A micro-vacuum biomass steam drying device

Abstract

The present invention discloses a micro-vacuum biomass steam drying device, which belongs to the field of biomass drying, and comprises a support part, wherein a drying unit is connected to one side of the support part, and the drying unit comprises a drying component fixedly connected to one side of the support part, a driving part fixedly connected to one side of the drying component, a venturi mixing part located above the drying component and used for mixing and improving steam, and a heat exchange part fixedly connected to one side of the support part, and the diffusion end of the venturi mixing part is connected to the input end of the heat exchange part; the drying component comprises a hollow insulation sleeve fixedly connected to one side of the support part; the present application realizes low-cost heating in the field of biomass township heating by first drying and then recovering the drying energy for heating, and solves the problem of excessively high drying cost caused by high-moisture raw materials existing at the front end of the current biomass cogeneration, rural heating, biomass molded fuel production, and biomass torrefied fuel production.

Description

Technical Field

[0001] The invention relates to the field of biomass drying, and more specifically to a micro-vacuum biomass steam drying device. Background Art

[0002] In the process of biomass energy utilization, the humidity of both northern straw and southern wood chips is relatively high, generally exceeding 30%. If the wet raw materials are used directly as fuel, the calorific value will be greatly reduced, and it will also bring many other unfavorable factors (increased flue gas volume, increased power consumption, increased acid dew point, and increased corrosion). If the moisture in the wet fuel can be removed or reduced at low cost before combustion, it will have important economic value.

[0003] Drying fuel before combustion is the main way to achieve fuel drying. The commonly used drying methods include high-temperature flue gas + drum drying equipment (the principle is to use the high-temperature hot flue gas formed by coal combustion to contact and exchange heat with the crushed wet straw for drying), hot air + fluidized hot air duct (the principle is that the hot flue gas formed by coal combustion heats the air through the heat exchange surface, and the hot air contacts and exchanges heat with the crushed wet straw for drying), and hot air + belt drying equipment. The most widely used drying technology in China is to achieve drying through direct contact between hot flue gas and crushed wet straw. The disadvantage of this method is that the dried material is flammable and prone to explosion, which may cause accidents.

[0004] At the same time, the above drying methods all have a problem: in the process of drying the wet material, water vapor will be generated when the wet material is dried and evaporated. The above drying methods are unable to recycle the latent heat of the evaporated water vapor, thus resulting in excessively high drying costs. Therefore, in most straw energy utilization occasions, drying technology is not used, but direct combustion is used, which will cause the straw energy utilization to always be in a "low-end" state. Summary of the invention

[0005] In view of the problems existing in the prior art, the object of the present invention is to provide a micro-vacuum biomass steam drying device.

[0006] To solve the above problems, the present invention adopts the following technical solutions.

[0007] A micro-vacuum biomass steam drying device comprises a support portion, a drying unit is connected to one side of the support portion, and the drying unit comprises a drying component fixedly connected to one side of the support portion, a driving portion fixedly connected to one side of the drying component, a venturi mixing portion located above the drying component and used for mixing and improving the quality of steam, and a heat exchange portion fixedly connected to one side of the support portion, wherein a diffusion end of the venturi mixing portion is connected to an input end of the heat exchange portion;

[0008] The drying assembly comprises a hollow heat-insulating casing body fixedly connected to one side of the support part, two heat-insulating seats respectively fixedly connected to the inner walls of the openings at both ends of the hollow heat-insulating casing body, a metal evaporation casing body located inside the hollow heat-insulating casing body and having its two ends respectively fixedly connected to the two heat-insulating seats, two spiral feeding paddles located inside the metal evaporation casing body, a metal heat-conducting pipe fixedly connected to the outer surface of the metal evaporation casing body, and a steam exhaust pipe connecting the inner cavity of the metal evaporation casing body with the throat of the venturi mixing part;

[0009] Both ends of the metal heat-conducting pipe extend outward through the hollow heat-insulating sleeve, and one end of the metal heat-conducting pipe is connected to the feed end of the venturi mixing part.

[0010] Furthermore, both ends of the spiral feeding paddle 2 are rotatably connected to two insulation seats respectively, the output shaft of the driving unit passes through one of the insulation seats and is fixedly connected to one end of the spiral feeding paddle 2, the other end of the metal heat conducting pipe 1 is connected to the air supply equipment, and the air supply equipment sends steam into the metal heat conducting pipe 1 and steam-dries the material in the metal evaporation sleeve, the exhaust pipe 1 sends the water vapor generated when the material in the metal evaporation sleeve is dried into the Venturi mixing section, and the water vapor is mixed with the steam exhausted from the metal heat conducting pipe 1 through the Venturi mixing section and then sent to the heat exchange section to recover the latent heat of the water vapor.

