Hot air penetration type drying system for wet spunlace and working method of hot air penetration type drying system

Abstract

The invention discloses a hot air penetration type drying system for wet spunlace and a working method of the hot air penetration type drying system. The system comprises a wall frame, a thermal cycle air supplement adjusting device and a circulating fan, and an upper-layer flow guide air plate, a rotary drum drying net and a lower-layer flow guide air plate are arranged in the wall frame; the upper-layer flow guide air plate is located above the rotary drum drying net, the lower-layer flow guide air plate is located below the rotary drum drying net, and the thermal cycle air supplement adjusting devices are arranged at an inlet and an outlet of the drying oven respectively. By means of the unique penetrating type design, hot air can directly act on the surfaces of materials, the drying time is greatly shortened, and meanwhile energy consumption is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of textile equipment, and more specifically, relates to a hot air penetration drying system for wet spunlace and a working method thereof. Background Art

[0002] In the production process of spunlace nonwovens, after the fiber web is spunlace into cloth, although it is pressed by a roller to remove water, a large amount of water is still adsorbed on the cloth. Therefore, a drying process needs to be set up in the production process of spunlace nonwovens. In traditional processes, hot air drying is mostly used, that is, hot air is used to dry the wet cloth on the surface of the conveyor belt. This drying method often results in poor drying effect of nonwovens due to incomplete drying, and then the product quality of nonwovens cannot be guaranteed.

[0003] The existing patent document CN109140975A (a new type of hot air circulation drying equipment for non-woven fabric production, 2019.01.04) records a drying and heating box, in which the non-woven fabric is distributed in an "S" shape on both sides of the heating box through the upper guide roller and the lower guide roller, so that the upper and lower surfaces of the non-woven fabric can be heated multiple times inside the drying box, which is conducive to quickly removing the moisture of the non-woven fabric and improving the drying efficiency. At the same time, the hot air can be recycled, reducing the energy consumption caused by the use of hot air. Since the non-woven fabric is distributed in an "S" shape, in order to improve the drying efficiency, a plurality of ceramic heating tubes need to be arranged in the heating box and arranged at intervals between the non-woven fabrics. The hot air generated by them dries the non-woven fabrics. In the actual industrial production process, due to the specific arrangement of the ceramic heating tubes and the non-woven fabrics, the heating box often needs to have a larger volume, which is not conducive to the optimal configuration of industrial land and production lines. At the same time, the utilization rate of thermal efficiency of this method is low, and the product feels hard.

[0004] The current hot air penetration dryer, such as "National Defense Textile Guide", No. 9, 2005, "Application of Dryers in the Production of Spunlace Nonwovens", Liu Dongsheng, Donglun Technology Industrial Co., Ltd. (China), records a penetration drying method, that is, when the spunlace fabric passes through the drying cylinder cover along the drum, the honeycomb structure adopted on the surface of the drum, and the vacuum suction system in the drum allows the steam hot air to pass through the spunlace fabric into the drum and be sucked away. The moisture on the fabric evaporates and is taken away with the hot air sucked into the drum. The extracted air is sent to the circulation system, and after the moisture is discharged, it is heated by the heat exchanger and then sent to the drying hood. Practice has proved that the thermal efficiency of steam hot air penetration drying is significantly higher than other hot air drying methods, and the product feels good. However, in the actual production process, it is still necessary to continuously provide steam hot air, which consumes a lot of energy. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to solve the deficiencies in the prior art and to provide a hot air penetration drying system and a working method thereof for wet spunlace.

[0006] Technical solution: The hot air penetration drying system for wet spunlace described in the present invention comprises a wall frame, a heat circulation air supply adjustment device and a circulation fan, wherein the wall frame is provided with an upper air guide plate, a rotary drum drying net and a lower air guide plate;

[0007] The upper air guide plate is located above the rotary drum drying net, the lower air guide plate is located below the rotary drum drying net, and the heat cycle air supply adjustment device is respectively arranged at the inlet and outlet of the oven.

[0008] In some embodiments, the wall frame includes a frame, an outer panel, an inner panel, and an intermediate insulation layer, and the intermediate insulation layer adopts a glass fiber / rock wool composite needle felt structure.

