TWI721487B - Infrared drying machine - Google Patents

Abstract

The invention describes an infrared material baking machine, which includes a barrel and an infrared heater. The infrared heater includes a lamp tube load and a lamp power modulator. Among them, the lamp tube load can be driven to emit infrared light to bake the material. The lamp power modulator is connected to the lamp load to drive the lamp load, and it includes different switching devices, an inverter and a control unit. Among them, the control unit can turn on or off different switching devices, so that the lamp tube load can simply receive the signal output by the inverter or simultaneously receive the signal from the mains and the inverter and emit infrared rays. Through the design of the above-mentioned infrared drying machine, the specifications required for the power components of the inverter can be reduced, thereby reducing the overall cost of the drying machine, and uniformly heating the plastic particles.

Description

Infrared drying machine

The invention relates to a drying machine for drying plastic particles, in particular to an infrared drying machine, which can uniformly heat the plastic particles and has a small area.

The traditional drum hot-air drying machine uses a resistance heater with a fan to dry the plastic particles. Compared with the infrared heat radiation drying technology, the traditional hot-air drying technology is indirect heating because the traditional hot-air dryer uses dry hot air to heat the plastic particles. The drying takes a long time and consumes more energy. The manufacturing cost is relatively high. In addition, due to the inclination of the barrel body of the traditional drum, it is easy to cause uneven thickness of the plastic particles inside the barrel or uneven turning of the material, resulting in uneven heating. In addition, the traditional drum hot air drying machine adopts continuous feeding and discharging. When it is necessary to increase the output, it is also necessary to use longer drying equipment, which will increase the floor area. Compared with owners with limited plant space It is not easy to use a conventional drying machine. In addition, the traditional drum hot-air dryer is continuously discharging, and it must be sucked continuously by the suction machine, so it also consumes more energy.

One of the objectives of the present invention is to propose a new infrared dryer design, which is relatively inexpensive but can also uniformly heat the plastic particles.

The reason is that according to the present invention, an infrared drying machine includes a first barrel and an infrared heater. The infrared heater is arranged in the first barrel and includes a lamp tube load and a lamp power modulator, and the lamp tube load can be driven to emit infrared rays. The lamp power modulator is connected to the lamp load to drive the lamp load. The lamp power modulator includes an inverter, a first switch device, a second switch device and a control unit. The inverter is coupled to the mains power and can use the mains power to output an AC drive signal. The first switch device is coupled to the inverter and the lamp load, the second switch device is coupled to the lamp load and the mains, and the control unit is coupled to the first switch device and the second switch device to control the first switch device and the second switch device. The two switching devices are turned on or off, and the control unit also controls the inverter to output an AC drive signal synchronized with the mains.

As a result, when the infrared drying machine is used to dry the wet plastic particles, the infrared light can be emitted by the lamp tube to directly heat the plastic particles, so the plastic particles can be heated more uniformly, and it can also be improved. The heating efficiency of plastic particles can save overall energy consumption and overall heating time. In addition, the first and second switch devices are controlled by the control unit. When the heating temperature of the infrared dryer reaches the baking temperature, the infrared dryer no longer needs full power output, and the first switch can be turned off by the control unit The device uses the inverter to output the AC drive signal to heat the plastic particles at low power, which can reduce the specifications required for the power components of the inverter, and you can buy a suitable lamp power regulator at a relatively low price. Converter, thereby reducing the overall cost of the infrared dryer.

In one aspect, the lamp power modulator also includes a feedback detection circuit, and through the feedback detection circuit to detect the phase of the AC drive signal and input the detected phase of the AC drive signal to the control Unit to facilitate the subsequent operation of synchronizing the AC drive signal with the mains.

In another aspect, the lamp power modulator further includes a temperature feedback circuit. The temperature feedback circuit detects an output power of the lamp load, and inputs the detected output power to the control unit, so that the control unit can correspond to the different heating processes of the plastic particles (such as the heating section and the temperature holding section) Ground control the inverter and the first and second switching devices, so that the lamp tube load can output infrared rays with suitable output power.

In another aspect, the lamp power modulator has a rated maximum output power. When the control unit detects that the output power of the lamp load is greater than or equal to the rated maximum output power through the temperature feedback circuit, the control unit is turned on. The switching device and the second switching device, the control unit adjusts the inverter output and the AC drive signal of the mains inverting, and uses this method to control the power; when the control unit performs temperature and power closed loop control through the temperature feedback circuit, when the When the control unit detects that the output power of the lamp load is less than the rated maximum output power, the control unit turns on the first switching device and disconnects the second switching device, and the control unit adjusts the inverter output and the AC drive of the mains in phase or reverse phase Signal. Through the above-mentioned control mechanism, the component specifications required for the power components of the inverter can be effectively reduced.

