Tunnel type continuous drying furnace with vacuum cavity microwaves and drying process of tunnel type continuous drying furnace

Abstract

The invention belongs to the technical field of glass fiber production equipment, and particularly relates to a tunnel type continuous drying furnace with vacuum cavity microwaves and a drying process of the tunnel type continuous drying furnace. The tunnel type continuous drying furnace with the vacuum cavity microwaves comprises a heating vaporization area. A microwave preheating area and a microwave drying area are technologically connected before and after the heating vaporization area; the heating vaporization area is used for mildly drying the moisture at the superficial part of the yarn roll so that the microwave drying area does not generate the rising of the yarn roll, and the microwave drying area is used for efficiently drying the blocked moisture in the yarn roll through vacuum microwaves. According to the combined drying process of vacuum microwave preheating, hot air circulation heating vaporization, vacuum microwave drying and hot air circulation heat preservation curing film forming, suitable drying modes and circulation modes can be configured in different drying stages according to the physical and chemical change rule of the glass fiber yarn in the drying process; the drying process can be optimized, and the quality of finished yarn balls is improved; the drying time is shortened, and the equipment power consumption is reduced; meanwhile, the space occupancy rate of equipment can be reduced, and the basic investment cost is saved.

Description

Technical Field

[0001] The present application belongs to the technical field of glass fiber production equipment, and specifically relates to a tunnel-type continuous drying furnace with vacuum cavity microwaves and a drying process thereof. Background Art

[0002] At present, the global energy crisis is intensifying. Glass fiber production cannot avoid consuming a large amount of energy to melt the kiln materials at high temperatures. Maximizing energy conservation is a difficult problem that glass fiber manufacturers have been working hard to overcome.

[0003] Drying is one of the important processes in the production of glass fiber yarn, which directly affects the internal material quality and technical performance of the finished glass fiber yarn.

[0004] At present, the heat sources provided to the drying furnace include waste hot air, natural gas heat exchange and microwave assisted heating and drying to replace the original steam heat exchanger. The waste hot air or heated hot air circulates inside the furnace cavity to heat and evaporate the moisture of the yarn balls. Usually, the moisture content of the yarn balls is about 11% to 14%. The dehumidification fan is required to continuously exhaust the humid hot air in the cavity to the outside of the furnace and then replenish natural air for replacement balance, so as to achieve the purpose of drying the yarn balls. The hot air circulation fan is a volute fan designed for steam heat exchangers with large wind resistance, and it continues to be used with low efficiency.

[0005] First, although under a certain circulation fan structure and power, the air volume and pressure are inversely proportional, and the current drying furnace structure requires a certain hot air pressure, otherwise the hot air cannot complete the circulation; but even if the wind pressure is very high and the air volume is small, the volute fan will still have a certain amount of ineffective work and waste energy. The patent "Heat-resistant and Moisture-resistant Axial Flow Fan for Drying Furnace" with application number CN201921943694.7 and announcement number: CN 210949195 U has initially solved this problem in actual application, but it is only temporarily applied to the preheating area in front of the drying furnace.

[0006] Secondly, in addition to heating the yarn balls, the heat source also needs to make up for the heat emitted by the furnace body due to radiation. The smaller the size of the furnace body, the greater the energy saving. The existing tunnel furnace adopts a double-layer air duct structure on the top and is equipped with left and right circulation air ducts in different sections of the tunnel furnace. This is not conducive to reducing energy consumption and improving energy utilization efficiency.

[0007] Third, at the current stage, whether it is high-temperature waste heat wind, steam heat exchange or natural gas heat exchange as the heat source, the yarn ball is still at room temperature before entering the drying furnace. After entering the drying furnace, it will absorb heat to a large extent to reduce the temperature in the furnace, so that the first zone needs high-power heating to supplement energy to quickly heat up, and the surface of the yarn ball is easily filmed by high-temperature radiation, which hinders the evaporation of water, and the heat radiation inside the yarn ball is difficult, the heat absorption is slow, and the heating time is long, that is, the entire drying process is lengthened, which means energy consumption; the patent "Drying Furnace Inlet Preheating Structure" with application number CN201720597965.2 and announcement number: CN206891125U provides a solution, at the inlet of the drying furnace, there is a non-consumption preheating zone, which utilizes the energy in the high-temperature water vapor discharged from the drying furnace, and the yarn ball that is about to enter the drying furnace is first preheated to about 40 to 50 degrees by radiation to recover heat energy. However, this method will have the problem of condensation in periods or areas with low temperature and high humidity.

[0008] Fourth, in order to fully utilize the efficiency of microwave-assisted heating, the existing drying furnaces with microwave assisted heating have more microwaves arranged in more areas, resulting in higher microwave power. Usually, the total microwave power is around 70-80kw, and microwave leakage is difficult to control, with low efficiency and high basic cost. The general reason is that the high linear density and thickness of the yarn balls affect the evaporation of water molecules inside. In the heat preservation and simmering stage, the closer to the drying zone, the more time it takes to dehumidify, and the new air is constantly added to replace the humid hot air, so all power consumption has to be amplified to achieve the purpose of drying.

[0009] That is to say, the yarn balls have been dried during the heat preservation and simmering stage, so there is no need for a high-power, high-pressure, and high-air-volume fan, nor is there a need for dehumidification to replenish new air and replace the hot and humid air. However, the existing drying furnaces, due to the structure of the furnace body, uniformly use a large number of high-power, high-pressure, and high-air-volume fans and dehumidification in the simmering section, which cannot save energy and reduce consumption. Summary of the invention

[0010] In view of this, the present application provides a tunnel-type continuous drying furnace with vacuum cavity microwave and a drying process thereof to solve all or part of the technical problems described in the background technology section of the present application.

[0011] The innovative ideas of this application are: 1. A lifting vacuum cavity microwave cover is arranged outside the entrance door of the drying furnace, and it is synchronously lifted and lowered together with the drying furnace door. When it descends, it can cover the first row of yarn carts in front of the door, and draw a micro-vacuum microwave to open or open in the middle. The moisture in the yarn ball evaporates faster due to the vacuum and microwave heating, which will cause the yarn ball to swell and the impregnant to be moved. The microwave is intermittently operated to control the vaporization speed, ensuring that the first row of yarn carts entering the drying furnace is in a high-temperature evaporation state, so that there is no 100-120 minutes of heating process in the furnace, and the yarn cart moves inward from the entrance of the furnace according to the beat to the position where the moisture in the yarn ball is completely vaporized or does not cause the yarn ball to swell and the impregnant to be moved. At this position, a second lifting vacuum cavity microwave cover is arranged, which will continuously and maximally vacuum and microwave to vaporize the moisture inside the yarn ball, so as to maximize the vacuum and microwave efficiency and achieve the purpose of rapid drying. The drying furnace body between the two vacuum cavity microwave covers will also be significantly shortened, and the hot air circulation of the furnace body adopts the axial flow fan disclosed in the patent [Announcement No.: CN 210949195 U] to ensure a certain hot air pressure and increase the number of hot air circulations, and then increase the positive and reverse direction circulation drying control of the hot air, so that the wind-receiving surface of the yarn ball is evenly rotated, which not only improves the drying quality but also reduces the power of the circulation fan.

