Papermaking drying device with wireless heating function

Abstract

The utility model discloses a wireless heating papermaking drying device which structurally comprises a drying cylinder barrel, a driving shaft, a power receiving coil barrel, a transmitting coil barrel, a bearing, a first cable, a second cable, a first driving circuit board, a transmitting coil, a receiving coil, a second driving circuit board, a packaging layer, an electrothermal film, a Darlington tube, a rib plate, a supporting shaft and a lead. The wireless heating device is adopted to replace steam heating, devices such as a boiler, a cooling device and a pipeline are not needed, the technological process is simplified, the equipment investment is reduced, the maintenance cost is reduced, and the production cost is further reduced; no pressure container is needed, and production risks are reduced. Compared with the traditional steam heating, the wireless heating can reduce the required equipment and cost, eliminate the potential safety hazard and control the starting and stopping of the heating more quickly.

Description

Technical Field

[0001] The utility model relates to the field of chemical equipment, and relates to a paper drying device heated by radio waves. Background Art

[0002] A drying cylinder is a hollow cylinder made of cast iron with covers at both ends, consisting of a cylinder body and cylinder covers at both ends. The outer diameter is mostly 1000 - 3000 mm. During operation, steam is passed through the inside to dry and iron the conveyed paper. The cast iron drying cylinder used in a paper machine is a key component for paper drying - a Class I pressure vessel. The number of cast iron drying cylinders accounts for about 2 / 3 of the total number of pressure vessels in the paper industry. The drying cylinder is heated by steam. The saturated steam introduced from the steam joint condenses inside the drying cylinder, and the released heat causes the temperature of the drying cylinder to rise, thereby heating the paper web running on the surface of the roll shell. Heat is transferred to the paper during the contact between the paper and the surface of the drying cylinder. A large amount of condensed water is generated after the steam releases heat and condenses. Due to the rotation of the drying cylinder, the condensed water adheres to the inner surface of the drying cylinder under the action of centrifugal force and forms a water ring at a relatively high angular velocity, which hinders the transfer of heat to the surface of the drying cylinder. Therefore, a siphon is needed to drain the condensed water in time. When the vehicle speed is low, a water ring will not be formed, but there will still be condensed water splashing and accumulating inside the drying cylinder.

[0003] Therefore, traditional paper drying cylinders require many equipment such as a boiler steam generating device and a cooling water circulation device, and they are pressure vessels with a relatively high risk factor.

[0004] In addition, during the papermaking process, the wet paper web needs to be transferred from the felt to the surface of the drying cylinder through a press roll for drying. The surface of the drying cylinder is coated with a coating. Usually, the width of the wet paper web is smaller than the width of the coating. Since the hot steam inside the drying cylinder is evenly distributed, the temperature of the surface of the drying cylinder is the same when there is no wet paper web passing through the drying cylinder. When the wet paper web is dried on the surface of the drying cylinder, the water in the wet paper web evaporates at a high temperature. Since the evaporation of water requires heat absorption, the temperature of the coating surface where the wet paper web passes will decrease. As a result, the temperature of the coating surface of the drying cylinder without the wet paper web passing through is higher than that of the coating surface of the drying cylinder with the wet paper web passing through. When the temperature of the drying cylinder coating is higher than a certain critical temperature, the drying cylinder coating will undergo crosslinking and curing, manifested as hardening of the drying cylinder coating. The coatings on both sides of the drying cylinder are more likely to harden compared to the part of the coating where the wet paper web passes through in the middle, which is the so-called "yellow edge" problem of the drying cylinder coating in the paper industry. Summary of the Invention

[0005] The technical problem solved by the utility model is that, without changing the original structure of the drying cylinder, by installing a radio heating device to dry the paper, it is possible to stop using many equipment such as a boiler steam and a condensate water circulation device, eliminate the potential danger of using a pressure vessel, reduce the consumption of energy and water, and achieve precise control of the drying temperature.