In another aspect, the temperature feedback circuit further includes a temperature detector. The temperature detector detects the temperature of the plastic particles arranged in the first barrel, and the temperature feedback circuit is based on the detected plastic particles. Obtain the output power of the lamp load corresponding to the temperature.

In another aspect, the infrared material drying machine further includes a support frame and a first lifting mechanism, wherein the first material barrel is horizontally arranged on the support frame, the first lifting mechanism is arranged on the support frame and connected to the material barrel, and A lifting mechanism can be driven to lift the first barrel so that the first barrel is in an inclined state. Through the above-mentioned first lifting mechanism, when the plastic particles are dried, the first lifting mechanism can be directly driven to facilitate subsequent extraction of the dried plastic particles, and since the first lifting mechanism can quickly pour out the plastic particles, the drying can be reduced. The contact time of the later plastic particles with the external environment makes the moisture content of the plastic particles less susceptible to the influence of the temperature and humidity of the external environment. In addition, since the lamp load can evenly heat the plastic particles, the length of the first barrel does not need to be designed to be very long, so the footprint of the infrared dryer can be effectively reduced, and it is suitable for Smaller-scale plant.

On the other hand, in order to allow the infrared drying machine to dry plastic particles in batches and achieve a modular design to meet the needs of customers for drying materials. The infrared dryer can also include a second barrel and a second lifting mechanism (or a third barrel and a third lifting device...). The second barrel is horizontally arranged on the support frame and located at the first Above the barrel, the second lifting mechanism is arranged on the support frame and connected to the second barrel. The second lifting mechanism can be driven to lift the barrel to make the barrel in an inclined state. In addition, due to different types of plastic particles, some of the plastic particles need to be crystallized, so the second barrel can also be used for crystallization, so that the infrared drying machine can simultaneously have the two functions of crystallization and drying.

In another aspect, the first lifting mechanism (or the second lifting mechanism) includes a pneumatic cylinder, a first connecting rod and a second connecting rod, wherein one end of the first connecting rod is connected to the first barrel, and the second connecting rod One end of the rod is connected to the support frame, and the end of the first link relative to the end and the end of the second link relative to the support frame are both connected to a telescopic rod of a pneumatic cylinder, and the pneumatic cylinder is arranged on the support frame.

On the other hand, after the infrared drying machine completes the drying of the material, the material can be discharged quickly by the discharging mechanism device, which reduces the combination of the plastic material and the moisture in the environment, and the plastic material maintains a dry moisture content.

In another aspect, the infrared drying machine can also be used with the particle size screening device, and the particle size screening device is provided on the second barrel and connected to the second barrel. In this way, the use area of the plant can be better reduced.

In the following, the technical content and features of the present invention will be described in detail by means of several embodiments listed in conjunction with the drawings. The content of this specification refers to “upper”, “lower”, “inner”, “outer”, “top”, Directional adjectives such as "bottom" are merely exemplary descriptive terms based on the normal direction of use, and are not intended to limit the scope of claims.

In order to explain the technical features of the present invention in detail, the following two embodiments are given in conjunction with the drawings to illustrate the following, in which:

Please refer to FIGS. 1 and 3, the first embodiment provides an infrared baking machine 1, which includes a first barrel 20, a supporting frame 30, and an infrared heater 10. Wherein, the first barrel 20 is horizontal (that is, the axial direction of the first barrel 20 is parallel to the ground) and is rotatably installed on the support frame 30. The support frame 30 is provided with four sets of rollers 41 (the two sets of rollers 41 are covered in FIG. 1) and a set of motors 40. The rollers 41 are divided into two groups and are respectively arranged on two sides of the first barrel 20, and The above-mentioned four sets of rollers 41 are rotatably installed on the support frame 30. The set of motors 40 (including a reduction gear box) is connected to one of the sets of rollers 41 and can drive the rollers 41 to rotate, thereby driving the first barrel 20 to rotate. As shown in Figure 3, the inner side wall of the first barrel 20 is equiangularly provided with a plurality of paddles 21. Through the rotation of the paddles 21 and the first barrel 20, the first barrel 20 can be flipped evenly. Plastic particles inside (not shown in the picture). In addition, the support frame 30 is also provided with two sets of dehumidifiers 50, which are connected to the first barrel 20 by pipes (not shown in the figure), so that the damp plastic particles can pass through the dehumidifiers after being heated to generate moisture. 50 and get rid of moisture.

