced draft fan 5. Inside the pressure stabilizing chamber, along the exhaust gas flow direction, are sequentially arranged a trumpet-shaped diffuser section 12, a perforated plate 13, and a honeycomb rectifier section 15. The exhaust gas first passes through the trumpet-shaped diffuser section 12, gradually increasing the cross-sectional area of ​​the airflow channel, thereby reducing the airflow velocity and smoothing out instantaneous pressure fluctuations caused by changes in the dust collector resistance. Subsequently, the airflow passes through the perforated plate 13 and is divided into multiple small airflow streams by through-holes 14 to eliminate velocity differences across the cross-section, achieving pressure and flow uniformity. Finally, the exhaust gas enters the honeycomb rectifier section 15, where, under the direction-limiting effect of the honeycomb perforated units 16, the airflow direction tends to be consistent and the velocity distribution more uniform. The exhaust gas, after being treated by the pressure stabilizing chamber 11, enters the induced draft fan 5 with a stable flow rate and direction, effectively improving the operational stability of the induced draft fan and enhancing the airflow balance performance of the entire spray fluidized bed drying system.

[0025] Through the above working process, the spray fluidized bed dryer described in this embodiment can achieve stable premixing of raw material liquid, uniform atomization, and effective stabilization of system exhaust gas volume, thereby improving spray drying efficiency and the quality of dried products.

Claims

1. A spray fluidized bed drying device, comprising a spray fluidized bed, wherein an atomizing nozzle is provided inside the spray fluidized bed, the atomizing nozzle being connected to the feed end of the spray fluidized bed for receiving compressed air and raw material liquid to be dried, the compressed air being connected to the feed end of the spray fluidized bed via a gas pipeline, and the raw material liquid entering the feed end of the spray fluidized bed via a raw material liquid storage tank and a feed pump connected in sequence by a liquid pipeline; the device further comprising a blower and a heater, wherein external air enters the lower air chamber of the spray fluidized bed via the blower and the heater connected in sequence by a gas pipeline; the top exhaust outlet of the spray fluidized bed is connected in sequence to a cyclone dust collector, a bag dust collector, and an induced draft fan via a gas pipeline, characterized in that: A premixing device is installed on the liquid pipeline between the feed pump and the feed end of the spray fluidized bed to homogenize and pre-disperse the raw material liquid before it enters the spray fluidized bed; a pressure stabilizing chamber is installed on the gas pipeline between the bag filter and the induced draft fan to buffer and homogenize the exhaust gas pressure.

2. A spray fluidized bed drying apparatus according to claim 1, characterized in that: The premixing device is a spiral static mixer.

3. The spray fluidized bed drying device according to claim 1, characterized in that: The main body of the pressure stabilizing chamber is a cylindrical structure, including a trumpet-shaped diffuser section, a perforated plate and a honeycomb rectifying section arranged sequentially along the exhaust gas flow direction. The trumpet-shaped diffuser section is a conical or trumpet-shaped diffuser structure with a cross-section that gradually increases in size from small to large. The perforated plate is arranged vertically at the cross-sectional position of the airflow channel and is welded to the inner wall of the pressure stabilizing chamber. Multiple through holes are evenly opened on the perforated plate. The honeycomb rectifying section is composed of multiple parallel honeycomb channel units.

4. A spray fluidized bed drying apparatus according to claim 3, characterized in that: The honeycomb channel unit can be any of the hexagonal, square, and circular channels.

5. A spray fluidized bed drying apparatus according to claim 3 or 4, characterized in that: The pressure stabilizing chamber is provided with flange interfaces at both ends that match the gas pipeline. The inlet flange of the pressure stabilizing chamber is sealed to the outlet flange of the bag filter, and the outlet flange is sealed to the inlet flange of the induced draft fan.

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