[0009] In some embodiments, the frame is an I-beam structure, and the frame, outer panel and inner panel are all made of stainless steel material, and the thickness of the outer panel and the inner panel is 0.8~1.2mm.

[0010] In some embodiments, the glass fiber in the intermediate insulation layer has a fineness of 10-25 μm, a length of 51-76 mm, and a content of 60%-80%. The rock wool fiber has a fineness of 7-15 μm, a length of 51-76 mm, and a content of 20%-40%. The two fibers are opened and mixed, and then air-laid and needle-punched for compounding. The single-layer density of the composite felt is 1000-1500 g / m 2 , thickness is 30~40mm.

[0011] In some embodiments, the upper and lower air guide plates are both made of stainless steel with a thickness of 1.5 to 2.0 mm, and the surfaces are both hydrophobic and anti-corrosion surfaces. The upper and lower layers are perforated in opposite positions with a hole diameter of 15 to 20 mm and a hole spacing of 2.5 to 3 times the hole diameter.

[0012] In some embodiments, the middle air guide plate of two adjacent rows of holes of the upper air guide plate is streamlined and installed at an angle of 10° to 15°, and the lower end is directly connected to the guide groove.

[0013] In some embodiments, the rotary drum drying net is a cylindrical structure, located in the middle of the oven, and is a nickel-chromium alloy net with high thermal conductivity. The number of holes in the net is 17 to 20 meshes.

[0014] In some embodiments, a hot air wind shielding plate of the drum is further included. The hot air wind shielding plate of the drum is fixed to the upper inner part of the drum drying net, has a semicircular structure, is made of stainless steel metal material, and has a thickness of 2.0-3.0 mm.

[0015] In some embodiments, the circulation fan includes a hot air exhaust circulation fan and a burner and oven air supply circulation fan.

[0016] On the other hand, the present invention also discloses a method for a hot air penetration drying system for wet spunlacing, comprising:

[0017] The wet-laid spunlace nonwoven materials that need to be dried enter the hot air penetration drying system at a design speed of 5-200 m / min after negative pressure dehydration in the front process, and are fed into the drying net of the oven drum by the cloth guide roller group. The wrap angle of the wet-laid spunlace nonwoven materials to the drying net of the oven drum is 110°~150°;

[0018] The hot air exhaust circulation fan of the circulation fan, the burner and the oven air supply circulation fan work in coordination to form a gradient pressure distribution area where the internal pressure of the drum drying net is less than the external pressure, so that the wet spunlace nonwoven material is adsorbed on the surface of the drum drying net; after the supply air is heated by the burner and the oven air supply circulation fan, it passes through the lower guide air plate, the wet spunlace nonwoven material, and the lower half of the drum drying net from bottom to top, and most of it enters the interior of the drum drying net. At this time, the moisture in the material is partially taken away, the hot air temperature drops from 110°~130° to 80°~100°, and the humidity increases from 10%~20% to more than 65%. This hot and humid air is no longer suitable for the material Drying requires the use of hot air exhaust circulation fans to discharge the drying system, and then re-enter the air supply system after external steam-water separation and filtration, while the drier hot and dry air continues to circulate in the system, and the other part of the humid hot air that has not entered the hot air exhaust circulation fan will bypass the drum hot air baffle and rise to the upper guide air plate, where the moisture will condense on the streamlined ridges of the upper guide air plate and be discharged to the lower end under the action of the installation inclination angle, while the humid hot air with humidity reduced to 30%~40% is discharged from the drying system by the hot air exhaust circulation fan at the top of the mechanism, and re-enters the air supply system after external steam-water separation and filtration, so as to save energy. The oven drum baffle is installed on the upper half of the inner part of the oven circular net, and its function is to close the hot air flow and form an effective circulation of hot air. The baffle sealing part is a non-working surface, and its wrap angle to the drum drying net must match the wrap angle of the wet spunlace nonwoven material to the drum drying net;

[0019] In addition to the above-mentioned functions of airflow penetration, condensation and moisture extraction, the upper and lower perforated guide plates also have the function of airflow rectification, so that the hot air can vertically, evenly and orderly penetrate the wet-laid spunlace nonwoven materials, and the moisture of the materials can be evaporated quickly; the burner and the oven air supply circulation fan and the hot air exhaust circulation fan work together to ensure that part of the hot air is taken away and discharged outside the machine, and part is circulated, so that the drying system can operate continuously and orderly and continuously complete the drying effect.

