Spiral conveying barrel and spiral conveyor

Abstract

The utility model provides a spiral material conveying barrel and a spiral material conveying machine. The spiral material conveying barrel comprises a material conveying shaft, an outer barrel and a magnetic suspension support. A spiral blade is arranged on the material conveying shaft, and a magnet is arranged on the blade. The outer cylinder and the material conveying shaft are coaxially arranged, the material conveying shaft and the blades are located in the outer cylinder, and a material conveying space is formed among the outer cylinder, the material conveying shaft and the blades. The magnetic suspension support is arranged on the outer surface of the outer cylinder and surrounds the outer cylinder in the radial direction of the outer cylinder, and the magnetic suspension support interacts with magnets of the blades, so that the blades do not make contact with the outer cylinder in the material conveying process. The arrangement of the magnetic suspension support prevents the far end of the material conveying shaft from perturbing in the material conveying process due to deflection, and prevents the edge of the blade from being damaged by friction with the inner wall of the outer cylinder.

Description

Technical Field

[0001] The present application relates to the technical field of biomass biogas production, and in particular to a screw conveyor barrel and a screw conveyor. Background Art

[0002] In the existing biogas production using corn stalks as raw materials, a screw conveyor is usually used to convey the raw materials to the reaction tank, and a conveying shaft and stirring blades are usually set in the screw conveyor. Since corn stalks contain a lot of fiber materials during the conveying process, the fluidity is cross-flowing, the device is complex, and the maintenance is difficult, the screw conveyors used in most of the biomass biogas reaction tanks currently use two types of screw conveyors: shafted screw conveyors and shaftless screw conveyors.

[0003] In both forms, the length of the shafted screw conveyor and the shaftless screw conveyor will be customized according to the size and structure of the factory. Due to the length, the screw conveyor is placed horizontally or vertically, which occupies a lot of factory space. The inclined placement will cause the blades of the screw conveyor shaft to contact and rub against the inner wall of the outer cylinder due to the deflection caused by the length of the screw conveyor and the rotation of the screw conveyor shaft during the conveying process, which will affect the service life of the conveyor shaft.

[0004] At the same time, since the spiral conveyor barrel needs to extend into the reaction tank, the side of the spiral conveyor shaft extending into the tank cannot be supported, that is, the end of the conveyor shaft that extends deep into the reaction tank is a free end. During the feeding process, the free end of the conveyor shaft will bend. Even if a bearing support is installed on the end of the conveyor shaft extending into the tank, it is easy to corrode, get stuck, etc. due to the inability to quickly repair it, resulting in long-term downtime. Utility Model Content

[0005] The main purpose of the present application is to overcome at least one defect of the above-mentioned prior art and to provide a screw conveyor barrel and a screw conveyor that can avoid the deflection of the conveyor shaft and does not require bearing supports.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] According to one aspect of the present application, a spiral feed cylinder is provided, comprising a feed shaft, an outer cylinder and a magnetic suspension support. The feed shaft is provided with blades arranged continuously in a spiral shape, and magnets are provided on the blades. The outer cylinder is coaxially arranged with the feed shaft, so that the feed shaft and the blades are both located in the outer cylinder, and a feed space is formed between the outer cylinder, the feed shaft and the blades. The magnetic suspension support is arranged on the outer surface of the outer cylinder and surrounds the outer cylinder in the radial direction of the outer cylinder, and the magnetic suspension support interacts with the magnets of the blades, so that the blades do not contact the outer cylinder during the feeding process.

[0008] According to one of the embodiments of the present application, the magnet is a permanent magnet, and the permanent magnet is arranged at the end of the blade away from the feeding shaft.

[0009] According to one of the embodiments of the present application, the magnetic levitation support includes at least four electromagnetic coils, which are arranged at intervals and radially surround the outer cylinder.

[0010] According to one of the embodiments of the present application, a sensor is disposed inside the electromagnetic coil, and the sensor detects the relative position between the blade and the electromagnetic coil and sends the detection result.

[0011] According to one embodiment of the present application, the sensor is a displacement sensor, and the displacement sensor detects the distance between the blade and the electromagnetic coil.

[0012] According to one of the embodiments of the present application, the magnetic levitation support includes two half rings, wherein at least two electromagnetic coils are arranged in each half ring.

[0013] According to one of the embodiments of the present application, the magnetic force of the magnetic suspension support is greater than the maximum radial load force of the spiral feed cylinder.

[0014] According to one of the embodiments of the present application, the magnetic force of the magnetic suspension support is twice the maximum radial load force of the spiral feed cylinder.

[0015] According to one of the embodiments of the present application, the spiral feeding cylinder is arranged at an angle.

[0016] According to another aspect of the present application, a screw conveyor is provided, comprising a controller, an actuator, a driver and a screw conveyor barrel as described above, wherein the driver drives the conveying shaft of the screw conveyor barrel, the controller receives a signal from the magnetic levitation support, and controls the actuator to adjust the magnetic levitation support.

