An apparatus and method for on-line detection of bed thickness of a jig

Abstract

The application discloses a jig bed layer thickness on-line detection device and method, the device comprises a stroke measurement unit, a weight measurement unit, a limiting unit, a control unit and a frame; the method comprises component motion control and bed layer thickness detection module, measurement device weight measurement module, measurement device limiting module and measurement device detection module, adopts a periodic detection mode, a controller controls a stepping motor movement through a stepping motor controller, and calculates the stroke of a conical weight according to the incremental rotation number of an electric screw rod, and simultaneously detects the weight change of the stroke measurement unit by a weighing sensor, when the conical weight is lowered to contact the bed layer and the gravity data change exceeds a threshold value, it is considered that the upper surface position of the bed layer is reached, thereby calculating the bed layer thickness. After the measurement is completed, the conical weight returns to the upper limit position, and waits for the detection of the next period. The application can automatically calculate the jig bed layer thickness in real time, can realize the accurate detection of the jig bed layer thickness, and has an important role for the optimization of jigging separation indexes.

Description

TECHNICAL FIELD

[0001] The present application relates to a jig bed thickness on-line detection device and detection method, belonging to the field of mineral processing automation. BACKGROUND

[0002] The jig is a widely used gravity separation equipment in the mineral processing industry. The jig uses the impact of water flow and mechanical piston to form a pulsating upward water flow in the jig separation tank, which drives the bed layer to disperse, so that the minerals are separated according to their specific gravity. The heavy minerals resist the buoyancy of the upward water flow, pass through the gap formed by the bed layer dispersion, and enter the concentrate. The minerals with small specific gravity will be washed up by the water flow and enter the tailings, thereby realizing the reasonable separation of minerals with different specific gravities. In the production process of the jig, part of the minerals with medium specific gravity will stay in the bed layer, forming a dynamic bed layer. The minerals at the output end of the jig are usually divided into concentrate and tailings, which need to be taken separately. The concentrate can be used as a product, and the tailings are directly discarded or used for other purposes. Since the changes in the bed layer cannot be observed by the naked eye, manual prediction is required, and the bed layer thickness needs to be adjusted constantly according to the grade of the concentrate and tailings. Continuous analysis and observation of the color change of the product are required to adjust the bed layer thickness, thereby affecting the quality and recovery rate of the jig product. When the jig is working, the bed layer is in a dispersed state under the pulsating action of the water flow. The existing detection technology cannot measure the bed layer in a stable and compact state. Since the jig bed layer is below the slurry and in a loose state, the existing radar level meter, ultrasonic level meter, and laser level meter cannot be used for detection. SUMMARY

[0003] In order to overcome the shortcomings of the existing jig bed layer thickness detection device, solve the problem of relying on manual observation of the jig bed layer thickness in mineral processing production, and address the issues of difficult observation, high economic cost, high labor intensity, and delayed operation, the present application provides a jig bed layer thickness on-line detection device and method, which can detect the changes in the jig bed layer thickness in real time and replace manual observation, thereby providing a basis for operation or control in jigging and mineral processing production.

[0004] The technical scheme of the present application is as follows: a jig bed layer thickness on-line detection device, comprising a stroke measurement unit, a weight measurement unit, a limiting unit, a control unit, and a frame.

[0005] The stroke measurement unit is used to measure the stroke of the conical weight, the weight measurement unit is used to measure the weight of the stroke measurement unit, the limiting unit is used to limit the stroke of the conical weight between the upper limit switch and the lower limit switch, the control unit is used for data acquisition, component control, and calculation, and the frame is used for component fixation and provides overall support for the entire detection device.

[0006] The stroke measuring unit comprises a stepping motor, an electric screw rod, a nut piece, a connecting piece, a sleeve, a connecting rod conical heavy hammer and an inner frame; the stepping motor is fixed on the inner frame, the output end of the stepping motor is connected with the electric screw rod, the electric screw rod is connected with the sleeve through the nut piece and the connecting piece, one end of the connecting rod extends into the sleeve, and the other end of the connecting rod is provided with the conical heavy hammer.

[0007] The weight measuring unit comprises a weighing sensor, one end of the weighing sensor is fixed on the outer top of the inner frame, and the other end of the weighing sensor is fixed on the outer frame, that is, the frame.

[0008] The limiting unit comprises an upper limiting switch, a lower limiting switch and a limiting rod; the upper limiting switch and the lower limiting switch are both installed inside the inner frame, the upper limiting switch is installed on the inner top of the inner frame, the lower limiting switch is installed on the inner bottom of the inner frame, one end of the limiting rod is fixed on the connecting piece connected with the electric screw rod, and the other end of the limiting rod is suspended between the upper limiting switch and the lower limiting switch, and is used for triggering the upper limiting switch or the lower limiting switch, so as to limit the conical heavy hammer.