[0020] The drying part of the production line is composed of several of the above-mentioned drying units. When the wet-laid spunlace nonwoven material passes by a drum drying mesh working surface and has not yet reached the expected moisture regain, the material enters the next drying unit in sequence and simultaneously switches the contact surface between the material and the drum drying mesh working surface. After multiple alternating dryings of the front and back sides, the material is sent out and wound up by the cloth guide roller at the cloth outlet until the moisture regain reaches the winding standard.

[0021] Beneficial effects: The beneficial effects of the present invention are as follows:

[0022] (1) The drying system of the present invention adopts a penetrating structure design, so that the hot air can directly act on the surface of the material, greatly shortening the drying time and reducing energy consumption;

[0023] (2) The drying system of the present invention optimizes the hot air circulation system, ensures uniform temperature distribution inside the oven, uniform drying, and improves product quality. It is expected that the thermal efficiency of the new system will increase by 20%, production efficiency will increase by 30%, and product qualification rate will increase by 5%. At the same time, the energy consumption of the oven will be reduced by 20%, and the production cost will be reduced accordingly;

[0024] (3) In the drying system of the present invention, two rows of holes adjacent to each other are arranged on the upper perforated guide plate, the middle guide plate is streamlined and installed at an angle of 10° to 15°, and the lower end is directly connected to the guide groove to ensure smooth air flow and timely discharge of condensed water;

[0025] (4) The wall frame of the drying system of the present invention is composed of a frame, inner and outer panels and an intermediate insulation layer. The frame and the inner and outer panels are made of stainless steel metal materials. The frame is an I-beam structure. The panel thickness is 0.8-1.2 mm. The outer surface is a smooth surface, and the inner surface is a hydrophobic and anti-corrosion surface. The intermediate insulation layer is a glass fiber / rock wool composite needle-punched felt, wherein the glass fiber has a fineness of 10-25 μm, a length of 51-76 mm, and a content of 60%-80%. The rock wool fiber has a fineness of 7-15 μm, a length of 51-76 mm, and a content of 20%-40%. The two fibers are opened and mixed, and then air-laid and needle-punched for compounding. The single-layer density of the composite felt is 1000-1500 g / m 2 , the thickness is 30~40mm. During assembly, 3~4 layers of composite are used according to the thermal insulation requirements. The thickness after composite is controlled at 90~130mm to maintain a reasonable air static layer;

[0026] (5) The servo motor transmission of the drying system of the present invention eliminates the shutdown caused by cloth breakage in the oven, thereby improving production efficiency. At the same time, the intelligent control system of the oven can set and adjust the drying parameters according to the characteristics of different materials, achieve precise control, and reduce energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1This is a schematic diagram of the structure of an oven according to an embodiment of the present invention;

[0028] Figure 2 A cross-sectional view of a wall structure of an oven according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of an upper air guide plate according to an embodiment of the present invention;

[0030] Figure 4 The figure is a schematic diagram of the structure of the lower air guide plate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center", "up", "down", "left", "right", "inside" and "outside" are the directions or positional relationships shown, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] The present invention is further described in detail below through specific implementation examples in conjunction with the accompanying drawings.

[0035] Example 1

[0036] like Figure 1 As shown, a hot air penetration drying system for wet spunlace comprises a wall frame 1, a heat circulation air supply adjustment device 4 and a circulation fan, wherein the wall frame 1 is provided with an upper air guide plate 2, a rotary drum drying net 5 and a lower air guide plate 6;

[0037] The upper air guide plate 2 is located above the rotary drum drying net 5, the lower air guide plate 6 is located below the rotary drum drying net 5, and the heat cycle air supply regulating device 4 is respectively arranged at the inlet and outlet of the oven.