As shown in Figures 2 and 4, the support frame 30 includes a first frame body 31 and a second frame body 32. The first frame body 31 is erected on the ground, and the second frame body 32 is erected on the first frame. On a frame 31, the motor 40 and the first barrel 20 are both mounted on the second frame 32. The features of this part will be described in more detail in subsequent paragraphs.

As shown in Fig. 3, the infrared heater 10 is arranged inside the first barrel 20, which includes a lamp tube holder 11, a lamp shade 12 arranged on the lamp tube holder 11, a lamp load 13 and a lamp power Modulator 60 (Figure 6). The lamp tube load 13 can be driven to emit infrared rays, and the emitted infrared rays can directly irradiate plastic particles under the guidance of the lampshade 12. The angle of the lamp holder 11 can be adjusted to change the infrared radiation range.

Please refer to FIGS. 5 to 7, the lamp power modulator 60 is connected to the lamp load 13 to drive the lamp load 13 to emit infrared rays. The lamp power modulator 60 includes an inverter 61, a first switching device 62, a second switching device 63 and a control unit 64. The inverter 61 is a full-bridge inverter 61 in this embodiment, and the full-bridge inverter 61 has a plurality of transistors T1-T4 (such as MOSFETs or IGBTs). As shown in Fig. 7, after the mains AC passes through a rectifier 65 and a booster circuit 66, and after the power factor correction and filtering, an AC signal of the mains AC will be converted into a direct current signal, and the inverter 61 will do this again. The DC signal is converted into a high frequency AC drive signal.

The first switch device 62 is coupled to the inverter 61 and the lamp load 13, and the first switch device 62 can be turned on or off under the control of the control unit 64, thereby controlling the inverter 61 to output or not output an AC driving signal to the lamp Tube load 13 (output to lamp tube load 13 through isolation transformer F).

The second switching device 63 is coupled to the mains AC and the lamp load 13. The second switching device 63 can also be turned on or off under the control of the control unit 64 to control whether the mains AC is output or not output to the lamp load 13 (through Isolate the transformer F and output to the lamp load 13)

In this embodiment, the control unit 64 is a dsPIC digital signal processing chip. As shown in FIG. 7, the control unit 64 detects the phase of the AC drive signal through a feedback detection circuit 67, and drives the detected AC drive signal. The phase of the signal is input to the control unit 64. The control unit 64 has a built-in analog-to-digital converter 641, and writes a PLL phase-locked counter 642 in a programmatic manner for phase-locking, and a system sine control signal amplitude modulation mechanism 643, so that the control unit 64 can follow-up A series of front-end drive and isolation circuits 68 are used to output a modulated PWM signal, so that the inverter 61 can output an AC drive signal synchronized with the mains AC according to the above modulated PWM signal, so that the frequency of the AC drive signal can be equal On mains AC (60 Hz) and the phase of the AC drive signal is the same as the mains AC. The front-end driving and isolation circuit 68 includes a digital-to-analog converter 68a, an inner loop waveform control circuit 68b, a power transistor driving circuit 68c, and an optical coupling isolation circuit 68d, which are sequentially coupled. The digital-to-analog converter 68a is used for digital/analog conversion of the signal. The inner loop waveform control circuit 68b is used to output the PWM signal correspondingly. The power transistor driving circuit 68c receives the above-mentioned PWM signal and can modulate the PWM signal for subsequent driving. The transistors T1-T4 of the inverter 61 and the optical coupling isolation circuit 68d serve as isolation protection and input the modulated PWM signal to the inverter 61 to drive the transistors T1-T4.

On the other hand, as shown in FIG. 5, the lamp power modulator 60 also includes a temperature feedback circuit 69, the temperature feedback circuit 69 includes a temperature sensor (such as a thermocouple, not shown), a control unit 64. The temperature of the plastic particles (or the first barrel 20) is detected by a temperature sensor. The detected temperature corresponds to an output power of the lamp load 13, and the control unit 64 then depends on the lamp load 13 The output power is used to control the baking process of the plastic pellets.

