Edible salt drying equipment and method

Abstract

The invention provides edible salt drying equipment and method. The edible salt drying equipment comprises a vibration dehumidification tower and a drying conveying chamber. A plurality of layers of vibrating plates which are inclined from top to bottom and are horizontally arranged in a staggered manner are arranged in the vibrating dehumidification tower to form a channel for materials to fall down along a zigzag track; an air guide pipeline is arranged below each layer of vibration plate and is used for conveying hot air to the surface of the adjacent vibration plate below; the drying conveying chamber is provided with a feeding port connected to the bottom of the vibration dehumidification tower, and a conveying belt and an air supply mechanism are arranged in the drying conveying chamber. According to the invention, in a first-stage vibration dehumidification tower, materials are repeatedly scattered and turned over along a zigzag track and are always exposed in a loose thin layer state; and meanwhile, hot air from the upper side scours the falling materials in the side direction, so that surface moisture is rapidly stripped, the drying time is shortened, the unit energy consumption is reduced, internal wet cores caused by accumulation are avoided, and local accumulation is not prone to occurring.

Description

Technical Field

[0001] This invention relates to the field of edible salt preparation technology, specifically to an edible salt drying device and method. Background Technology

[0002] Fluidized bed dryers are widely used in salt drying because they allow materials to suspend and boil in hot air, resulting in a large gas-solid contact area and good heat transfer. For example, Chinese Patent 202320165826.8 discloses a fluidized bed that easily disperses salt materials, including a fluidized bed body and a rotating body movably disposed inside the fluidized bed body; a first groove is fixedly opened at the right end of the fluidized bed body, the outer wall of the right end of the rotating body is in contact with the inner wall of the first groove, symmetrical support blocks are fixedly installed at the lower end of the fluidized bed body, a base plate is fixedly installed at the lower end of the support blocks, and a blower is fixedly installed at the upper end of the base plate.

[0003] In the aforementioned existing technology, when salt is dried using a fluidized bed, if the salt material is too wet and sticky, the particles tend to stick together and clump, increasing weight and resistance. Higher air velocities are required for fluidization, and local accumulation can easily occur due to the salt being difficult to disperse. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an edible salt drying device to solve the technical problem that, in the prior art, edible salt tends to accumulate locally in fluidized bed drying processes, making it difficult to disperse.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an edible salt drying apparatus, comprising: The vibrating dehumidification tower contains multiple layers of horizontally staggered, inclined vibrating plates arranged from top to bottom, forming a channel for materials to fall along a zigzag trajectory. Each layer of vibrating plates has an air guide duct below it for supplying hot air to the surface of the adjacent vibrating plates below. The drying conveying chamber has a feed inlet connected to the bottom of the vibrating dehumidification tower. The interior of the drying conveying chamber is equipped with a conveyor belt and an air supply mechanism. The air supply mechanism is used to deliver horizontal laminar airflow in the opposite direction to the material conveying direction on the conveyor belt.

[0006] In some embodiments, the air duct includes a heat exchange coil and a diversion air outlet plate. The heat exchange coil is connected to the bottom of the vibrating plate and is used to heat the vibrating plate. One end of the heat exchange coil is connected to the diversion air outlet plate, and the other end is used to connect to the hot air duct through a flexible hose. The bottom of the diversion air outlet plate is provided with a plurality of air outlet holes facing downwards and adjacent to the vibrating plate.

[0007] In some embodiments, a baffle is provided at the top of the vibrating plate.

[0008] In some embodiments, the top of the vibrating dehumidification tower is provided with an air outlet duct, and the inner side of the air outlet duct is provided with multiple layers of perforated plates from bottom to top, and the perforations on the adjacent layers of the perforated plates are arranged alternately.

[0009] In some embodiments, the perforated plate is shaped like a concave arc surface.

[0010] In some embodiments, the inner side of the drying conveying chamber is provided with a flat plate for spreading materials, and the side of the drying conveying chamber corresponding to the flat plate is provided with a baffle plate located on the other side of the feed inlet.