[0038] In this embodiment, in order to improve the heat preservation effect, Figure 2 As shown, the wall frame 1 includes a frame, an outer panel 11, an inner panel 13 and an intermediate insulation layer 12, and the intermediate insulation layer 12 adopts a glass fiber / rock wool composite needle felt structure.

[0039] Furthermore, the frame is an I-beam structure, and the frame, outer panel 11 and inner panel 13 are all made of stainless steel material, the outer surface is a smooth surface, and the inner surface is a hydrophobic and corrosion-resistant surface. The thickness of the outer panel 11 and the inner panel 13 is 0.8~1.2mm.

[0040] Furthermore, the glass fiber in the intermediate insulation layer 12 has a fineness of 10-25 μm, a length of 51-76 mm, and a content of 60%-80%. The rock wool fiber has a fineness of 7-15 μm, a length of 51-76 mm, and a content of 20%-40%. The two fibers are opened and mixed, and then air-laid and needle-punched for compounding. The single-surface density of the composite felt is 1000-1500 g / m 2 , the thickness is 30~40mm. During assembly, 3~4 layers are used according to the insulation requirements. After the composite, the thickness of the middle insulation layer is controlled at 90~130mm to maintain a reasonable air static layer.

[0041] In this embodiment, the upper guide air plate 2 and the lower guide air plate 6 are both made of stainless steel with a thickness of 1.5~2.0mm. The surfaces are both hydrophobic and anti-corrosion surfaces. The upper and lower air plates are perforated in position with a hole diameter of 15~20mm and a hole spacing of 2.5~3 times the hole diameter.

[0042] In order to discharge the water accumulated on the upper guide plate in time, Figure 3 As shown, the upper deflector plate 2 includes a first plate body 21, and a plurality of first through holes 22 are distributed on the first plate body 21. The deflector plate between two adjacent rows of first through holes 22 in the first plate body 21 is a streamlined ridge structure 23, and the first plate body 21 is installed at an angle of 10° to 15°, and the lower end is directly connected to the guide groove to ensure smooth airflow and timely discharge of condensed water. The upper deflector plate 2 is close to the air outlet of the system, and the air has a high moisture content, which will produce condensed water. The conventional perforated deflector plate is slow to dehydrate and has low drying efficiency, so an inclined structure is required.

[0043] In this embodiment, Figure 4As shown, the lower air guide plate 6 is close to the air outlet of the system, the air moisture content is very low, and no condensation water is generated. A conventional perforated air guide plate can be used. The second plate body 61 is made of stainless steel metal material with a thickness of 1.5-2.0 mm and a hydrophobic and anti-corrosion surface. The second through holes 62 are evenly perforated on the plate vertically, with a hole diameter of 15-20 mm and a hole spacing of 2.5-3 times the hole diameter.

[0044] In this embodiment, Figure 1 As shown, the oven drum drying net 5 is a direct-acting component of the hot air penetration drying system for wet spunlacing. It is cylindrical and located in the middle of the oven. It is a nickel-chromium alloy net with high thermal conductivity. The number of holes in the net is 17-20 meshes. The objects to be dried are wavy and closely attached to the surface of the oven drum drying net 5. The heated hot air enters from the periphery of the oven drum drying net 5, passes through the objects to be dried, and then passes through the oven drum drying net 5 into the interior.

[0045] In this embodiment, Figure 1 As shown, the system also includes a rotary drum hot air shielding plate 3, which is fixed to the upper inner part of the rotary drum drying net 5, has a semicircular structure, is made of stainless steel metal material, and has a thickness of 2.0-3.0 mm. The main function of the rotary drum hot air shielding plate 3 is to send the hot air heated by the hot air furnace into the drying area according to a predetermined direction, working temperature and air volume, thereby completing the drying of the material.

[0046] In this embodiment, Figure 1 As shown, the heat cycle air supply regulating device 4 is respectively arranged at the inlet and outlet of the oven. The heat cycle air supply regulating device 4 adopts a mature PLC control system to improve the automation degree and operation convenience of the oven.