[0012] 2. Since the second lifting vacuum chamber microwave cover is located at the rear where the yarn balls are prone to fall and the impregnating agent is prone to be pulled, the vacuum combined with the microwave can play a stronger and more penetrating role in completely vaporizing the moisture in the yarn balls and shortening the drying time. The dried yarn balls enter the 6-hour film-forming and curing zone. The moisture content of the yarn balls in the film-forming and curing zone has reached the standard, and the energy consumed is only required for heat preservation. Therefore, the horizontal multiple volute fan hot air circulation in the film-forming and curing zone is converted into the longitudinal front and rear two axial flow fan hot air circulation, which makes the width of the air ducts on both sides of the furnace body smaller, and the height of a return air duct on the upper part of the furnace body is lowered, which is more compact and energy-saving.

[0013] In short: this tunnel-type continuous drying furnace can reduce the total number of fans by 1 / 4, that is, the total fan power is reduced by 1 / 4, and the total microwave power is only 1 / 4 of the original, through the reasonable layout of two sets of vacuum and microwave control for drying with different processes, the smooth air duct circulation design of the front and rear furnace bodies, the compact and smaller rear furnace body without side air ducts and the design of no exhaust of moist hot air, and the conversion of the volute fan to a large-volume axial flow fan and other innovations. Under the premise of ensuring the quality of yarn ball film formation and curing, the drying capacity is increased by 1 / 6, that is, through the reduction of the total power of the fan and microwave and the improvement of the drying capacity, the tunnel-type continuous drying furnace can achieve greater energy saving and consumption reduction.

[0014] The solutions provided by this application to solve its technical problems are: A tunnel-type continuous drying furnace with vacuum cavity microwaves, comprising a tunnel-type continuous drying furnace body; the tunnel-type continuous drying furnace body comprises a temperature-raising vaporization zone; A microwave preheating zone is arranged before the temperature-raising vaporization zone, and a microwave drying zone is arranged after the temperature-raising vaporization zone; The microwave preheating zone and the microwave drying zone both include a vacuum cavity microwave cover; The temperature-raising vaporization zone also includes an entrance furnace door frame, a conjoined furnace door, and a conjoined lifting mechanism; the conjoined furnace door is arranged on the entrance furnace door frame and is fixedly connected to the vacuum cavity microwave cover of the microwave preheating zone; The vacuum cavity microwave cover and the one-piece furnace door in the microwave preheating zone share a one-piece lifting mechanism; The vacuum cavity microwave cover and the one-piece furnace door in the microwave preheating area can be raised and lowered synchronously under the action of the one-piece lifting mechanism; The microwave drying area also includes a drying area lifting mechanism, and the vacuum cavity microwave cover of the microwave drying area can move up and down under the action of the drying area lifting mechanism; The vacuum cavity microwave cover comprises a vacuum microwave cover body, a vacuum generator, a microwave generator and a waveguide; The vacuum generator and the microwave generator are both arranged on the vacuum microwave enclosure, and the waveguide is arranged in the vacuum microwave enclosure and connected to the microwave generator.

[0015] The heated vaporization zone is used to gently dry the moisture on the surface of the yarn so that the yarn will not swell in the microwave drying zone. The microwave drying zone is used to efficiently dry the blocked moisture inside the yarn by vacuum microwaves.

[0016] For glass fiber yarn products that do not require curing to form a film, the three-stage configuration of "microwave preheating zone + heating vaporization zone + microwave drying zone" is used for drying, which can greatly reduce the length of the tunnel furnace, shorten the drying time, and reduce energy consumption.

[0017] Preferably, for glass fiber yarn products that need to be cured and film-formed, the main body of the tunnel-type continuous drying furnace also includes a curing and film-forming zone; and the microwave drying zone is arranged between the temperature rising vaporization zone and the curing and film-forming zone.

[0018] Preferably, a connecting tunnel is provided between the temperature rising gasification zone and the solidification film forming zone, and a microwave cover lifting port is provided on the top of the connecting tunnel; the vacuum cavity microwave cover of the microwave drying zone is arranged in the microwave cover lifting port and is sealed and connected to the connecting tunnel.

[0019] The microwave preheating zone, heating vaporization zone, microwave drying zone and solidification film-forming zone can form a continuous yarn ball drying process. For every row of yarn carts entering the microwave preheating zone, a row of yarn carts that have completed drying and film-forming will drive out of the solidification film-forming zone. According to actual needs, it can be set to single-in and single-out, double-in and double-out, etc. The production rhythm or intermittent cycle is the time to complete one microwave preheating or microwave drying.

[0020] The moisture contained in the yarn ball evaporates easily at the surface, while the moisture inside the yarn ball will be hindered and evaporate more slowly. If the traditional glass fiber yarn hot air plus microwave drying method is used for drying, although it is faster than without microwave, it still takes a long time, consumes more power, and has a low output; and it is easy to cause the yarn ball to swell and the moisture to bubble from the inside of the yarn ball to the surface under the action of microwaves, causing a large amount of wetting agent to migrate outward. The existing hot air plus microwave drying requires a large number of microwave installation points, has poor efficiency, and has a high basic cost; and it is easy to cause the yarn ball to swell and the wetting agent to migrate in large quantities. The present application proposes a combined drying process of hot air plus vacuum microwaves based on the changing rules of different stages in the drying process of glass fiber yarn, which is not only conducive to shortening the drying time and reducing the power consumption of drying, but also can improve the quality of the finished yarn by optimizing the drying process.

[0021] Among them: the microwave preheating zone mainly uses intermittent vacuum and microwave preheating to raise the temperature to the highest temperature that the yarn can withstand (the temperature is as high as possible but the yarn will not swell), shortening the heating time of the yarn in the heating and vaporization zone; The heating vaporization zone is mainly used to promote the gentle evaporation of moisture inside the yarn through hot air circulation, while removing part of the moisture to ensure that the yarn will not swell and the wetting agent will not migrate in large quantities during the high-efficiency drying process in the vacuum microwave drying zone; The microwave drying area is mainly used to efficiently evaporate the water in the yarn that is not easy to remove through the technical measures of vacuuming and microwave drying. Since the yarn has been preliminarily dehydrated in the heated vaporization area, the phenomenon of cascading and large-scale migration of the impregnating agent will not occur. The curing and film-forming area is mainly used to heat and solidify the yarn balls whose moisture content has reached the standard.

[0022] Preferably, the vacuum cavity microwave cover further comprises a sealing strip; the sealing strip is used to form a sealed connection between the bottom of the vacuum microwave cover and the contact position between the infrastructure, such as the ground of the microwave preset area.

[0023] Preferably, the integrated lifting mechanism of the temperature-raising vaporization zone includes a plurality of lifting power cylinders, which are connected to the vacuum cavity microwave cover of the microwave preheating zone by transmission. The lifting power cylinders can be oil cylinders, gas cylinders or electric cylinders.

[0024] The vacuum cavity microwave cover of the microwave preheating zone and the integrated furnace door of the temperature-raising vaporization zone can perform synchronous lifting and lowering movements under the action of the lifting power cylinder.

[0025] Preferably, the integrated lifting mechanism of the temperature-raising vaporization zone may also include a lifting motor, a cover counterweight, a lifting sprocket, and a transmission chain; the transmission chain is arranged on the lifting sprocket and its two ends are respectively connected to the cover counterweight and the vacuum cavity microwave cover, and the lifting motor is connected to the lifting sprocket. The lifting motor can drive the vacuum cavity microwave cover to perform lifting motion through the lifting sprocket.