[0011] In some embodiments, there are multiple paving boards, and the bottom of each paving board is provided with rake teeth, with the rake teeth on adjacent paving boards arranged in an alternating pattern.

[0012] In some embodiments, a plurality of the flat plates are arranged sequentially along the material conveying direction of the drying conveying chamber, dividing the drying conveying chamber into several drying sections. The drying conveying chamber is provided with air outlet mesh holes corresponding to each of the drying sections. The air supply mechanism includes an air guide box with an air outlet, and the air guide box is installed in each of the drying sections, corresponding to the air outlet mesh holes.

[0013] In some embodiments, the top of the vibrating dehumidification tower is connected to a feed hopper via a star-shaped discharge valve, and the bottom of the vibrating dehumidification tower is connected to the feed inlet of the drying conveying chamber via a star-shaped discharge valve.

[0014] Secondly, the present invention also provides a drying method, which uses the edible salt drying equipment described in any one of the above claims, and includes the following steps: S1: Supply wet salt to the uppermost vibrating plate of the vibrating dehumidification tower; S2: The wet salt falls along a zigzag trajectory under the action of vibration, and is washed layer by layer by hot air from the bottom of the upper vibrating plate, removing most of the moisture; S3: The wet salt, after being vibrated and dried, has its moisture content controlled to the first critical value. It leaves the vibrating plate and is evenly spread on the conveyor belt in the drying conveyor chamber to form a thin layer. S4: The material is moved slowly while a low-speed, parallel flow of warm air is delivered from the air supply mechanism in the opposite direction to the material flow to gently dry the surface of the material until the moisture content reaches below the second critical value. S5: The dried material is discharged through the outlet of the drying conveyor chamber.

[0015] Compared with existing technologies, the edible salt drying equipment provided by this invention, in the first stage of the vibrating dehumidification tower, the material is repeatedly scattered and turned along a zigzag trajectory, always exposed in a loose thin layer state; at the same time, hot air from above laterally washes the falling material, forming a strong coupling effect of dynamic turning and sweeping, with sufficient gas-solid contact area and sufficient relative velocity, so that surface moisture is quickly stripped off, and the heat and mass transfer efficiency is far superior to traditional static or fluidized bed drying, which can significantly shorten the drying time, reduce unit energy consumption, and avoid internal wet core caused by accumulation, and is not prone to local accumulation; the second stage of horizontal counter-current laminar flow air forms a stable and uniform temperature and humidity gradient on the material surface, realizing gentle and thorough balanced drying. Attached Figure Description

[0016] Figure 1 This is a three-dimensional diagram of the edible salt drying equipment provided in an embodiment of the present invention; Figure 2 This is a partial cross-sectional view of the left side of the edible salt drying equipment provided in an embodiment of the present invention; Figure 3 This is a partial cross-sectional view of the edible salt drying equipment provided in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Vibrating dehumidification tower; 11. Vibrating plate; 12. Air duct; 121. Heat exchange coil; 122. Diverting air outlet plate; 123. Air outlet; 13. Baffle; 14. Spring support; 15. Vibrating motor; 2. Drying conveying chamber; 201. Feed inlet; 202. Air outlet mesh; 21. Conveyor belt; 22. Air supply mechanism; 221. Air guide box; 3. Air outlet duct; 4. Multi-layer perforated plate; 5. Flat plate; 501. Rake teeth; 6. Baffle plate; 7. Rotary rotary valve; 701. Feed hopper. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] To address the technical problem of localized accumulation of salt that is difficult to disperse during fluidized bed drying, this invention provides an edible salt drying device. In the first stage, a vibrating dehumidification tower repeatedly scatters and tumbles the material along a zigzag trajectory, ensuring it remains exposed in a loose, thin layer. Simultaneously, hot air from above laterally washes over the falling material, creating a strong coupling effect of dynamic tumbling and sweeping. This provides sufficient gas-solid contact area and relative velocity, allowing for rapid removal of surface moisture. The heat and mass transfer efficiency far exceeds that of traditional static or fluidized bed drying, significantly shortening drying time, reducing unit energy consumption, and preventing internal damp core formation due to accumulation, thus minimizing localized buildup. The second stage features horizontal counter-current laminar flow, creating a stable and uniform temperature and humidity gradient on the material surface, achieving gentle yet thorough balanced drying.

