An automatic measuring device for moisture content of forestry biomass raw materials

Abstract

The invention belongs to the technical field of measuring the moisture content of forestry biomass raw materials, and discloses an automatic measuring device for the moisture content of forestry biomass raw materials, wherein a lifting mechanism is vertically fixedly arranged at the right inner position of a bracket; a flexible buffer mechanism is fixedly arranged at the left upper position of the lifting mechanism; a weighing mechanism is fixedly arranged at the upper center position of the flexible buffer mechanism; a refractory placing table is fixedly arranged at the upper part of the weighing mechanism; a rotary switching mechanism is fixedly arranged at the connection between the bracket and the upper part of the counterweight body; the outer side of a drying box is fixedly arranged at the upper right position of the rotary switching mechanism; and a drying box is fixedly arranged at the upper left position of the rotary switching mechanism. The invention has the following beneficial effects: 1. The test measuring process is simplified, and the degree of automation of measuring the moisture content of forestry biomass raw material samples is improved; 2. The efficient and rapid calculation of data is realized, and the precise control of the drying time, the drying temperature and the drying cooling temperature is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of forestry biomass raw material moisture content determination, and in particular relates to an automatic determination device for the moisture content of forestry biomass raw material. Background Art

[0002] Forestry biomass raw materials mainly include biomass energy provided by the growth of trees and the production process of trees, including firewood forests, scattered wood in forest tending and thinning operations, residual branches, leaves and wood chips, etc. In addition, it also includes branches, sawdust, wood chips, tips, board skins and cut heads in the process of wood harvesting and processing, as well as waste by-products of forestry, such as fruit shells and fruit cores. With the change of seasons, the above-mentioned forestry biomass raw materials fall off naturally and grow again next year. Therefore, it is called a renewable biomass raw material that can be recycled. Forestry biomass raw materials are also the most important economic raw materials in the forestry economy.

[0003] Forestry biomass raw materials are crushed and granulated for use as combustion raw materials for biomass power generation. At the same time, they can also be crushed, extruded and granulated to form biomass pellets for heating. Since these biomass pellet fuels are easy to transport and store, and can reduce environmental pollution caused by direct combustion when used, they have good recyclable and renewable biomass fuel characteristics. Especially for biomass raw materials used for bio-power generation, strict requirements are placed on the moisture content of forestry biomass raw materials, requiring not only the wet basis moisture content of biomass raw materials, but also the dry basis moisture content of biomass raw materials. Therefore, the moisture content of forestry biomass raw materials is tested and determined in the forest farm, and the moisture content of forestry biomass is determined according to the test determination method of the national standard GB / T36055-2018. In the above national standards, the specific method for determining the moisture content of forestry biomass raw materials is as follows: when sampling the same biomass raw material, two portions should be taken, and 2g~10g of the sample should be weighed with a balance and placed in a pre-dried, weighed and marked container. The container with the sample is covered and placed in an oven that can keep the temperature at 105℃±2℃. The container lid is opened and dried. The first drying time is not less than 4h. Then weigh the container with the sample and calculate the mass of the dried sample. Repeat the above operation, and the drying time again should be no less than 1h. When the sampling amount is large, the drying time should be at least half of the first drying time. When the difference in weighing is no more than 0.1% of the mass of the sample before drying for two consecutive times at a specified time interval, the sample can be considered to have reached constant weight. Finally, the wet basis moisture content of the forestry biomass raw material is calculated according to the calculation formula of the wet basis moisture content of the forestry biomass raw material, and the dry basis moisture content of the forestry biomass raw material is calculated according to the calculation formula of the dry basis moisture content of the forestry biomass raw material.

[0004] In the prior art, for the crushed forestry biomass raw materials, the main technical problems in the test determination of their wet basis moisture content and dry basis moisture content using the above test method are: each forestry biomass raw material sample needs to be dried twice, and the drying time needs to be precisely controlled. It is also necessary to judge whether the forestry biomass raw material sample has reached a constant weight state based on the difference before and after the forestry biomass raw material sample is dried, and it is also necessary to calculate the wet basis moisture content and dry basis moisture content of the forestry biomass raw material sample based on the mass of the forestry biomass raw material sample before and after drying. The main problems in the test determination of the above forestry biomass raw material samples are: 1. The forestry biomass raw material sample needs to be switched between the drying box and the drying box, and the test determination process is cumbersome, complicated, and has a low degree of automation; 2. It requires a large amount of calculation, the control of the drying time, the drying temperature, and the precise control of the drying cooling temperature cannot be precisely controlled manually, resulting in a decrease in the determination accuracy of the wet basis moisture content and dry basis moisture content of the forestry biomass raw material sample. Based on the above technical defects in the prior art, an automatic determination device for the moisture content of forestry biomass raw materials has been developed, which can well solve the above technical problems existing in the prior art. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an automatic determination device for the moisture content of forestry biomass raw materials. The present invention can solve the problems of cumbersome and complicated test and determination process and low degree of automation in the test and determination of forestry biomass raw material samples; at the same time, it also solves the problems of large amount of calculation in the test and determination process of forestry biomass raw material samples, and the inability to accurately control the drying time, drying temperature and drying cooling temperature.

[0006] The technical solution adopted by the present invention is: an automatic determination device for the moisture content of forestry biomass raw materials, including a bracket 1, a counterweight frame 2, a counterweight body 3, and a control panel 4; the counterweight frame 2 is fixedly arranged at the bottom of the left side of the bracket 1, and the counterweight body 3 is fixedly arranged on the upper part of the counterweight frame 2; the control panel 4 is fixedly arranged on the right side of the bracket 1 near the upper position, and the control panel 4 is used for automatically controlling the lifting mechanism 5, the rotation switching mechanism 10, the temperature of the drying box 11, the temperature of the drying box 12, and the sample drying time; the lifting mechanism 5 is vertically fixedly arranged at the right inner position of the bracket 1, and the lifting mechanism 5 is used to lift and push the sample container 9 into the drying box 11 or the drying box 12 for drying; the flexible buffer mechanism 6 is fixedly arranged at the upper left position of the lifting mechanism 5, and the flexible buffer mechanism 6 is used for the sample container 9 to play a flexible buffering role when the sample container 9 vibrates due to the inertia of the lifting kinetic energy during the lifting process; the weighing mechanism 7 is fixedly arranged at the upper center position of the flexible buffer mechanism 6, and the weighing mechanism 7 is fixedly arranged at the upper center position of the flexible buffer mechanism 6. The mechanism 7 is used to weigh the sample container 9; the refractory placement table 8 is fixedly arranged on the upper part of the weighing mechanism 7, and the refractory placement table 8 is used to place the sample container 9; the sample container 9 includes a container body 91, and the container body 91 is a cylindrical shape with a conical bottom, and the container cover 92 covers the upper part of the container body 91; the rotation switching mechanism 10 is fixedly arranged at the connection between the bracket 1 and the upper part of the counterweight body 3, and the rotation switching mechanism 10 is used to rotate and switch the positions of the drying box 11 and the drying box 12; the outer side of the drying box 11 is fixed to the upper right position of the rotation switching mechanism 10, and the drying box 11 is used to perform constant temperature drying on the forestry biomass raw material sample of the sample container 9; the drying box 12 is fixedly arranged on the upper left position of the rotation switching mechanism 10, and the drying box 12 is used to cool and dry the forestry biomass raw material sample to room temperature; the heat insulation board 13 is fixedly arranged at the bottom of the drying box 11 and the drying box 12 through four fixing columns 14, and a circular hole 15 is opened in the center of the heat insulation board 13.

[0007] The support 1 and the counterweight frame 2 are fixed by welding, and the heights of the support 1 and the counterweight frame 2 are equal; a convex opening is provided on the upper portion of the support 1 for the refractory placement platform 8 to be raised and lowered and for fixing the lifting mechanism 5 .

[0008] The control panel 4 includes a display screen 41, which is fixedly arranged at the middle position of the upper front side of the control panel 4, a start button 42 is fixedly arranged at the middle position of the lower part of the display screen 41, a close button 43 is fixedly arranged at the left position corresponding to the start button 42, an indicator light 44 is fixedly arranged at the lower position of the close button 43, and an emergency stop button 45 is fixedly arranged at the lower position of the start button 42; a PLC control mainboard 46 is fixedly arranged inside the control panel 4 body, and the PLC control mainboard 46 includes a control board body 461, a gain amplification operation module 462 is fixedly arranged at the upper part of the control board body 461, a control module 463 is fixedly arranged at the lower part of the gain amplification operation module 462, an operation module 464 is fixedly arranged at the lower position of the control module 463, and a timing module 465 is fixedly arranged at the lower part of the operation module 464; the display screen 41 is used for human-computer interaction and control parameter setting, and the gain amplification operation module 462 calculates the parameters calculated by the gain amplification operation module 464 through the gain amplification circuit.

[0009] The PLC control main board 46 is fixedly connected with the linear module 53, the electromagnetic weighing sensor 74, the thermocouple three 77, the stepper motor 102, the initial position limit switch 108, the heating rod 118 control switch, the thermocouple one 119, and the thermocouple two 1215 through a signal transmission line.

[0010] The lifting mechanism 5 includes a support body 51, which is fixedly arranged at the upper part of the bracket 1 near the front side, and the linear module 53 is fixedly arranged on the support body 51. The fixed block 52 is fixedly connected to the right side of the convex opening at the upper part of the bracket 1, and the fixed block 52 is fixedly arranged at the front and rear sides of the upper right end of the linear module 53 body in a front-to-back symmetrical manner; the sliding body 54 is fixedly arranged on the screw of the linear module 53, and the lifting arm 55 is symmetrically arranged at the front and rear sides of the sliding body 54, and the lifting arm 55 is L-shaped.