[0026] The vacuum cavity microwave cover in the microwave preheating zone and the integrated furnace door in the heating vaporization zone can be synchronously lifted and lowered under the drive of the lifting motor; the cover counterweight can reduce the load of the lifting motor through its own gravity, thereby reducing system power consumption.

[0027] As a preference, the drying zone lifting mechanism of the microwave drying zone can be the same as the integrated lifting mechanism, that is, it can also be a lifting power cylinder or a lifting mechanism composed of a lifting motor, a cover counterweight, a lifting sprocket, and a transmission chain.

[0028] The drying zone lifting mechanism can drive the vacuum cavity microwave cover of the microwave drying zone to move up and down.

[0029] Preferably, the temperature-raising vaporization zone includes a furnace frame and an insulation layer; the insulation layer is sealed and arranged outside the furnace frame; a product drying tunnel is arranged inside the furnace frame; left and right circulation air ducts are arranged on the left and right sides of the product drying tunnel; a top transverse channel is arranged on the top of the product drying tunnel; the left and right circulation air ducts are interconnected and circulated with the top transverse channel; wherein the top transverse channel is a single-layer structure. Further preferably, left and right axial flow fans are arranged in the middle of the top transverse channel for promoting left and right circulation of hot air.

[0030] Existing tunnel drying furnaces for glass fiber yarns are generally double-layer structures and are equipped with several volute fans, which occupy a large space and have low hot air circulation efficiency. The present application adopts a top transverse channel of a hot air circulation axial flow fan with a single-layer structure. The low wind resistance channel can increase the circulating air by 20%, and the hot air circulation efficiency is significantly improved while the fan power is also reduced. In addition, the hot air circulation direction of the temperature rise vaporization zone can be adjusted by adjusting the forward and reverse rotation of the left and right axial flow fans. For example, when the fan rotates forward, the hot air circulates from left to right, and when the fan rotates reversely, the hot air circulates from right to left; the technical effect of hot air drying the yarn balls from the left and right sides of the yarn car is achieved.

[0031] Preferably, the curing and film-forming area includes a furnace frame and an insulation layer; the insulation layer is sealed and arranged on the outside of the furnace frame; a product curing tunnel is arranged in the furnace frame; a top longitudinal channel is arranged on the top of the product curing tunnel; circulating air duct openings connected to the top longitudinal channel are arranged in front and behind the product curing tunnel; further preferably, the top longitudinal channel is a single-layer structure and is interconnected with the product curing tunnel for front and back longitudinal circulation.

[0032] Preferably, the curing film forming area further comprises front and rear axial flow fans, which are arranged in the top longitudinal channel of the curing film forming area. Further preferably, the number of the front and rear axial flow fans can be one or two.

[0033] Preferably, the furnace frames of the heating vaporization zone and the curing film forming zone include a left wall panel, a right wall panel and a top frame; the top frame is arranged on the left wall panel and the right wall panel and defines a product drying tunnel or a product curing tunnel between the left wall panel and the right wall panel, and the top horizontal channel or the top longitudinal channel is arranged in the top frame.

[0034] Preferably, the tunnel-type continuous drying furnace with vacuum cavity microwave also includes a yarn car track; the yarn car track extends through the microwave preheating zone, the temperature rising vaporization zone, the microwave drying zone, and the curing film forming zone.

[0035] Preferably, the tunnel-type continuous drying furnace with vacuum cavity microwave also includes an exit furnace door frame, an exit lifting furnace door, and an exit furnace door lifting device; the exit furnace door frame is arranged at the tunnel exit of the curing film forming area, and the exit lifting furnace door can be lifted and lowered on the exit furnace door frame and can rise to open the tunnel exit or fall to seal the tunnel exit under the action of the exit furnace door lifting device.

[0036] Description of implementation principle and technical effect: Before the yarn car enters the heating and vaporization zone, the vacuum cavity microwave hood in the microwave preheating zone preheats the yarn ball; after the preheating is completed, the vacuum cavity microwave hood and the integrated furnace door move upward synchronously to open the furnace door; the yarn car enters the heating and vaporization zone along the yarn car track for heating and vaporization; after the yarn car gently evaporates and removes an appropriate amount of moisture in the heating and vaporization zone, it is transported forward to the microwave drying zone, and the vacuum cavity microwave hood in the microwave drying zone vacuumizes the yarn ball for ultra-strong microwave drying; after microwave drying, the moisture content of the yarn ball has reached the standard and then enters the curing and film-forming zone for heat preservation and curing and film-forming; after the curing and film-forming is completed, the yarn car drives out of the tunnel furnace.

[0037] Among them: when the yarn car completes preheating in the microwave preheating zone and is about to enter the heating vaporization zone, the vacuum cavity microwave cover, the integrated furnace door and the exit lifting furnace door of the microwave preheating zone and the microwave drying zone rise at the same time; while the preheated yarn car enters the heating vaporization zone through the entrance furnace door frame, the yarn car that has completed vacuum microwave high-efficiency drying in the microwave drying zone enters the curing film forming zone; at the same time, the yarn car that has been cured and film-formed at the end of the curing film forming zone passes through the exit furnace door frame to leave the tunnel; then the vacuum cavity microwave cover, the integrated furnace door and the exit lifting furnace door of the microwave preheating zone and the microwave drying zone descend at the same time, the vacuum cavity microwave cover of the microwave preheating zone preheats the yarn car that comes to the preheating zone, and the vacuum cavity microwave cover of the microwave drying zone performs vacuum microwave drying on the yarn car that comes to the microwave drying zone; such a cycle realizes continuous production.

[0038] The drying process corresponding to the aforementioned tunnel-type continuous drying furnace with vacuum cavity microwave includes the following process steps: Preheating steps: the vacuum cavity microwave cover and the one-piece furnace door of the microwave preheating zone are lowered together by the one-piece lifting device, the vacuum cavity microwave cover covers the yarn car entering the microwave preheating zone, and the one-piece furnace door seals the entrance furnace door of the heating vaporization zone; the vacuum generator and microwave generator of the microwave preheating zone are started successively or simultaneously; the microwave generator adopts intermittent operation to control the yarn ball swell and the migration of the impregnating agent; Heating and vaporizing step: the vacuum cavity microwave cover and the one-piece furnace door in the microwave preheating zone rise together under the action of the one-piece lifting device, and the preheated yarn carriage enters the heating and vaporizing zone; at the same time, the vacuum cavity microwave cover and the one-piece furnace door descend to close the entrance of the heating and vaporizing zone, and the next row of yarn carriages enter the preheating step; the heating and vaporizing zone is used to dry the moisture on the surface of the yarn ball so that the yarn ball will not swell in the microwave drying zone; Microwave drying steps: the vacuum cavity microwave cover of the microwave drying area rises under the action of the drying area lifting mechanism, and the yarn car that has completed the temperature rise and vaporization step enters the microwave drying area; then the vacuum cavity microwave cover descends to cover the yarn car that enters the microwave drying area; the vacuum cavity microwave cover of the microwave drying area continuously evacuates and adds microwaves to dry the yarn; the microwave drying area is used to dry the moisture blocked inside the yarn; Curing and film-forming step: the vacuum cavity microwave cover of the microwave drying zone rises under the action of the drying zone lifting mechanism, and the yarn carriage that has completed the microwave drying step enters the curing and film-forming zone; the furnace body of the curing and film-forming zone only includes the product curing tunnel and the top longitudinal channel, and the top longitudinal channel is a single-layer structure, and front and rear axial flow fans are used to promote the front and rear circulation of hot air to complete the curing and film-forming of the glass fiber yarn group; Finished yarn out of the oven step: the outlet oven door lifting device drives the outlet oven door to open the outlet oven door of the curing film forming area, and the yarn carriage that has completed the curing film forming step drives out of the curing film forming area; Among them: the vacuum cavity microwave cover in the microwave preheating zone, the one-piece furnace door, the vacuum cavity microwave cover in the microwave drying zone, and the exit lifting furnace door are raised and lowered synchronously to realize continuous operation.

