CN112815628A

CN112815628A - Microwave dryer

Info

Publication number: CN112815628A
Application number: CN201911118384.6A
Authority: CN
Inventors: 居峥; 刘远辉; 唐瑞波
Original assignee: Shanghai Yushi Technology Development Co ltd
Current assignee: Shanghai Yushi Technology Development Co ltd
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2021-05-18

Abstract

The application discloses microwave dryer includes: the device comprises a barrel, a feed inlet, a discharge outlet and a filter, wherein the barrel is provided with a cavity for containing granular materials; a microwave magnetron disposed on the cylinder; the blowing pipe is arranged in the cylinder and connected with the bottom of the cylinder, and a plurality of feeding holes are formed in the blowing pipe; the bottom of the material blowing pipe is also communicated with a blowing air source channel and a material discharging channel. This application adopts pnematic equal stirring granule material circulation to utilize the microwave as the heating source, dry the granule material through lower heating temperature, have energy-conservation, high-efficient, to the environment heat dissipation can be few and air pollution advantage such as little.

Description

Microwave dryer

Technical Field

The application belongs to the technical field of microwave drying, and particularly relates to a microwave dryer.

Background

In the production and processing of plastic products, if the raw plastic particles contain high moisture, the size precision and the product quality of parts are greatly influenced, and even the parts are scrapped. Therefore, before the parts are formed, drying the raw material of the plastic with strong water absorption is one of the most important links.

In order to reduce the moisture in the raw material particles, drying measures are generally adopted in the industry before injection molding, an electric heating tube oven or a hot air oven is generally adopted, the air in the oven is heated by an electric heating wire, and meanwhile, a blower is adopted to blow the generated heat into a drying device to dry the plastic raw material. However, this drying method has obvious disadvantages: 1) the power consumption is overlarge, and the energy utilization rate is low; 2) the drying period is long, and the production efficiency is low; 3) the heating temperature of the particles is high, and the original performance of the particles is damaged; 4) and heat, dust and the like can be discharged to the external environment continuously in the drying process.

Tunnel type microwave drying equipment is also more common, and it is used for drying grain, tealeaves, medicinal material, fodder etc. more, and the main shortcoming is: 1) the occupied area is large, the equipment cost is high, the equipment usually occupies dozens of squares, the equipment utilization is limited, and the equipment is not suitable for compact factories; 2) because the 'through type' heating is adopted, the real heating time is short, multiple microwave tubes are generally adopted to work cooperatively at the same time, the required power configuration and energy consumption are high, and the efficiency and energy consumption ratio are low; 3) manual feeding and discharging are needed, and the labor intensity of personnel is high.

Disclosure of Invention

To the shortcoming or not enough of above-mentioned prior art, the technical problem that this application will be solved provides a microwave dryer, adopts pnematic equal stirring granule material circulation to utilize the microwave as the heating source, dry the granule material through lower heating temperature, have energy-conservation, high-efficient, to the environment heat dissipation can be few and air pollution advantage such as little.

In order to solve the technical problem, the application is realized by the following technical scheme:

a microwave dryer, comprising: the device comprises a barrel, a feed inlet, a discharge outlet and a filter, wherein the barrel is provided with a cavity for containing granular materials; a microwave magnetron disposed on the cylinder; the blowing pipe is arranged in the cylinder and connected with the bottom of the cylinder, and a plurality of feeding holes are formed in the blowing pipe; the bottom of the material blowing pipe is also communicated with a blowing air source channel and a material discharging channel.

Further, in the microwave dryer, a cover is further disposed on the blowing pipe, and the cover is disposed near the bottom of the blowing pipe and above the feeding hole.

Further, in the microwave dryer, the cover is detachably connected to the blowing pipe and can slide up and down along the blowing pipe.

Further, in the microwave dryer, the material blowing pipe is further provided with a protruding structure, and the protruding structure is arranged between the material inlet hole and the cover.

Further, in the microwave dryer, the hood is a bamboo hat type hood.

Further, in the microwave dryer, a bulk material tray is further installed at the top of the blowing pipe, and a particle material dispersing channel is reserved between the top of the blowing pipe and the bulk material tray.

Further, in the microwave dryer, the bulk material tray is detachably mounted on the top of the blowing pipe through a bracket.

Further, in the microwave dryer, the bulk material tray is made of glass or ceramic material.

Further, in the microwave dryer, a metal nano coating is disposed on the surface of the bulk material tray.