[0006] The technical solution adopted by the present utility model is to install a radio heating device on the basis of a traditional papermaking drying device, including: a power receiving coil cylinder, a transmitting coil cylinder, a bearing, a cable, a driving circuit board, a transmitting coil, a receiving coil, a packaging layer, a heating film, a relay switch group, a rib plate, a support shaft, and a lead wire.

[0007] A papermaking drying device with radio heating includes a drying cylinder and a driving shaft. The driving shaft penetrates the drying cylinder, and the drying cylinder is driven to rotate by one end of the driving shaft. An outer sleeve of the other end of the driving shaft is provided with a power receiving coil cylinder, and a receiving coil is wound outside the power receiving coil cylinder. The receiving coil is electrically connected to a driving circuit board two in the power receiving coil cylinder; A transmitting coil cylinder is rotatably sleeved on the power receiving coil cylinder, and a transmitting coil is wound inside the transmitting coil cylinder. The transmitting coil is electrically connected to a driving circuit board one in the transmitting coil cylinder, and the transmitting coil and the receiving coil do not contact each other; The driving circuit board one is electrically connected to a cable one of the power supply, and the driving circuit board two is electrically connected to a relay switch group inside the drying cylinder;

[0008] The outer surface of the drying cylinder is divided into a plurality of annular regions, and a heating film is provided in each annular region. The heating film is electrically connected to the relay switch group to control the temperature of the annular region, and the heating films of the plurality of annular regions are connected in parallel to the driving circuit board two through the relay switch group.

[0009] The annular region includes a middle annular region, a widened annular region, and an extra-wide annular region. The middle annular region is located in the middle of the drying cylinder, the widened annular region is located at both ends of the middle annular region, and the extra-wide annular region is located on one side of the widened annular region away from the middle annular region; A heating film is laid on the surface of each annular region by means of slurry coating or adhesion, and the heating films of different annular regions do not contact each other.

[0010] The heating film is set to have a certain width and a plurality of non-connected winding structures at the head and tail. Pins are provided at the head and tail of each heating film, and the pins are electrically connected to the relay switch group.

[0011] The relay switch group includes a plurality of temperature relays. The number of temperature relays is equal to the number of heating films. Each heating film is connected in series with a temperature relay to form a heating circuit. The temperature relay is closely attached to the annular region where the heating film it is connected to is located, and each heating circuit is connected in parallel to the driving circuit board two.

[0012] The outer surface of the drying cylinder is further provided with a packaging layer, and the packaging layer encapsulates the heating film on the surface of the drying cylinder. The packaging layer is a PI film or a PET film.

[0013] The power receiving coil cylinder is rotatably connected to the transmitting coil cylinder through a bearing.

[0014] There is a support shaft inside the dryer cylinder, and a plurality of annular rib plates are arranged along the axis on the outer edge of the support shaft.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] 1. Compared with traditional paper-making drying equipment, there is no longer a need to use many equipment supporting devices such as boiler steam generating devices and cooling water circulation devices. The construction cost and operation cost are saved.

[0017] 2. High-pressure equipment such as boilers is no longer used, eliminating potential safety hazards.

[0018] 3. Using radio heating, the instant on and off of heating can be achieved faster.

[0019] 4. The installation of radio heating equipment is carried out on a traditional paper-making dryer cylinder, realizing the utilization of traditional equipment and reducing the application cost.

[0020] 5. The temperature of a local area on the dryer cylinder can be controlled to avoid the problem of yellow edges appearing after the paper is dried. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the utility model;

[0022] Figure 2 It is a schematic diagram of the annular area partition of the dryer cylinder;

[0023] Figure 3 It is a circuit schematic diagram of the electrothermal film.

[0024] Among them, 1 is the dryer cylinder, 2 is the drive shaft, 3 is the power receiving coil cylinder, 4 is the transmitting coil cylinder, 5 is the bearing, 6 is the first cable, 7 is the second cable, 8 is the first drive circuit board, 9 is the transmitting coil, 10 is the receiving coil, 11 is the second drive circuit board, 12 is the encapsulation layer, 13 is the electrothermal film, 14 is the relay switch group, 15 is the rib plate, and 16 is the support shaft. Specific Embodiments

[0025] The following further describes the utility model in detail in conjunction with embodiments, but the protection scope of the utility model is not limited thereto.