[0039] Beneficial technical effects: 1. The combined drying process of "vacuum microwave preheating + hot air circulation heating vaporization + vacuum microwave drying + hot air circulation insulation curing film formation" proposed in this application can configure appropriate drying methods and circulation methods in different drying stages according to the physical and chemical changes of glass fiber yarn in the drying process; it can not only optimize the drying process and improve the quality of finished yarn balls; it is also beneficial to shorten the drying time and reduce equipment power consumption; at the same time, it can also reduce the equipment space occupancy rate and save basic investment costs.

[0040] 2. A vacuum cavity microwave cover is used to preheat the yarn car before it enters the heating and vaporization zone, reducing the heating time of the yarn car in the tunnel furnace from the current 100-120 minutes to 50-70 minutes; this is beneficial to shorten the tunnel length of the heating and evaporation zone and reduce the power consumption of heating and evaporation.

[0041] 3. The "heating vaporization zone + microwave drying zone" is used to complete the evaporation and removal of water in different combinations of different parts of the yarn ball. This can not only prevent the yarn ball from swelling and a large amount of migration of the wetting agent, but also make full use of the high-efficiency drying characteristics of "vacuum + microwave". According to the reaction characteristics of the yarn ball at different stages of the drying process, the drying process is optimized to minimize the drying time and save equipment power consumption while ensuring the drying quality.

[0042] 4. The return air duct in the existing glass fiber yarn tunnel drying furnace is generally a double-layer structure, and both layers of the return air duct are equipped with volute fans to complete the hot air circulation. This application improves the double-layer return air duct structure into a single duct structure by adopting an axial flow fan, which not only reduces the height of the tunnel furnace, but also greatly reduces the power of the supporting fan due to the smaller circulation space. In the curing and film-forming area, since the moisture content of the yarn ball has reached the standard, the energy consumed is mainly used for heat preservation, so only a top longitudinal channel is provided on the furnace structure, and the left and right return air channels are omitted on both sides of the product curing tunnel; the width of the tunnel furnace body is reduced and the height is reduced, and the structure is more compact and energy-saving.

[0043] 5. The tunnel-type continuous drying furnace disclosed in the present application can reduce the total number of fans by 1 / 4, that is, the total fan power is reduced by 1 / 4, and the total microwave power is only 1 / 4 of the original one, through the reasonable layout of two sets of vacuum and microwave control for drying with different processes, the smooth air duct circulation design of the front and rear furnace bodies, the compact and smaller rear furnace body without side air ducts and the design without exhaust of moist hot air, and the conversion of the volute fan to a large-volume axial flow fan and other innovations. Under the premise of ensuring the quality of film formation and curing of the yarn balls, the drying capacity is increased by 1 / 6. That is, the tunnel-type continuous drying furnace can achieve greater energy saving and consumption reduction through the reduction of the total power of the fan and microwave and the improvement of the drying capacity.

[0044] The technical solution and technical effects of the present application are described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 : Front view of tunnel-type continuous drying furnace with vacuum cavity microwave; Figure 2 : Left view of tunnel-type continuous drying furnace with vacuum cavity microwave; Figure 3 : Figure 1 A magnified view of the structure of the microwave preheating zone; Figure 4 : Figure 1 AA section diagram in; Figure 5 : Figure 1 BB cross-section diagram in; Figure 6 : Figure 1 Schematic diagram of CC cross section; Figure 7 : Figure 1 DD cross-section diagram in; Figure 8 : Front view of the vacuum cavity microwave cover; Fig. 9 : Side view of vacuum cavity microwave cover; Fig.10 : Temperature curve inside the yarn; Fig.11 : Schematic diagram of the existing tunnel furnace structure; Icon Description: 1- tunnel type continuous drying furnace main body, 2- microwave preheating zone, 3- microwave drying zone, 4- vacuum cavity microwave cover, 5- drying zone lifting mechanism; 11-heating and vaporizing area, 12-curing and film-forming area, 13-connecting tunnel, 14-microwave cover lifting port, 15-furnace frame, 16-insulating layer, 17-yarn car track; 41- vacuum microwave cover, 42- vacuum generator, 43- microwave generator, 44- waveguide, 45- sealing strip; 51-lifting power cylinder, 52-lifting motor, 53-cover counterweight, 54-lifting sprocket, 55-transmission chain; 111- entrance furnace door frame, 112- one-piece furnace door, 113- one-piece lifting mechanism, 114- left and right axial flow fans; 121-front and rear axial fans; 151-product drying tunnel, 152-top transverse channel, 153-left and right circulation channels, 154-product curing tunnel, 155-top longitudinal channel; 10-upper air duct, 20-lower air duct, 30-volute fan, 40-left and right air ducts. DETAILED DESCRIPTION

[0046] Direction description: In this application, the extension direction of the tunnel-type continuous drying furnace is the front-to-back direction, and the direction perpendicular to the tunnel-type continuous drying furnace is the left-to-right direction. Alternatively, the extension direction of the yarn car track is the front-to-back direction, and the two sides of the yarn car track are perpendicular to the left-to-right direction.

[0047] See also Figure 1-Figure 10The tunnel-type continuous drying furnace with vacuum cavity microwave disclosed in the present application comprises a tunnel-type continuous drying furnace body 1; the tunnel-type continuous drying furnace body 1 comprises a temperature rising vaporization zone 11, a curing film-forming zone 12 and a connecting tunnel 13 between the temperature rising vaporization zone 11 and the curing film-forming zone 12; the temperature rising vaporization zone 11, the connecting tunnel 13 and the curing film-forming zone 12 are sealed and connected. A microwave preheating zone 2 is arranged before the temperature rising vaporization zone 11, and a microwave drying zone 3 is arranged between the temperature rising vaporization zone 11 and the curing film-forming zone 12, that is, in the connecting tunnel 13.

[0048] The heating and vaporization zone 11 includes a heating zone and an evaporation zone. The heating zone is mainly used to heat the yarn to reach the temperature required for stable evaporation of water, and the evaporation zone is mainly used for vaporization and evaporation of water in the yarn. When implementing, the number of heating zones and evaporation zones can be flexibly configured according to different yarns. Figure 1 For the implementation method including three functional zones shown in , the temperature rising zone may be the first zone, the evaporation zone may be the second zone and the third zone, and so on.

[0049] The heating vaporization zone 11 is mainly used to promote gentle evaporation of moisture inside the yarn ball through hot air circulation, while removing part of the moisture to ensure that the yarn ball will not swell and a large amount of wetting agent will not migrate during the high-efficiency drying process in the vacuum microwave drying zone.