[0011] The flexible buffer mechanism 6 includes a base plate 61, which is fixedly arranged on the upper part of the lifting arm 55 symmetrically arranged front and rearward. Four connecting columns 63 are arranged, and the connecting columns 63 pass through the base plate 61 and are arranged at the four corners of the base plate 61. The square plate 62 passes through the bottom of the connecting column 63 to fix the connecting column 63 to the bottom of the base plate 61; the spring 64 is sleeved on the connecting column 63, and the spring 64 is located on the upper connecting column 63 of the base plate 61. The upper part of the connecting column 63 is sleeved with a cylinder 65 with a closed upper part and a hollow lower part, and a gap is reserved between the upper part of the cylinder 65 and the bottom of the refractory brick mounting shell 81.

[0012] The weighing mechanism 7 comprises a weighing shell 71, which is a hollow square body with an upper opening, and a conductive coating 72 is sprayed on the inner periphery and the bottom of the weighing shell 71; pole needles 73 are evenly fixedly arranged on the inner periphery of the weighing shell 71, and the pole tips of the pole needles 73 face the center of the weighing shell 71; four electromagnetic weighing sensors 74 are symmetrically arranged front and back and left and right, and the electromagnetic weighing sensors 74 are fixedly arranged on the bottom surface of the weighing shell 71, and a limit column 75 is set on the upper center of each electromagnetic weighing sensor 74, and the upper part of the limit column 75 is aligned with the weighing shell 71. The bottom of the weighing plate 76 is fixedly connected, the area of ​​the weighing plate 76 is smaller than the upper opening area of ​​the weighing shell 71, and an equidistant gap is reserved between the weighing plate 76 and the inner side of the upper opening of the weighing shell 71; the thermocouple three 77 is fixedly arranged on the rear inner side of the weighing shell 71 near the upper position, and the thermocouple three 77 is used to detect the temperature in the weighing shell 71 in real time; the cooling pipe 78 is fixedly arranged on the front inner side of the weighing shell 71 near the upper position, and the cooling pipe 78 is used to transport cooling gas to the weighing shell 71 to cool the electromagnetic weighing sensor 74.

[0013] A ground wire is fixedly connected to the outer wall of the weighing housing 71 , an upper end of the ground wire is fixedly connected to the outer wall of the weighing housing 71 , and a lower end of the ground wire is connected to the earth.

[0014] The refractory placement platform 8 includes a refractory brick mounting shell 81, which is a hollow square body. A refractory brick 82 is fixedly installed in the refractory brick mounting shell 81, and the volume of the refractory brick 82 is smaller than the volume of the refractory brick mounting shell 81; the boss refractory brick 83 is fixedly arranged at the upper center position of the refractory brick 82, and a conical placement hole 84 for placing the sample container 9 is opened in the upper center of the boss refractory brick 83, and the diameter of the conical placement hole 84 is larger than the bottom diameter of the sample container 9.

[0015] The rotary switching mechanism 10 includes a support frame 101, which is an inverted U-shape and is fixedly arranged on the upper part of the bracket 1 and the counterweight body 3; a dividing mechanism 103 is connected and fixedly arranged at the rear end of the stepper motor 102, and the stepper motor 102 is used to drive the dividing mechanism 103 to rotate at a certain angle, and the stepper motor 102 and the dividing mechanism 103 are fixedly arranged at the lower position of the support frame 101; a slewing bearing 104 is fixedly arranged at the upper center position of the support frame 101, and a driving shaft 105 is fixedly arranged on the upper part of the power output shaft of the dividing mechanism 103, and the driving shaft 105 passes through the upper center of the support frame 101 and is fixedly connected to the inner ring of the slewing bearing 104, and a rotating disk 106 is fixedly arranged on the outer ring of the slewing bearing 104, and the driving shaft 105 passes through the rotating disk The center of 106 extends to the upper part and is fixed by the shaft end cover; the square hole 107 is symmetrically opened at the left and right center positions of the rotating disk 106, the size of the square hole 107 is larger than the outer dimensions of the drying box 11 and the drying box 12, and the square hole 107 is used to fix the drying box 11 or the drying box 12; the initial position limit switch 108 is fixedly set in the middle of the left side surface of the drying box shell box 111 near the upper position, and the initial position limit switch 108 is used to keep the drying box 11 always at the corresponding position on the upper part of the refractory placement table 8; the initial position limit switch 108 includes a sensing sheet 1081, the sensing sheet 1081 is fixedly set in the middle position of the upper right side of the support frame 101, and the sensing contact 1082 is fixedly set in the middle position of the upper left side of the drying box shell box 111 corresponding to the sensing sheet 1081.

[0016] The drying box 11 comprises a drying box shell 111, which is a hollow square body with a hole at the bottom. Refractory brick plates 112 are arranged on the inner walls around the drying box shell 111. An upper refractory plate 113 is fixedly arranged on the upper inner wall of the drying box shell 111. A lower refractory plate 114 is fixedly arranged on the lower inner wall of the drying box shell 111. An installation groove 115 is arranged on the upper part of the lower refractory plate 114. A through hole 1110 is arranged at the center of the lower refractory plate 114. The through hole 1110 is connected to the lower part of the drying box shell 111. The holes opened in the center have equal diameters; the heating refractory cylinder 116 is a hollow cylinder, and the heating refractory cylinder 116 is installed in the installation groove 115. A heating rod installation groove 117 is opened at an equal angle on the axial end face of the heating refractory cylinder 116. The heating rod installation groove 117 runs through the axial direction of the heating refractory cylinder 116, and a heating rod 118 is fixedly installed in each heating rod installation groove 117. A thermocouple 119 is fixedly arranged at the upper center position of the drying box shell 111, and the thermocouple 119 is used to detect the drying temperature in the drying box 11 in real time.

[0017] The drying box 12 comprises a drying box shell 121, which is a hollow square body with an opening at the top and a closed bottom. An upper heat preservation plate 122 is fixedly arranged at the upper position of the drying box shell 121, and a lower heat preservation plate 123 is fixedly arranged at the lower position of the drying box shell 121. A through hole 124 is provided at the center of the lower heat preservation plate 123, and a placement groove 125 is provided on the upper surface of the lower heat preservation plate 123. The diameter of the placement groove 125 is larger than the diameter of the through hole 124. The cooling cylinder 126 is a hollow cylindrical body with an opening at the top and a closed bottom. The axial end surface of the cooling cylinder 126 is provided with vertical cooling grooves 127 at equal angles. The vertical cooling grooves 127 axially penetrate the upper end surface of the cooling cylinder 126, and cooling through holes 128 are uniformly provided on the inner side surface of each vertical cooling groove 127. An annular square box 129 is fixedly installed on the upper end surface of the cooling cylinder 126. The annular square box 129 is a hollow body with an opening at the bottom. The annular box body, the lower opening of the annular square box 129 is connected to the vertical cooling groove 127 opened on the end surface of the cooling cylinder 126; the vortex tube 1210 is fixedly arranged on the upper part of the upper insulation board 122 near the left end, the cold air end 1212 of the vortex tube 1210 is fixedly sleeved in the fixed cylinder 1211, and the fixed cylinder 1211 is fixed on the upper surface of the upper insulation board 122, and the cold air end 1212 of the vortex tube 1210 extends to the lower end of the upper insulation board 122. And it is fixedly connected with the upper part of the annular square box 129; the hot air end 1213 of the vortex tube 1210 faces upward, and the hot air is discharged through the connecting pipe; the air inlet connector 1214 is arranged on the upper side of the vortex tube 1210, and the air inlet connector 1214 is used to transport high-pressure gas to the vortex tube 1210; the thermocouple 1215 is fixedly arranged in the middle position of the upper insulation plate 122, and the thermocouple 1215 is used to detect the drying temperature in the drying box 12 in real time.

[0018] The solenoid valve on the air inlet connector 1214 of the vortex tube 1210 is fixedly connected to the start button 42, the close button 43, the indicator light 44, and the emergency stop button 45 through wires. The start button 42 and the close button 43 are used to control the start and shut down of the vortex tube 1210; the indicator light 44 is used to display the status indication of the normal operation of the vortex tube 1210; the emergency stop button 45 is used to directly cut off the power supply of the vortex tube 1210 in an emergency.

[0019] The automatic determination process of moisture content of forestry biomass raw materials is as follows:

[0020] Step 1, sample preparation and sample container preheating: a certain type of forestry biomass raw material is crushed to make a forestry biomass raw material sample. First, the operator presses the start button 42 to put the control panel 4, lifting mechanism 5, weighing mechanism 7, rotary switching mechanism 10, drying box 11 and drying box 12 into working state; then the conical bottom of the sample container 9 is aligned with the conical placement hole 84 of the refractory placement table 8, the sample container 9 is placed in the conical placement hole 84, and the container cover 92 of the sample container 9 is covered; the operator uses the preheating mode of the display screen 41 of the control panel 4 (the weighing of the sample container 9 is not recorded and stored in this mode) to press the control key to start the upward lifting action of the linear module 53 of the lifting mechanism 5. When the linear module 53 rises to the limit position, the boss refractory brick 83 on the refractory placement table 8 is completely passed through the circular hole of the heat insulation board 13 and the through hole 1110 of the drying box 11. Enter the center position of the heating refractory cylinder 116 of the drying box 11, and the refractory brick 82 is now in close contact with the bottom of the drying box shell 111 of the drying box 11; the control module 463 of the control panel 4 controls the preheating residence time of the sample container 9 in the drying box 11 (the pre-set preheating time and preheating temperature). When the sample container 9 reaches the preheating time and preheating temperature, the control module 463 sends a control signal of the descending action to the linear module 53 of the lifting mechanism 5. When the linear module 53 descends to the limit position, the control module 463 sends a stop control signal to the linear module 53. At this time, the sample container 9 is removed from the top of the boss refractory brick 83 by a clamp and waits for standby; finally, repeat the above actions to preheat another sample container 9 according to the above preheating steps.