[0011] Furthermore, an insulating vacuum cavity is formed between the hollow insulation casing and the metal evaporation casing, and a feed part and a discharge part are provided inside the metal evaporation casing and the hollow insulation casing, and the feed part of the metal evaporation casing is connected to the feed part of the hollow insulation casing, and the discharge part of the metal evaporation casing is connected to the discharge part of the hollow insulation casing.

[0012] Furthermore, a plurality of stirring and flow-changing parts are fixedly connected to the inner wall of the metal evaporation sleeve, and a single stirring and flow-changing part is located between two adjacent spiral blades on the outer surface of the second spiral feeding paddle.

[0013] Furthermore, a plurality of heat conducting plates are fixedly connected to the outer surface of the metal evaporation sleeve, and the plurality of heat conducting plates are connected via parallel heat conducting parts. The outer surface of the metal heat conducting tube is in contact with the parallel heat conducting parts and the heat conducting plates. One ends of the plurality of stirring and current converting parts extend outward through the metal evaporation sleeve and are respectively fixedly connected to the plurality of heat conducting plates.

[0014] Furthermore, the multiple spiral blades on the outer surface of the second spiral feeding paddle are divided into a feed front end area, a feed middle end area and a feed rear end area according to the pitch between adjacent spiral blades, the pitch of adjacent spiral blades in the feed front end area is greater than the pitch of adjacent spiral blades in the feed middle end and feed rear end areas, and the pitch of adjacent spiral blades in the feed middle end area is greater than the pitch of adjacent spiral blades in the feed rear end area, and the multiple stirring and flow changing parts are evenly arranged in the feed front end area and the feed middle end area.

[0015] Furthermore, the output end of the heat exchange part is fixedly connected to an exhaust pipe 2, and the inner wall of the exhaust pipe 2 is fixedly connected to a diverter baffle for separating the steam discharged from the output end of the heat exchange part from the non-condensable gas in the steam, the other end of the exhaust pipe 2 is fixedly connected to a cover body 2, and the output port of the cover body 2 is fixedly connected to a second delivery pipe, and a metal heat-conducting pipe 2 is also fixedly connected to the outer wall of the metal evaporator casing, and both ends of the metal heat-conducting pipe 2 extend outward through the hollow insulation casing, and one of the extended ends of the metal heat-conducting pipe 2 is connected to the second delivery pipe.

[0016] Furthermore, the other end of the exhaust pipe 2 is also fixedly connected to the cover body 1, and the output port of the cover body 1 is fixedly connected to the first conveying pipe, the other end of the first conveying pipe is fixedly connected to the metal heat conducting pipe 3, and the metal heat conducting pipe 3 is spirally fixed to the outer surface of the spiral feeding part 1.

[0017] Furthermore, it also includes a screw conveyor fixedly connected to the upper end of the support part, a loader connected to one side of the screw conveyor, a second spiral feeding part fixedly connected to the inside of the support part and connected to the discharge part, and a feeding part located at the lower end of the second spiral feeding part, wherein the first spiral feeding part is fixedly connected to one side of the support part and the input end of the spiral feeding part is connected to the output end of the screw conveyor, and the input end of the second spiral feeding part is connected to the discharge part.

[0018] Furthermore, the spiral unloading part 1 and the spiral unloading part 2 both include a conical shell with a cavity opened inside, a feed port opened at the upper end of the conical shell and connected to the cavity, a motor fixedly connected to the upper end of the conical shell, a spiral feeding paddle 1 rotatably connected to the inner wall of the cavity, a material removal rod fixedly connected to the outer lower end of the spiral feeding paddle 1, and a discharge port opened at the lower end of the conical shell and connected to the cavity, and the output shaft of the motor passes through the conical shell and is fixedly connected to one end of the spiral feeding paddle 1.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) This scheme sends steam with certain parameters into the metal heat-conducting pipe 1, and the heat of the metal heat-conducting pipe 1 is transferred to the metal evaporating sleeve. The metal evaporating sleeve contacts and exchanges heat with the wet material, thereby achieving steam drying of the wet material and taking away most of the moisture in the wet material. The water vapor generated during the drying process of the wet material can be mixed with the steam discharged from the metal heat-conducting pipe 1 and sent to the heat exchange part to achieve latent heat recovery of the water vapor. By drying first and then recovering the drying energy for heating, low-cost heating in the field of biomass township heating can be achieved, solving the problem of high drying costs caused by high-moisture raw materials at the front end of biomass cogeneration, rural heating, biomass molded fuel production, and biomass torrefied fuel production.