[0017] According to one of the embodiments of the present application, the controller is a PLC controller, the actuator is a frequency converter, the signal of the magnetic levitation support is a current signal, and the frequency converter adjusts the current of the magnetic levitation support according to the control instruction of the PLC controller.

[0018] According to one of the embodiments of the present application, there are multiple magnetic levitation supports, and the multiple magnetic levitation supports are arranged at intervals, and the spacing between the magnetic levitation supports gradually decreases from the driving end of the conveying shaft to the free end of the conveying shaft.

[0019] According to a third aspect of the present application, a control method for a screw conveyor is provided, wherein the screw conveyor adopts the screw conveyor as described above, and the control method comprises the following steps:

[0020] Step S1: calibrating the zero position between the magnetic suspension support and the blade, and storing the zero position in the controller;

[0021] Step S2: During the feeding process, the magnetic suspension support detects the position information of the blade and sends the detection result to the controller;

[0022] Step S3: the controller controls the actuator to adjust the magnetic suspension support according to the detection result, so that the position relationship between the magnetic suspension support and the blade always remains at zero position.

[0023] According to one embodiment of the present application, the magnetic levitation support includes an electromagnetic coil and a displacement sensor. In step S2, the displacement sensor of the magnetic levitation support detects the distance between the edge of the blade and the corresponding electromagnetic coil, and converts the detection result into a current signal and sends it to the controller.

[0024] According to one of the embodiments of the present application, in step S3, the controller compares the current signal with the position zero and outputs a control instruction to the actuator, and the actuator adjusts the current of the electromagnetic coil of the magnetic levitation support so that the position relationship between the magnetic levitation support and the blade always remains at zero.

[0025] It can be seen from the above technical solution that the advantages and positive effects of the spiral feeding barrel proposed in this application are:

[0026] The spiral feed cylinder proposed in the present application has magnets arranged on the edge of the blades of the conveying shaft, and a magnetic suspension support arranged on the outer surface of the outer cylinder of the spiral feed cylinder. The magnetic suspension support surrounds the outer cylinder in the radial direction of the outer cylinder, and can utilize the magnetic suspension support to interact with the magnets of the blades, so that the blades remain in a state of not contacting the outer cylinder during the feeding process. The support force and axial positioning force that can be provided to the cantilever part of the spiral feed shaft realize high-precision support for the rotating shaft, so that the blades of the spiral conveying shaft will not contact the inner wall of the outer cylinder during the rotation process.

[0027] The spiral feed barrel of the present application fully solves the deflection problem caused by the lack of support on the free end of the spiral conveying shaft while meeting the feeding requirements of the spiral conveying machine. In addition, the free end of the conveying shaft does not directly contact the material in the reaction tank, which increases the service life of the spiral conveying machine. Even if the magnetic suspension support fails, it is easy and quick to replace because it is installed on the outer surface of the outer barrel, and it will not cause long-term shutdown for maintenance, which more effectively ensures the continuity of production and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various objects, features and advantages of the present application will become more apparent by considering the following detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. The accompanying drawings are merely exemplary illustrations of the present application and are not necessarily drawn to scale. In the accompanying drawings, the same reference numerals always represent the same or similar parts. Among them:

[0029] Figure 1 It is a structural schematic diagram of the spiral feeding cylinder of the present application.

[0030] Figure 2 yes Figure 1 Schematic diagram of the structure of direction A.

[0031] Figure 3 yes Figure 2 BB cross-sectional view.

[0032] Figure 4 yes Figure 1 CC section view of (flange not shown).

[0033] Figure 5 It is a schematic diagram of the screw conveyor of the present application and the installation of the conveyor.

[0034] Figure 6 It is a schematic diagram of the control process of this application.

[0035] The following are the descriptions of the reference numerals:

[0036] 1.Spiral feed tube;

[0037] 2. Driver;

[0038] 3. Controller;

[0039] 4. Actuator;

[0040] 5. Pretreatment workshop;

[0041] 6.Anaerobic reaction tank;

[0042] 7. Support;

[0043] 10. Feed shaft;

[0044] 11. Leaves;

[0045] 12. Magnet;

[0046] 13.Outer cylinder;

[0047] 14. Magnetic levitation support;

[0048] 15. Feeding port;

[0049] 16. Flange;

[0050] 141. A first electromagnetic coil;

[0051] 142. Second electromagnetic coil;

[0052] 143. The third electromagnetic coil;

[0053] 144. The fourth electromagnetic coil;

[0054] 145. First sensor;

[0055] 146. Second sensor;

[0056] 147. The third sensor;

[0057] 148. The fourth sensor;

[0058] D0. Position zero. DETAILED DESCRIPTION

[0059] Typical embodiments that embody the features and advantages of the present application will be described in detail in the following description. It should be understood that the present application can have various changes in different embodiments without departing from the scope of the present application, and the descriptions and drawings therein are essentially for illustrative purposes rather than for limiting the present application.