Further, in the microwave dryer, the bottom of the material blowing pipe is connected with a first port of a three-way electric ball valve, a second port of the three-way electric ball valve is connected with the air blowing gas source channel, and a third port of the three-way electric ball valve is connected with the material discharging channel.

Further, in the microwave dryer, the bottom of the blowing pipe is connected with the first port of the three-way electric ball valve through a connecting pipeline.

Further, in the microwave dryer, the connecting pipeline has a horizontal section.

Further, in the microwave dryer, an air inlet end of the blowing air source channel is further connected with an air source device, wherein the air source device includes a blower.

Further, in the microwave dryer, the exhaust outlet and the feed inlet are both provided with a pipe which is lengthened inwards, wherein the length-diameter ratio of the pipe is greater than or equal to 2.

Further, in the microwave dryer described above, the drum includes a cylindrical structure provided at an upper portion and a funnel structure provided at a lower portion, wherein the cylindrical structure and the funnel structure are smoothly connected.

Further, the microwave dryer further comprises a temperature sensor, wherein the temperature sensor is arranged at the upper part of the cylinder body.

Further, the microwave dryer further comprises a feeding level sensor and a discharging level sensor, wherein the feeding level sensor and the discharging level sensor are respectively arranged on the upper portion and the lower portion of the barrel.

Further, the microwave dryer further comprises a driving power supply, wherein the driving power supply is electrically connected with the microwave magnetron.

Further, the microwave dryer further comprises a control electric box, wherein the control electric box is electrically connected with the microwave magnetron, the three-way electric ball valve and the air source device respectively.

Further, the microwave dryer further comprises a mounting frame with casters, and the mounting frame is used for mounting the barrel.

Compared with the prior art, the method has the following technical effects:

the method has the advantages of low energy consumption and high energy efficiency, and the particle materials are circulated by matching with an air source device by utilizing the characteristic that microwaves are heated from the interior of the water-containing particles;

the drying time is short, the working efficiency is high, the time of the traditional externally heated particle material drying method can be shortened by about half, and the drying effect required by production can be achieved by adopting the dryer to work for 40 min-1 h through experimental determination;

the temperature of the drying process is low due to good room temperature air or N₂When the gas is circulated for turning over, the temperature is moderate in the drying process of the particles, basically below 100 ℃, and the physical and chemical properties of the particles are not damaged;

the method has small influence on the environment, generates heat radiation in the low-temperature drying process and has small pollution to air;

the full-automatic control can be realized, the labor workload is reduced, the reserved interfaces are complete, and the full-automatic control device can be conveniently matched with the existing equipment for use;

the hot air dryer has the advantages of compact integral structure, small occupied area, low equipment manufacturing cost and obvious advantages compared with the traditional hot air dryer;

the method is not only suitable for the plastic product industry, but also can be used for drying the granular materials in other industries, such as chemical fiber, textile, medicine, grain, feed and the like, and is also suitable for the production process needing drying the granular materials.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

FIG. 1: the microwave dryer is a schematic overall structure diagram;

FIG. 2: the working principle of the microwave dryer is shown in the figure;

FIG. 3: the structure schematic diagram of the blowing pipe in the application;

FIG. 4: the structure of the cover in the application is shown schematically;

FIG. 5: the structure schematic diagram of the bulk material tray in the application;

FIG. 6: the structural schematic diagram of the support in this application.

Detailed Description

The conception, specific structure and technical effects of the present application will be further described in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present application.

As shown in fig. 1 and 2, the microwave dryer of the present embodiment includes: the device comprises a cylinder 02, a microwave magnetron 13 and a material blowing pipe 03, wherein the cylinder 02 is provided with a cavity for containing granular materials, and the cylinder 02 is provided with a feed inlet 09 and an air outlet 11; the microwave magnetron 13 is arranged on the cylinder 02; the material blowing pipe 03 is of a hollow pipe structure which is arranged in a vertically through mode, the material blowing pipe 03 is arranged in the cylinder 02 and connected with the bottom of the cylinder 02, a plurality of feeding holes 0301 are further formed in the material blowing pipe 03, and a gas blowing source channel 06 and a material discharging channel 08 are further communicated with the bottom of the material blowing pipe 03. The embodiment adopts pneumatic or N is introduced₂When gas blows upwards from blowing the lowest of material pipe 03 in proper order, upper portion granule material moves down in proper order, realize circulating the granule material of stirring in proper order, cooperate microwave magnetron 13 to heat the granule simultaneously, utilize the microwave to extremely the shape molecule sensitive, the characteristics of the moisture in the preferential heating granule, heat the granule from moisture particle inside and drive moisture, cooperation pneumatics etc. stirring granule material and even heat dissipation, the air current carries out gas exchange through air supply unit 07 inside and outside barrel 02, through the manifold cycles, the granule material that makes will dry accomplishes the loss of water and reaches drying effect under the operating mode of suitable temperature (below 100 ℃).