[0021] (2) The present scheme is provided with a plurality of stirring and deflecting parts. When the screw feed paddle 2 rotates, the plurality of spiral blades on the outer surface of the screw feed paddle 2 drive the wet material to move and convey the wet material. The material between the plurality of spiral blades will collide and rub against the plurality of protruding stirring and deflecting parts, thereby changing the flow direction of the wet material, so that the material near the center of the screw feed paddle 2 is stirred to the outside of the screw feed paddle 2, increasing the contact with the inner wall of the metal evaporation sleeve, thereby realizing uniform heating and drying of the wet material. The heat of the metal heat conduction pipe 1 is transferred to the stirring and deflecting part through the heat conduction plate and the parallel heat conduction part. During the stirring and deflecting part stirring the wet material, the inside of the wet material is directly heated, so that the moisture inside the wet material can evaporate, thereby improving the drying efficiency of the material and the evaporation efficiency of the water vapor.

[0022] (3) This scheme is provided with a second metal heat-conducting pipe, through which the steam in the first metal heat-conducting pipe is used to quickly dry the wet material in the metal evaporation sleeve, so that the moisture in the straw is quickly evaporated. The low-temperature steam discharged from the first metal heat-conducting pipe enters the second metal heat-conducting pipe after heat exchange in the heat exchange part, and the low-temperature steam is reused, thereby improving the energy utilization efficiency of the entire system, reducing energy consumption and operating costs. At the same time, the low-temperature steam in the second metal heat-conducting pipe can gently dry the material in the metal evaporation sleeve, further remove the residual moisture in the material, and avoid the material being heated again by the higher temperature steam after being quickly dried, resulting in overheating, over-drying or burning of the material, maintaining the temperature of the straw stable, avoiding local carbonization of the straw or changes in the material properties (such as cellulose degradation) due to excessively high heating temperature, so that the material is dried more evenly from the inside to the outside, and the drying quality is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the heat exchange part, the first delivery pipe, the cover body 1 and the cover body 2 of the present invention;

[0025] Figure 3 is a cross-sectional view of a drying component of the present invention;

[0026] Figure 4 It is a schematic structural diagram of a metal heat-conducting pipe 1, a metal heat-conducting pipe 2, a heat-conducting plate and a parallel heat-conducting part of the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the feed front end area, feed middle end area, feed rear end area and stirring variable flow part of the present invention;

[0028] Figure 6 For the present invention Figure 4 A magnified schematic diagram of the structure at B in the middle;

[0029] Figure 7 It is a schematic diagram of the structure of the exhaust pipe 2 and the flow dividing baffle of the present invention;

[0030] Figure 8 For the present invention Figure 2 A schematic diagram of the structure enlargement in the middle;

[0031] Fig. 9 It is a cross-sectional view of the spiral feeding part 1 and the spiral feeding part 2 of the present invention.

[0032] Description of the numbers in the figure:

[0033] 1. Support part; 2. Loader; 3. Screw conveyor; 4. Screw feeding part 1; 41. Conical shell; 42. Motor; 43. Feeding port; 44. Screw feeding paddle 1; 45. Material removal rod; 46. Discharging port; 5. Drying unit; 51. Drying assembly; 511. Hollow insulation casing; 512. Heat insulation seat; 513. Metal evaporation casing; 514. Metal heat conduction pipe 1; 515. Screw feeding paddle 2; 516. Exhaust pipe 1; 517. Feeding part; 518. Discharging part; 519. Insulation Thermal vacuum chamber; 52, driving part; 53, venturi mixing part; 54, heat exchange part; 541, exhaust pipe 2; 542, diverter baffle; 543, cover body 1; 544, cover body 2; 55, metal heat conduction pipe 2; 56, feed front end area; 57, feed middle end area; 58, feed rear end area; 59, stirring and changing part; 591, heat conduction plate; 592, parallel heat conduction part; 6, spiral feeding part 2; 7, feeding part; 8, first conveying pipe; 9, second conveying pipe; 10, metal heat conduction pipe 3. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0035] See also Figures 1 to 9 A micro-vacuum biomass steam drying device comprises a support portion 1, a drying unit 5 is connected to one side of the support portion 1, and the drying unit 5 comprises a drying component 51 fixedly connected to one side of the support portion 1, a driving portion 52 fixedly connected to one side of the drying component 51, a venturi mixing portion 53 located above the drying component 51 and used for mixing and improving the quality of steam, and a heat exchange portion 54 fixedly connected to one side of the support portion 1, and the diffusion end of the venturi mixing portion 53 is connected to the input end of the heat exchange portion 54;