[0060] In the following description of different exemplary embodiments of the present application, reference is made to the accompanying drawings, which form a part of the present application, and in which different exemplary structures, systems and steps that can realize multiple aspects of the present application are shown by way of example. It should be understood that other specific schemes of components, structures, exemplary devices, systems and steps can be used, and structural and functional modifications can be made without departing from the scope of the present application. When introducing the elements / components / etc. described and / or illustrated herein, the terms "first", "second" and "third" etc. are used to indicate the presence of one or more elements / components / etc. The terms "comprising", "including" and "having" are used to indicate the meaning of open-ended inclusion and mean that in addition to the listed elements / components / etc., there may be other elements / components / etc. Although the terms "upper", "lower", "between" etc. can be used in this specification to describe different exemplary features and elements of the present application, these terms are used herein only for convenience, such as according to the direction of the examples described in the accompanying drawings. Nothing in this specification should be understood as requiring a specific three-dimensional direction of the structure to fall within the scope of the present application.

[0061] At present, in the biogas reactor system using corn stalks as raw materials, a screw feeder consisting of a screw feed barrel is usually used to transport corn stalks from the pretreatment workshop to the anaerobic reactor. The screw feeder mainly includes a motor and a screw feed barrel. The screw feed barrel is provided with a feed shaft and blades. The corn stalks enter the screw feed barrel from the feed inlet of the screw feed barrel. Driven by the motor, the feed shaft rotates to drive the blades to rotate, thereby transporting the corn stalks to the anaerobic reactor. Since one end of the feed barrel needs to be extended into the reactor, and the corn stalks in the feed barrel need to be transported into the reactor, the end of the spiral feed barrel extending into the tank body cannot be installed with a support to support the feed shaft. The feed shaft is arranged in a cantilever state in the feed barrel. The bolt feed shaft is too long, and there is no support at the end and the deflection is affected. During the rotation of the feed shaft, the axis of the feed shaft is easily offset at the free end, so that the blades are easy to rub against the inner wall of the feed barrel.

[0062] The spiral feeding cylinder 1 of the present application, such as Figures 1 to 4 As shown, it includes a feed shaft 10, an outer cylinder 13 and a magnetic suspension support 14. The feed shaft 10 is provided with blades 11 arranged in a spiral shape. The blades 11 can be arranged in a continuous state or in an interval state, that is, the blades 11 can also be disconnected, but the disconnected gap cannot be too large, otherwise material accumulation is likely to occur. A magnet 12 is arranged on the blade 11. The outer cylinder 13 is coaxially arranged with the feed shaft 10, so that the feed shaft 10 and the blades 11 are both located in the outer cylinder 13, and a feed space is formed between the outer cylinder 13, the feed shaft 10 and the blades 11. The magnetic suspension support 14 is arranged on the outer surface of the outer cylinder 13, and surrounds the outer cylinder 13 in the radial direction of the outer cylinder 13. The magnetic suspension support 14 interacts with the magnet 12 of the blade 11, so that the blade 11 remains in a state of not contacting the outer cylinder 13 during the feeding process.

[0063] The spiral feeding cylinder 1 of the present application has a magnet 12 arranged on the edge of the blade 11 of the conveying shaft, and a magnetic suspension support 14 arranged on the outer surface of the outer cylinder 13 of the spiral feeding cylinder 1. The magnetic suspension support 14 surrounds the outer cylinder 13 in the radial direction of the outer cylinder 13, and can utilize the interaction between the magnetic suspension support 14 and the magnet 12 of the blade 11, so that the blade 11 remains out of contact with the outer cylinder 13 during the feeding process. The supporting force and axial positioning force that can be provided to the cantilever part of the spiral feeding shaft 10 realize high-precision support for the rotating shaft, so that the blade 11 of the spiral conveying shaft will not contact the inner wall of the outer cylinder 13 during the rotation process.

[0064] The screw feed barrel 1 of the present application not only meets the feeding requirements of the screw feeder, but also fully solves the deflection problem caused by the lack of support for the free end of the screw conveyor shaft. In addition, the free end of the conveyor shaft does not directly contact the material in the reaction tank, which increases the service life of the screw feeder. Even if the magnetic suspension support 14 fails, it is easy and quick to replace because it is installed on the outer surface of the outer barrel 13, and will not cause long-term shutdown for maintenance, which more effectively ensures the continuity of production.

[0065] In a more preferred case, during the feeding process, the magnetic suspension support 14 can keep the axis of the feeding shaft 10 in a straight line with the axis of the outer cylinder 13 at all times.

[0066] The design principle of this application is described in detail below:

[0067] The design of this application is mainly based on the interaction between magnetic field force and electromagnetic force. Through the electromagnetic force generated by the stator, the rotating shaft (i.e., the rotor) is suspended in the magnetic field, and there is a certain gap between the stator and the rotor. This non-contact support method enables the rotor shaft to maintain high precision and stability when running in a high-speed, low-friction, high (low) temperature environment.