[0026] Embodiment 1

[0027] As an example, such as Figure 1As shown in the figure, a paper drying device with radio heating includes: a drying cylinder 1, which is driven to rotate by a driving shaft 2 at one end. A current receiving coil cylinder 3 is sleeved on the driving shaft at the other end of the drying cylinder 1. An emitting coil cylinder 4 is sleeved outside the current receiving coil cylinder 3. An emitting coil 9 is wound inside the emitting coil cylinder 4. A receiving coil 10 is wound outside the current receiving coil cylinder 3. The emitting coil 9 is electrically connected to a driving circuit board one 8 in the emitting coil cylinder 4. The driving circuit board one 8 is electrically connected to a cable one 6 from a power source. The receiving coil 10 is electrically connected to a driving circuit board two 11 in the current receiving coil cylinder 3. The driving circuit board two 11 is electrically connected to a plurality of cable twos 7. The cable twos 7 are electrically connected to a relay switch group 14 inside the drying cylinder; the emitting coil 9 and the receiving coil 10 do not contact each other. The emitting coil 9 is used to transmit electrical energy to the receiving coil 10 in the form of radio waves. The driving circuit board one 8 is used to convert external direct current into alternating current and transmit the alternating current to the emitting coil cylinder 4. The driving circuit board two 11 is used to rectify, filter, and regulate the alternating current corresponding to the received electromagnetic energy and convert it, and lead out the stable direct current through the cable twos 7. The current receiving coil cylinder 3 and the emitting coil cylinder 4 are rotationally connected through a bearing 5.

[0028] The outer surface of the drying cylinder 1 is divided into multiple annular regions from the middle to both ends, including a middle annular region located in the middle of the drying cylinder 1, widened annular regions located at both ends of the middle annular region. There is also an extra-wide annular region between the widened annular region far from the middle annular side and the end of the drying cylinder 1. On the surfaces of the middle annular region, widened annular region, and extra-wide annular region, an electrothermal film 13 that does not contact each other is laid by means of slurry coating or adhesion respectively. The electrothermal film 13 in each annular region is set to have a certain width and a plurality of non-connected line segments with a meandering structure. Pins are respectively arranged at the head and tail of each electrothermal film 13. The pins of the electrothermal film 13 in each annular region are electrically connected to the relay switch group 14 respectively.

[0029] The relay switch group 14 includes multiple temperature relays. The number of temperature relays is equal to the number of electrothermal films 13. Each electrothermal film 13 is connected in series with a temperature relay to form an electrothermal circuit. Each heating circuit is connected in parallel to the driving circuit board two 1 through the cable two 7. The temperature relay is closely attached to the annular region where the electrothermal film 13 it is connected to is located.

[0030] An encapsulation layer 12 is also provided on the outer surface of the drying cylinder 1. The encapsulation layer 12 encapsulates the electrothermal film 13 between the encapsulation layer 12 and the surface of the drying cylinder 1. The encapsulation layer 12 is selected from PI film or PET film, preferably PI film. Because PI film (polyimide film) has excellent high and low temperature resistance, electrical insulation, adhesiveness, radiation resistance, and chemical resistance, it can be used for a long time in the temperature range of -269°C to 280°C, and can reach a high temperature of 400°C for a short time.

[0031] It is understandable that the wet paper is dried by covering the surface of the encapsulation layer 12 of the drying cylinder 1. When the width of the wet paper is smaller than that of the drying cylinder 1, the widened annular area or the extra-wide annular area at both ends of the drying cylinder is not completely covered by both sides of the wet paper. The moisture in the wet paper web evaporates at high temperature. Since the evaporation of moisture requires heat absorption, the surface temperature of the encapsulation layer 12 passed by the wet paper web will decrease. As a result, the surface temperature of some areas of the widened annular area or the extra-wide annular area without the wet paper web passing through is higher than the surface of the encapsulation layer 12 passed by the wet paper web. When the temperature of the widened annular area or the extra-wide annular area is higher than the critical temperature, the temperature relay can be disconnected to cut off the power supply to the heating film 13 in the over-temperature widened annular area or the extra-wide annular area. The over-temperature widened annular area or the extra-wide annular area starts to cool down. When the temperature drops to a certain value, the temperature relay can automatically close and reconnect the power supply, and the heating film 13 can heat normally to keep the temperature of the widened annular area or the extra-wide annular area within the safe range, preventing the problem of yellow edges from occurring on both sides of the wet paper web due to the too high surface temperature of the drying cylinder.