[0050] The curing film-forming zone 12 is mainly used to complete the curing film-forming of the yarn balls. After passing through the heating vaporization zone 11 and the microwave drying zone 3, the yarn balls need a relatively calm insulation environment to promote high-quality curing film-forming. At this time, it is not suitable to configure a high-power, high-pressure, and high-air volume fan and an appropriate duration needs to be set.

[0051] See also Fig.11 The furnace body structure of the existing tunnel furnace generally includes left and right air ducts 40 and a top air duct, wherein the top air duct is a double-layer air duct structure, including an upper air duct 10 and a lower air duct 20; a volute fan 30 is arranged between the upper and lower air ducts to promote hot air circulation.

[0052] This application adopts a single-layer air duct structure. Figure 4-Figure 6 The heating vaporization zone 11 and the curing film forming zone 12 of the present application both include a furnace frame 15 and a heat preservation layer 16; the heat preservation layer 16 is sealed and arranged outside the furnace frame 15. The furnace frame 15 includes a left wall panel, a right wall panel, and a machine top frame; the machine top frame is arranged on the top of the left and right wall panels.

[0053] See also Figure 4A product drying tunnel 151 is defined between the left and right wall panels of the temperature-raising and vaporizing zone 11, a top transverse channel 152 is provided in the top frame of the temperature-raising and vaporizing zone 11, and left and right circulation air ducts 153 are provided on the left and right sides of the product drying tunnel 151; wherein the top transverse channel 152 is a single-layer structure, and left and right axial flow fans 114 are provided in the top transverse channel 152. The number of the left and right axial flow fans 114 can be one or more.

[0054] The existing tunnel furnace structure with a double-layer air duct and a volute fan on the top occupies a large space and has a low hot air circulation efficiency. The present application adopts a top transverse channel with a single-layer structure and is equipped with left and right axial flow fans 114. The low wind resistance channel can increase the circulating air by 20%, and the hot air circulation efficiency is significantly improved while the fan power is also reduced. In addition, the hot air circulation direction of the temperature rise vaporization zone 11 can be adjusted by adjusting the forward and reverse rotation of the left and right axial flow fans 114. For example, when the fan rotates forward, the hot air circulates from left to right, and when the fan rotates reversely, the hot air circulates from right to left; the technical effect of hot air drying the yarn balls from the left and right sides of the yarn car is achieved.

[0055] See also Figure 5 and Figure 6 The product curing tunnel 154 is defined between the left and right wall panels of the curing film forming area 12, and a top longitudinal channel 155 is provided in the top frame of the curing film forming area 12; wherein the top longitudinal channel 155 is a single-layer structure, and front and rear axial flow fans 121 are provided in the top longitudinal channel 155; different from the structure of the temperature rising vaporization area 11, the product curing tunnel 154 of the curing film forming area 12 is not provided with left and right circulation ducts on both sides. The number of front and rear axial flow fans 121 can be one or more.

[0056] In the existing tunnel furnace with double-layer air ducts and volute fans on the top, the tunnel structure of the curing film-forming zone is consistent with the tunnel structure of the warming vaporization zone, and the hot air circulation direction is left and right horizontal circulation. The present application improves the top air duct structure of the film-forming and curing zone 12 into a single-layer structure and is equipped with front and rear axial flow fans 121; by changing the horizontal hot air circulation of multiple volute fans into the longitudinal hot air circulation of two front and rear axial flow fans, the width of the air ducts on both sides of the furnace body is reduced, and the height of a return air duct on the upper part of the furnace body is lowered, which is more compact and energy-saving.

[0057] The microwave preheating zone 2 is used to complete the preheating function of the yarn ball before entering the heating vaporization zone 11. Through intermittent vacuum and microwave preheating, the temperature is raised to the highest temperature that the yarn ball can withstand (the temperature is as high as possible but the yarn ball will not swell), shortening the heating time of the yarn ball in the heating vaporization zone.

[0058] The microwave drying zone 3 is mainly used to efficiently evaporate the water in the yarn that is not easy to remove through the technical measures of vacuuming and microwave drying. Since the yarn has undergone the preliminary removal of water in the heated vaporization zone 11, there will be no cascading and large-scale migration of the impregnating agent.

[0059] The microwave preheating zone 2 and the microwave drying zone 3 both include a vacuum cavity microwave cover 4; the temperature rising vaporization zone 11 also includes an entrance furnace door frame 111, a connected furnace door 112 and a connected lifting mechanism 113; the connected furnace door 112 and the vacuum cavity microwave cover 4 are arranged on the entrance furnace door frame 111 and are fixedly connected to the microwave preheating zone 11; the vacuum cavity microwave cover 4 and the connected furnace door 112 of the microwave preheating zone 2 can be synchronously lifted and lowered under the action of the connected lifting mechanism 113.

[0060] A microwave cover lifting port 14 is provided at the top of the connecting tunnel 13, and the vacuum cavity microwave cover 4 of the microwave drying zone 12 is provided in the microwave cover lifting port 14 and is sealedly connected to the connecting tunnel 13. The microwave drying zone 12 further includes a drying zone lifting mechanism 5, and the vacuum cavity microwave cover 4 of the microwave drying zone 12 can be lifted and lowered under the action of the drying zone lifting mechanism 5.

[0061] The drying zone lifting mechanism 5 of the microwave drying zone 12 is arranged in or around the microwave cover lifting port 14 , and can drive the vacuum cavity microwave cover 4 of the microwave drying zone 12 to perform lifting movement in the microwave cover lifting port 14 .

[0062] The vacuum cavity microwave cover 4 is sealed to the microwave cover lifting port 14, that is, no matter the vacuum cavity microwave cover 4 is lowered into the connecting tunnel 13 or raised above the connecting tunnel 13, the vacuum cavity microwave cover 4 is sealed to the microwave cover lifting port 14. The vacuum cavity microwave cover 4 can be provided with upper and lower sealing strips to achieve a sealed connection between the vacuum cavity microwave cover 4 and the microwave cover lifting port 14.

[0063] The vacuum cavity microwave covers 4 of the microwave preheating zone 2 and the microwave drying zone 3 each include a vacuum microwave cover body 41, a vacuum generator 42, a microwave generator 43, a waveguide tube 44, and a sealing strip 45; the vacuum generator 42 and the microwave generator 43 are both arranged on the vacuum microwave cover body 41, and the waveguide tube 44 is arranged in the vacuum microwave cover body 41 and connected to the microwave generator 43.

[0064] The sealing strip 45 includes an upper sealing strip and a lower sealing strip. The upper sealing strip is used to form a sealed connection at the connection between the vacuum microwave cover 41 and the microwave cover lifting port 14; the lower sealing strip is used to form a sealed connection at the bottom of the vacuum microwave cover 41 and the ground contact part of the infrastructure such as the microwave preset area 11 or the microwave drying area 12.

[0065] The vacuum microwave cover 41 can be a box or cover structure with the remaining five surfaces being sealed structures except the bottom surface; when the vacuum microwave cover 41 descends to the preheating zone, it can form a sealed connection with the infrastructure such as the ground or work surface of the preheating zone or drying zone through a sealing component such as a sealing strip 45.