[0068] The present invention utilizes controllable electromagnetic force to suspend the rotating shaft. The electromagnet is installed on the stator, and the rotor is suspended in the magnetic field generated by the electromagnets placed in radial symmetry. Each electromagnet is equipped with a sensor to continuously monitor the position change of the rotating shaft. The signal output from the sensor is used by the electronic control system to correct the current passing through the electromagnet, thereby controlling the attraction of the electromagnet, so that the rotating shaft can operate in a stable and balanced state and meet certain accuracy requirements.

[0069] In this embodiment, the magnet 12 is a permanent magnet 12, and the permanent magnet 12 is arranged at the end of the blade 11 away from the feeding shaft 10. The use of the permanent magnet 12 can ensure that the blade 11 always has magnetism. The permanent magnet 12 is arranged at the edge of the blade 11 so that the magnetic force of the magnetic suspension support 14 can act more effectively on the blade 11, thereby always keeping the axis of the feeding shaft 10 in a straight line with the axis of the outer cylinder 13, avoiding the free end of the feeding shaft 10 from deflecting during the feeding process, and preventing the edge of the blade 11 from contacting the inner wall of the outer cylinder 13 and causing wear.

[0070] The permanent magnet 12 can also release a small amount of electric energy while ensuring the position of the spiral conveyor shaft, and can be assisted by an electric storage device (not shown in the figure) to recover a small amount of electric energy for other purposes.

[0071] In this embodiment, see Figure 4The magnetic levitation support 14 includes at least four electromagnetic coils, namely a first electromagnetic coil 141, a second electromagnetic coil 142, a third electromagnetic coil 143 and a fourth electromagnetic coil 144. The four electromagnetic coils are arranged at intervals and radially surround the outer cylinder 13. By using four coils, a balance can be struck between the number of coils and the maximum magnetic force that the coils can provide, and coils of smaller sizes can be selected, which will not cause waste of the magnetic force of the coils, nor will it cause the problem of insufficient magnetic force due to a small number of coils. The coils are arranged at intervals, which facilitates the replacement of the coils and saves costs. The radial surrounding of the coils around the outer cylinder 13 enables the electromagnetic force to be applied to the entire radial direction of the outer cylinder 13, which is beneficial to provide uniform and appropriate support for the conveying shaft, thereby reducing the deflection of the free end of the conveying shaft.

[0072] The electromagnetic coils 141, 142, 143 and 144 are generally spaced at equal intervals. They may also be spaced at unequal intervals, as long as the distribution of the electromagnetic coils can make the electromagnetic force relatively uniform. The number of electromagnetic coils may also be more than four, and they may be evenly arranged in a ring shape.

[0073] In this embodiment, sensors are arranged inside the electromagnetic coil, namely, the first sensor 145, the second sensor 146, the third sensor 148 and the fourth sensor 148. Among them, the first sensor 145 is arranged in the first electromagnetic coil 141, the second sensor 146 is arranged in the second electromagnetic coil 142, the third sensor 147 is arranged in the third electromagnetic coil 143, and the fourth sensor 148 is arranged in the fourth electromagnetic coil 144. The above four sensors respectively detect the relative position between the blade 11 and the corresponding electromagnetic coil, and send the detection results. That is, the first sensor 145 detects the relative position between the blade 11 and the first electromagnetic coil 141, the second sensor 146 detects the relative position between the blade 11 and the second electromagnetic coil 142, and so on. Since the electromagnetic force of the electromagnetic coil is adjusted by the current input to the electromagnetic coil, and the feeding shaft 10 is deflected by the force of corn stalks and gravity during the feeding process, the relative position between the permanent magnet 12 at the edge of the blade 11 and the inner wall of the outer cylinder 13 will change. Since the electromagnetic coil is arranged around the outer surface of the outer cylinder 13, the positional relationship between the permanent magnet 12 at the edge of the blade 11 and each electromagnetic coil will also change. A sensor is arranged inside the electromagnetic coil to detect the change in the positional relationship, and the electromagnetic force of the electromagnetic coil can be adjusted in time, so that the blade 11 remains out of contact with the outer cylinder 13 during the feeding process.

[0074] In this embodiment, the sensors are displacement sensors 145, 146, 147 and 148, and the displacement sensors detect the distance between the blade 11 and the electromagnetic coils 141, 142, 143 and 144. By detecting the distance between the edge of the blade 11 and the corresponding electromagnetic coil by the displacement sensor, it is possible to detect in real time whether the axis of the feed shaft 10 and the axis of the outer cylinder 13 have deviated. The detection equipment is simple, low in cost, simple in calculation process, and uncomplicated in program design, which is conducive to reducing costs.

[0075] In this embodiment, the magnetic suspension support 14 includes two half rings, wherein at least two electromagnetic coils are arranged in each half ring. The use of two half rings can make the magnetic suspension support 14 easy to install and disassemble, and convenient for maintenance and overhaul. The arrangement of at least two electromagnetic coils in each half ring is conducive to providing a relatively uniform and omnidirectional electromagnetic support force to the blade 11.