[0036] The drying assembly 51 comprises a hollow heat-insulating casing 511 fixedly connected to one side of the support portion 1, two heat-insulating seats 512 respectively fixedly connected to the inner walls of the openings at both ends of the hollow heat-insulating casing 511, a metal evaporation casing 513 located inside the hollow heat-insulating casing 511 and fixedly connected to the two heat-insulating seats 512 at both ends, a second spiral feeding paddle 515 located inside the metal evaporation casing 513, a first metal heat-conducting pipe 514 fixedly connected to the outer surface of the metal evaporation casing 513, and a first exhaust pipe 516 connecting the inner cavity of the metal evaporation casing 513 with the throat of the venturi mixing section 53;

[0037] Both ends of the metal heat-conducting pipe 514 extend outward through the hollow heat-insulating casing 511 , and one end of the metal heat-conducting pipe 514 is connected to the feed end of the venturi mixing section 53 .

[0038] The two ends of the spiral feeding paddle 2 515 are rotatably connected to the two insulation seats 512 respectively, the output shaft of the driving part 52 passes through one of the insulation seats 512 and is fixedly connected to one end of the spiral feeding paddle 2 515, the other end of the metal heat conducting pipe 1 514 is connected to the gas supply equipment, and the gas supply equipment sends steam into the metal heat conducting pipe 1 514 and steam dries the material in the metal evaporation sleeve 513, the exhaust pipe 1 516 sends the water vapor generated when the material in the metal evaporation sleeve is dried into the venturi mixing part 53, and the water vapor is mixed with the steam exhausted from the metal heat conducting pipe 1 514 through the venturi mixing part 53 and sent to the heat exchange part 54 to recover the latent heat of the water vapor.

[0039] An insulating vacuum chamber 519 is formed between the hollow insulation casing 511 and the metal evaporation casing 513. A feed portion 517 and a discharge portion 518 are provided inside the metal evaporation casing 513 and the hollow insulation casing 511. The feed portion 517 of the metal evaporation casing 513 is connected to the feed portion 517 of the hollow insulation casing 511, and the discharge portion 518 of the metal evaporation casing 513 is connected to the discharge portion 518 of the hollow insulation casing 511.

[0040] It also includes a screw conveyor 3 fixedly connected to the upper end of the support part 1, a loader 2 connected to one side of the screw conveyor 3, a spiral feeding part 6 fixedly connected to the inside of the support part 1 and connected to the discharge part 518, and a feeding part 7 located at the lower end of the spiral feeding part 6, the spiral feeding part 1 4 is fixedly connected to one side of the support part 1 and the input end of the spiral feeding part is connected to the output end of the screw conveyor 3, and the input end of the spiral feeding part 6 is connected to the discharge part 518.

[0041] The spiral unloading part 1 4 and the spiral unloading part 2 6 both include a conical shell 41 with a cavity opened inside, a feed port 43 opened at the upper end of the conical shell 41 and connected to the cavity, a motor 42 fixed to the upper end of the conical shell 41, a spiral feeding paddle 1 44 rotatably connected to the inner wall of the cavity, a material removal rod 45 fixed to the lower end of the outer side of the spiral feeding paddle 1 44, and a discharge port 46 opened at the lower end of the conical shell 41 and connected to the cavity. The output shaft of the motor 42 passes through the conical shell 41 and is fixed to one end of the spiral feeding paddle 1 44.