[0021] Step 2, constant weight determination of the sample: weigh 2g~10g (two samples of the same mass) of the forestry biomass raw material sample prepared in step 1 with a balance and put them into two preheated sample containers 9 respectively, and cover the container cover 92; first, place the first sample container 9 in the conical placement hole 84 of the refractory placement table 8 with a clamp (remove the container cover of the sample container 9), and use the electromagnetic weighing sensor 74 of the weighing mechanism 7 to obtain the mass of the sample before drying, and transmit this weight signal to the calculation module 464 of the PLC control mainboard 46 for recording and storage; when the thermocouple 119 of the drying box 11 detects the heating refractory of the drying box 11 When the temperature of the fire tube 116 reaches the range of 105°C ± 2°C, the control module 463 of the PLC control main board 46 obtains the signal that the drying box 11 is in the initial position through the signal induction of the initial position limit switch, and the control module 463 sends a start control instruction to the servo motor of the linear module 53 of the lifting mechanism 5, and the linear module 53 starts to rise. When the linear module 53 rises to the limit position, a stop control signal is sent to the control module 463, and the control module 463 controls the linear module 53 to stop. At this time, the sample container 9 is lifted into the heating refractory tube 116 of the drying box 11. When the drying time is greater than 4 h (four hours and five minutes to four hours and fifteen minutes), when the drying time range set by the timing module 465 is reached, the timing module 465 sends a signal to the control module 463 to stop the heating rod 118 of the drying box 11 from heating. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the weight of the sample in the first sample container 9 after drying, and transmits the sample weight signal to the calculation module 464 for storage and calculation (the calculation module 464 subtracts the weight of the sample container 9 and the refractory placing table 8 through calculation, that is, the weight of the forestry biomass raw material sample in the sample container 9);Then the control module 463 sends a reset control instruction to the linear module 53, and the sample container 9 leaves the heating refractory cylinder 116 of the drying box 11. At the same time, the control module 463 sends a control instruction to start rotating 180° to the stepping motor 102 and the dividing mechanism 103 of the rotating switching mechanism 10. The rotating disk 106 of the rotating switching mechanism 10 rotates 180°. At this time, the drying box 12 is just rotated and switched to the upper position corresponding to the refractory placement table 8 (the container cover 92 is covered on the container body 91 at this time). The control module 463 sends an ascending control instruction to the linear module 53. The linear module 53 lifts the sample container 9 on the refractory placement table 8 into the cooling cylinder 126 of the drying box 12. At this time, the cooling airflow generated by the vortex tube 1210 is transported to the annular square box 129 through the cold air end 1212. The cooling airflow is distributed to the vertical cooling groove 127 through the annular square box 129. Finally, the cooling airflow is blown to the surface of the sample container 9 through the cooling through hole 128 to cool and dry the sample container 9. , when the thermocouple 1215 in the drying box 12 detects the temperature of the cooling cylinder 126 in real time, and transmits the real-time detected temperature signal to the control module 463 of the PLC control main board 46, when the temperature of the cooling cylinder 126 reaches the set room temperature (25°), the control module 463 sends a control instruction to move downward to the linear module 53 of the lifting mechanism 5, and the linear module 53 is reset, driving the sample container 9 to leave the drying box 12. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the weight of the sample in the sample container 9, and transmits the weight signal to the calculation module 464 of the PLC control main board 46, and the calculation module 464 records and stores the weight of the sample after drying to room temperature; finally, the forestry biomass raw material sample in the first sample container 9 is repeated with the above drying and drying operations, and the drying time is again greater than 1h (one hour and five minutes to one hour and fifteen minutes), and the electromagnetic weighing sensor 74 of the weighing mechanism 7 weighs the weight of the sample after drying and the weight of the sample when dried to room temperature, and the calculation module 464 records and stores it. The forestry biomass raw material sample in the second sample container 9 repeats the drying and drying operations of the sample in the first sample container 9, and the weight of the sample dried for more than 4 hours for the first time, the weight of the sample dried to room temperature, the weight of the sample dried again for more than 1 hour, and the weight dried again to room temperature are weighed by the electromagnetic weighing sensor 74, and recorded and stored by the operation module 464. When the operation module 464 of the PLC control mainboard 46 determines that the weight difference of the sample is not greater than 0.1% of the mass of the sample before drying for two consecutive times at a prescribed time interval, the operation module 464 compares and calculates the weight difference of the sample dried to room temperature twice with the mass of the sample before drying, and automatically determines whether the sample has reached a constant weight state. ;

[0022] Step 3: Calculation of the wet-basis moisture content and dry-basis moisture content of the sample: In step 2, after the two samples are dried and measured twice, the calculation module 464 of the PLC control mainboard 46 records and stores the sample mass before drying and the sample mass after drying as calculation parameters, and calculates the wet-basis moisture content x 1 The calculation formula (X 1 =m 1 -m 2 / m 1 *100%, where X 1 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The mass of the sample after drying (g) is first automatically calculated for the wet basis moisture content of the forestry biomass raw material sample; then the calculation module 464 of the PLC control main board 46 respectively records and stores the mass of the sample before drying and the mass of the sample after drying as calculation parameters, and calculates the mass of the sample after drying according to the dry basis moisture content (x) 2 The calculation formula (X 2 =m 1 -m 2 / m 2 *100%, where X 2 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The dry basis moisture content of the forestry biomass raw material sample is automatically calculated (the mass of the sample after drying, g); the calculation of the sample wet basis moisture content and the sample dry basis moisture content requires two measurements, and the calculation module 464 calculates the arithmetic mean value as the final measurement results of the sample wet basis moisture content and the sample dry basis moisture content based on the two measurement results, and displays the measurement results on the display screen 41.

[0023] The beneficial effects of the present invention are as follows: 1. By setting a rotary switching mechanism, the automatic switching between the drying box and the drying box is realized by utilizing the rotary switching mechanism, thereby simplifying the test measurement process and improving the degree of automation in measuring the moisture content of forestry biomass raw material samples; 2. By automatically controlling and coordinating the control module, the calculation module and the timing module on the PLC control mainboard on the control panel, efficient and rapid calculation of data is achieved, precise control of the drying time, the drying temperature and the drying and cooling temperature is achieved, and the measurement accuracy of the wet basis moisture content and the dry basis moisture content of the forestry biomass raw material samples is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 It is a schematic diagram of the initial position limit switch structure of the rotary switching mechanism of the present invention;

[0026] Figure 3 It is a structural schematic diagram of the lifting mechanism, the flexible buffer mechanism, the weighing mechanism, and the refractory placement table of the present invention;

[0027] Figure 4 It is a partial enlarged upward view of the flexible buffer mechanism, weighing mechanism and refractory placement table of the present invention;

[0028] Figure 5 It is a structural schematic diagram of the weighing mechanism of the present invention;

[0029] Figure 6 is a cross-sectional view of the weighing mechanism of the present invention;

[0030] Figure 7 It is a cross-sectional view of the drying box of the present invention;

[0031] Figure 8 is a cross-sectional view of a drying oven of the present invention;

[0032] Fig. 9 It is a front view of the PLC control mainboard structure of the present invention;

[0033] Markings in the figure: 1. bracket, 2. counterweight frame, 3. counterweight body, 4. control panel, 41. display screen, 42. start button, 43. close button, 44. indicator light, 45. emergency stop button, 46. PLC control main board, 461. control board body, 462. gain amplification operation module, 463. control module, 464. operation module, 465. timing module, 5. lifting mechanism, 51. support body, 52. fixed block, 53. linear module, 54. sliding body, 55. lifting arm, 6. flexible Buffer mechanism, 61, bottom plate, 62, square plate, 63, connecting column, 64, spring, 65, cylinder, 7, weighing mechanism, 71, weighing shell box, 72, conductive coating, 73, pole needle, 74, electromagnetic weighing sensor, 75, limit column, 76, weighing plate, 77, thermocouple three, 78, cooling pipe, 8, refractory placement table, 81, refractory brick installation shell, 82, refractory brick, 83, boss refractory brick, 84, conical placement hole, 9, sample container, 91, container body, 92, container cover, 10, rotation switch Mechanism, 101, support frame, 102, stepper motor, 103, indexing mechanism, 104, slewing bearing, 105, drive shaft, 106, rotating disk, 107, square hole, 108, initial position limit switch, 1081, induction sheet, 1082, induction contact, 11, drying box, 111, drying box shell, 112, refractory brick board, 113, upper refractory board, 114, lower refractory board, 115, installation groove, 116, heating refractory cylinder, 117, heating rod installation groove, 118, heating rod, 119, Thermocouple one, 1110, through hole, 12, drying box, 121, drying box shell, 122, upper insulation board, 123, lower insulation board, 124, through hole, 125, placement groove, 126, cooling cylinder, 127, vertical cooling groove, 128, cooling through hole, 129, annular square box, 1210, vortex tube, 1211, fixed cylinder, 1212, cold air end, 1213, hot air end, 1214, air inlet joint, 1215, thermocouple two, 13, insulation board, 14, fixed column, 15, round hole. DETAILED DESCRIPTION

[0034] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0035] The present invention provides an automatic measuring device for the moisture content of forestry biomass raw materials:

[0036] like Figure 1As shown, a counterweight frame 2 is fixedly provided at the bottom left side of the bracket 1, and a counterweight body 3 is fixedly provided at the upper part of the counterweight frame 2. By setting the counterweight frame 2 and the counterweight body 3, the weight of the counterweight body 3 is utilized to provide a stable support for the rotating switching mechanism 10, the drying box 11 and the drying box 12. After the forestry biomass raw material sample is dried to a constant weight state in the drying box 11, it is necessary to put the sample container 9 containing the sample into the drying box 12 for cooling and drying. At this time, the rotating switching mechanism 10 needs to be rotated to rotate the drying box 12 to the upper vertical position of the sample container 9, so that the lifting mechanism 5 is used to lift and push the sample container 9 containing the sample into the drying box 12, so as to realize drying and cooling the forestry biomass raw material sample in the sample container 9 to room temperature.

[0037] like Figure 1 As shown in FIG. 3 , the lifting mechanism 5 is vertically fixedly arranged at the right inner position of the bracket 1, and the lifting mechanism 5 is used to lift and push the sample container 9 into the drying box 11 or the drying box 12 for drying. Through the arrangement of the lifting mechanism 5, on the one hand, the motor and the lead screw of the linear module 53 and the sliding body 54 are used to realize the lifting and pushing of the sample container 9 into the drying box 11 or the drying box 12; on the other hand, the lifting mechanism 5 provides a stable support for the flexible buffer mechanism 6, the weighing mechanism 7 and the refractory placement table 8; on the other hand, it provides a mounting and fixing carrier for the flexible buffer mechanism 6, the weighing mechanism 7 and the refractory placement table 8.