[0076] In this embodiment, the magnetic force of the magnetic suspension support 14 is greater than the maximum radial load force of the spiral feeding cylinder 1. In this way, the feeding shaft 10 can be suspended in the outer cylinder 13 by electromagnetic force to avoid contact between the blades 11 and the inner wall of the outer cylinder 13.

[0077] In this embodiment, the magnetic force of the magnetic suspension support 14 is twice the maximum radial load force of the spiral feed drum 1. The magnetic force of the magnetic suspension support 14 is twice the maximum radial load force of the spiral feed drum 1, which can improve the support reliability of the entire magnetic suspension support 14. It can also adapt to the situation where the maximum radial load force of the spiral feed drum 1 may increase slightly. It is more conducive to the smooth and safe operation of the entire device.

[0078] In this embodiment, the screw feeder barrel 1 is tilted. When the inner wall of the outer barrel 13 or the blades 11 of the screw feeder are worn, the machine has to be shut down for replacement and repair, and continuous disassembly is required to achieve the purpose of maintenance. In view of the complicated maintenance actions and long downtime, the screw feeder has to be installed horizontally or vertically to eliminate the impact of the end being unsupported. This brings about new problems. When the relative position of the reaction tank and the feeding workshop is certain, the horizontal installation and vertical installation make the conveying device particularly complicated, and there are problems such as raising the material height and changing the conveying direction, so that the investment cost is increased while the maintenance cost is also increased.

[0079] The inclined setting of the spiral feed barrel 1 can reduce the plant space compared with the horizontal setting; compared with the vertical setting, the problems of too fast feeding and uneven mixing due to the gravity of the corn stalks will not occur. The inclined setting can increase the service life of the spiral feeder while optimizing the design space, and reduce the maintenance cost, so as to achieve quick repair and replacement without stopping the machine.

[0080] The spiral feed barrel 1 of the present application also includes a feed inlet 15 and a flange 16, and the feed material enters the spiral feed barrel 1 from the feed inlet 15. The outer barrel 13 may be a multi-segment structure fixedly connected by the flange 16. The number of segments of the outer barrel 13 may be selected according to actual needs.

[0081] The present application only uses corn stalks as an example for illustration, and the spiral feed cylinder 1 of the present application can transport other materials that need to be transported except corn stalks.

[0082] like Figure 5 As shown, the present application also provides a screw conveyor, comprising a controller 3, an actuator 4, a driver 2 and the above screw conveyor barrel 1, wherein the driver 2 drives the conveying shaft 10 of the screw conveyor barrel 1, and the controller 3 receives the signal of the magnetic suspension support 14, and controls the actuator 4 to adjust the magnetic suspension support 14. By controlling the screw conveyor to work through the mutual cooperation of the controller 3, the actuator 4 and the driver 2, it is possible to avoid the blades 11 of the screw conveying shaft from contacting the inner wall of the outer barrel 13 during the rotation process.

[0083] In this embodiment, the controller 3 is a PLC controller, the actuator 4 is a frequency converter, the signal of the magnetic suspension support 14 is a current signal, and the frequency converter adjusts the current of the magnetic suspension support 14 according to the control instruction of the PLC controller. The magnetic suspension force provided by the magnetic suspension support 14 is controlled and adjusted by the current, and the control is accurate, the adjustment is real-time, and the control effect is good.

[0084] In this embodiment, the number of magnetic suspension supports 14 is one, and in some other embodiments, the number of magnetic suspension supports 14 is multiple, and the multiple magnetic suspension supports 14 are arranged at intervals, and the spacing between the magnetic suspension supports 14 gradually decreases from the driving end of the conveying shaft to the free end of the conveying shaft. The arrangement of multiple magnetic suspension supports 14 can be applied to a longer conveying shaft 10, and the shorter the spacing distance near the free end, the more appropriate support can be provided to the long conveying shaft 10 in time, so as to prevent the blades 11 of the spiral conveying shaft from contacting the inner wall of the outer cylinder 13 during the rotation process.

[0085] The screw conveyor of the present application is arranged between the pretreatment workshop 5 and the anaerobic reaction tank 6, and conveys the material pretreated in the pretreatment workshop 5 to the anaerobic reaction tank 6. The screw conveyor is arranged in an inclined manner, and a support 7 is arranged in the pretreatment workshop 5 to support it.

[0086] The above is a detailed description of several exemplary embodiments of the screw conveyor barrel 1 and the screw conveyor proposed in the present application. The following is an exemplary description of the control method of the screw conveyor proposed in the present application.