[0020] It should be noted that the edible salt drying equipment described in this invention is used for, but not limited to, edible salt preparation. For ease of explanation, this invention will only use the application of the edible salt drying equipment in edible salt preparation as an example. The principle of the edible salt drying equipment applied to other types of equipment is essentially the same as that applied to edible salt preparation, and will not be described in detail here.

[0021] Please see Figure 1 , Figure 2 and Figure 3 This invention provides an edible salt drying device, which includes a vibrating dehumidification tower 1 and a drying conveying chamber 2. The vibrating dehumidification tower 1 is responsible for rapid and intense primary dehydration of wet salt, using the synergistic effect of mechanical vibration and hot air washing to remove most of the moisture. The drying conveying chamber 2 receives the initially dehydrated salt particles and performs final balanced drying in an extremely mild environment to ensure that the product has a uniform moisture content and that the crystal structure is protected.

[0022] The vibrating dehumidification tower 1 contains multiple layers of horizontally staggered, inclined vibrating plates 11 arranged from top to bottom, forming a channel for the material to fall along a zigzag trajectory. The vibrating dehumidification tower 1 is the first-stage drying unit of the equipment, providing a zigzag channel for the falling wet salt particles. When the equipment is running, the high-frequency, micro-amplitude vibrations generated by the vibrating plates 11 cause the salt particles on the plate surface to continuously jump, advance, and be thrown from one plate surface to the next. During this process, the material is fully agitated and dispersed. Furthermore, each layer of vibrating plates 11 has a guide pipe 12 below it, used to deliver hot air to the surface of the adjacent vibrating plates 11 below, allowing the hot air to directly wash over the thin layer of salt particles moving on the plate surface and about to fall, achieving sufficient gas-solid relative velocity and heat and mass transfer efficiency. The moisture content of the material is reduced to a first critical value, which is approximately 1% moisture content. The inclination angle of the vibrating plates relative to the horizontal plane is 15° to 40°.

[0023] In addition, the drying conveying chamber 2 has a feed inlet 201 connected to the bottom of the vibrating dehumidification tower 1. The interior of the drying conveying chamber 2 is equipped with a conveyor belt 21 and an air supply mechanism 22. The air supply mechanism 22 is used to send out horizontal laminar air in the opposite direction to the material conveying direction on the conveyor belt 21, thereby completely drying the edible salt.

[0024] Understandably, rapid drying is carried out in the vibrating dehumidification tower 1. In order to avoid the generation of a large amount of particulate dust during the vibration when the drying is complete, the drying conveying chamber 2 is connected after the vibrating dehumidification tower 1 for gentle drying to achieve the final drying effect. In addition, the whole adopts a non-porous conveying structure to avoid the bottom-outflow airflow, which would cause fluctuations in heat dissipation efficiency when the pores are blocked by salt particles, and to reduce the maintenance frequency.

[0025] In one embodiment, please refer to Figure 2 In order to heat the vibrating plate 11 and form a vertically distributed heating with the hot air, the air guide duct 12 includes a heat exchange coil 121 and a diversion air outlet plate 122. The heat exchange coil 121 is connected to the bottom of the vibrating plate 11 and is used to heat the vibrating plate 11. One end of the heat exchange coil 121 is connected to the diversion air outlet plate 122, and the other end is used to connect to the hot air duct through a flexible hose. The bottom of the diversion air outlet plate 122 is provided with a number of air outlet holes 123 facing the adjacent vibrating plate 11 below. The orientation of these air outlet holes 123 is set to align with the upper surface of the adjacent vibrating plate 11 below, so that the hot air can accurately wash the thin layer of material during the falling process.