[0038] like Figure 1 , 3 As shown in Figure 4, the flexible buffer mechanism 6 is fixedly arranged at the upper left side of the lifting mechanism 5, and the flexible buffer mechanism 6 is used to play a flexible buffering role when the sample container 9 vibrates due to the inertia of the lifting kinetic energy during the lifting process; the flexible buffer mechanism 6 includes a bottom plate 61, the bottom plate 61 is fixedly arranged on the upper part of the lifting arm 55 symmetrically arranged front and back, four connecting columns 63 are arranged, the connecting columns 63 pass through the bottom plate 61 and are arranged at the four corners of the bottom plate 61, and the square plate 62 passes through the bottom of the connecting column 63 to fix the connecting column 63 to the bottom of the bottom plate 61; the spring 64 is sleeved on the connecting column 63, and the spring 64 is located on the upper connecting column 63 of the bottom plate 61. The upper part of the connecting column 63 is sleeved with a cylinder 65 with a closed upper part and a hollow lower part, and a gap is reserved between the upper part of the cylinder 65 and the bottom of the refractory brick mounting shell 81.

[0039] The above-mentioned setting of the flexible buffer mechanism 6, on the one hand, plays a role in protecting the weighing mechanism 7 and reducing the impact vibration of the weighing mechanism 7; on the other hand, it prevents the refractory placement table 8 from directly impacting the lifting arm 55 of the lifting mechanism 5, thereby protecting the sample container 9 on the refractory placement table 8 and reducing the direct impact vibration on the sample container 9.

[0040] Through the arrangement of the connecting column 63, the spring 64 and the cylinder 65, when the refractory placing table 8 contacts the surface of the cylinder 65, the refractory placing table 8 applies pressure to the cylinder 65, and the cylinder 65 slides downward through the connecting column 63. At this time, the elastic effect of the spring 64 is utilized to reduce the buffering impact on the refractory placing table 8.

[0041] like Figure 1 , 3 As shown in Figures 4 and 5, the weighing mechanism 7 is fixedly arranged at the upper center position of the flexible buffer mechanism 6, and the weighing mechanism 7 is used to weigh the weight of the sample container 9. By setting the weighing mechanism 7, the weight of the forestry biomass raw material sample in the sample container 9 can be weighed in real time, providing an accurate weight parameter basis for the determination of the wet basis moisture content and dry basis moisture content of the forestry biomass raw material sample.

[0042] like Figure 1 , 3 As shown in , 4, 5, and 6, the weighing mechanism 7 includes a weighing shell 71, which is a hollow square body with an upper opening, and a conductive coating 72 is sprayed on the inner periphery and the bottom of the weighing shell 71; pole needles 73 are evenly fixedly arranged on the inner periphery of the weighing shell 71, and the pole tips of the pole needles 73 face the center of the weighing shell 71; four electromagnetic weighing sensors 74 are symmetrically arranged front and back and left and right, and the electromagnetic weighing sensors 74 are fixedly arranged on the bottom surface of the weighing shell 71, and a limit column 75 is set on the upper center of each electromagnetic weighing sensor 74, and the upper limit column 75 The bottom of the weighing plate 76 is fixedly connected to the bottom of the weighing plate 76, the area of ​​the weighing plate 76 is smaller than the upper opening area of ​​the weighing shell 71, and an equidistant gap is reserved between the weighing plate 76 and the inner side of the upper opening of the weighing shell 71; the thermocouple three 77 is fixedly arranged on the rear inner side of the weighing shell 71 near the upper position, and the thermocouple three 77 is used to detect the temperature in the weighing shell 71 in real time; the cooling pipe 78 is fixedly arranged on the front inner side of the weighing shell 71 near the upper position, and the cooling pipe 78 is used to transport cooling gas to the weighing shell 71 to cool the electromagnetic weighing sensor 74.

[0043] The conductive coating 72 is sprayed on the inner periphery and the bottom of the weighing shell 71; the pole needle 73 is evenly fixedly arranged on the inner periphery of the weighing shell 71, and the pole tip of the pole needle 73 faces the center of the weighing shell 71. The main purpose of such arrangement is: with the cooperation of the ground wire, the conductive coating 72 is used to increase the resistance value of the weighing shell 71, and at the same time, under the discharge effect of the pole needle 73, on the one hand, the static electricity inside the weighing shell 71 is eliminated; on the other hand, the dust in the air in the weighing shell 71 can be collected on the pole needle 73 by the electric field effect, eliminating the problem of reduced weighing accuracy of the electromagnetic weighing sensor 74 caused by dust pollution in the air.

[0044] The above-mentioned electromagnetic weighing sensor 74 is fixedly arranged on the bottom surface inside the weighing shell 71, and a limiting column 75 is set on the central upper part of each electromagnetic weighing sensor 74. The upper part of the limiting column 75 is fixedly connected to the bottom of the weighing plate 76. The area of ​​the weighing plate 76 is smaller than the upper opening area of ​​the weighing shell 71, and an equidistant gap is reserved between the weighing plate 76 and the inner side surface of the upper opening of the weighing shell 71. The main purpose of such arrangement is: on the one hand, to limit the weighing plate 76 at the central position of the upper opening of the weighing shell 71; on the other hand, to enable the weighing plate 76 to move freely in the upper opening of the weighing shell 71, thereby improving the weighing accuracy of the electromagnetic weighing sensor 74 on the sample in the sample container 9 and reducing the interference of the upper opening edge of the weighing shell 71 on the weighing accuracy caused by contact.

[0045] The above-mentioned thermocouple three 77 is fixedly arranged on the rear inner side surface of the weighing shell 71 near the upper position, and the thermocouple three 77 is used to detect the temperature in the weighing shell 71 in real time; the cooling pipe 78 is fixedly arranged on the front inner side surface of the weighing shell 71 near the upper position, and the cooling pipe 78 is used to transport cooling gas into the weighing shell 71 to cool the electromagnetic weighing sensor 74. When the weighing shell 71 is close to the refractory placement table 8, the temperature in the drying box 11 will inevitably be transferred to the refractory placement table 8, and the refractory placement table 8 will inevitably further transfer the heat to the weighing shell 71. When the temperature in the weighing shell 71 is high, it will lead to a decrease in the weighing accuracy of the electromagnetic weighing sensor 74 (causing the coil temperature inside the electromagnetic weighing sensor 74 to drift, thereby reducing the weighing accuracy of the electromagnetic weighing sensor 74); however, the temperature in the weighing shell 71 cannot be too low. If the temperature is too low, it will easily cause the weighing shell 71 to produce an electrostatic effect, which will also cause a decrease in the weighing accuracy of the electromagnetic weighing sensor 74; therefore, a thermocouple 77 is provided for real-time detection of the temperature in the weighing shell 71. According to work experience, the temperature in the weighing shell 71 is controlled between 25° and 28°, which does not affect the weighing accuracy of the electromagnetic weighing sensor 74 and is not easy to produce an electrostatic effect in the weighing shell 71. The main purpose of doing the above is: through the setting of thermocouple three 77, the temperature in the weighing shell box 71 can be detected in real time. When the temperature in the weighing shell box 71 reaches the highest threshold of the temperature range set in the control module 463, the control module 463 opens the solenoid valve for ventilation to the cooling pipe 78, and supplies cooling gas to the cooling pipe 78, thereby lowering the temperature in the weighing shell box 71. Until the temperature reaches the lowest threshold of the set temperature, the control module 463 sends a closing control instruction to the solenoid valve for ventilation to the cooling pipe 78, so that the temperature in the weighing shell box 71 can always be maintained in the range of 25°~28°.

[0046] like Figure 1 , 3As shown in , 4, the refractory placement table 8 includes a refractory brick mounting shell 81, which is a hollow square body. A refractory brick 82 is fixedly installed in the refractory brick mounting shell 81, and the volume of the refractory brick 82 is smaller than the volume of the refractory brick mounting shell 81; the boss refractory brick 83 is fixedly arranged at the upper center position of the refractory brick 82, and the upper center of the boss refractory brick 83 is provided with a conical placement hole 84 for placing the sample container 9, and the diameter of the conical placement hole 84 is larger than the bottom diameter of the sample container 9.

[0047] The above-mentioned arrangement of the refractory brick mounting shell 81, the refractory bricks 82, and the boss refractory bricks 83, on the one hand, plays a role of heat insulation, preventing the heat of the drying box 11 from being directly transferred to the weighing mechanism 7, and plays a role of high temperature protection for the weighing mechanism 7, solving the temperature drift phenomenon of the coil inside the electromagnetic weighing sensor 74 of the weighing mechanism 7 caused by high temperature, thereby improving the weighing accuracy of the electromagnetic weighing sensor 74; on the other hand, when the sample container 9 enters the drying box 11 or the drying box 12, the refractory bricks 82 and the boss refractory bricks 83 are tightly attached to each other, which plays a role of preventing heat loss in the drying box 11 or preventing cooling gas in the drying box 12 from overflowing.

[0048] like Figure 1 As shown, the rotation switching mechanism 10 is fixedly arranged at the connection between the bracket 1 and the upper part of the counterweight body 3, and the rotation switching mechanism 10 is used to rotate and switch the positions of the drying box 11 and the drying box 12. Through the setting of the rotation switching mechanism 10, the control module 463 of the PLC control main board 46 sends a control instruction to start the rotation of 180° to the stepping motor 102 and the indexing mechanism 103 of the rotation switching mechanism 10, and the rotating disk 106 of the rotation switching mechanism 10 rotates 180°, and the drying box 12 is just rotated and switched to the upper position corresponding to the refractory placement table 8, thereby realizing the rotation switching of the positions of the drying box 11 and the drying box 12. On the one hand, it simplifies the test measurement process and improves the automation degree of the moisture content measurement of the forestry biomass raw material sample; on the other hand, it improves the convenience of the moisture content measurement of the forestry biomass raw material sample.