[0087] like Figure 6As shown, the present application also provides a control method for a screw conveyor, wherein the screw conveyor adopts the screw conveyor as above, and the control method comprises the following steps:

[0088] Step S1: calibrate the zero position D0 between the magnetic suspension support 14 and the blade 11, and store the zero position in the controller 3;

[0089] Step S2: During the feeding process, the magnetic suspension support 14 detects the position information of the blade 11 and sends the detection result to the controller 3;

[0090] Step S3: the controller 3 controls the actuator 4 to adjust the magnetic suspension support 14 according to the detection result, so that the position relationship between the magnetic suspension support 14 and the blade 11 always maintains the position zero D0.

[0091] The control method of the present application compares the position information of the magnetic levitation support 14 and the blade 11 detected in real time with the initial calibrated position zero D0, and adjusts the position relationship between the magnetic levitation support 14 and the blade 11 according to the comparison result. The entire control method is simple and timely, with good adjustment effect, and can maintain the gap between the blade 11 and the inner wall of the outer tube 13 to avoid problems such as wear caused by contact.

[0092] In this embodiment, the magnetic suspension support 14 includes electromagnetic coils 141, 142, 143, 144 and displacement sensors 145, 146, 147, 148. In step S2, the displacement sensor of the magnetic suspension support 14 detects the distance between the edge of the blade 11 and the corresponding electromagnetic coil, and converts the detection result into a current signal and sends it to the controller 3. By detecting the distance between the edge of the blade 11 and the corresponding electromagnetic coil by the displacement sensors 145, 146, 147, 148, it is possible to detect in real time whether the axis of the feed shaft 10 has deviated from the axis of the outer cylinder 13. The detection equipment is simple, the cost is low, and the calculation process is simple.

[0093] In this embodiment, in step S3, the controller 3 compares the current signal with the position zero position D0 and then outputs a control instruction to the actuator 4. The actuator 4 adjusts the current of the electromagnetic coil of the magnetic suspension support 14 so that the position relationship between the magnetic suspension support 14 and the blade 11 always maintains the zero position D0. The electromagnetic force is adjusted by adjusting the current of the magnetic suspension support 14, so that the position relationship between the magnetic suspension support 14 and the blade 11 always maintains the zero position. The control system is simple to collect data, the calculation process is simple, and the control accuracy is high.

[0094] After the displacement sensor detects a change in distance, it gives a 4-20mA analog signal to the PLC controller 3. The PLC controller 3 compares the signal with the initial zero point signal, and gives the current and frequency signals that need to be adjusted as feedback to the frequency converter. The frequency converter outputs the corresponding current and frequency to act on the electromagnetic coil according to the instructions given by the PLC, generates magnetic force, and corrects the displacement of the corresponding blade 11 position.

[0095] When the screw feeder is working, when the torque value of the driver 2 and the position signal of the displacement sensor begin to change relative to the initial signal, the PLC controller 3 calculates and gives the corresponding current to adjust the electromagnetic signal in the magnetic suspension support 14, and continuously corrects the position of the feed shaft 10. The control signal is converted into a control current, and the control current generates a magnetic force in the electromagnetic coil so that the feed shaft 10 maintains its stable suspension position unchanged. The stiffness, damping and stability of the suspension system are determined by the control system. The following is a detailed introduction to the screw feeder:

[0096] 1. Screw conveyor parameter matching

[0097] Table 1: Types of LS screw conveyors:

[0098]

[0099] Basic parameters of screw conveyor:

[0100] Specifications: Taking LS type 500 as an example, screw diameter: 500mm, pitch: 400mm, speed: 63r / min, conveying capacity: 98m3 / h, conveying length: 6m.

[0101] Table 2: Screw conveyor design calculation:

[0102]

[0103] According to item 10 in the table above and the motor selection manual, the 6-level motor is selected with a power of 5.5KW, a voltage of 220V, a speed of 960r / min, a rated torque of 54.7NM, and a reduction ratio of 1:15.2.

[0104] Table 3: Motor selection standard table for screw feed shaft:

[0105]

[0106] According to the above data, the maximum torque of the screw feed shaft 10 at the location where the magnetic suspension support 14 is installed is 54.7 NM.

[0107] 2. Stress conditions at position 14 of the magnetic suspension support

[0108] The maximum torque of the spiral feed shaft 10 is 54.7 NM, and the diameter of the spiral blade 11 is 500 mm, so the following conclusions can be drawn:

[0109] F=54.7 / 0.5=109.4N.

[0110] See also Figure 1 The shaded part of the blade 11 in the figure shows that the weight of the screw feed shaft 10 + the screw blade 11 is 375 kg through measurement.

[0111] The gravity of the screw feed shaft 10 and the blade 11 is G = 375Kg*9.8N / Kg = 3675N

[0112] The angle between the tilt direction of the feed shaft 10 and the horizontal direction is d, assuming d = 30°

[0113] Radial component of gravity: F1 = Cosd*G = 3675·Cosd = 3675*0.87 = 3197.25N

[0114] Axial component of gravity: F2 = Sind*G = 3675·Sind = 3675*0.5 = 1837.5N

[0115] The supporting force that the magnetic suspension end needs to overcome is the superposition of the torque F generated by the screw feed shaft 10 and F1 after the gravity decomposition of the screw feed shaft 10, that is, 109.4N+3197.25N=3.3KN.