Regarding the operation of the infrared drying machine 1 of this embodiment, please refer to FIG. 5, FIG. 8 and FIG. 9 and the following table. time First switching device Second switching device AC drive signal status 0-t1 disconnect Conduction 0 Heating section t1-t2 Conduction Conduction Inverted Process of reducing output power t2-t3 Conduction disconnect Normal phase t3~ Conduction disconnect Normal phase Temperature-holding section

First, when the user starts to transport the wet plastic particles into the first barrel 20, the control unit 64 turns on the motor 40 to rotate the first barrel 20, and the control unit 64 also turns off the first switch device 62 and turns on the first barrel 20. The second switch device 63 enables the lamp load 13 to output 100% of the rated maximum output power of infrared light (corresponding to the voltage of 220 volts, as shown in the upper diagram of Fig. 9) using the mains AC only, and maintain 100% of the output power for a period of time ( That is, the time from 0 to t1 in Fig. 8), this period of time is the heating section in the baking process of the plastic particles, so that the temperature in the first barrel 20 rises to a baking temperature. The baking temperature is based on the plastic particles. Set according to the actual material.

When the baking temperature or specific power is reached, the control unit 64 starts to reduce the output power of the lamp load 13. At this time, the control unit 64 controls the inverter 61 to output an AC drive signal that is inverted from the mains AC (as shown in Figure 9). Figure), and gradually increase the voltage amplitude of the AC drive signal, so that the voltage amplitude of the composite signal (the signal obtained by the addition of the mains and the AC drive signal) finally delivered to the lamp load 13 decreases until the lamp load The output power of 13 is equal to the rated maximum output power of the infrared heater 10 (at this time the time point t2 is reached, the voltage amplitude of the AC driving signal is -110 volts).

Next, the control unit 64 turns off the second switching device 63 (at this time the first switching device 62 is on), and controls the inverter 61 to output an AC drive signal in the same phase as the mains AC (at this time, the mains AC no longer passes through the second The switch device 63 is input to the lamp load 13), and the lamp load 13 will simply use the AC driving signal. From time t2 to t3, the control unit 64 gradually reduces the voltage amplitude of the AC driving signal until the plastic particles begin to reach thermal equilibrium.

It should be noted that since the second switch device 63 is off and the first switch device 62 is on, in this case, only the AC drive signal is input to the lamp load 13. In this case, the control Even if the unit 64 controls the AC drive signal to reverse the AC drive signal and the mains AC, in this case, the lamp load 13 can also use the AC drive signal output by the inverter 61 to emit infrared rays.

Finally, after the time point t3, the lamp load 13 maintains a low output power (for example, the corresponding ground voltage amplitude is 44 volts), at this time the AC drive signal is still in positive phase, and the second switch device 63 is still off Yes, until the moisture content of the plastic particles reaches the requirement, turn off the infrared heater 10, and the dried plastic particles can be used for plastic molding.

Therefore, it can be seen that through the above control method, the inverter 61 only needs to output an AC drive signal with a maximum voltage amplitude of 110 volts, and the output power of the lamp load 13 can be adjusted to exceed the rated output of the infrared heater 10. The maximum output power, therefore, the requirements of various power element specifications of the infrared heater 10 can be reduced, so the overall cost of the infrared dryer 1 can be reduced, and the plastic particles can also be uniformly heated.

Finally, in order to facilitate the extraction of the dried plastic particles, a first lifting mechanism 70 is also designed in this embodiment, please refer to FIG. 2 and FIG. 4. The first lifting mechanism 70 includes a pneumatic cylinder 71, a first connecting rod 73 and a second connecting rod 74. One end of the pneumatic cylinder 71 is pivotally connected to the first frame 31, and the pneumatic cylinder 71 is electrically connected to the control unit 64 and has A telescopic rod 72 enables the control unit 64 to control the pneumatic cylinder 71 to extend or contract the telescopic rod 72. One end of the first link 73 is pivotally connected to the telescopic rod 72, and the other end of the first link 73 is pivotally connected to the bottom of the second frame 32 (that is, the first lifting mechanism 70 passes through the second frame 32 While connected to the first barrel 20), one end of the second connecting rod 74 is pivotally connected to the first connecting rod 73 and the telescopic rod 72, and the other end of the second connecting rod 74 is pivotally connected to the first frame body 31. In this way, when the control unit 64 drives the first lifting mechanism 70, the second frame 32 and the first barrel 20 can be raised to make the first barrel 20 in an inclined state (as shown in FIG. 4), so as to facilitate subsequent extraction and drying. Plastic pellets after drying. In addition, the infrared dryer 1 is also designed with a discharging mechanism 80 for opening the outer cover 22 of the first barrel 20 so that the plastic particles can be quickly discharged from the first barrel 20 to a storage barrel.