[0049] like Figure 1 and Figure 2As shown, the initial position limit switch 108 is fixedly arranged at the middle of the left side of the drying box shell 111 near the upper position, and the initial position limit switch 108 is used to keep the drying box 11 always at the corresponding position on the upper part of the fireproof placing table 8; the initial position limit switch 108 includes a sensing sheet 1081, which is fixedly arranged at the middle position of the upper right side of the support frame 101, and a sensing contact 1082 is fixedly arranged at the middle position of the upper left side of the drying box shell 111 corresponding to the sensing sheet 1081. Through the setting of the initial position limit switch 108, when the drying box 11 rotates to the position of the sensing sheet 1081, the sensing contact 1082 arranged at the upper middle position of the left side of the drying box shell 111 senses the signal of the sensing sheet 1081, and the sensing contact 1082 transmits the sensed position signal to the control module 463 of the PLC control mainboard 46, thereby determining whether the drying box 11 is in the initial position; providing an accurate reference basis for the precise angle rotation of the rotating disk 106 of the rotation switching mechanism 10.

[0050] like Figure 1 and Figure 7 As shown, the outer side of the drying box 11 is fixed to the upper right position of the rotating switching mechanism 10, and the drying box 11 is used to perform constant temperature drying on the forestry biomass raw material sample of the sample container 9; the drying box 11 includes a drying box shell 111, and the drying box shell 111 is a hollow square body with a hole in the lower part, and the refractory brick plate 112 is arranged on the inner wall around the drying box shell 111, the upper refractory plate 113 is fixedly arranged on the upper inner wall of the drying box shell 111, and the lower refractory plate 114 is fixedly arranged on the lower inner wall of the drying box shell 111, and the installation groove 115 is opened on the upper part of the lower refractory plate 114, and the through hole 1110 is opened on the lower The center position of the refractory plate 114 has a hole 1110 with a diameter equal to that of the hole opened in the center of the lower part of the drying box shell 111; the heating refractory tube 116 is a hollow cylinder, and the heating refractory tube 116 is installed in the installation groove 115. A heating rod installation groove 117 is opened at an equal angle on the axial end surface of the heating refractory tube 116. The heating rod installation groove 117 runs through the axial direction of the heating refractory tube 116, and a heating rod 118 is fixedly installed in each heating rod installation groove 117. A thermocouple 119 is fixedly arranged at the upper center position of the drying box shell 111. The thermocouple 119 is used to detect the drying temperature in the drying box 11 in real time.

[0051] The above-mentioned arrangement of the drying box shell 111, the refractory brick board 112, the upper refractory board 113, and the lower refractory board 114, on the one hand, provides high-temperature protection for the drying box shell 111, thereby extending the service life of the drying box shell 111 in a high-temperature process environment; on the other hand, it prevents the loss of high-temperature heat.

[0052] The above-mentioned arrangement of the heating refractory cylinder 116, the heating rod installation groove 117, and the heating rod 118, on the one hand, plays a role in uniform drying. Under the structural characteristics of uniformly arranging a plurality of heating rod installation grooves 117 and heating rods 118, the uniform arrangement of the heating rods 118 naturally improves the uniform drying effect of the sample. On the other hand, it plays a role in increasing the heating refractory cylinder 116 temperature rise speed, thereby improving the drying efficiency of the sample.

[0053] like Figure 1 and Figure 8 As shown, the drying box 12 includes a drying box shell 121, which is a hollow square body with an opening at the top and a closed bottom. The upper insulation board 122 is fixedly arranged at the upper position of the drying box shell 121, and the lower insulation board 123 is fixedly arranged at the lower position of the drying box shell 121. A through hole 124 is opened at the center of the lower insulation board 123, and a placement groove 125 is opened on the upper surface of the lower insulation board 123. The diameter of the placement groove 125 is The cooling tube 126 is a hollow cylinder with an upper opening and a lower closing. The axial end surface of the cooling tube 126 is provided with vertical cooling grooves 127 at equal angles. The vertical cooling grooves 127 axially penetrate the upper end surface of the cooling tube 126. The inner side surface of each vertical cooling groove 127 is evenly provided with cooling holes 128. The annular square box 129 is fixedly mounted on the upper end surface of the cooling tube 126. The annular square box 129 is a hollow cylinder with an upper opening and a lower closing. The annular box body, the lower opening of the annular square box 129 is connected to the vertical cooling groove 127 opened on the end surface of the cooling cylinder 126; the vortex tube 1210 is fixedly arranged on the upper part of the upper insulation board 122 near the left end, the cold air end 1212 of the vortex tube 1210 is fixedly sleeved in the fixed cylinder 1211, the fixed cylinder 1211 is fixed on the upper surface of the upper insulation board 122, and the cold air end 1212 of the vortex tube 1210 extends to the lower end of the upper insulation board 122 and is fixedly connected to the upper part of the annular square box 129; the hot air end 1213 of the vortex tube 1210 faces upward, and the hot air is discharged through the connecting pipe; the air inlet connector 1214 is arranged on one side of the upper part of the vortex tube 1210, and the air inlet connector 1214 is used to transport high-pressure gas to the vortex tube 1210; the thermocouple 1215 is fixedly arranged in the middle position of the upper insulation plate 122, and the thermocouple 1215 is used to detect the drying temperature in the drying box 12 in real time.

[0054] The above-mentioned arrangement of the drying box shell 121, the upper insulation plate 122, and the lower insulation plate 123 plays a role in heat preservation of the temperature of the cooling gas output from the vortex tube, thereby improving the cooling effect of the cooling gas.

[0055] The above-mentioned arrangement of the cooling cylinder 126, the vertical cooling groove 127, and the cooling through hole 128, on the one hand, plays a role in forcibly guiding the cooling and drying angle, because for the sample in the sample container 9, the cooling and drying effect of the circumferential surface of the aligner sample container 9 is the best, and the cooling and drying efficiency is also the highest. On the other hand, it plays a role in homogenizing the cooling gas, because the temperature of the middle airflow and the outer airflow of the high-pressure cooling gas coming out of the vortex tube 1210 is different. Only through the cooperation of the annular square box 129, the vertical cooling groove 127 and the cooling through hole 128 opened on the end surface of the cooling cylinder 126, the space becomes larger and then smaller, which provides a homogenizing effect on the cooling airflow, thereby improving the cooling and drying effect of the cooling airflow on the sample in the sample container 9.

[0056] The power supply of the heating rod 118 and the thermocouple 1 119 in the drying box 11 and the power supply of the thermocouple 2 1215 in the drying box 12 can be provided through electric slip rings, so that when the drying box 11 and the drying box 12 rotate, there will be no entanglement of the power supply line due to the rotation. The air source supply of the vortex tube 1210 in the drying box 12 can be provided by a pneumatic slip ring to provide a high-pressure air source to the vortex tube 1210 of the drying box 12 during the rotation process.

[0057] like Figure 1 , 7 As shown in Figures 1 and 8, the heat insulation board 13 is fixedly arranged at the bottom of the drying box 11 and the drying box 12 through four fixing columns 14, and a circular hole 15 is opened in the center of the heat insulation board 13. The above-mentioned heat insulation board 13 and the fixing columns are arranged to mainly prevent the heat of the drying box 11 or the cold air of the drying box 12 from being transferred to the rotating disk 106 of the rotating switching mechanism 10. The above-mentioned circular hole 15 opened in the center of the heat insulation board 13 mainly serves as a through hole for the refractory placing table 8 and the sample container 9 when they are lifted or lowered.

[0058] like Figure 1-9 As shown, based on the present invention, combined with Figure 1-9 The specific embodiments of the present invention are described in detail. Example 1

[0059] Step 1, sample preparation and sample container preheating: a certain type of forestry biomass raw material is crushed to make a forestry biomass raw material sample. First, the operator presses the start button 42 to put the control panel 4, lifting mechanism 5, weighing mechanism 7, rotary switching mechanism 10, drying box 11 and drying box 12 into working state; then the conical bottom of the sample container 9 is aligned with the conical placement hole 84 of the refractory placement table 8, the sample container 9 is placed in the conical placement hole 84, and the container cover 92 of the sample container 9 is covered; the operator uses the preheating mode of the display screen 41 of the control panel 4 (the weighing of the sample container 9 is not recorded and stored in this mode) to press the control key to start the upward lifting action of the linear module 53 of the lifting mechanism 5. When the linear module 53 rises to the limit position, the boss refractory brick 83 on the refractory placement table 8 is completely passed through the circular hole of the heat insulation board 13 and the through hole 1110 of the drying box 11. Enter the center position of the heating refractory cylinder 116 of the drying box 11, and the refractory brick 82 is now in close contact with the bottom of the drying box shell 111 of the drying box 11; the control module 463 of the control panel 4 controls the preheating residence time of the sample container 9 in the drying box 11 (the pre-set preheating time and preheating temperature). When the sample container 9 reaches the preheating time and preheating temperature, the control module 463 sends a control signal of the descending action to the linear module 53 of the lifting mechanism 5. When the linear module 53 descends to the limit position, the control module 463 sends a stop control signal to the linear module 53. At this time, the sample container 9 is removed from the top of the boss refractory brick 83 by a clamp and waits for standby; finally, repeat the above actions to preheat another sample container 9 according to the above preheating steps.