[0116] The material transported in the present application is corn stalks, whose physical properties do not affect the distribution of the magnetic field. In addition, the maximum torque of the spiral feed shaft 10 in this calculation process does not consider the influence of the material on the torque of the spiral feed shaft 10.

[0117] 4. Electromagnetic force of magnetic suspension support 14

[0118] In order to obtain the general calculation formula of radial magnetic levitation electromagnetic force, the most general method is to pre-formulate magnetic potential boundary conditions when calculating the suction force, and the general calculation formula of electromagnetic force is obtained as follows:

[0119] F=(μ0S / 2Kf 2 δ 2 )(NI) 2

[0120] in,

[0121] Vacuum magnetic permeability μ0=4πX10 -7 ,

[0122] B is the magnetic flux density,

[0123] S is the cross-sectional area of ​​the magnetic circuit, S = 506mm*581mm

[0124] Kf is the magnetic flux leakage coefficient, which is generally 1.5-5. This application takes 4.

[0125] δ is the nominal air gap length, this spacing is 0.5mm

[0126] When powered on, the current is I=2.5A. After working for a long time, the coil temperature rises and the current becomes smaller. I=2AN is the number of coil turns, and the number of coil turns is set to 200 turns.

[0127] Speed: 63r / min,

[0128] Maximum radial load QMAX=3.3KN,

[0129] The maximum current density of the coil JMAX = 2A / mm2,

[0130] F=(μ0S / 2Kf 2 δ 2 )(NI) 2 =(4πX10 -7 X506X581 / 2X4 2 X0.5 2 )(200X2) 2 =7.38KN

[0131] Through calculation, it can be known that the set magnetic force is greater than the maximum radial load force of the screw conveyor after decomposition, that is, 2 times the safety factor. In the control system, by adjusting the current, the magnetic force is appropriately adjusted to achieve the purpose of balance.

[0132] Through the control method of the screw feeder of the present application, it can be concluded that the screw feeder 1 of the present application has a magnet 12 set on the edge of the blade 11 of the conveying shaft, and a magnetic suspension support 14 is set on the outer surface of the outer cylinder 13 of the screw feeder 1. The magnetic suspension support 14 surrounds the outer cylinder 13 in the radial direction of the outer cylinder 13, and can utilize the interaction between the magnetic suspension support 14 and the magnet 12 of the blade 11, so that the blade 11 is always not in contact with the inner wall of the outer cylinder 13. The support force and axial positioning force that can be provided to the cantilever part of the screw feeder shaft 10 realize high-precision support for the rotating shaft, so that the blade 11 of the screw conveying shaft will not contact the inner wall of the outer cylinder 13 during the rotation process.

[0133] In summary, the spiral feed cylinder 1 proposed in the present application includes a feed shaft 10, an outer cylinder 13 and a magnetic suspension support 14. The feed shaft 10 is provided with blades 11 arranged continuously in a spiral shape, and a magnet 12 is arranged on the blade 11. The outer cylinder 13 is coaxially arranged with the feed shaft 10, so that the feed shaft 10 and the blades 11 are both located in the outer cylinder 13, and a feed space is formed between the outer cylinder 13, the feed shaft 10 and the blades 11. The magnetic suspension support 14 is arranged on the outer surface of the outer cylinder 13 and surrounds the outer cylinder 13 along the radial direction of the outer cylinder 13. The magnetic suspension support 14 interacts with the magnet 12 of the blade 11, so that the blade 11 and the inner wall of the outer cylinder 13 are always kept out of contact. Avoiding the wear of the blades 11 and the outer cylinder 13, while satisfying the feeding of the screw conveyor, fully solves the deflection problem caused by the lack of support at the free end of the screw conveyor shaft. And the free end of the conveying shaft does not directly contact the material in the reaction tank, which increases the service life of the screw conveyor. Even if the magnetic suspension support 14 fails, since it is installed on the outer surface of the outer cylinder 13, it is easy and quick to replace without causing long-term shutdown for maintenance, which more effectively ensures the continuity of production and reduces production costs.

[0134] The screw conveyor proposed in the present application includes a controller 3, an actuator 4, a driver 2 and the screw conveyor barrel 1 as described above, wherein the driver 2 drives the conveying shaft 10 of the screw conveyor barrel 1, and the controller 3 receives the signal of the magnetic suspension support 14 and controls the actuator 4 to adjust the magnetic suspension support 14.

[0135] During the material feeding process, the screw conveyor is subjected to the reverse thrust of the weight of the feeding object in the axial direction and the reaction material in the reaction tank, so that the torque of the screw conveyor shaft changes in real time during the movement. The change of torque will cause relative displacement with the far end of the shaft. The screw conveyor of the present application improves the rigidity of the shaft and is assisted by the magnetic force of the magnetic suspension support 14 device to better control the screw conveyor shaft within the center line.