In this embodiment, an air inlet end of the blowing air source channel 06 is communicated with an air outlet 0701 of an air source device 07, and further, the air source device 07 includes a blower or N₂And the like. The drying process of this example is carried out at a lower temperature due to the use of good room temperature air or N₂When the gas is circulated for turning over, the temperature is moderate in the drying process of the granules, the temperature is basically below 100 ℃, and the physical and chemical properties of the granules are not damaged.

The air source device 07 is arranged on the lower layer of the mounting frame 01, and the air inlet is arranged downwards, so that foreign matters can be prevented from being sucked.

Wherein, above-mentioned air-blower is preferred to be adopted turbofan, and the wind pressure is less than 50Kpa and can satisfy the requirement, through this pnematic stirring granule material, more energy-conserving, high-efficient, few and air pollution little etc. to environment heat dissipation ability.

The cylinder body 02 comprises a cylindrical structure 0201 arranged at the upper part and a funnel-shaped structure 0202 arranged at the lower part, the cylindrical structure 0201 and the funnel-shaped structure 0202 are smoothly connected, and the cylinder body 02 is preferably of an integrally formed structure. The inclination angle of the funnel-shaped structure 0202 is preferably around 45 °.

In this embodiment, the cylinder 02 is preferably made of stainless steel, the blowing pipe 03 is also preferably made of stainless steel, and the cylinder 02 may also be a glass pipe, which has higher hole opening cost but better wear resistance.

Further, an internal threaded pipe 0203 is welded at the bottom of the cylinder body 02, an external thread structure matched with the threaded pipe for use is arranged on the outer wall of the bottom of the blowing pipe 03, and the blowing pipe 03 and the cylinder body 02 are fixed by matching the external thread structure with the internal threaded pipe 0203.

An openable cover 0204 is further arranged on the upper portion of the cylinder body 02, and after the cover 0204 is covered, the cylinder body 02 forms a sealing space.

The feed port 09, the exhaust port 11, and the microwave magnetron 13 described above are preferably provided on the lid 0204, i.e., the top of the cylinder 02. Of course, in order to obtain a better drying effect, the microwave magnetrons 13 may be disposed in plural and disposed at the side surface or the bottom of the upper portion (the cylindrical structure 0201) of the cylinder 02, and of course, the specific arrangement manner may be uniform or non-uniform, for example, a plurality of microwave magnetrons 13 may be uniformly arranged along the circumference of the circumferential structure. Wherein, the waveguide port of the microwave magnetron 13 is arranged towards the surface of the granular material, for example, when the microwave magnetron 13 is arranged on the top of the cylinder 02, the waveguide port of the microwave magnetron 13 is arranged downwards and towards the upper surface of the granular material.

Further, the feed port 09 and the exhaust port 11 are both arranged in parallel with the waveguide port direction of the microwave magnetron 13. The feed inlet 09 and the exhaust outlet 11 are both provided with a pipe which is arranged in an inward lengthening manner, wherein the length-diameter ratio of the pipe is more than or equal to 2, so that the microwave is prevented from leaking to the outer side of the cylinder 02 through the internal reflection of the pipe. The practical measurement in the prototype work shows that when the length-diameter ratio of the adopted pipe is more than or equal to 2, the microwave instrument can hardly detect the microwave leakage at the pipe orifice. In the actual measurement state of the embodiment, the diameter of the pipe is 50mm, and the length is 120mm, but when the pipe diameter is thickened, the length-diameter ratio may need to be increased.

In this embodiment, the exhaust outlet 11 may further be provided with a damper 12.

This embodiment still disposes a mounting bracket 01, mounting bracket 01 is used for installing barrel 02, barrel 02 can stand upright and sit on mounting bracket 01 a plurality of truckles are installed to mounting bracket 01 lower extreme so that mobile device.