[0060] Step 2, constant weight determination of the sample: weigh 2g~10g (two samples of the same mass) of the forestry biomass raw material sample prepared in step 1 with a balance and put them into two preheated sample containers 9 respectively, and cover the container cover 92; first, place the first sample container 9 in the conical placement hole 84 of the refractory placement table 8 with a clamp (remove the container cover of the sample container 9), and use the electromagnetic weighing sensor 74 of the weighing mechanism 7 to obtain the mass of the sample before drying, and transmit this weight signal to the calculation module 464 of the PLC control main board 46 for recording and storage; when the thermocouple 119 of the drying box 11 detects that the temperature of the heating refractory cylinder 116 of the drying box 11 reaches a value of 103°C, at this time, the control module 463 of the PLC control main board 46 obtains the signal that the drying box 11 is in the initial position through the signal induction of the initial position limit switch, and the control module 463 sends the linear module 53 of the lifting mechanism 5 to the control module 464 of the lifting mechanism 5. The servo motor sends a start control command, and the linear module 53 starts to rise. When the linear module 53 rises to the limit position, a stop control signal is sent to the control module 463. The control module 463 controls the linear module 53 to stop. At this time, the sample container 9 is lifted into the heating refractory cylinder 116 of the drying box 11. When the drying time is four hours and five minutes, reaching the drying time value set by the timing module 465, the timing module 465 sends a signal to the control module 463 to stop the heating rod 118 of the drying box 11. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the sample weight of the sample in the first sample container 9 after drying, and transmits the sample weight signal to the calculation module 464 for storage and calculation (the calculation module 464 subtracts the weight of the sample container 9 and the refractory placement table 8 through calculation, that is, the weight of the forestry biomass raw material sample in the sample container 9);Then the control module 463 sends a reset control instruction to the linear module 53, and the sample container 9 leaves the heating refractory cylinder 116 of the drying box 11. At the same time, the control module 463 sends a control instruction to start rotating 180° to the stepping motor 102 and the dividing mechanism 103 of the rotating switching mechanism 10. The rotating disk 106 of the rotating switching mechanism 10 rotates 180°. At this time, the drying box 12 is just rotated and switched to the upper position corresponding to the refractory placement table 8 (the container cover 92 is covered on the container body 91 at this time). The control module 463 sends an ascending control instruction to the linear module 53. The linear module 53 lifts the sample container 9 on the refractory placement table 8 into the cooling cylinder 126 of the drying box 12. At this time, the cooling airflow generated by the vortex tube 1210 is transported to the annular square box 129 through the cold air end 1212. The cooling airflow is distributed to the vertical cooling groove 127 through the annular square box 129, and finally the cooling airflow is blown to the surface of the sample container 9 through the cooling through hole 128, so as to cool the sample container. 9 is cooled and dried. When the thermocouple 1215 in the drying box 12 detects the temperature of the cooling cylinder 126 in real time and transmits the real-time detected temperature signal to the control module 463 of the PLC control main board 46, when the temperature of the cooling cylinder 126 reaches the set room temperature (25°), the control module 463 sends a control instruction to move downward to the linear module 53 of the lifting mechanism 5. The linear module 53 is reset, driving the sample container 9 to leave the drying box 12. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the weight of the sample in the sample container 9 and transmits the weight signal to the operation module 464 of the PLC control main board 46. The operation module 464 records and stores the weight of the sample after drying to room temperature. Finally, the forestry biomass raw material sample in the first sample container 9 is repeated with the above drying and drying operations. The drying time is one hour and five minutes again. The weight of the sample after drying and the weight of the sample when drying to room temperature are weighed by the electromagnetic weighing sensor 74 of the weighing mechanism 7, and the weight of the sample is recorded and stored by the operation module 464. The forestry biomass raw material sample in the second sample container 9 repeats the drying and drying operations of the sample in the first sample container 9, and the weight of the sample dried for more than 4 hours for the first time, the weight of the sample dried to room temperature, the weight of the sample dried again for more than 1 hour, and the weight dried again to room temperature are weighed by the electromagnetic weighing sensor 74, and recorded and stored by the operation module 464. When the operation module 464 of the PLC control mainboard 46 determines that the weight difference of the sample is not greater than 0.1% of the mass of the sample before drying for two consecutive times at a prescribed time interval, the operation module 464 compares and calculates the weight difference of the sample dried to room temperature twice with the mass of the sample before drying, and automatically determines whether the sample has reached a constant weight state. ;

[0061] Step 3: Calculation of the wet-basis moisture content and dry-basis moisture content of the sample: In step 2, after the two samples are dried and measured twice, the calculation module 464 of the PLC control mainboard 46 records and stores the sample mass before drying and the sample mass after drying as calculation parameters, and calculates the wet-basis moisture content x 1 The calculation formula (X 1 =m 1 -m 2 / m 1 *100%, where X 1 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The mass of the sample after drying (g) is first automatically calculated for the wet basis moisture content of the forestry biomass raw material sample; then the calculation module 464 of the PLC control main board 46 respectively records and stores the mass of the sample before drying and the mass of the sample after drying as calculation parameters, and calculates the mass of the sample after drying according to the dry basis moisture content (x) 2 The calculation formula (X 2 =m 1 -m 2 / m 2 *100%, where X 2 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The dry basis moisture content of the forestry biomass raw material sample is automatically calculated (the mass of the sample after drying, g); the calculation of the sample wet basis moisture content and the sample dry basis moisture content requires two measurements, and the calculation module 464 calculates the arithmetic mean value as the final measurement results of the sample wet basis moisture content and the sample dry basis moisture content based on the two measurement results, and displays the measurement results on the display screen 41. Example 2

[0062] Step 1, sample preparation and sample container preheating: a certain type of forestry biomass raw material is crushed to make a forestry biomass raw material sample. First, the operator presses the start button 42 to put the control panel 4, lifting mechanism 5, weighing mechanism 7, rotary switching mechanism 10, drying box 11 and drying box 12 into working state; then the conical bottom of the sample container 9 is aligned with the conical placement hole 84 of the refractory placement table 8, the sample container 9 is placed in the conical placement hole 84, and the container cover 92 of the sample container 9 is covered; the operator uses the preheating mode of the display screen 41 of the control panel 4 (the weighing of the sample container 9 is not recorded and stored in this mode) to press the control key to start the upward lifting action of the linear module 53 of the lifting mechanism 5. When the linear module 53 rises to the limit position, the boss refractory brick 83 on the refractory placement table 8 is completely passed through the circular hole of the heat insulation board 13 and the through hole 1110 of the drying box 11. Enter the center position of the heating refractory cylinder 116 of the drying box 11, and the refractory brick 82 is now in close contact with the bottom of the drying box shell 111 of the drying box 11; the control module 463 of the control panel 4 controls the preheating residence time of the sample container 9 in the drying box 11 (the pre-set preheating time and preheating temperature). When the sample container 9 reaches the preheating time and preheating temperature, the control module 463 sends a control signal of the descending action to the linear module 53 of the lifting mechanism 5. When the linear module 53 descends to the limit position, the control module 463 sends a stop control signal to the linear module 53. At this time, the sample container 9 is removed from the top of the boss refractory brick 83 by a clamp and waits for standby; finally, repeat the above actions to preheat another sample container 9 according to the above preheating steps.

[0063] Step 2, constant weight determination of the sample: weigh 2g~10g (two samples of the same mass) of the forestry biomass raw material sample prepared in step 1 with a balance and put them into two preheated sample containers 9 respectively, and cover the container cover 92; first, place the first sample container 9 in the conical placement hole 84 of the refractory placement table 8 with a clamp (remove the container cover of the sample container 9), and use the electromagnetic weighing sensor 74 of the weighing mechanism 7 to obtain the mass of the sample before drying, and transmit this weight signal to the calculation module 464 of the PLC control main board 46 for recording and storage; when the thermocouple 119 of the drying box 11 detects that the temperature of the heating refractory cylinder 116 of the drying box 11 reaches a value of 105°C, at this time, the control module 463 of the PLC control main board 46 obtains the signal that the drying box 11 is in the initial position through the signal induction of the initial position limit switch, and the control module 463 sends the linear module 53 of the lifting mechanism 5 to the control module 464 of the lifting mechanism 5. The servo motor sends a start control command, and the linear module 53 starts to rise. When the linear module 53 rises to the limit position, a stop control signal is sent to the control module 463. The control module 463 controls the linear module 53 to stop. At this time, the sample container 9 is lifted into the heating refractory cylinder 116 of the drying box 11. When the drying time is four hours and ten minutes, which reaches the drying time range set by the timing module 465, the timing module 465 sends a signal to the control module 463 to stop the heating rod 118 of the drying box 11. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the sample weight of the sample in the first sample container 9 after drying, and transmits the sample weight signal to the calculation module 464 for storage and calculation (the calculation module 464 subtracts the weight of the sample container 9 and the refractory placement table 8 through calculation, that is, the weight of the forestry biomass raw material sample in the sample container 9);Then the control module 463 sends a reset control instruction to the linear module 53, and the sample container 9 leaves the heating refractory cylinder 116 of the drying box 11. At the same time, the control module 463 sends a control instruction to start rotating 180° to the stepping motor 102 and the dividing mechanism 103 of the rotating switching mechanism 10. The rotating disk 106 of the rotating switching mechanism 10 rotates 180°. At this time, the drying box 12 is just rotated and switched to the upper position corresponding to the refractory placement table 8 (the container cover 92 is covered on the container body 91 at this time). The control module 463 sends an ascending control instruction to the linear module 53. The linear module 53 lifts the sample container 9 on the refractory placement table 8 into the cooling cylinder 126 of the drying box 12. At this time, the cooling airflow generated by the vortex tube 1210 is transported to the annular square box 129 through the cold air end 1212. The cooling airflow is distributed to the vertical cooling groove 127 through the annular square box 129, and finally the cooling airflow is blown to the surface of the sample container 9 through the cooling through hole 128, so as to cool the sample container. 9 is cooled and dried. When the thermocouple 1215 in the drying box 12 detects the temperature of the cooling cylinder 126 in real time and transmits the real-time detected temperature signal to the control module 463 of the PLC control main board 46, when the temperature of the cooling cylinder 126 reaches the set room temperature (25°), the control module 463 sends a control instruction to move downward to the linear module 53 of the lifting mechanism 5. The linear module 53 is reset, driving the sample container 9 to leave the drying box 12. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the weight of the sample in the sample container 9 and transmits the weight signal to the operation module 464 of the PLC control main board 46. The operation module 464 records and stores the weight of the sample after drying to room temperature. Finally, the forestry biomass raw material sample in the first sample container 9 is repeated with the above drying and drying operations. The drying time is one hour and ten minutes again. The weight of the sample after drying and the weight of the sample when drying to room temperature are weighed by the electromagnetic weighing sensor 74 of the weighing mechanism 7, and the weight of the sample is recorded and stored by the operation module 464. The forestry biomass raw material sample in the second sample container 9 repeats the drying and drying operations of the sample in the first sample container 9, and the weight of the sample dried for more than 4 hours for the first time, the weight of the sample dried to room temperature, the weight of the sample dried again for more than 1 hour, and the weight dried again to room temperature are weighed by the electromagnetic weighing sensor 74, and recorded and stored by the operation module 464. When the operation module 464 of the PLC control mainboard 46 determines that the weight difference of the sample is not greater than 0.1% of the mass of the sample before drying for two consecutive times at a prescribed time interval, the operation module 464 compares and calculates the weight difference of the sample dried to room temperature twice with the mass of the sample before drying, and automatically determines whether the sample has reached a constant weight state. ;