[0047] In this embodiment, the circulating fan includes a hot air exhaust circulating fan 7 and a burner and oven air supply circulating fan 8. The hot air exhaust circulating fan 7 drives the fan blades to rotate through the motor, generating a negative pressure effect, sucking in the hot and humid air passing through the rotary drum drying net 5 and discharging it into the steam-water separator through the exhaust port, and the recovered hot air after separation and filtration is re-sent into the air supply system to save energy. Figure 1 As shown, the hot air exhaust circulation fans 7 include two, one of which is installed in the rotary drum drying net 5, and the other is installed outside the drying oven.

[0048] The burner and oven air supply circulation fan 8 are components of the air supply system. The oven burner is heated by direct combustion of natural gas. The added air consists of two parts: fresh air from the outdoors and recycled hot air after heating. The heated hot air is sent into the drying area by the oven air supply circulation fan through the lower guide air plate 6.

[0049] Example 2

[0050] A method for a hot air penetration drying system for wet spunlacing, comprising:

[0051] Combination Figure 1 The wet spunlaced nonwoven materials to be dried enter the hot air penetration drying system at a design speed of 5-200 m / min after negative pressure dehydration in the front process, and are fed into the drying oven drum drying net 5 by the cloth guide roller group. The wrap angle of the wet spunlaced nonwoven materials to the drying oven drum drying net 5 is 110°~150°. From the perspective of drying efficiency, the larger the wrap angle, the higher the efficiency, but at the same time, the wet strength of the wet spunlaced nonwoven materials must be taken into account. For materials with greater wet strength, the wrap angle to the drying oven drum drying net 5 can even be increased to 180°, but for materials with less wet strength, such as flushable wet wipes rolls, the wrap angle to the drying oven drum drying net 5 should be smaller, otherwise it will break and cannot be driven normally and continuously.

[0052] The hot air exhaust circulation fan 7 of the circulation fan and the burner and oven air supply circulation fan 8 work in coordination to form a gradient pressure distribution area where the internal pressure of the drum drying net 5 is lower than the external pressure, so that the wet-laid spunlace nonwoven material is adsorbed on the surface of the drum drying net 5. After being heated by the burner and the oven air supply circulation fan 8, the air passes through the lower guide air plate 6, the wet-laid spunlace nonwoven material, and the lower half of the drum drying net 5 from bottom to top, and most of it enters the interior of the drum drying net 5. At this time, the moisture in the material is partially taken away, the hot air temperature drops from 110°~130° to 80°~100°, and the humidity increases from 10%~20% to more than 65%. This hot and humid air is no longer suitable for material drying and needs to be discharged from the drying system with the help of the hot air exhaust circulation fan 7, and then re-enters the drying system after external steam-water separation and filtration. The drier hot and dry air continues to circulate in the system, and the other part of the humid hot air that has not entered the hot air exhaust circulation fan 7 will bypass the drum hot air baffle 3 and rise to the upper guide air plate 2, where the moisture will condense on the streamlined ridge of the upper guide air plate 2 and be discharged to the lower end under the action of the installation inclination angle, while the humid hot air with humidity reduced to 30%~40% is discharged from the drying system by the hot air exhaust circulation fan 7 at the top of the mechanism, and after external steam-water separation and filtration, it will be re-entered into the air supply system to save energy. The oven drum baffle 3 is installed on the upper half of the inner part of the oven circular net, and its function is to close the hot air flow and form an effective circulation of hot air. The baffle sealing part is a non-working surface, and its wrapping angle to the drum drying net 5 must match the wrapping angle of the wet-process spunlace nonwoven material to the drum drying net 5.

[0053] In addition to the above-mentioned functions of air flow, condensation and water extraction, the upper perforated air guide plate 2 and the lower perforated air guide plate 6 also have the function of air flow rectification, so that the hot air can vertically, evenly and orderly penetrate the wet spunlace nonwoven material, and the water in the material can evaporate quickly. The burner and the oven air supply circulation fan 8 and the hot air exhaust circulation fan 7 work together to ensure that part of the hot air is taken away and discharged outside the machine, and part is circulated, so that the drying system can operate continuously and orderly and continuously complete the drying effect.