[0026] Understandably, the hot air duct can use a steam heat exchange coil to exchange heat with the air, heat the air and introduce it into the heat exchange coil 121 through a hose to heat the vibrating plate 11, and introduce it into the diversion air outlet plate 122, where the air is diverted and evenly distributed and the falling edible salt is obliquely washed away from each air outlet 123.

[0027] In this embodiment, the vibrating plate 11 is mounted inside the vibrating dehumidification tower 1 via a spring bracket 14 and is equipped with a vibrating motor 15 to provide the vibration action of the vibrating plate.

[0028] In one embodiment, please refer to Figure 2 The top of the vibrating plate 11 is provided with a baffle 13, which is used to block and bounce the material back, so as to prevent the material from being carried away by the hot air and detached from the lower vibrating plate 11 at the falling position of each layer of vibrating plate 11. In addition, it will also promote the material to collide with the baffle 13 and to fully contact the hot air for drying.

[0029] In one embodiment, please refer to Figure 2To further optimize the airflow organization and dust control of the vibrating dehumidification tower 1, an air outlet duct 3 is provided at the top of the vibrating dehumidification tower 1. The inner side of the air outlet duct 3 is provided with multiple layers of perforated plates 4 from bottom to top, and the mesh holes on the adjacent layers of the perforated plates 4 are arranged in an alternating manner. This alternating arrangement of mesh holes can change the path of the rising airflow, increase the collision between the airflow and the plate surface, and cause the larger salt particles carried in it to be intercepted and settled due to inertia, thereby reducing dust escape.

[0030] Furthermore, the perforated plate 4 has a concave arc shape. To improve the dust interception efficiency of the perforated plate 4, its shape is specifically defined as a concave arc shape. The concave arc structure is more conducive to the intercepted dust particles gathering and sliding down along the plate surface towards the center, returning to the drying chamber, avoiding accumulation on the horizontal plate surface, and realizing automatic dust recovery.

[0031] Understandably, the perforated plate 4 can also be an inclined surface, allowing the material to slide off.

[0032] In one embodiment, please refer to Figure 3 To optimize the uniformity of the material distribution in the drying conveying chamber 2, a flat plate 5 is provided on the inner side of the drying conveying chamber 2 to initially flatten the material falling from the feed inlet 201. A baffle plate 6 is provided on the other side of the feed inlet 201 on the side of the drying conveying chamber 2 corresponding to the flat plate 5, which is the starting end of the material conveying path. The flat plate 5 and the baffle plate 6 cooperate with each other to accommodate and work together to form an initially uniform material layer with controlled thickness.

[0033] Furthermore, to enhance the spreading effect and gently comb the material, there are multiple spreading plates 5, and the bottom of each spreading plate 5 is provided with rake teeth 501. The rake teeth 501 on adjacent spreading plates 5 are arranged in an alternating manner. When the material passes through, these alternating high and low rake teeth 501 can break up clumps and evenly distribute the material layer.

[0034] Furthermore, to achieve precise drying in sections within the drying conveying chamber 2, multiple flat plates 5 are arranged sequentially along the material conveying direction of the drying conveying chamber 2, dividing the drying conveying chamber 2 into several drying sections. The drying conveying chamber 2 is provided with air outlet meshes 202 corresponding to each drying section. The air supply mechanism 22 includes an air guide box 221 with an air outlet, and the air guide box 221 is installed in each drying section, corresponding to the air outlet meshes 202. This allows airflows of different temperatures, humidity levels, or air volumes to be independently delivered to different drying sections.