[0064] Step 3: Calculation of the wet-basis moisture content and dry-basis moisture content of the sample: In step 2, after the two samples are dried and measured twice, the calculation module 464 of the PLC control mainboard 46 records and stores the sample mass before drying and the sample mass after drying as calculation parameters, and calculates the wet-basis moisture content x 1 The calculation formula (X 1 =m 1 -m 2 / m 1 *100%, where X 1 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The mass of the sample after drying (g) is first automatically calculated for the wet basis moisture content of the forestry biomass raw material sample; then the calculation module 464 of the PLC control main board 46 respectively records and stores the mass of the sample before drying and the mass of the sample after drying as calculation parameters, and calculates the mass of the sample after drying according to the dry basis moisture content (x) 2 The calculation formula (X 2 =m 1 -m 2 / m 2 *100%, where X 2 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The dry basis moisture content of the forestry biomass raw material sample is automatically calculated (the mass of the sample after drying, g); the calculation of the sample wet basis moisture content and the sample dry basis moisture content requires two measurements, and the calculation module 464 calculates the arithmetic mean value as the final measurement results of the sample wet basis moisture content and the sample dry basis moisture content based on the two measurement results, and displays the measurement results on the display screen 41. Example 3

[0065] Step 1, sample preparation and sample container preheating: a certain type of forestry biomass raw material is crushed to make a forestry biomass raw material sample. First, the operator presses the start button 42 to put the control panel 4, lifting mechanism 5, weighing mechanism 7, rotary switching mechanism 10, drying box 11 and drying box 12 into working state; then the conical bottom of the sample container 9 is aligned with the conical placement hole 84 of the refractory placement table 8, the sample container 9 is placed in the conical placement hole 84, and the container cover 92 of the sample container 9 is covered; the operator uses the preheating mode of the display screen 41 of the control panel 4 (the weighing of the sample container 9 is not recorded and stored in this mode) to press the control key to start the upward lifting action of the linear module 53 of the lifting mechanism 5. When the linear module 53 rises to the limit position, the boss refractory brick 83 on the refractory placement table 8 is completely passed through the circular hole of the heat insulation board 13 and the through hole 1110 of the drying box 11. Enter the center position of the heating refractory cylinder 116 of the drying box 11, and the refractory brick 82 is now in close contact with the bottom of the drying box shell 111 of the drying box 11; the control module 463 of the control panel 4 controls the preheating residence time of the sample container 9 in the drying box 11 (the pre-set preheating time and preheating temperature). When the sample container 9 reaches the preheating time and preheating temperature, the control module 463 sends a control signal of the descending action to the linear module 53 of the lifting mechanism 5. When the linear module 53 descends to the limit position, the control module 463 sends a stop control signal to the linear module 53. At this time, the sample container 9 is removed from the top of the boss refractory brick 83 by a clamp and waits for standby; finally, repeat the above actions to preheat another sample container 9 according to the above preheating steps.

[0066] Step 2, constant weight determination of the sample: weigh 2g~10g (two samples of the same mass) of the forestry biomass raw material sample prepared in step 1 with a balance and put them into two preheated sample containers 9 respectively, and cover the container cover 92; first, place the first sample container 9 in the conical placement hole 84 of the refractory placement table 8 with a clamp (remove the container cover of the sample container 9), and use the electromagnetic weighing sensor 74 of the weighing mechanism 7 to obtain the mass of the sample before drying, and transmit this weight signal to the calculation module 464 of the PLC control main board 46 for recording and storage; when the thermocouple 119 of the drying box 11 detects that the temperature of the heating refractory cylinder 116 of the drying box 11 reaches a value of 107°C, at this time, the control module 463 of the PLC control main board 46 obtains the signal that the drying box 11 is in the initial position through the signal induction of the initial position limit switch, and the control module 463 sends the linear module 53 of the lifting mechanism 5 to the control module 464 of the lifting mechanism 5. The servo motor sends a start control command, and the linear module 53 starts to rise. When the linear module 53 rises to the limit position, a stop control signal is sent to the control module 463. The control module 463 controls the linear module 53 to stop. At this time, the sample container 9 is lifted into the heating refractory cylinder 116 of the drying box 11. When the drying time is four hours and fifteen minutes, reaching the drying time value set by the timing module 465, the timing module 465 sends a signal to the control module 463 to stop the heating rod 118 of the drying box 11. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the sample weight of the sample in the first sample container 9 after drying, and transmits the sample weight signal to the calculation module 464 for storage and calculation (the calculation module 464 subtracts the weight of the sample container 9 and the refractory placement table 8 through calculation, that is, the weight of the forestry biomass raw material sample in the sample container 9);Then the control module 463 sends a reset control instruction to the linear module 53, and the sample container 9 leaves the heating refractory cylinder 116 of the drying box 11. At the same time, the control module 463 sends a control instruction to start rotating 180° to the stepping motor 102 and the dividing mechanism 103 of the rotating switching mechanism 10. The rotating disk 106 of the rotating switching mechanism 10 rotates 180°. At this time, the drying box 12 is just rotated and switched to the upper position corresponding to the refractory placement table 8 (the container cover 92 is covered on the container body 91 at this time). The control module 463 sends an ascending control instruction to the linear module 53. The linear module 53 lifts the sample container 9 on the refractory placement table 8 into the cooling cylinder 126 of the drying box 12. At this time, the cooling airflow generated by the vortex tube 1210 is transported to the annular square box 129 through the cold air end 1212. The cooling airflow is distributed to the vertical cooling groove 127 through the annular square box 129, and finally the cooling airflow is blown to the surface of the sample container 9 through the cooling through hole 128, so as to cool the sample container. 9 is cooled and dried. When the thermocouple 1215 in the drying box 12 detects the temperature of the cooling cylinder 126 in real time and transmits the real-time detected temperature signal to the control module 463 of the PLC control main board 46, when the temperature of the cooling cylinder 126 reaches the set room temperature (25°), the control module 463 sends a control instruction to move downward to the linear module 53 of the lifting mechanism 5, and the linear module 53 is reset, driving the sample container 9 to leave the drying box 12. At this time, the electromagnetic weighing sensor 74 of the weighing mechanism 7 obtains the weight of the sample in the sample container 9, and transmits the weight signal to the calculation module 464 of the PLC control main board 46. The calculation module 464 records and stores the weight of the sample after drying to room temperature; finally, the forestry biomass raw material sample in the first sample container 9 is repeated with the above drying and drying operations, and the drying time is one hour and fifteen minutes again. The weight of the sample after drying and the weight of the sample when drying to room temperature are weighed by the electromagnetic weighing sensor 74 of the weighing mechanism 7, and the calculation module 464 records and stores them. The forestry biomass raw material sample in the second sample container 9 repeats the drying and drying operations of the sample in the first sample container 9, and the weight of the sample dried for more than 4 hours for the first time, the weight of the sample dried to room temperature, the weight of the sample dried again for more than 1 hour, and the weight dried again to room temperature are weighed by the electromagnetic weighing sensor 74, and recorded and stored by the operation module 464. When the operation module 464 of the PLC control mainboard 46 determines that the weight difference of the sample is not greater than 0.1% of the mass of the sample before drying for two consecutive times at a prescribed time interval, the operation module 464 compares and calculates the weight difference of the sample dried to room temperature twice with the mass of the sample before drying, and automatically determines whether the sample has reached a constant weight state. ;

[0067] Step 3: Calculation of the wet-basis moisture content and dry-basis moisture content of the sample: In step 2, after the two samples are dried and measured twice, the calculation module 464 of the PLC control mainboard 46 records and stores the sample mass before drying and the sample mass after drying as calculation parameters, and calculates the wet-basis moisture content x 1 The calculation formula (X 1 =m 1 -m 2 / m 1 *100%, where X 1 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The mass of the sample after drying (g) is first automatically calculated for the wet basis moisture content of the forestry biomass raw material sample; then the calculation module 464 of the PLC control main board 46 respectively records and stores the mass of the sample before drying and the mass of the sample after drying as calculation parameters, and calculates the mass of the sample after drying according to the dry basis moisture content (x) 2 The calculation formula (X 2 =m 1 -m 2 / m 2 *100%, where X 2 is the wet basis moisture content of the sample, m 1 is the mass of the sample before drying, g, m 2 The dry basis moisture content of the forestry biomass raw material sample is automatically calculated (the mass of the sample after drying, g); the calculation of the sample wet basis moisture content and the sample dry basis moisture content requires two measurements, and the calculation module 464 calculates the arithmetic mean value as the final measurement results of the sample wet basis moisture content and the sample dry basis moisture content based on the two measurement results, and displays the measurement results on the display screen 41.