[0054] The drying part of the production line is composed of several drying units mentioned above. When the wet-process spunlace nonwoven material bypasses a working surface of the drum drying net 5 and has not reached the expected moisture regain, the material enters the next drying unit in sequence, and at the same time changes the contact surface between the material and the working surface of the drum drying net 5. After multiple alternating dryings on the front and back sides, the material is sent out and rolled up by the cloth guide roller at the cloth outlet when the moisture regain reaches the winding standard. The structures of the drying units are basically similar, but the drying temperature and discharge speed are configured in a gradient, that is, the drying unit that first contacts the material has a higher temperature and a faster exhaust speed, and the temperature of the subsequent drying units will gradually decrease, and the discharge speed will also gradually decrease. The overall gradient design must conform to the drying curve, which is conducive to improving the drying efficiency and saving energy.

[0055] The present invention discloses a hot air penetration drying system for wet spunlace, and its unique penetration design enables the hot air to act directly on the surface of the material, greatly shortening the drying time and reducing energy consumption. The internal structure of the oven is innovatively designed, and the hot air circulation system is optimized to ensure uniform distribution of temperature inside the oven, uniform drying, and improved product quality. It is expected that the thermal efficiency of the new system will increase by 20%, production efficiency will increase by 30%, and product qualification rate will increase by 5%. At the same time, the energy consumption of the oven will be reduced by 20%, and production costs will be reduced accordingly. The servo motor transmission eliminates the shutdown caused by broken cloth in the oven, thereby improving production efficiency. Using the intelligent control system of the oven, the drying parameters can be set and adjusted according to the characteristics of different materials, achieving precise control and reducing energy consumption.

[0056] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A hot air penetration drying system for wet spunlacing, characterized in that: It comprises a wall frame (1), a heat circulation air supply adjustment device (4) and a circulation fan, wherein an upper air guide plate (2), a rotary drum drying net (5) and a lower air guide plate (6) are arranged in the wall frame (1); The upper air guide plate (2) is located above the rotary drum drying net (5), the lower air guide plate (6) is located below the rotary drum drying net (5), and the heat cycle air supply adjustment device (4) is respectively arranged at the inlet and outlet of the drying oven.

2. A hot air penetration drying system for wet spunlacing according to claim 1, characterized in that: The wall frame (1) comprises a frame, an outer panel (11), an inner panel (13) and an intermediate thermal insulation layer (12); the intermediate thermal insulation layer (12) adopts a glass fiber / rock wool composite needle felt structure.

3. The hot air penetration drying system for wet spunlacing according to claim 2, characterized in that: The frame is an I-beam structure; the frame, the outer panel (11) and the inner panel (13) are all made of stainless steel; the thickness of the outer panel (11) and the inner panel (13) is 0.8-1.2 mm.

4. The hot air penetration drying system for wet spunlacing according to claim 2, characterized in that: The glass fiber in the intermediate insulation layer (12) has a fineness of 10-25 μm, a length of 51-76 mm, and a content of 60%-80%. The rock wool fiber has a fineness of 7-15 μm, a length of 51-76 mm, and a content of 20%-40%. The two types of fibers are opened and mixed, then air-laid and needle-punched for compounding. The single-layer density of the composite felt is 1000-1500 g / m 2 , thickness is 30~40mm.

5. The hot air penetration drying system for wet spunlacing according to claim 1, characterized in that: The upper air guide plate (2) and the lower air guide plate (6) are both made of stainless steel, with a thickness of 1.5 to 2.0 mm, and both surfaces are hydrophobic and anti-corrosion surfaces. The upper and lower layers are perforated in opposite positions, with a hole diameter of 15 to 20 mm, and a hole spacing of 2.5 to 3 times the hole diameter.

6. The hot air penetration drying system for wet spunlacing according to claim 5, characterized in that: The middle air guide plate of the two adjacent rows of holes of the upper air guide plate (2) is streamlined and is installed at an angle of 10° to 15°, with the lower end directly connected to the guide groove.