The material blowing pipe 03 is preferably fixed at the center of the cylinder 02, the material blowing pipe 03 adopts a structural form that wind force is fed from the bottom of the material blowing pipe, holes are formed on the periphery of the pipe wall close to the bottom for feeding, and outlets at the top for discharging, the material feeding holes 0301 are vertical rectangles, and the number of the material feeding holes 0301 is 4, as shown in fig. 3. The structure and number of the feed holes 0301 are only one of the realizable modes, and the protection scope of the present application is not limited, and those skilled in the art can adopt other structures or other numbers of feed holes 0301 according to the actual needs.

As shown in fig. 3, a protrusion 0305 structure is further disposed on the blowing pipe 03, wherein the protrusion 0305 structure is disposed between the feeding hole 0301 and the cover 0304. Said bulge 0305 structure prevents hood 0304 from excessively lowering down into contact with the inner wall of funnel-shaped structure 0202, thus closing said inlet port 0301.

As shown in fig. 1, 2 and 4, a cover 0304 is further disposed on the blowing pipe 03, and the cover 0304 is disposed near the bottom of the blowing pipe 03 and above the feeding hole 0301. The cover 0304 is used for dispersing the particles into the feed holes 0301, so that the particles in the cylinder 02 uniformly enter the blowing pipe 03 from the periphery through the feed holes 0301, but the height of the particles entering the blowing pipe 03 does not exceed the upper end of the feed holes 0301.

The cover 0304 is detachably connected with the material blowing pipe 03 and can slide up and down along the material blowing pipe 03, and the distance between the lower edge of the cover 0304 and the bottom of the funnel-shaped structure 0202 is adjusted, so that the speed of the particle materials entering the material blowing pipe 03 is controlled.

Further, the cover 0304 is a bamboo hat type cover, wherein the material for making the cover 0304 is preferably non-metal material, preferably heat-resistant plastic or glass. The inclined plane of the bamboo hat-shaped cover and the horizontal plane preferably form an included angle of 45 degrees, and the inclined plane and the plane of the funnel-shaped structure 0202 correspondingly arranged are perpendicular to each other. The lower end of the central circular ring of the bamboo hat type cover is welded with a circle of bamboo hat type edge, and the bamboo hat type cover is sleeved on the material blowing pipe 03 through the central circular ring and fixed on the material blowing pipe 03 through screws.

In this embodiment, as shown in fig. 1, fig. 2, fig. 3 and fig. 5, a bulk material tray 0303 is further installed on the top of the blowing pipe 03, wherein a particle material dispersing channel is further reserved between the top of the blowing pipe 03 and the bulk material tray 0303. The material scattering disk 0303 is preferably in a circular arc structure, wherein a small hole for installation and fixation is arranged in the center of the material scattering disk 0303.

The bulk material tray 0303 is detachably mounted on the top of the blowing pipe 03 through a support 0302. The bulk material tray 0303 is installed on the top end of the bracket 0302 through configured holes, so that a space distance is reserved between the bulk material tray 0303 and the top of the material blowing pipe 03, and a particle dispersing channel is reserved.

As shown in fig. 6, a circular ring is arranged at the bottom of the bracket 0302, the top end of the herringbone bracket 0302 is provided with a section of thread and is inserted into a hole of the bulk material tray 0303 and is fixed by a nut, the circular ring is sleeved at the top end of the blowing pipe 03, and the side surface of the circular ring can be locked on the blowing pipe 03 by a set screw.

Wherein the bulk tray 0303 is made of glass or ceramic material. The material drying and turning device is used for dispersing the particle materials blown from the material blowing pipe 03 during drying and turning by utilizing the characteristics of high hardness, wear resistance and no microwave blocking of glass, ceramic and the like, and blocking the particles from directly impacting the microwave magnetron 13; when wind power is adopted to feed materials into the material blowing cylinder, the material dispersing disc 0303 can disperse the impact force of the material feeding particles, and the material dispersing disc 0303 at the pipe opening of the material blowing pipe 03 can also prevent particles from entering the material blowing pipe 03 from the upper opening to cause the material accumulation in the material blowing pipe 03 to be too high and blocked and the like.

Certainly, the surface of the bulk tray 0303 can be further provided with a metal nano coating for dispersing the particle materials blown from the material blowing pipe 03 during drying and turning, and blocking the particles from impacting the microwave magnetron 13; when wind power is used for feeding materials into the material blowing cylinder, the material dispersing disc 0303 provided with the metal nano coating can disperse impact force of feeding particles, and the material dispersing disc 0303 at the pipe opening of the material blowing pipe 03 can also prevent particles from entering the material blowing pipe 03 from the upper opening to cause too high and blockage of the particles accumulated in the material blowing pipe 03.