[0042] By adopting the above technical solution, the crushed wet material is transported into the screw conveyor 3 (the screw conveyor is a machine that uses a motor to drive the screw to rotate and push the material to achieve the purpose of transportation. It is a mature existing technology and will not be described here) through the feeder 2 (belt feeder, which belongs to the mature existing technology and will not be described here), and the wet material discharged from the discharge end of the screw conveyor 3 enters the conical shell 41 of the spiral unloading part 4 from the feed port 43. The motor 42 drives the spiral feeding paddle 44 inside the conical shell 41 to rotate, which can make the conical shell 4 1 moves toward the discharge port 46 and is discharged from the discharge port 46. At the same time, the rotation of the screw feeding paddle 1 44 can also drive the material lever 45 to rotate, stirring the material above the discharge port 46 to improve the fluidity of the material. The material discharged from the discharge port 46 enters the metal evaporation casing 513 from the feeding portion 517. The driving portion 52 drives the screw feeding paddle 2 515 to rotate. The screw feeding paddle 2 515 rotates to transport the material in the metal evaporation casing 513, so that the material moves toward the discharge portion 518. The material discharged from the discharge portion 518 falls on the feeding portion 517. The feeding part 7 sends the dried material to the next process. During the material movement, the gas supply device sends high-pressure steam with certain parameters into the metal heat-conducting pipe 1 514. The heat of the metal heat-conducting pipe 1 514 is transferred to the metal evaporation sleeve 513. The metal evaporation sleeve 513 is in contact with the wet material driven by the spiral feeding paddle 2 515 to exchange heat, steam-dry the wet material, and take away most of the moisture in the wet material. The water vapor generated during the drying process of the wet material can Compared with being discharged from the exhaust pipe 516, since the steam discharged from the metal heat conducting pipe 514 can enter the feed end of the venturi mixing section 53, when the steam enters the throat from the feed end of the venturi mixing section 53, under the venturi effect, the steam passes through the throat at a faster speed, and at the same time, the low-pressure water vapor discharged from the exhaust pipe 516 is sucked into the venturi mixing section 53, and the high-pressure steam (estimated absolute pressure 3.92MPa) induces the low-pressure steam (estimated absolute pressure 0.06MPa) to mix and expand at the diffusion end of the venturi mixing section 53 to form low-pressure steam (estimated absolute pressure 0.06MPa).14MPa), providing a quality basis for its reuse, the mixed steam discharged from the diffusion end of the venturi mixing section 53 can enter the heat exchange section 54 (the heat exchange section 54 is a steam-water heat exchanger, which is a device that exchanges the heat in the steam of substance A to the water of substance B to increase the temperature of the water, thereby realizing energy conversion, and is a mature existing technology, which will not be repeated here). This part of the water heat obtained by heat exchange in the heat exchange section 54 is mainly used for low-temperature heat. For example, in the current urban centralized heating, whether it is central air conditioning, water heating, floor heating, etc., hot water is required as a heat source; by drying first and then recovering the drying energy for heating, low-cost heating in the field of biomass township heating can be achieved, solving the problem of high drying costs caused by high-moisture raw materials in the front end of biomass cogeneration, rural heating, biomass molded fuel production, and biomass torrefied fuel production. .

[0043] like Figure 3-Figure 6 As shown, a plurality of stirring and deflecting parts 59 are fixedly connected to the inner wall of the metal evaporation casing 513 , and a single stirring and deflecting part 59 is located between two adjacent spiral blades on the outer surface of the second spiral feeding paddle 515 .

[0044] A plurality of heat conducting plates 591 are fixedly connected to the outer surface of the metal evaporation sleeve 513, and the plurality of heat conducting plates 591 are connected via a parallel heat conducting portion 592. The outer surface of the metal heat conducting pipe 514 is in contact with the parallel heat conducting portion 592 and the heat conducting plates 591. One ends of the plurality of stirring and variable flow portions 59 extend outward through the metal evaporation sleeve 513 and are respectively fixedly connected to the plurality of heat conducting plates 591.

[0045] The multiple spiral blades on the outer surface of the spiral feeding paddle 2 515 are divided into a feed front end area 56, a feed middle end area 57 and a feed rear end area 58 according to the pitch between adjacent spiral blades. The pitch of adjacent spiral blades in the feed front end area 56 is greater than the pitch of adjacent spiral blades in the feed middle end and feed rear end areas 58, and the pitch of adjacent spiral blades in the feed middle end area 57 is greater than the pitch of adjacent spiral blades in the feed rear end area 58. The multiple stirring and flow changing parts 59 are evenly arranged in the feed front end area 56 and the feed middle end area 57.

[0046] By adopting the above technical solution, when the spiral feeding paddle 2 515 rotates, the multiple spiral blades on the outer surface of the spiral feeding paddle 2 515 drive the wet material to move and transport the wet material, and the material between the multiple spiral blades will collide and rub with the multiple protruding stirring and deflecting parts 59, thereby changing the flow direction of the wet material, so that the material close to the center of the spiral feeding paddle 2 515 is stirred to the outside of the spiral feeding paddle 2 515, increasing the contact with the inner wall of the metal evaporation sleeve 513, and realizing uniform heating and drying of the wet material, and the heat of the metal heat conduction pipe 1 514 is transferred to the stirring and deflecting part 59 through the heat conduction plate 591 and the parallel heat conduction part 592, and the material in the stirring and deflecting part 59 is heated and dried. During the stirring process of the wet material, the inside of the wet material is directly heated so that the moisture inside the wet material can evaporate, thereby improving the drying efficiency of the material and the evaporation efficiency of the water vapor; at the same time, by setting the front end area 56, the middle end area 57 and the rear end area 58 of the feed, the pitch of the multiple spiral blades on the outer surface of the spiral feeding paddle 2 515 can be gradually reduced from the feed end to the discharge end, so that during the feeding process, the material advances relatively fast in the front end area 56 (where the pitch is large), while the speed in the rear end area 58 (where the pitch is small) is slowed down, so that the material in the center is continuously squeezed outward, thereby increasing the contact opportunity with the outer wall, which is beneficial to heat exchange.