The present invention further provides a second embodiment, please refer to FIG. 10. The material drying machine 1'of the second embodiment includes a particle size screening device 91, a first material drying unit 92, and a second material drying unit 93. The second drying material unit 93 is located above the first drying material unit 92, and the particle size screening device 91 is located above the second drying material unit 93. The first material drying unit 92 has the first material barrel 20, a support frame 30, an infrared heater 10, a first lifting mechanism 70 and other elements as described in the first embodiment to perform material drying treatment. The second drying unit 93 has a second barrel (not shown in the figure), an infrared heater 10, a second lifting mechanism (not shown in the figure) and other elements, and uses the support frame 30 of the first drying unit 92, The structure of the second barrel is the same as that of the first barrel 20, the structure of the second lifting mechanism and the first lifting mechanism 70 are also the same, and one end of the first connecting rod of the second lifting mechanism is connected to the second barrel (or The second barrel is connected through a third frame), one end of the second link is connected to the support frame, the end of the first link relative to the second barrel and the end of the second link relative to the support frame are both connected One of the pneumatic cylinders is a telescopic rod, and the pneumatic cylinder is arranged on the support frame. The supporting frame 30 of the second baking unit 93 is the same as the infrared heater 10. The second drying unit 93 is used to crystallize the plastic particles. Between the first material drying unit 92 and the second material drying unit 93, and between the second material drying unit 93 and the particle size screening device 91, there are pipes for transporting plastic particles. The particle size screening device 91 includes a particle size screener (not shown in the figure) and an inlet 911. The particle size screener is used to screen plastic particles, and the defective plastic particles will be discharged to the pulverizer G for pulverization. After the first baking unit 92 completes the baking of the plastic particles, it can be transported to the injection molding machine M through the pipeline for plastic molding operations.

Through the structural design of the infrared drying machine 1'of the second embodiment, one infrared drying machine 1'can have the three functions of particle size screening, crystallization and drying plastic particles, and the first drying unit 92, The second drying unit 93 and the particle size screening device 91 are arranged vertically, which can effectively reduce the use area of the plant, so it can make the most effective use of the plant area, and can be applied to smaller plants, or It is used for customized drying of materials. Of course, a third drying unit (not shown in the figure) can be provided between the second drying unit 93 and the first drying unit 92 if the production demand is met.

The examples listed above are used to clarify the feasible implementation aspects of the embodiments of the present invention. The present invention is not limited to the implementation aspects exemplified above, and it is slightly modified within the scope of the ideas disclosed in the present invention. And changes should still fall within the scope of the present invention.

1,1’ Baking machine 10 Infrared heater 11 Lamp bracket 12 Lamp shade 13 Lamp load 20 first barrel 21 Recordings 22 Outer cover 30 support frame 31 The first frame 32 The second frame 40 motors 41 roller 50 dehumidifier 60 Lamp Power Modulator 61 Inverter 62 First switch device 63 Second switch device 64 control unit 641 Analog-to-digital converter 642 PLL phase lock counter 643 System sinusoidal control signal amplitude modulation mechanism 65 Rectifier 66 Boost circuit 67 Feedback detection circuit 68 Front-end drive and isolation circuit 68a Digital analog converter 68b Inner loop wave type control circuit 68c Power transistor drive circuit 68d Optical coupling isolation circuit 69 Temperature feedback circuit 70 First lifting mechanism 71 Air cylinder 72 Telescopic rod 73 First link 74 Second link 80 Discharge mechanism 91 particle size screening device 911 inlet 92 The first drying unit 93 The second drying unit T1-T4 Transistor F transformer AC mains G shredder M injection molding machine

The detailed structure, characteristics, assembly or use of the infrared dryer will be described in the following embodiments. However, it should be understood that the embodiments and drawings described below are only illustrative, and not Application to limit the scope of patent application of the present invention, where:

Figure 1 is a perspective view of the infrared drying machine of the first embodiment; Figure 2 is a side view of Figure 1; Figure 3 is a cross-sectional view of Figure 2 drawn along the line 3-3; 4 is a schematic diagram of the operation of the infrared material drying machine of the first embodiment, to illustrate the situation after the first barrel is lifted; 5 to 7 are circuit block diagrams of the lamp power modulator, the lamp load and the mains in the first embodiment; Figure 8 is a diagram of the relationship between the load power percentage and the heating time of the embodiment; Figure 9 is a schematic diagram of the synthesis of mains and AC drive signals; and Fig. 10 is a schematic diagram of the structure of the infrared dryer of the second embodiment.