The bottom of the material blowing pipe 03 is connected with a first port A of a three-way electric ball valve 05, a second port B of the three-way electric ball valve 05 is connected with the air blowing air source channel 06, and a third port C of the three-way electric ball valve 05 is connected with the material discharging channel 08. The three-way electric ball valve 05 is used for controlling material turning and discharging.

The bottom of the blowing pipe 03 is connected with a first port A of the three-way electric ball valve 05 through a connecting pipeline 04. Wherein, connecting line 04 has a horizontal segment, and the setting of this horizontal segment can prevent that too much granule material whereabouts from getting into tee bend electric ball valve 05 and piling up, influences the switching-over switching of tee bend electric ball valve 05.

The present embodiment is further provided with a temperature sensor 15, wherein the temperature sensor 15 is arranged at the upper part of the cylinder 02, and the temperature sensor 15 is used for monitoring the working temperature of the granular materials.

This embodiment still is configured with material loading level sensor 16 and unloading level sensor 17, material loading level sensor 16 unloading level sensor 17 sets up respectively the upper portion of barrel 02 with the lower part of barrel 02. The material loading level sensor 16 and the material unloading level sensor 17 are used for monitoring the material level state of the granular materials.

Further, the present embodiment is further provided with a driving power supply 14, and the driving power supply 14 is electrically connected to the microwave magnetron 13.

The present embodiment is further provided with a control electric box 18, the control electric box 18 is installed on the mounting rack 01, and the control electric box 18 is electrically connected with the microwave magnetron 13, the three-way electric solenoid valve 05 and the gas source device 07 respectively. The control electric box 18 is internally provided with a microcomputer and an electric appliance control switch and is used for controlling the microwave magnetron 13, the three-way electric ball valve 05 and the air source device 07 to work coordinately according to a set program.

Furthermore, a power supply interface of the feeding machine is reserved in the control electric box 18, a power supply of the external feeding box discharging machine is connected to a corresponding position, the external feeding machine can be directly controlled to work, and automatic control is achieved.

The working principle of the present application is as follows (the air source device described below is described by taking a blower as an example):

the particle material feeding process comprises the following steps: the outside feeder starts, and inside the cavity that the granule material added barrel 02 through feed inlet 09 through outside feeder earlier, stopped reinforced after material level sensor 16 detects full material.

The material turning and heating working process comprises the following steps: the control electronic box 18 automatically starts the air source device 07 to blow air, wind power blows upwards through the air source channel 06 of blowing, then through the port B of the three-way electric ball valve 05 to the lower end of the material blowing pipe 03, the particle materials which enter the material blowing pipe 03 through the feed hole 0301 at the bottommost part are blown upwards, the particle materials are scattered around along with the wind power after impacting the bulk material tray 0303 at the top part, and the particles fall to the topmost layer of the particle materials in a scattered manner. When the air source device 07 is started to turn over the materials, the microwave magnetron 13 also starts to work, and the particles are heated by microwaves from the upper end. The granule material moves downwards and turns upwards layer by layer in the working process. The microwave emits microwave to the granular material, and the granular material is dynamically and uniformly heated. And in the process that the bottom granular materials are turned upwards along with wind power, the granular materials are cooled again by the wind power, and the granular materials are dried after multiple cycles. The particles are heated and cooled uniformly in the drying process, and local overheating or heating failure can not occur.

The microwave irradiation drying and the wind-up granule material turning can be carried out simultaneously, or the working time of the wind supply and the microwave magnetron 13 can be separately controlled according to the set program, and the program can properly adjust the frequent proportion of the work according to the initial temperature condition and the drying intensity requirement. When the temperature sensor 15 detects that the heating temperature is low, the operation mode of the gas source device 07 can be adjusted to be intermittent operation, and the microwave magnetron 13 is operated all the time. When the set temperature is reached, the microcomputer in the control electric box 18 automatically controls and reduces the working strength of the microwave magnetron 13 to prevent the particle materials from being overheated. And when the heating drying time reaches the time preset by the program, controlling the program to automatically stop heating and blowing to finish drying the cylinder of granular materials.