[0047] like Figure 2 , Figure 4 , Figure 7 , Figure 8 As shown, the output end of the heat exchange part 54 is fixedly connected to an exhaust pipe 541, and the inner wall of the exhaust pipe 541 is fixedly connected to a diverter baffle 542 for separating the steam discharged from the output end of the heat exchange part 54 from the non-condensable gas in the steam, the other end of the exhaust pipe 541 is fixedly connected to a cover body 544, and the output port of the cover body 544 is fixedly connected to a second conveying pipe 9, and a metal heat-conducting pipe 55 is also fixedly connected to the outer wall of the metal evaporation sleeve 513, and both ends of the metal heat-conducting pipe 55 extend outward through the hollow insulation sleeve 511, and one of the extended ends of the metal heat-conducting pipe 55 is connected to the second conveying pipe 9.

[0048] By adopting the above technical solution, since the density of non-condensable gas (air) is generally less than that of steam, inside the heat exchange part 54, the non-condensable gas tends to move upward and gather at the top. When the non-condensable gas is discharged from the heat exchange part 54 at the same time as the steam and enters the exhaust pipe 541, the diverter baffle 542 can separate the non-condensable gas from the steam, and the non-condensable gas (which may be mixed with some steam) is discharged from the area above the diverter baffle 542, and the steam is discharged from the bottom of the diverter baffle 542, thereby realizing the release of the non-condensable gas. In the present application, the low-temperature steam discharged from the exhaust pipe 541 enters the cover body 544, and enters the second conveying pipe 9 (which must be a thermal insulation material to avoid heat loss during steam transportation) from the cover body 544, and enters the metal heat conducting pipe 55 from the second conveying pipe 9. The low-temperature steam in the metal heat conducting pipe 55 can dry the material in the area near the discharge part 518 of the metal evaporation sleeve 513 at low temperature, thereby realizing the self-circulation of the low-temperature steam. The low-temperature steam discharged from the second pipe 541 is used for its own evaporation heat or for industrial steam to form power; in the present application, two metal heat-conducting pipes are provided, wherein the steam in the metal heat-conducting pipe 1 514 is used to quickly dry the wet material in the metal evaporation sleeve 513, so that the moisture in the straw evaporates quickly, and the low-temperature steam discharged from the metal heat-conducting pipe 1 514 enters the metal heat-conducting pipe 2 55 after heat exchange in the heat exchange part 54, and the low-temperature steam is reused, thereby improving the energy utilization efficiency of the entire system, reducing energy consumption and operating costs, and the low-temperature steam in the metal heat-conducting pipe 2 55 can gently dry the material in the metal evaporation sleeve 513, further remove residual moisture in the material, avoid the material that has been quickly dried from being heated again by the higher temperature steam, resulting in overheating, over-drying or burning of the material, maintain the temperature of the straw stable, avoid local carbonization of the straw or change of material properties (such as cellulose degradation) due to excessively high heating temperature, make the material dry more evenly from the inside to the outside, and improve the drying quality.

[0049] like Figure 1 , Figure 2 and Figure 8 As shown, the other end of the exhaust pipe 541 is also fixedly connected to a cover body 543, and the output port of the cover body 543 is fixedly connected to a first conveying pipe 8, and the other end of the first conveying pipe 8 is fixedly connected to a metal heat-conducting pipe 3 10, and the metal heat-conducting pipe 3 10 is spirally fixed to the outer surface of the spiral feeding part 4.

[0050] By adopting the above technical scheme, the non-condensable gas (which may be mixed with some steam) discharged from the area above the diverter baffle 542 enters the cover body 543, enters the first conveying pipe 8 (which must be made of thermal insulation material to avoid heat loss during steam conveying) from the cover body 543, and enters the metal heat-conducting pipe 3 10 from the first conveying pipe 8. The heat of the non-condensable gas in the metal heat-conducting pipe 3 10 is transferred to the conical shell 41 of the spiral feeding part 4 through the metal heat-conducting pipe 3 10. The heat of the non-condensable gas is used to preheat the wet material inside the conical shell 41, which can increase the temperature of the raw material and accelerate the migration of moisture from the inside of the straw to the surface. When rapid drying is performed subsequently, moisture is more easily evaporated from the surface, thereby increasing the overall drying speed. Due to the preheating, the initial temperature of the straw is increased, the temperature difference with the drying medium (such as hot air, etc.) is increased, and the heat transfer driving force is enhanced. Under the same drying conditions, the drying target can be achieved more quickly, the residence time in the drying equipment is reduced, and the production capacity of the drying equipment is improved.