[0068] Various modifications to the above embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An automatic determination device for the moisture content of forestry biomass raw materials, comprising a bracket, a counterweight frame, a counterweight body, and a control panel; the counterweight frame is fixedly arranged at the bottom of the left side of the bracket, and the counterweight body is fixedly arranged on the upper part of the counterweight frame; the control panel is fixedly arranged on the right side of the bracket near the upper position, and the control panel is used for automatically controlling the lifting mechanism, the rotation switching mechanism, the drying box temperature, the drying box temperature, and the sample drying time; the lifting mechanism is vertically fixedly arranged at the right inner position of the bracket, and the lifting mechanism is used to lift and push the sample container into the drying box or drying box for drying; the flexible buffer mechanism is fixedly arranged at the upper left position of the lifting mechanism, and the flexible buffer mechanism is used for the sample container to be lifted during the lifting process It plays a flexible buffering role when vibration is generated due to the inertia of the kinetic energy of lifting and lowering; the weighing mechanism is fixedly arranged at the upper center position of the flexible buffering mechanism, and the weighing mechanism is used to weigh the weight of the sample in the sample container; the weighing mechanism includes a weighing shell box, which is a hollow square body with an upper opening, and the inner periphery and bottom of the weighing shell box are sprayed with a conductive coating; a ground wire is fixedly connected to the outer wall of the weighing shell box, the upper end of the ground wire is fixedly connected to the outer wall of the weighing shell box, and the lower end of the ground wire is connected to the earth; the pole needles are evenly fixedly arranged around the inner periphery of the weighing shell box, and the pole tips of the pole needles face the center of the weighing shell box; four electromagnetic weighing sensors are symmetrically arranged front and back and left and right, and the electromagnetic weighing sensors are fixedly arranged on the bottom surface of the inside of the weighing shell box, and each electromagnetic A limit column is set on the central upper part of the weighing sensor, and the upper part of the limit column is fixedly connected to the bottom of the weighing plate. The area of ​​the weighing plate is smaller than the upper opening area of ​​the weighing shell box, and an equidistant gap is reserved between the inner side of the weighing plate and the upper opening of the weighing shell box; the thermocouple three is fixedly arranged on the rear inner side of the weighing shell box near the upper position, and the thermocouple three is used to detect the temperature in the weighing shell box in real time; the cooling pipe is fixedly arranged on the front inner side of the weighing shell box near the upper position, and the cooling pipe is used to transport cooling gas into the weighing shell box to cool down the electromagnetic weighing sensor; the refractory placement table is fixedly arranged on the upper part of the weighing mechanism, and the refractory placement table is used to place the sample container; the refractory placement table includes a refractory brick mounting shell, and the refractory brick mounting shell is central An empty square body, a refractory brick is fixedly installed in the refractory brick installation shell, and the volume of the refractory brick is smaller than the volume of the refractory brick installation shell; a boss refractory brick is fixedly arranged at the upper center of the refractory brick, and a conical placement hole for placing a sample container is opened at the upper center of the boss refractory brick, and the diameter of the conical placement hole is larger than the bottom diameter of the sample container; the sample container includes a container body, which is a cylinder with a conical bottom, and the container cover is covered on the upper part of the container body; a rotary switching mechanism is fixedly arranged at the connection between the bracket and the upper part of the counterweight body, and the rotary switching mechanism is used to rotate and switch the position of the drying box and the drying box; the rotary switching mechanism includes a support frame, which is an inverted U-shape, and the support frame is fixedly arranged on the upper part of the bracket and the counterweight body;A dividing mechanism is connected and fixed to the rear end of the stepper motor. The stepper motor is used to drive the dividing mechanism to rotate at a certain angle. The stepper motor and the dividing mechanism are fixedly arranged at the lower position of the support frame; the slewing bearing is fixedly arranged at the upper center position of the support frame, and a driving shaft is fixedly arranged on the upper part of the power output shaft of the dividing mechanism. The driving shaft passes through the upper center of the support frame and is fixedly connected to the inner ring of the slewing bearing. The rotating disk is fixedly arranged on the outer ring of the slewing bearing. The driving shaft passes through the center of the rotating disk and extends to the upper part and is fixed by the shaft end cover; square holes are symmetrically opened at the left and right center positions of the rotating disk. The size of the square holes is larger than the outer size of the drying box and the drying box. The square holes are used to fix the drying box or the drying box; the initial position limit switch is fixedly arranged on the left side of the drying box shell. The initial position limit switch is located near the upper position of the side, and is used to keep the drying box always at the corresponding upper position of the fireproof placement table; the initial position limit switch includes a sensing sheet, which is fixedly arranged at the middle position of the upper right side of the support frame, and the sensing contact is fixedly arranged at the middle position of the upper left side of the drying box shell box corresponding to the sensing sheet; the outer side of the drying box is fixed at the upper right position of the rotating switching mechanism, and the drying box is used to perform constant temperature drying on the forestry biomass raw material sample in the sample container; the drying box is fixedly arranged at the upper left position of the rotating switching mechanism, and the drying box is used to cool and dry the forestry biomass raw material sample to room temperature; the heat insulation board is fixedly arranged at the bottom of the drying box and the drying box through four fixing columns, and a circular hole is opened in the center of the heat insulation board. ; 2. The automatic measuring device for the moisture content of forestry biomass raw materials according to claim 1, characterized in that: The bracket and the counterweight frame are fixed by welding, and the heights of the bracket and the counterweight frame are equal; a convex opening is provided on the upper part of the bracket for the refractory placing platform to pass through and fix the lifting mechanism.

3. The automatic measuring device for the moisture content of forestry biomass raw materials according to claim 1 is characterized in that: The control panel includes a display screen, which is fixedly arranged at the middle position of the upper front side of the control panel, a start button is fixedly arranged at the middle position of the lower part of the display screen, a close button is fixedly arranged at the left position corresponding to the start button, an indicator light is fixedly arranged at the lower position of the close button, and an emergency stop button is fixedly arranged at the lower position of the start button; a PLC control mainboard is fixedly arranged inside the control panel body, and the PLC control mainboard includes a control board body, a gain amplification operation module is fixedly arranged at the upper part of the control board body, a control module is fixedly arranged at the lower part of the gain amplification operation module, the operation module is fixedly arranged at the lower position of the control module, and a timing module is fixedly arranged at the lower part of the operation module; the display screen is used for human-computer interaction and control parameter setting, and the gain amplification operation module calculates the parameters calculated by the gain amplification operation module through the gain amplification circuit.

4. The automatic measuring device for the moisture content of forestry biomass raw materials according to claim 2, characterized in that: The lifting mechanism includes a support body, which is fixedly arranged on the upper part of the bracket near the front side, the linear module is fixedly arranged on the support body, the fixed block is fixedly connected to the right side surface of the convex opening on the upper part of the bracket, and the fixed block is fixedly arranged on the front and rear sides of the upper right end of the linear module in a front-to-back symmetrical manner; the sliding body is fixedly arranged on the lead screw of the linear module, and the lifting arm is symmetrically arranged on the front and rear sides of the sliding body, and the lifting arm is L-shaped.

5. The automatic measuring device for the moisture content of forestry biomass raw materials according to claim 4, characterized in that: The flexible buffer mechanism includes a base plate, which is fixedly arranged on the upper part of the lifting arm symmetrically arranged front and back, and four connecting columns are arranged, which pass through the base plate and are arranged at the four corners of the base plate, and the square plate passes through the bottom of the connecting column to fix the connecting column to the bottom of the base plate; the spring is sleeved on the connecting column, and the spring is located on the upper connecting column of the base plate, and the upper part of the connecting column is sleeved with a cylinder with a closed upper part and a hollow lower part, and a gap is reserved between the upper part of the cylinder and the bottom of the refractory brick mounting shell.

6. The automatic measuring device for the moisture content of forestry biomass raw materials according to claim 1, characterized in that: The drying box includes a drying box shell, which is a hollow square body with a hole in the lower part, refractory brick plates are arranged on the inner walls around the drying box shell, an upper refractory plate is fixedly arranged on the upper inner wall of the drying box shell, and a lower refractory plate is fixedly arranged on the lower inner wall of the drying box shell, a mounting groove is arranged on the upper part of the lower refractory plate, a through hole is arranged at the center position of the lower refractory plate, and the through hole has the same diameter as the hole arranged at the center of the lower part of the drying box shell; the heating refractory cylinder is a hollow cylindrical type, the heating refractory cylinder is arranged in the mounting groove, and a heating rod mounting groove is arranged at an equal angle on the axial end face of the heating refractory cylinder, the heating rod mounting groove runs through the axial direction of the heating refractory cylinder, and a heating rod is fixedly installed in each heating rod mounting groove, a thermocouple 1 is fixedly arranged at the upper center position of the drying box shell, and the thermocouple 1 is used to detect the drying temperature in the drying box in real time.

7. The automatic measuring device for the moisture content of forestry biomass raw materials according to claim 1, characterized in that: The drying box comprises a drying box shell, a hollow square body with an opening at the bottom and a closed top, an upper heat-insulating plate fixedly arranged at the upper position of the drying box shell, a lower heat-insulating plate fixedly arranged at the lower position of the drying box shell, a through hole is opened at the center position of the lower heat-insulating plate, a placement groove is opened on the upper surface of the lower heat-insulating plate, the diameter of the placement groove is larger than the diameter of the through hole, and the placement groove is used to place the cooling cylinder; the cooling cylinder is a hollow cylindrical type with an opening at the bottom and a closed top, and vertical cooling grooves are opened at equal angles on the axial end face of the cooling cylinder, the vertical cooling grooves axially penetrate the upper end face of the cooling cylinder, and cooling through holes are evenly opened on the inner side face of each vertical cooling groove; the annular square box is fixedly installed on the upper end face of the cooling cylinder The annular square box is a hollow annular box body with an opening at the bottom, and the lower opening of the annular square box is connected with a vertical cooling groove provided on the end face of the cooling cylinder; the vortex tube is fixedly arranged at the upper part of the upper insulation plate near the left end, and the cold air end of the vortex tube is fixedly sleeved in the fixed cylinder, and the fixed cylinder is fixed on the upper surface of the upper insulation plate, and the cold air end of the vortex tube extends to the lower end of the upper insulation plate and is fixedly connected with the upper part of the annular square box; the hot air end of the vortex tube faces upward, and the hot air is discharged through the connecting pipe; the air inlet joint is arranged on one side of the upper part of the vortex tube, and the air inlet joint is used to transport high-pressure gas to the vortex tube; the thermocouple 2 is fixedly arranged in the middle position of the upper insulation plate, and the thermocouple 2 is used to detect the drying temperature in the drying box in real time.

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