[0066] The vacuum generator 42 can evacuate the vacuum microwave enclosure 41 , the microwave generator 43 can emit microwaves, and the waveguide 44 can conduct the microwaves from the microwave generator 43 into the vacuum microwave enclosure 41 .

[0067] To ensure the heat preservation function, the vacuum microwave cover 41 is provided with heat preservation cotton layers on the other five surfaces except the bottom surface; to ensure the preheating effect of the yarn ball, a plurality of, for example, 4-8 microwave generators 43 can be arranged on the vacuum microwave cover 41; to ensure the energy utilization efficiency, the waveguide 44 can transmit the microwave to the yarn hanging part of the yarn car or surround the yarn ball that needs to be preheated.

[0068] The microwave preheating zone 2, the heating vaporization zone 11, the microwave drying zone 12, and the solidification film-forming zone 3 can form a continuous yarn ball drying process. For every row of yarn carts entering the microwave preheating zone 2, a row of yarn carts that have completed drying and film-forming will drive out of the solidification film-forming zone 12. According to actual needs, it can be set to single-in and single-out, double-in and double-out, etc.; the production rhythm or intermittent cycle is the time to complete one microwave preheating or microwave drying of the yarn ball.

[0069] The integrated lifting mechanism 113 of the temperature-raising vaporization zone 11 can use the same mechanism as the drying zone lifting mechanism 5 of the microwave drying zone 12 to complete the lifting and driving function of the vacuum cavity microwave cover 4.

[0070] In this embodiment, the drying zone lifting mechanism 5 adopts Figure 5 The lifting power cylinder 51 shown is used as a lifting drive component, and the lifting power cylinder 51 can be an oil cylinder, a gas cylinder or an electric cylinder. The vacuum cavity microwave cover 4 is fixed to the piston rod of the lifting power cylinder 51, and the vacuum cavity microwave cover 4 can be automatically lifted and lowered by regulating the lifting power cylinder 51.

[0071] In this embodiment, the combined lifting mechanism 113 adopts Figure 2 The components and connection relationships shown realize the lifting and lowering drive of the vacuum cavity microwave cover 4 and the integrated furnace door 112. The integrated lifting mechanism 113 includes a lifting motor 52, a cover counterweight 53, a lifting sprocket 54, and a transmission chain 55; the transmission chain 55 is arranged on the lifting sprocket 54 and its two ends are respectively connected to the cover counterweight 53 and the vacuum cavity microwave cover 4, and the lifting motor 52 is transmission-connected to the lifting sprocket 54. The lifting motor 52 can drive the vacuum cavity microwave cover 4 to perform lifting and lowering motions through the lifting sprocket 54.

[0072] In a modified embodiment of the present application, the drying zone lifting mechanism 5 may also adopt a lifting drive mechanism consisting of a lifting motor 52, a cover counterweight 53, a lifting sprocket 54, and a transmission chain 55; the connected lifting mechanism 113 may also adopt a lifting power cylinder 51 as a lifting drive component.

[0073] The main body 1 of the tunnel-type continuous drying furnace also includes an exit furnace door frame, an exit lifting door and an exit lifting device; the exit furnace door frame is arranged at the tunnel exit of the curing film forming area 12, and the exit lifting door is arranged to be liftable on the exit furnace door frame and can rise to open the tunnel exit or fall to seal the tunnel exit under the action of the exit lifting device. The exit furnace door frame and the exit lifting door can adopt a structure and connection relationship similar to the aforementioned entrance furnace door frame 111 and the integrated furnace door 112, and the exit lifting device can be a power cylinder or a lifting mechanism composed of a lifting motor, a cover counterweight, a lifting sprocket, and a transmission chain. The components of the exit furnace door frame, the exit lifting door, and the exit lifting device and their connection relationship are not described in detail here.

[0074] The yarn car track 17 is arranged on the infrastructure such as the work surface of the drying furnace or the floor of the workshop, and extends from the microwave preheating zone 2 through the temperature rising vaporization zone 11, the microwave preheating zone 3, and the curing film forming zone 12. A continuous yarn car transport route can be formed from the microwave preheating zone 2 to the curing film forming zone 12.

[0075] Description of implementation principle and technical effect: before the yarn car enters the heating and vaporization zone 11, the vacuum cavity microwave cover 4 of the microwave preheating zone 2 preheats the yarn ball; after the preheating is completed, the vacuum cavity microwave cover 4 makes an upward movement and opens the integrated furnace door 112; the yarn car enters the heating zone of the heating and vaporization zone 11 along the yarn car track 17 for heating and then continues to be transported forward to the evaporation zone of the heating and vaporization zone 11; after the yarn car completes evaporation in the evaporation zone of the heating and vaporization zone 11, it continues to be transported forward to the microwave drying zone 3, and the vacuum cavity microwave cover 4 of the microwave drying zone 3 performs microwave and vacuum drying on the yarn ball with high efficiency; after high-efficiency drying in the microwave drying zone 3, the moisture content of the yarn ball has reached the standard, and then enters the curing and film-forming zone 12 for heat preservation and curing to form a film.

[0076] Among them: when the yarn car has completed preheating in the microwave preheating zone 11 and is about to enter the temperature rising vaporization zone 11, the vacuum cavity microwave cover 4, the integrated furnace door 112 and the exit lifting door of the microwave preheating zone 2 and the microwave drying zone 3 rise at the same time; while the preheated yarn car enters the temperature rising vaporization zone 11 through the entrance furnace door frame 111, the yarn car that has completed drying in the microwave drying zone 3 enters the curing film forming zone 12, and at the end of the curing film forming zone 12, the yarn car that has been cured and formed into a film leaves the tunnel through the exit furnace door frame; then the vacuum cavity microwave cover 4, the integrated furnace door 112 and the exit lifting door of the microwave preheating zone 2 and the microwave drying zone 3 descend at the same time; the vacuum cavity microwave cover 4 of the microwave preheating zone 2 preheats the yarn car that comes to the preheating zone, and such a cycle is used to realize continuous production.

[0077] The production rhythm of the tunnel-type continuous drying furnace with vacuum cavity microwave in the present application is: the yarn cart to be dried at the feeding end continuously enters the microwave preheating zone 2, and the yarn cart that has completed the solidification and film formation at the discharging end continuously drives out of the tunnel exit of the solidification and film formation zone 12; every time a yarn cart to be dried enters, a yarn cart that has completed the drying and film formation drives out at the same time, and the vacuum cavity microwave covers 4 of the two processes synchronously complete a lifting movement during the process.