[0136] The control method of the screw feeder proposed in the present application detects the position information of the blade 11 through the real-time detection of the magnetic suspension support 14 and compares it with the initial calibrated position zero D0, and adjusts the position relationship between the electromagnetic coil and the blade 11 according to the comparison result. The whole control method is simple and timely, with good adjustment effect, and can maintain the gap between the blade 11 and the inner wall of the outer cylinder 13 to avoid problems such as wear caused by contact.

[0137] In this exemplary embodiment, the spiral feed barrel proposed in this application is described by taking the application in the biomass biogas industry as an example. It is easy for those skilled in the art to understand that in order to apply the relevant design of this application to other applications, various modifications, additions, substitutions, deletions or other changes are made to the following specific embodiments, and these changes are still within the scope of the principle of the spiral feed barrel proposed in this application.

[0138] It should be noted that the screw conveyor shown in the drawings and described in this specification are only a few examples of many screw conveyor tubes that can adopt the principles of the present application. It should be clearly understood that the principles of the present application are by no means limited to any details or any parts of the screw conveyor tube shown in the drawings or described in this specification.

[0139] The exemplary embodiments of the spiral feed drum proposed by the present application are described and / or illustrated in detail above. However, the embodiments of the present application are not limited to the specific embodiments described herein. On the contrary, the components and / or steps of each embodiment can be used independently and separately from other components and / or steps described herein. Each component and / or each step of an embodiment can also be used in combination with other components and / or steps of other embodiments. When introducing the elements / components / etc. described and / or illustrated herein, the terms "one", "an" and "above" are used to indicate the presence of one or more elements / components / etc.

[0140] The embodiments of the present application are not limited to the specific embodiments described herein, on the contrary, the components of each embodiment can be used independently and separately from the other components described herein. Each component of an embodiment can also be used in combination with other components of other embodiments. In the description of this specification, the description of the terms "one embodiment", "some embodiments", "other embodiments" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the application embodiment. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0141] In the embodiments, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments can be understood according to the specific circumstances.

[0142] Although the screw conveyor proposed by the present application has been described in terms of various specific embodiments, those skilled in the art will recognize that the present application can be implemented with modifications within the spirit and scope of the claims.

Claims

1. A spiral feed cylinder, characterized in that: include: A feeding shaft, wherein the feeding shaft has blades arranged in a spiral shape, and the blades are provided with magnets; An outer cylinder is coaxially arranged with the feeding shaft, the feeding shaft and the blades are both located in the outer cylinder, and a feeding space is formed between the outer cylinder, the feeding shaft and the blades; A magnetic suspension support is provided on the outer surface of the outer cylinder and surrounds the outer cylinder in the radial direction of the outer cylinder. The magnetic suspension support interacts with the magnet of the blade so that the blade does not contact the outer cylinder during the feeding process.

2. The screw feed cylinder according to claim 1, characterized in that: The magnet is a permanent magnet, and the permanent magnet is arranged at the end of the blade away from the feeding shaft.

3. The screw feed cylinder according to claim 1, characterized in that: The magnetic suspension support includes at least four electromagnetic coils, which are arranged at intervals and radially surround the outer cylinder.

4. The screw feed cylinder according to claim 3, characterized in that: A sensor is arranged inside the electromagnetic coil, and the sensor detects the relative position between the blade and the electromagnetic coil and sends the detection result.

5. The screw feed cylinder according to claim 4, characterized in that: The sensor is a displacement sensor, and the displacement sensor detects the distance between the blade and the electromagnetic coil.

6. The screw feed cylinder according to claim 1, characterized in that: The magnetic suspension support comprises two half rings, wherein at least two electromagnetic coils are arranged in each half ring.

7. The screw feed cylinder according to claim 1, characterized in that: The magnetic force of the magnetic suspension support is greater than the maximum radial load force of the spiral feed cylinder.

8. The screw feed cylinder according to claim 1, characterized in that: The magnetic force of the magnetic suspension support is twice the maximum radial load force of the spiral feed cylinder.

9. The spiral feed cylinder according to any one of claims 1 to 8, characterized in that: The spiral feeding cylinder is arranged in an inclined manner.

10. A screw conveyor, characterized in that: It comprises a controller, an actuator, a driver and a spiral feed cylinder as described in any one of claims 1 to 9, wherein the driver drives the feed shaft of the spiral feed cylinder, and the controller receives a signal from the magnetic levitation support and controls the actuator to adjust the magnetic levitation support.

11. The screw conveyor according to claim 10, characterized in that: The controller is a PLC controller, the actuator is a frequency converter, the signal of the magnetic suspension support is a current signal, and the frequency converter adjusts the current of the magnetic suspension support according to the control instruction of the PLC controller.

12. The screw conveyor according to claim 10, characterized in that: There are multiple magnetic suspension supports, and the multiple magnetic suspension supports are arranged at intervals. The interval between the magnetic suspension supports gradually decreases from the driving end of the feed shaft to the free end of the feed shaft.

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