[0032] Preferably, a support shaft 16 is provided in the drying cylinder 1. A plurality of annular rib plates 15 are arranged along the axis on the outer edge of the support shaft 16. The rib plates 15 are used to support the shell of the drying cylinder 1 and reduce the degree of deformation of the drying cylinder 1 after being heated.

Claims

1. A radio-heated papermaking drying device, comprising a drying cylinder and a driving shaft, characterized in that: The driving shaft (2) passes through the drying cylinder (1), and the drying cylinder (1) is driven to rotate by one end of the driving shaft (2). The other end of the driving shaft (2) is sleeved with a receiving coil cylinder (3), and a receiving coil (10) is wound around the receiving coil cylinder (3). The receiving coil (10) is electrically connected to a second driving circuit board (11) in the receiving coil cylinder (3); a transmitting coil cylinder (4) is rotatably sleeved on the receiving coil cylinder (3), and a transmitting coil (9) is wound around the transmitting coil cylinder (4). The transmitting coil (9) is electrically connected to a first driving circuit board (8) in the transmitting coil cylinder (4), and the transmitting coil (9) and the receiving coil (10) do not contact each other; the first driving circuit board (8) is electrically connected to a first power cable (6), and the second driving circuit board (11) is electrically connected to a relay switch group (14) in the drying cylinder; The outer surface of the drying cylinder (1) is divided into a plurality of annular areas, each of which is provided with an electric heating film (13), the electric heating film (13) being electrically connected to a relay switch group (14) to control the temperature of the annular area, and the electric heating films (13) of the plurality of annular areas being connected in parallel to a second driving circuit board (11) via the relay switch group (14).

2. A radio-heated papermaking drying device according to claim 1, characterized in that: The annular area comprises a middle annular area, a widened annular area and an extra-wide annular area, wherein the middle annular area is located in the middle of the drying cylinder (1), the widened annular area is located at both ends of the middle annular area, and the extra-wide annular area is located on the side of the widened annular area away from the middle annular area; the surface of each annular area is laid on an electric heating film (13) by slurry coating or adhesion, and the electric heating films (13) in different annular areas do not contact each other.

3. A radio-heated papermaking drying device according to claim 1, characterized in that: The electric heating film (13) is configured as line segments with a certain width and a plurality of serpentine structures that are not connected at the head and tail. Pins are provided at the head and tail of each electric heating film, and the pins are electrically connected to the relay switch group (14).

4. A radio-heated papermaking drying device according to claim 1, characterized in that: The relay switch group (14) comprises a plurality of temperature relays, the number of the temperature relays being equal to the number of the electric heating films (13), each electric heating film (13) being connected in series with a temperature relay to form an electric heating circuit, the temperature relay being closely attached to the annular region where the electric heating film (13) to which it is connected is located, and each heating circuit is connected in parallel with the second driving circuit board (11).

5. A radio-heated papermaking drying device according to claim 1, characterized in that: The outer surface of the drying cylinder is also provided with a packaging layer (12), and the packaging layer (12) packages the electric heating film (13) on the surface of the drying cylinder (1), and the packaging layer (12) is a PI film or a PET film.

6. A radio-heated papermaking drying device according to claim 1, characterized in that: The receiving coil drum (3) is rotatably connected to the transmitting coil drum (4) via a bearing (5).

7. A radio-heated papermaking drying device according to claim 1, characterized in that: A support shaft (16) is arranged inside the drying cylinder (1), and a plurality of annular ribs (15) are arranged outside the support shaft (16) along the axis.

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