[0051] Method of use: The wet material after crushing is conveyed into the screw conveyor 3 through the feeder 2, and the wet material discharged from the discharge end of the screw conveyor 3 enters the screw feeder 4, and the material discharged from the screw feeder 4 enters the metal evaporation casing 513 from the feeder 517, and the driving part 52 drives the screw feeder paddle 2 515 to rotate, and the screw feeder paddle 2 515 rotates to convey the material in the metal evaporation casing 513, and the gas supply equipment sends high-pressure steam with certain parameters into the metal heat conduction pipe 514, and the metal heat conduction pipe 514 is The heat of 14 is transferred to the metal evaporation sleeve 513, and the metal evaporation sleeve 513 is in contact with the wet material driven by the spiral feeding paddle 2 515 to rotate and move, and the wet material is steam-dried. The water vapor generated during the drying of the wet material can be discharged from the exhaust pipe 1 516, and the steam discharged from the metal heat conducting pipe 1 514 can enter the feed end of the venturi mixing section 53. When the steam enters the throat from the feed end of the venturi mixing section 53, the low-pressure water vapor discharged from the exhaust pipe 1 516 is sucked into the venturi mixing section. 53, the mixed steam discharged from the diffusion end of the venturi mixing section 53 can enter the heat exchange section 54, and the water heat obtained by heat exchange in the heat exchange section 54 is used for low-temperature heat. In the heat exchange section 54, the non-condensable gas tends to move upward and gather at the top. When the non-condensable gas is discharged from the heat exchange section 54 together with the steam and enters the exhaust pipe 2 541, the diverter baffle 542 can separate the non-condensable gas from the steam, and the non-condensable gas (which may be mixed with some steam) is discharged from the area above the diverter baffle 542 into the cover 2 544 The non-condensable gas discharged from the area above the diverter baffle 542 enters the cover body 1 543, enters the first conveying pipe 8 from the cover body 1 543, and enters the metal heat-conducting pipe 3 10 from the first conveying pipe 8, and the heat of the non-condensable gas is used to preheat the wet material inside the conical shell 41.

[0052] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A micro-vacuum biomass steam drying device, comprising a support portion (1), characterized in that: A drying unit (5) is connected to one side of the support portion (1), and the drying unit (5) comprises a drying component (51) fixedly connected to one side of the support portion (1), a driving component (52) fixedly connected to one side of the drying component (51), a venturi mixing component (53) located above the drying component (51) and used for mixing and improving the quality of steam, and a heat exchange component (54) fixedly connected to one side of the support portion (1), wherein a diffusion end of the venturi mixing component (53) is connected to an input end of the heat exchange component (54); The drying component (51) comprises a hollow heat-insulating casing (511) fixedly connected to one side of the support portion (1), two heat-insulating seats (512) respectively fixedly connected to the inner walls of the openings at both ends of the hollow heat-insulating casing (511), a metal evaporating casing (513) located inside the hollow heat-insulating casing (511) and respectively fixedly connected to the two heat-insulating seats (512) at both ends, two spiral feeding paddles (515) located inside the metal evaporating casing (513), a metal heat-conducting pipe (514) fixedly connected to the outer surface of the metal evaporating casing (513), and a steam exhaust pipe (516) connecting the inner cavity of the metal evaporating casing (513) with the throat of the venturi mixing section (53); Both ends of the first metal heat-conducting pipe (514) extend outward through the hollow heat-insulating casing (511), and one end of the metal heat-conducting pipe is connected to the feed end of the Venturi mixing section (53); The two ends of the second screw feeding paddle (515) are rotatably connected to the two heat insulation seats (512), respectively; the output shaft of the driving unit (52) passes through one of the heat insulation seats (512) and is fixedly connected to one end of the second screw feeding paddle (515); the other end of the first metal heat conducting pipe (514) is connected to an air supply device, and the air supply device sends steam into the first metal heat conducting pipe (514) and steam dries the material in the metal evaporation sleeve (513); the first exhaust pipe (516) sends the water vapor generated when the material in the metal evaporation sleeve is dried into the venturi mixing unit (53); the water vapor is mixed with the steam discharged from the first metal heat conducting pipe (514) through the venturi mixing unit (53) and then sent to the heat exchange unit (54) to recover the latent heat of the water vapor; The output end of the heat exchange part (54) is fixedly connected to a second exhaust pipe (541), and the inner wall of the second exhaust pipe (541) is fixedly connected to a flow dividing baffle (542) for separating the steam discharged from the output end of the heat exchange part (54) from the non-condensable gas in the steam; the other end of the second exhaust pipe (541) is fixedly connected to a second cover body (544), and the output port of the second cover body (544) is fixedly connected to a second conveying pipe (9); the outer wall of the metal evaporation casing (513) is also fixedly connected to a second metal heat conducting pipe (55), and both ends of the second metal heat conducting pipe (55) extend outward through the hollow heat insulating casing (511), and one of the extended ends of the second metal heat conducting pipe (55) is connected to the second conveying pipe (9); The other end of the exhaust pipe 2 (541) is also fixedly connected to the cover body 1 (543), and the output port of the cover body 1 (543) is fixedly connected to the first conveying pipe (8), and the other end of the first conveying pipe (8) is fixedly connected to the metal heat conducting pipe 3 (10), and the metal heat conducting pipe 3 (10) is spirally fixed to the outer surface of the spiral feed portion 1 (4).