7. The hot air penetration drying system for wet spunlacing according to claim 1, characterized in that: The rotary drum drying net (5) is of cylindrical structure, located in the middle of the oven, and is a nickel-chromium alloy net with high thermal conductivity, and the number of holes of the net is 17-20 meshes.

8. The hot air penetration drying system for wet spunlacing according to claim 7, characterized in that: It also comprises a rotary drum hot air shielding plate (3), which is fixed to the upper inner part of the rotary drum drying net (5), has a semicircular structure, is made of stainless steel metal material, and has a thickness of 2.0-3.0 mm.

9. The hot air penetration drying system for wet spunlacing according to claim 1, characterized in that: The circulating fan comprises a hot air exhaust circulating fan (7) and a burner and oven air supply circulating fan (8).

10. A method for a hot air penetration drying system for wet spunlacing according to any one of claims 1 to 9, characterized in that: include: The wet-laid spunlace nonwoven material to be dried enters the hot air penetration drying system at a designed speed of 5-200 m / min after negative pressure dehydration in the front process, and is fed into the drying oven drum drying net (5) by the cloth guide roller group. The wrap angle of the wet-laid spunlace nonwoven material to the drying oven drum drying net (5) is 110°-150°; The hot air exhaust circulation fan (7) of the circulation fan and the burner and oven air supply circulation fan (8) work in coordination to form a gradient pressure distribution area where the internal pressure of the drum drying net (5) is lower than the external pressure, so that the wet spunlace nonwoven material is adsorbed on the surface of the drum drying net (5); after the supply air is heated by the burner and the oven air supply circulation fan (8), it passes through the lower guide air plate (6), the wet spunlace nonwoven material, and the lower half of the drum drying net (5) from bottom to top, and most of it enters the interior of the drum drying net (5). At this time, the moisture in the material is partially taken away, the hot air temperature drops from 110°~130° to 80°~100°, and the humidity increases from 10%~20% to more than 65%. This hot and humid air is no longer suitable for For material drying, the hot air exhaust circulation fan (7) is used to discharge the drying system, and then after external steam-water separation and filtration, it is re-entered into the air supply system, while the relatively dry hot air continues to circulate in the system. The other part of the moist hot air that has not entered the hot air exhaust circulation fan (7) will bypass the drum hot air baffle (3) and rise to the upper guide air plate (2), where the moisture will condense on the streamlined ridge of the upper guide air plate (2) and be discharged to the lower end under the effect of the installation inclination angle. The relatively moist hot air with the humidity reduced to 30% to 40% is discharged from the drying system by the hot air exhaust circulation fan (7) at the top of the mechanism, and after further external steam-water separation and filtration, it is re-entered into the air supply system, so as to save energy. The drying drum wind baffle (3) is installed on the upper half of the inner part of the drying drum net, and its function is to seal the hot air flow and form an effective circulation of the hot air. The sealing part of the baffle is a non-working surface, and its wrapping angle to the drying drum net (5) must match the wrapping angle of the wet-laid spunlace nonwoven material to the drying drum net (5); In addition to the above-mentioned functions of air flow, condensation and moisture extraction, the upper perforated air guide plate (2) and the lower perforated air guide plate (6) also have the function of air flow rectification, so that the hot air vertically, evenly and orderly penetrates the wet-laid spunlace nonwoven material, and the moisture of the material evaporates rapidly; the burner and the oven air supply circulation fan (8) and the hot air exhaust circulation fan (7) work together to ensure that part of the hot air is taken away and discharged outside the machine, and part is circulated, so that the drying system operates continuously and orderly and continuously completes the drying effect. The drying part on the production line is composed of a plurality of the above-mentioned drying units. When the wet-laid spunlace nonwoven material bypasses a working surface of a rotary drum drying net (5) and has not yet reached the expected moisture regain, the material enters the next drying unit in sequence, and at the same time changes the contact surface between the material and the working surface of the rotary drum drying net (5). After multiple alternating drying of the front and back sides, the material is sent out and rolled up by the cloth outlet guide roller when the moisture regain of the material reaches the winding standard.

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