And (3) discharging: and after drying, preparing for discharging. The control electronic box 18 controls the three-way electric ball valve 05 to rotate, so that channels of a first port A and a second port B in the three-way electric ball valve 05 are disconnected, the channels of the first port A and a third port C are communicated, then, the air source device 07 is closed, the particles are downward along the material blowing pipe 03 through the feed hole 0301 under the action of gravity, enter the material discharging channel 08 through the three-way electric ball valve 05 to complete material discharging, when the blanking position sensor 17 at the bottom detects that no material exists, the operation is stopped, and the working cycle is finished. Waiting for the command to enter the next drying cycle, and circularly and repeatedly working.

It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present application to describe certain components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. For example, a first certain component may also be referred to as a second certain component, and similarly, a second certain component may also be referred to as a first certain component without departing from the scope of embodiments herein.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.

The above embodiments are merely to illustrate the technical solutions of the present application and are not limitative, and the present application is described in detail with reference to preferred embodiments. It will be understood by those skilled in the art that various modifications and equivalent arrangements may be made in the present invention without departing from the spirit and scope of the present invention and shall be covered by the appended claims.

Claims

1. A microwave dryer, comprising:

the device comprises a barrel, a feed inlet, a discharge outlet and a filter, wherein the barrel is provided with a cavity for containing granular materials;

a microwave magnetron disposed on the cylinder;

the blowing pipe is arranged in the cylinder and connected with the bottom of the cylinder, and a plurality of feeding holes are formed in the blowing pipe;

the bottom of the material blowing pipe is also communicated with a blowing air source channel and a material discharging channel.

2. The microwave dryer according to claim 1, wherein the blow pipe further comprises a hood disposed adjacent to a bottom of the blow pipe and above the feed opening.

3. A microwave dryer as claimed in claim 2 wherein the hood is removably connected to the blow tube and is slidable up and down the blow tube.

4. A microwave dryer according to claim 2 or 3 wherein the blow pipe is further provided with a raised structure, wherein the raised structure is provided between the feed aperture and the hood.

5. A microwave dryer according to claim 2 or 3 wherein the hood is a bamboo hat type hood.

6. The microwave dryer according to claim 1, wherein a bulk material tray is further installed on the top of the blowing pipe, and a particle material dispersing channel is further reserved between the top of the blowing pipe and the bulk material tray.

7. A microwave dryer as claimed in claim 6 wherein the bulk tray is removably mounted on top of the blow tube by a bracket.

8. A microwave dryer as claimed in claim 6, wherein the bulk discs are made of glass or ceramic material.

9. A microwave dryer as claimed in claim 6, 7 or 8, wherein the surface of the bulk discs is provided with a metallic nanocoating.

10. A microwave dryer as claimed in claim 1, 2, 6, 7 or 8, wherein the bottom of the blowing pipe is connected to a first port of a three-way electric ball valve, a second port of the three-way electric ball valve is connected to the blowing air source passage, and a third port of the three-way electric ball valve is connected to the discharging passage.

11. A microwave dryer as claimed in claim 10 wherein the bottom of the blow tube is connected to the first port of the three-way motorized ball valve by a connecting line.

12. A microwave dryer as claimed in claim 11 wherein the connecting conduit has a horizontal section.

13. A microwave dryer as claimed in claim 10 wherein an air supply means is further connected to the air inlet end of the insufflation air supply passage, wherein the air supply means comprises a blower.

14. A microwave dryer according to claim 1 or 2 or 6 or 7 or 8 wherein the exhaust outlet and the inlet are each provided with an inwardly extending tube, wherein the length to diameter ratio of the tube is 2 or more.

15. A microwave dryer according to claim 1 wherein the cartridge comprises an upper cylindrical structure and a lower funnel structure, wherein the cylindrical structure and the funnel structure are smoothly connected.

16. A microwave dryer as claimed in claim 1 or 2 or 6 or 7 or 8 or 15 further comprising a temperature sensor disposed in an upper portion of the drum.

17. The microwave dryer according to claim 1, 2, 6, 7, 8 or 15, further comprising a feeding level sensor and a discharging level sensor, wherein the feeding level sensor and the discharging level sensor are respectively disposed at an upper portion and a lower portion of the drum.

18. A microwave dryer as claimed in claim 1 or 2 or 6 or 7 or 8 or 15 further comprising a drive power supply electrically connected to the microwave magnetron.

19. A microwave dryer as claimed in claim 1 or 2 or 6 or 7 or 8 or 15 further comprising a control electrical box electrically connected to the microwave magnetron, the three-way motorized ball valve and the gas supply means respectively.

20. A microwave dryer according to claim 1 or 2 or 6 or 7 or 8 or 15 further comprising a castellated mounting for mounting the drum.