2. A micro-vacuum biomass steam drying device according to claim 1, characterized in that: A heat-insulating vacuum chamber (519) is formed between the hollow heat-insulating casing (511) and the metal evaporating casing (513); a feeding portion (517) and a discharging portion (518) are provided inside the metal evaporating casing (513) and the hollow heat-insulating casing (511); the feeding portion (517) of the metal evaporating casing (513) is connected to the feeding portion (517) of the hollow heat-insulating casing (511); and the discharging portion (518) of the metal evaporating casing (513) is connected to the discharging portion (518) of the hollow heat-insulating casing (511).

3. A micro-vacuum biomass steam drying device according to claim 2, characterized in that: A plurality of stirring and flow-changing parts (59) are fixedly connected to the inner wall of the metal evaporation sleeve (513), and a single stirring and flow-changing part (59) is located between two adjacent spiral blades on the outer surface of the second spiral feeding paddle (515).

4. The micro-vacuum biomass steam drying device according to claim 3, characterized in that: A plurality of heat conducting plates (591) are fixedly connected to the outer surface of the metal evaporation sleeve (513), and the plurality of heat conducting plates (591) are connected via a parallel heat conducting portion (592); the outer surface of the metal heat conducting pipe 1 (514) is in contact with the parallel heat conducting portion (592) and the heat conducting plates (591); and one end of the plurality of stirring and flow changing portions (59) penetrates the metal evaporation sleeve (513), extends outward, and is respectively fixedly connected to the plurality of heat conducting plates (591).

5. The micro-vacuum biomass steam drying device according to claim 4, characterized in that: The plurality of spiral blades on the outer surface of the second spiral feeding paddle (515) are divided into a feed front end region (56), a feed middle end region (57) and a feed rear end region (58) according to the pitch between adjacent spiral blades, the pitch of adjacent spiral blades in the feed front end region (56) is greater than the pitch of adjacent spiral blades in the feed middle end region and the feed rear end region (58), and the pitch of adjacent spiral blades in the feed middle end region (57) is greater than the pitch of adjacent spiral blades in the feed rear end region (58), and the plurality of stirring flow change parts (59) are evenly arranged in the feed front end region (56) and the feed middle end region (57).

6. The micro-vacuum biomass steam drying device according to claim 5, characterized in that: It also includes a screw conveyor (3) fixedly connected to the upper end of the support part (1), a loading machine (2) connected to one side of the screw conveyor (3), a second screw feeding part (6) fixedly connected to the inside of the support part (1) and connected to the discharge part (518), and a feeding part (7) located at the lower end of the second screw feeding part (6), wherein the first screw feeding part (4) is fixedly connected to one side of the support part (1) and the input end of the screw feeding part is connected to the output end of the screw conveyor (3), and the input end of the second screw feeding part (6) is connected to the discharge part (518).

7. The micro-vacuum biomass steam drying device according to claim 6, characterized in that: The spiral unloading part 1 (4) and the spiral unloading part 2 (6) both comprise a conical shell (41) with a cavity formed therein, a feed port (43) formed at the upper end of the conical shell (41) and connected to the cavity, a motor (42) fixedly connected to the upper end of the conical shell (41), a spiral feed paddle 1 (44) rotatably connected to the inner wall of the cavity, a material removal rod (45) fixedly connected to the lower end of the outer portion of the spiral feed paddle 1 (44), and a discharge port (46) formed at the lower end of the conical shell (41) and connected to the cavity. The output shaft of the motor (42) passes through the conical shell (41) and is fixedly connected to one end of the spiral feed paddle 1 (44).

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