[0009] The control unit comprises a controller, a signal amplification conditioner, a stepping motor controller and a case; the controller, the signal amplification conditioner and the stepping motor controller are all installed in the case, the signal amplification conditioner and the stepping motor controller are electrically connected with the controller respectively, the stepping motor controller is electrically connected with the stepping motor, the upper limiting switch and the lower limiting switch are electrically connected with the controller respectively, and the weighing sensor is electrically connected with the signal amplification conditioner.

[0010] The present application also provides a method for detecting the bed layer thickness of the jigging machine by the jigging machine bed layer thickness online detection device, the jigging machine bed layer thickness detection method adopts a periodic detection mode, the controller controls the stepping motor to move through the stepping motor controller, the stroke of the conical heavy hammer is calculated according to the rotation number of the electric screw rod, the weight change of the stroke measuring unit is detected by the weighing sensor, when the conical heavy hammer contacts the bed layer and the gravity data change exceeds the threshold value, it is considered that the upper surface position of the bed layer is reached, and thus the bed layer thickness is calculated. Specifically, four technical modules are included, which are as follows:

[0011] The T11 component motion control and bed layer thickness detection module: the controller controls the stepping motor to move through the stepping motor controller, the stroke of the conical heavy hammer is calculated according to the rotation number of the electric screw rod, the weight change of the stroke measuring unit is detected by the weighing sensor, when the conical heavy hammer contacts the bed layer and the gravity data change exceeds the threshold value, it is considered that the upper surface position of the bed layer is reached, and thus the bed layer thickness is calculated; after the measurement is completed, the controller controls the stepping motor to move through the stepping motor controller, so that the conical heavy hammer returns to the upper limit position, and the next period of detection is waited;

[0012] The T12 measuring device weight measurement module detects the weight change of the stroke measurement unit through a weighing sensor, and according to the change of the upward force given by water and the bed layer when the conical weight descends, the gravity measurement value changes, and the change is used to judge whether the conical weight touches the bottom, that is, when the gravity measurement value change is greater than a threshold value, it is considered that the conical weight reaches the upper surface position of the bed layer thickness of the jig;

[0013] The T13 measuring device limiting module has one end of the limiting rod fixed on the connecting sheet connected with the electric screw rod, and the other end suspended between the upper limiting switch and the lower limiting switch, and the position of the conical weight when the limiting rod just touches the upper limiting switch is taken as the base point; the height of the conical weight is changed by adjusting the connecting rod, so that the limiting rod just touches the lower limiting switch when the conical weight just touches the jig screen, and the distance between the upper limiting switch and the lower limiting switch is the maximum stroke H;

[0014] The T14 measuring device detection module drives the electric screw rod to rotate through the stepping motor movement, and calculates the stroke h of the conical weight through the incremental rotation number N of the electric screw rod and the pitch p, wherein the incremental rotation number N = the down rotation number - the up rotation number, h = N x p, and the bed layer thickness L = H - h = H - N x p, and when the conical weight is at the base point position, the incremental rotation number N = 0.

[0015] The beneficial effects of the present application are:

[0016] The present application can realize online real-time detection of the bed layer thickness of the jig, so as to realize accurate control of the jigging separation, and data visualization of invisible factors.

[0017] The present application can provide detection data of the bed layer thickness of the jig, which has a positive effect on stabilizing product quality and improving the recovery rate of useful minerals.

[0018] The present application provides the required data for improving the automation and informatization technical level of jigging production, greatly saves labor and reduces labor intensity, and brings significant economic and social benefits to enterprises. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the control principle diagram of the present application;

[0020] Figure 2 is the device structure diagram of the present application;

[0021] The figure shows the following reference numerals: 1-controller, 2-signal amplification conditioner, 3-weight sensor, 4-stepping motor controller, 5-stepping motor, 6-upper limit switch, 7-lower limit switch, 8-electric screw, 9-nut piece, 10-limit rod, 11-connecting piece, 12-sleeve, 13-connecting rod, 14-conical weight, 15-inner frame, 16-outer frame, 17-machine box. DETAILED DESCRIPTION

[0022] The application will be further described in detail below in combination with the drawings and examples, and the examples are only used to specifically illustrate the application, and the protection scope of the application is not limited to the content described.

[0023] Example 1: The example is applied to the bed layer thickness online detection of a jig for tungsten mineral recovery. The pulp concentration is about 25%, the tungsten grade of the run-of-mine ore is about 5%, the jig specification is 750X550, the concentrate is obtained, the concentrate Ca[WO4] grade is required to be 60%, and the concentrate is directly used as a product.