[0035] In one embodiment, please refer to Figure 2To ensure the airtightness of the entire equipment system, prevent airflow short circuits, and achieve airlock conveying of materials, the top of the vibrating dehumidification tower 1 is connected to the feed hopper 701 via a star-shaped discharge valve 7, and the bottom of the vibrating dehumidification tower 1 is connected to the feed inlet 201 of the drying conveying chamber 2 via the star-shaped discharge valve 7. This effectively isolates the airflow inside the tower from the external environment and the airflow interference between the two drying chambers, ensuring the independence and stability of the airflow field of each unit.

[0036] Understandably, with the setting of the star-shaped discharge valve 7, the airflow direction can be controlled to avoid excessive airflow disturbance that could interfere with the preset airflow direction, thus ensuring drying efficiency and the stability of drying operation, and making the final drying quality reliable.

[0037] To better understand this invention, the following is combined with... Figures 1 to 3 The technical solution of the present invention is described in detail as follows: Wet salt particles first enter the vibrating dehydration tower 1 through the top feed hopper 701 and the star-shaped discharge valve 7. The star-shaped discharge valve 7 plays a crucial airlock role here, preventing external air from interfering with the stable airflow field inside the tower. After the material falls onto the uppermost vibrating plate 11, it begins to jump and slide along the inclined plate surface under the action of high-frequency micro-amplitude vibration. When the material moves to the edge of the vibrating plate 11, it is thrown onto the adjacent vibrating plates 11 arranged below it under inertia. This process is repeated, and the material falls along a preset zigzag trajectory inside the tower. The core power for dehydration comes from the hot air delivered by the air duct 12. The hot air circulates in the heat exchange coil 121, first directly conducting heat to the vibrating plate 11 to prevent wet salt from sticking to the plate. A portion of the hot air is sprayed out at a certain angle and speed through the air outlet 123 at the bottom of the diversion air outlet plate 122. The airflow stream precisely washes over the salt particles moving on the surface of the adjacent vibrating plate 11 below. After the first stage of rapid dehydration, the salt particles, whose moisture content has been significantly reduced, are conveyed through the airlock of another star-shaped discharge valve 7 at the bottom of the tower and enter the drying conveying chamber 2 through the feed inlet 201. This valve once again ensures the independence of the airflow field between the two drying stages. In the drying conveying chamber 2, the salt particles first fall onto the low-speed conveyor belt 21. Multiple flat plates 5 above the conveyor belt 21 and the staggered rake teeth 501 at its bottom work together with the baffle plate 6 on one side to comb and spread the material into a very thin layer of uniform and stable thickness. The air supply mechanism 22 is activated, and multiple air guide boxes 221 send dry low-temperature air with independently adjustable parameters to their respective drying sections. The airflow is in the form of horizontal laminar flow, blowing smoothly across the surface of the material layer against the conveying direction of the material on the conveyor belt 21, drying the material to the required quality.

[0038] The present invention also provides a drying method, which uses the edible salt drying equipment as described in any of the above embodiments, and includes the following steps: S1: Supply wet salt to the uppermost vibrating plate 11 of the vibrating dehumidification tower 1; S2: The wet salt falls along a zigzag trajectory under the action of vibration, and is washed layer by layer by the hot air from the bottom of the upper vibrating plate 11, removing most of the moisture; S3: The wet salt, after being vibrated and dried, controls the moisture content to the first critical value, leaves the vibrating plate 11 and is evenly spread on the conveyor belt 21 in the drying conveyor chamber 2 to form a thin layer. S4: The material is moved slowly while warm air with a low speed and horizontal flow opposite to the material flow direction is sent out from the air supply mechanism 22 to gently dry the surface of the material until the moisture content reaches below the second critical value. S5: The dried material is discharged through the outlet of the drying conveyor chamber 2.

[0039] In step S2, by controlling the negative pressure fan at the top of the tower, a stable upward airflow is formed inside the drying tower, and the speed of the upward airflow is controlled at 0.5-1.5 m / s.

[0040] The first critical value mentioned in step S3 is a water content of about 1%; the second critical value mentioned in step S4 is a water content of 0.1% or less.

[0041] In step S2, dust in the rising airflow is intercepted and recovered through a multi-layered staggered perforated plate.