[0078] The drying process corresponding to the aforementioned tunnel-type continuous drying furnace with vacuum cavity microwave includes the following process steps: Preheating step: the vacuum cavity microwave cover 4 and the integrated furnace door 112 of the microwave preheating zone 2 are lowered together under the action of the integrated lifting device 113, the vacuum cavity microwave cover 4 covers the yarn carriage entering the microwave preheating zone, and the integrated furnace door 112 closes the entrance furnace door of the temperature rising vaporization zone 11; the vacuum generator and the microwave generator of the microwave preheating zone 2 are started successively or simultaneously; the microwave generator adopts intermittent operation to control the occurrence of yarn ball swell and impregnation agent migration problems; Heating and vaporizing step: the vacuum cavity microwave cover 4 and the integrated furnace door 112 of the microwave preheating zone 2 rise together under the action of the integrated lifting device 113, and the preheated yarn carriage enters the heating and vaporizing zone 11; at the same time, the vacuum cavity microwave cover 4 and the integrated furnace door 112 descend to close the entrance of the heating and vaporizing zone, and the next row of yarn carriages enters the preheating step; The furnace body of the temperature-raising vaporization zone includes a product drying tunnel, a top transverse channel, and left and right circulation channels. The top transverse channel is a single-layer structure, and left and right axial flow fans are used to promote the left and right circulation of hot air. By adjusting the forward and reverse rotation of the left and right axial flow fans, the hot air circulation direction of the temperature-raising vaporization zone can be adjusted. For example, when the fan rotates forward, the hot air circulates from left to right, and when the fan rotates reversely, the hot air circulates from right to left. Microwave drying step: the vacuum cavity microwave cover 4 of the microwave drying zone 3 rises under the action of the drying zone lifting mechanism 5, and the yarn car that has completed the temperature rise and vaporization step enters the microwave drying zone 3; then the vacuum cavity microwave cover 4 descends to cover the yarn car that has entered the microwave drying zone 3; the vacuum cavity microwave cover 4 of the microwave drying zone 3 continuously evacuates and microwaves to dry the yarn balls; Curing film forming step: the vacuum cavity microwave cover 4 of the microwave drying zone 3 rises under the action of the drying zone lifting mechanism 5, and the yarn car that has completed the microwave drying step enters the curing film forming zone 12; the furnace body of the curing film forming zone 12 only includes a product curing tunnel 154 and a top longitudinal channel 155, and the top longitudinal channel is a single-layer structure, and front and rear axial flow fans 121 are used to promote the front and rear circulation of hot air to complete the curing film forming of the glass fiber yarn group; Finished yarn out of the oven step: the outlet oven door lifting device drives the outlet oven door lifting device to open the outlet oven door of the curing film forming area 12, and the yarn carriage that has completed the curing film forming step drives out of the curing film forming area 12; Among them: the vacuum cavity microwave cover 4 of the microwave preheating zone 2, the integrated furnace door 121, the vacuum cavity microwave cover 4 of the microwave drying zone 3, and the lifting action of the outlet lifting furnace door are synchronized to realize continuous operation; In addition: in the heating and vaporization step, the left and right axial flow fans 114 drive the hot air to circulate along the left and right directions of the tunnel; in the curing and film forming step, the front and rear axial flow fans 121 drive the hot air to circulate along the front and rear directions of the tunnel.

[0079] See also Fig.10 In order to verify the drying effect of the tunnel-type continuous drying furnace with vacuum cavity microwave, two groups of experiments with and without vacuum microwave were designed. During the drying process, a temperature tracker was used to track the temperature inside the yarn ball entering the drying furnace.

[0080] Depend on Fig.10 It can be seen that in the drying process using vacuum microwave: The heating section is about 1.5 h (including 0.5 h of vacuum microwave preheating and about 1 h of drying heating time in the furnace), the evaporation section is about 4.25 h, the climbing section is about 2.75 h, and the film forming section is about 6 h; the total drying time is about 14 h.

[0081] Depend on Fig.10 It can be seen that in the drying process without using vacuum microwave: The heating stage is about 2 hours, the evaporation stage is about 4.5 hours, the climbing stage is about 4.5 hours, and the film-forming stage is about 6 hours; the total drying time is about 17 hours.

[0082] Comparing the two, the vacuum microwave drying process has a shorter total drying time (from 17h to 14h) under the premise of the same film forming time (6h), so the vacuum microwave drying process has lower power consumption and higher drying efficiency.

[0083] A vacuum cavity microwave cover 4 is used to preheat the yarn car before it enters the heating vaporization zone 11, reducing the heating time of the yarn car in the tunnel furnace from about 2 hours without using the vacuum microwave preheating mode to less than 1 hour; this is beneficial to shortening the tunnel length of the heating evaporation zone 11 and reducing the power consumption of heating evaporation.

[0084] Therefore, the present application can increase the temperature of the yarn balls entering the heating vaporization zone 11 and reduce the drying time by setting up the microwave preheating zone 2 before the heating vaporization zone 11; at the same time, it can also perform penetrating preheating on the yarn balls by vacuum microwaves to prevent the formation of a protective film on the outside of the yarn balls due to insufficient heating inside the yarn balls; by adopting a liftable vacuum cavity microwave cover with a waveguide, it can not only improve the energy utilization rate of microwaves, reduce the on-site microwave installed power and layout points, but also reduce the width and volume of the furnace body, thereby maximizing the production capacity of the workshop.

[0085] Furthermore, the moisture contained in the yarn ball is easy to evaporate at the surface, while the moisture inside the yarn ball will be hindered and evaporate more slowly. If the traditional glass fiber yarn hot air plus microwave drying method is used for drying, although it is faster than without microwave, it still takes a long time, consumes more power, and the output is not high; and it is easy to produce yarn swelling and water bubbling from the inside of the yarn ball to the surface under the action of microwaves, causing a large amount of wetting agent to migrate outward. The existing hot air plus microwave drying requires a large number of microwave installation points, has poor efficiency, and has a high basic cost; and it is easy to cause yarn swelling and a large amount of wetting agent migration. The present application proposes a combined drying process of hot air plus vacuum microwaves based on the changing rules of different stages in the drying process of glass fiber yarn, which is not only conducive to shortening the drying time and reducing the power consumption of drying, but also can improve the quality of the finished yarn by optimizing the drying process.

[0086] The "heating vaporization zone + microwave drying zone" is used to complete the evaporation and removal of moisture in different combinations of different parts of the yarn ball. This can not only prevent the yarn ball from swelling and a large amount of migration of the wetting agent, but also make full use of the high-efficiency drying characteristics of "vacuum + microwave". According to the reaction characteristics of the yarn ball at different stages of the drying process, the appropriate drying method is configured. Under the premise of ensuring the quality of drying and film formation, the drying time is minimized and the power consumption of the equipment is saved.

[0087] In addition, during the drying process of the glass fiber yarn, the temperature of the yarn ball entering the temperature rising vaporization zone and the temperature of the yarn ball in the curing film-forming zone are important factors affecting the efficiency of the drying process, power consumption and film-forming quality. The present application can also increase the adaptability of the drying furnace by setting a vacuum cavity microwave cover before the temperature rising vaporization zone and before the curing film-forming zone. When yarn balls with different water contents and / or yarn balls using different types of impregnants need to be dried, the microwave density and microwave action time in the microwave preheating zone 2 and the curing film-forming zone 3 can be flexibly adjusted to adapt to the changes in the yarn balls.

[0088] Finally, the tunnel-type continuous drying furnace disclosed in the present application can reduce the total number of fans by 1 / 4, that is, the total fan power is reduced by 1 / 4, and the total microwave power is only 1 / 4 of the original, through the reasonable layout of two sets of vacuum and microwave control for drying with different processes, the smooth air duct circulation design of the front and rear furnace bodies, the compact and smaller rear furnace body without side air ducts and the design without exhaust of moist hot air, and the conversion of the volute fan to a large-volume axial flow fan and other innovations. Under the premise of ensuring the quality of yarn ball film formation and curing, the drying capacity is increased by 1 / 6. That is, through the reduction of the total power of the fan and microwave and the improvement of the drying capacity, the tunnel-type continuous drying furnace can achieve greater energy saving and consumption reduction.