1 Baking machine 20 First barrel 22 Outer cover 30 support frame 31 The first frame 32 The second frame 40 Motor 41 Roller 50 dehumidifier 70 First promotion agency 80 Distributing agency

Claims (10)

An infrared material baking machine, comprising: a first barrel; an infrared heater, arranged in the first barrel and including a lamp tube load and a lamp power modulator, the lamp tube load can be driven When infrared rays are emitted, the lamp power modulator is connected to the lamp load to drive the lamp load. The lamp power modulator includes: an inverter, which is coupled to the mains and can use the mains to output an AC drive Signal; a first switch device, coupled to the inverter and the lamp load; a second switch device, coupled to the lamp load and the mains; a control unit, coupled to the first switch device and the second The switch device controls the conduction or disconnection of the first switch device and the second switch device, and the control unit also controls the inverter to output the AC driving signal that is synchronized and in phase with the mains or is synchronized and inverted to the lamp Tube load. The infrared baking machine according to claim 1, wherein the lamp power modulator further includes a feedback detection circuit, the feedback detection circuit detects the phase of the AC drive signal and detects the The phase of the AC drive signal is input to the control unit. The infrared baking machine of claim 1, wherein the lamp power modulator further includes a temperature feedback circuit, and the temperature detection result of the temperature feedback circuit corresponds to an output power of the lamp load, and The detected output power is input to the control unit. The infrared baking machine according to claim 3, wherein the lamp power modulator has a rated maximum output power, and when the control unit performs temperature and power closed-loop control through the temperature feedback circuit, when the control unit detects It is measured that the output power of the lamp load is greater than or equal to the rated maximum When outputting power, the control unit turns on the first switching device and the second switching device, and the control unit adjusts the inverter output and the AC drive signal inverted from the mains; when the control unit passes the temperature feedback circuit When it is detected that the output power of the lamp load is less than the rated maximum output power, the control unit turns on the first switch device and turns off the second switch, and the control unit adjusts the inverter output to be in phase or reverse to the mains. The corresponding AC drive signal. According to the infrared baking machine of claim 3, the temperature feedback circuit further includes a temperature detector that detects the temperature of the plastic particles arranged in the first barrel, and the temperature returns The power supply circuit obtains the output power based on the detected temperature of the plastic particles. The infrared material dryer according to claim 1, further comprising a support frame and a first lifting mechanism, the first barrel is horizontally and rotatably installed on the support frame, and the first lifting mechanism is It is arranged on the support frame and connected with the material barrel, and the first lifting mechanism can be driven to lift the material barrel so that the first material barrel is in an inclined state. The infrared material drying machine according to claim 6, further comprising a second barrel and a second lifting mechanism, the second barrel is horizontally arranged on the support frame and located above the first barrel, The second lifting mechanism is arranged on the support frame and connected to the second material barrel, and the second lifting mechanism can be driven to lift the second material barrel to make the material barrel in an inclined state. The infrared dryer according to claim 6, wherein the support frame includes a first frame body and a second frame body, the second frame body is set up on the first frame body in a liftable manner, and the first frame body A barrel is set on the second frame, the first lifting mechanism includes a pneumatic cylinder, a first connecting rod and a second connecting rod, one end of the first connecting rod is connected to the second frame, the first One end of the two connecting rods is connected to the first frame body, and the end of the first connecting rod opposite to the first frame body and the end of the second connecting rod opposite to the second frame body are both connected to a telescopic rod of the pneumatic cylinder , The pneumatic cylinder is arranged on the first frame. The infrared dryer according to claim 7, wherein the support frame includes a first frame body and a third frame body, and the second lifting mechanism includes a pneumatic cylinder, a first connecting rod and a second connecting rod. Rod, one end of the first link is connected to the third frame, one end of the second link is connected to the first frame, one end of the first link opposite to the second barrel and the second link One end of the first frame body is connected with a telescopic rod of the pneumatic cylinder, and the pneumatic cylinder is arranged on the first frame body. The drying machine according to claim 7, further comprising a particle size screening device, the particle size screening device is arranged on the second barrel and connected to the second barrel.

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