[0042] In step S4, the exhaust volume of the drying conveying chamber 2 is controlled to maintain a slight negative pressure of -5 to -15 Pa inside the drying chamber to prevent airflow from escaping from the outlet.

[0043] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A salt drying device, characterized in that, include: The vibrating dehumidification tower contains multiple layers of horizontally staggered, inclined vibrating plates arranged from top to bottom, forming a channel for materials to fall along a zigzag trajectory. Each layer of vibrating plates has an air guide duct below it for supplying hot air to the surface of the adjacent vibrating plates below. The drying conveying chamber has a feed inlet connected to the bottom of the vibrating dehumidification tower. The interior of the drying conveying chamber is equipped with a conveyor belt and an air supply mechanism. The air supply mechanism is used to deliver horizontal laminar airflow in the opposite direction to the material conveying direction on the conveyor belt.

2. The edible salt drying equipment according to claim 1, characterized in that, The air duct includes a heat exchange coil and a diversion air outlet plate. The heat exchange coil is connected to the bottom of the vibrating plate and is used to heat the vibrating plate. One end of the heat exchange coil is connected to the diversion air outlet plate, and the other end is used to connect to the hot air duct through a flexible hose. The bottom of the diversion air outlet plate is provided with several air outlet holes facing downwards and adjacent to the vibrating plate.

3. The edible salt drying equipment according to claim 1, characterized in that, The top of the vibrating plate is equipped with a baffle.

4. The edible salt drying equipment according to claim 1, characterized in that, The top of the vibrating dehumidification tower is provided with an air outlet duct, and the inner side of the air outlet duct is provided with multiple layers of perforated plates from bottom to top, and the perforations on the adjacent layers of the perforated plates are arranged alternately.

5. The edible salt drying equipment according to claim 4, characterized in that, The perforated plate has a concave arc shape.

6. The edible salt drying equipment according to claim 1, characterized in that, The inner side of the drying conveying chamber is provided with a flat plate for spreading materials, and a baffle plate is provided on the side of the drying conveying chamber corresponding to the flat plate, located on the other side of the feed inlet.

7. The edible salt drying equipment according to claim 6, characterized in that, The number of the flat slabs is multiple, and the bottom of the flat slabs is provided with rake teeth, with the rake teeth on adjacent flat slabs arranged in an alternating pattern.

8. The edible salt drying equipment according to claim 7, characterized in that, Multiple flat plates are arranged sequentially along the material conveying direction of the drying conveying chamber, dividing the drying conveying chamber into several drying sections. The drying conveying chamber has air outlet mesh holes that correspond one-to-one with the drying sections. The air supply mechanism includes an air guide box with an air outlet, and the air guide box is installed one-to-one with each of the drying sections, corresponding one-to-one with the air outlet mesh holes.

9. The edible salt drying equipment according to claim 1, characterized in that, The top of the vibrating dehumidification tower is connected to a feed hopper via a star-shaped discharge valve, and the bottom of the vibrating dehumidification tower is connected to the feed inlet of the drying conveying chamber via a star-shaped discharge valve.

10. A drying method, characterized in that, The process, using the edible salt drying equipment as described in any one of claims 1-9, includes the following steps: S1: Supply wet salt to the uppermost vibrating plate of the vibrating dehumidification tower; S2: The wet salt falls along a zigzag trajectory under the action of vibration, and is washed layer by layer by hot air from the bottom of the upper vibrating plate, removing most of the moisture; S3: The wet salt, after being vibrated and dried, has its moisture content controlled to the first critical value. It leaves the vibrating plate and is evenly spread on the conveyor belt in the drying conveyor chamber to form a thin layer. S4: The material is moved slowly while a low-speed, parallel flow of warm air is delivered from the air supply mechanism in the opposite direction to the material flow to gently dry the surface of the material until the moisture content reaches below the second critical value. S5: The dried material is discharged through the outlet of the drying conveyor chamber.

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