[0089] It should be noted that the above implementation mode is applicable to glass fiber yarn that needs to be dried and cured into a film. For glass fiber yarn that does not need to be cured into a film, the tunnel-type continuous drying furnace with vacuum cavity microwave disclosed in the present application can also adopt a three-stage configuration of "microwave preheating zone + temperature rising vaporization zone + microwave drying zone" to dry the yarn balls. The three-stage configuration can greatly reduce the length of the tunnel furnace, shorten the drying time, and reduce energy consumption.

[0090] The technical scheme and technical effects of the present application are described in detail above in combination with the drawings and specific implementation methods of the specification. It should be noted that technicians in this field can also develop other implementation methods on this basis; any simple deformation and equivalent substitution that does not deviate from the innovative concept of the present application are covered by the present application and belong to the protection scope of the present application.

Claims

1. A tunnel-type continuous drying furnace with vacuum cavity microwave, comprising a tunnel-type continuous drying furnace body; characterized in that: The tunnel-type continuous drying furnace body (1) comprises a temperature-raising vaporization zone (11); A microwave preheating zone (2) is provided before the temperature-raising vaporization zone (11), and a microwave drying zone (3) is provided after the temperature-raising vaporization zone (11); The microwave preheating zone (2) and the microwave drying zone (3) both include a vacuum cavity microwave cover (4); The temperature-raising vaporization zone (11) further comprises an entrance furnace door frame (111), a conjoined furnace door (112), and a conjoined lifting mechanism (113); the conjoined furnace door (112) is arranged on the entrance furnace door frame (111) and is fixedly connected to the vacuum cavity microwave cover (4) of the microwave preheating zone (2); The vacuum cavity microwave cover (4) and the integrated furnace door (112) of the microwave preheating zone (2) can be raised and lowered synchronously under the action of the integrated lifting mechanism (113); The microwave drying zone (3) further comprises a drying zone lifting mechanism (5), and the vacuum cavity microwave cover (4) of the microwave drying zone (3) can perform lifting movement under the action of the drying zone lifting mechanism (5); The vacuum cavity microwave cover (4) comprises a vacuum microwave cover body (41), a vacuum generator (42), a microwave generator (43), and a waveguide (44); The vacuum generator (42) and the microwave generator (43) are both arranged on the vacuum microwave enclosure (41); the waveguide (44) is arranged in the vacuum microwave enclosure (41) and connected to the microwave generator (43); The temperature-raising vaporization zone (11) is used to dry the moisture in the superficial part of the yarn ball so that the yarn ball will not swell in the microwave drying zone (12), and the microwave drying zone (12) is used to dry the moisture blocked inside the yarn ball.

2. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 1, characterized in that: The tunnel-type continuous drying furnace body (1) further comprises a curing film-forming zone (12); A connecting tunnel (13) is provided between the temperature-raising gasification zone (11) and the solidification film-forming zone (12), and a microwave cover lifting port (14) is provided at the top of the connecting tunnel (13); The vacuum cavity microwave cover (4) of the microwave drying zone (3) is arranged in the microwave cover lifting port (14) and is sealedly connected to the connecting tunnel (13).

3. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 1, characterized in that: The connected lifting mechanism (113) comprises a lifting motor (52), a cover counterweight (53), a lifting sprocket (54), and a transmission chain (55); The transmission chain (55) is arranged on the lifting sprocket (54) and has two ends respectively connected to the cover body counterweight (53) and the vacuum cavity microwave cover (4); the lifting motor (52) is transmission-connected to the lifting sprocket (54).

4. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 1, characterized in that: The drying zone lifting mechanism (5) comprises a plurality of lifting power cylinders (51).

5. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 1, characterized in that: The microwave preheating zone (2) and the microwave drying zone (3) both comprise a furnace frame (15) and a heat-insulating layer (16), wherein the heat-insulating layer (16) is sealed and arranged outside the furnace frame (15).

6. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 5, characterized in that: The furnace frame (15) of the microwave preheating zone (2) is provided with a product drying tunnel (151), a top transverse channel (152), and left and right circulation channels (153); Left and right axial flow fans (114) are arranged in the top transverse channel (152), and the top transverse channel (152) is a single-layer structure channel.

7. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 5, characterized in that: A product curing tunnel (154) and a top longitudinal channel (155) are arranged in the furnace frame (15) of the microwave drying zone (3); Front and rear axial flow fans (121) are arranged in the top longitudinal channel (155), and the top longitudinal channel (155) is a single-layer structure channel.

8. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 1, characterized in that: The tunnel-type continuous drying furnace with vacuum cavity microwave further comprises a yarn car track (17); The yarn wheel track (17) extends through the microwave preheating zone (2), the temperature rising vaporization zone (11), and the microwave drying zone (3).

9. The tunnel-type continuous drying furnace with vacuum cavity microwave according to claim 1, characterized in that: The vacuum cavity microwave cover (4) further comprises a sealing strip (45), wherein the sealing strip (45) is arranged at the bottom of the vacuum microwave cover body (41).

10. A drying process in a tunnel-type continuous drying furnace with a vacuum cavity microwave, characterized in that: The tunnel-type continuous drying furnace with vacuum cavity microwave as claimed in claim 1; The process steps include: Preheating steps: the vacuum cavity microwave cover and the one-piece furnace door of the microwave preheating zone are lowered together by the one-piece lifting device, the vacuum cavity microwave cover covers the yarn car entering the microwave preheating zone, and the one-piece furnace door seals the entrance furnace door of the heating vaporization zone; the vacuum generator and microwave generator of the microwave preheating zone are started successively or simultaneously; the microwave generator adopts intermittent operation to control the yarn ball swell and the migration of the impregnating agent; Heating and vaporizing step: the vacuum cavity microwave cover and the one-piece furnace door in the microwave preheating zone rise together under the action of the one-piece lifting device, and the preheated yarn carriage enters the heating and vaporizing zone; at the same time, the vacuum cavity microwave cover and the one-piece furnace door descend to close the entrance of the heating and vaporizing zone, and the next row of yarn carriages enter the preheating step; the heating and vaporizing zone is used to dry the moisture on the surface of the yarn ball so that the yarn ball will not swell in the microwave drying zone; Microwave drying steps: the vacuum cavity microwave cover of the microwave drying area rises under the action of the drying area lifting mechanism, and the yarn car that has completed the temperature rise and vaporization step enters the microwave drying area; then the vacuum cavity microwave cover descends to cover the yarn car that enters the microwave drying area; the vacuum cavity microwave cover of the microwave drying area continuously evacuates and adds microwaves to dry the yarn; the microwave drying area is used to dry the moisture blocked inside the yarn; Curing film forming step: the vacuum cavity microwave cover of the microwave drying area rises under the action of the drying area lifting mechanism, and the yarn car that has completed the microwave drying step enters the curing film forming area; the furnace body of the curing film forming area only includes the product curing tunnel and the top longitudinal channel, and the top longitudinal channel is a single-layer structure, and front and rear axial flow fans are used to promote the front and rear circulation of hot air; Among them: the vacuum cavity microwave cover in the microwave preheating zone, the integrated furnace door, and the vacuum cavity microwave cover in the microwave drying zone are raised and lowered synchronously to realize continuous operation.

Images