[0024] The hardware selection of the example is as follows: the controller 1 is a PLC touch screen all-in-one machine, the model is MM-40MR-12MT-700-FX-B; the signal amplification conditioner 2 has the following specifications: input signal 0-15mV, output 4-20mA, power supply 24VDC; the weight sensor 3 is a cantilever type weight sensor, the measurement range is 0-10kg; the stepping motor controller 4 has the following specifications: DM422, power supply 24VDC; the stepping motor 5 has the following model: 23HS5628S-1204, 40 lead, power supply 24VDC; the upper limit switch 6 is a micro switch, the model is V-15-1C25; the lower limit switch 7 is a micro switch, the model is V-15-1C25; the electric screw 8 has a diameter of 8mm and a pitch of 1mm; the nut piece 9 has a diameter of 30mm and a thickness of 5mm; the limit rod 10 has a length of 200mm, the connecting piece 11 has a diameter of 30mm and a thickness of 5mm; the sleeve 12 has an outer diameter of 20mm, and the lower part is a screw hole with a diameter of 8mm; the connecting rod 13 has a diameter of 8mm, and the upper end is an M8 screw; the conical weight 14 has a diameter of 30mm at the lower part and a height of 30mm; the inner frame 15 has the following specifications: length*height=150mm*150mm; the outer frame 16 has the following specifications: length*height=180mm*180mm; the machine box has the following specifications: 500mm*600mm*300mm.

[0025] The jig bed layer thickness online detection device of the example comprises a stroke measurement unit, a weight measurement unit, a limiting unit, a control unit and a frame.

[0026] The stroke measuring unit is used for measuring the stroke of the conical weight 14, the weight measuring unit is used for measuring the weight of the stroke measuring unit, the limiting unit is used for limiting the stroke of the conical weight 14 between the upper limit switch 6 and the lower limit switch 7, the control unit is used for data acquisition, component control and calculation, and the frame is used for component fixation and providing overall support for the entire detection device.

[0027] As shown in Figure 2 The stroke measuring unit comprises a stepping motor 5, an electric screw rod 8, a nut piece 9, a connecting piece 11, a sleeve 12, a connecting rod 13, a conical weight 14 and an inner rack 15; the stepping motor 5 is fixed on the inner rack 15, the output end of the stepping motor 5 is connected with the electric screw rod 8, the electric screw rod 8 is connected with the sleeve 12 through the nut piece 9 and the connecting piece 11, one end of the connecting rod 13 extends into the sleeve 12, and the other end of the connecting rod 13 is installed with the conical weight 14.

[0028] The weight measuring unit comprises a weighing sensor 3, one end of the weighing sensor 3 is fixed on the outer top of the inner rack 15, and the other end of the weighing sensor 3 is fixed on an outer rack 16, that is, the frame.

[0029] The limiting unit comprises an upper limit switch 6, a lower limit switch 7 and a limiting rod 10; the upper limit switch 6 and the lower limit switch 7 are both installed inside the inner rack 15, the upper limit switch 6 is installed on the inner top of the inner rack 15, the lower limit switch 7 is installed on the inner bottom of the inner rack 15, one end of the limiting rod 10 is fixed on the connecting piece 11 connected with the electric screw rod 8, and the other end of the limiting rod 10 is suspended between the upper limit switch 6 and the lower limit switch 7, and is used for touching the upper limit switch 6 or the lower limit switch 7, so as to limit the conical weight 14.

[0030] The control unit comprises a controller 1, a signal amplification conditioner 2, a stepping motor controller 4 and a case 17; the controller 1, the signal amplification conditioner 2 and the stepping motor controller 4 are all installed in the case 17, the signal amplification conditioner 2 and the stepping motor controller 4 are respectively electrically connected with the controller 1, the stepping motor controller 4 is electrically connected with the stepping motor 5, the upper limit switch 6 and the lower limit switch 7 are respectively electrically connected with the controller 1, and the weighing sensor 3 is electrically connected with the signal amplification conditioner 2.

[0031] The embodiment of the present application is a jig bed layer thickness online detection method, as shown in Figure 1 The method comprises four method modules, that is, a component motion control and bed layer thickness detection module, a measurement device weight measurement module, a measurement device limiting module and a measurement device detection module, and the technical solutions of the modules are as follows.

[0032] T11 component motion control and bed thickness detection module: the controller 1 controls the stepping motor 5 to move through the stepping motor controller 4, and calculates the stroke of the conical weight 14 according to the number of rotation of the electric screw 8, and the weight change of the stroke measurement unit is detected by the weighing sensor 3, when the conical weight 14 is lowered to contact the bed, and the gravity data change exceeds the threshold value, it is considered that the upper surface position of the bed is reached, and the bed thickness is calculated; after the measurement is completed, the controller 1 controls the stepping motor 5 to move through the stepping motor controller 4, so that the conical weight 14 returns to the upper limit position, and waits for the detection of the next cycle;

[0033] T12 measurement device weight measurement module: the weight change of the stroke measurement unit is detected by the weighing sensor 3, according to the change of the upward force given by water and the bed when the conical weight 14 is lowered, the gravity measurement value changes accordingly, and the change is used to judge whether the conical weight 14 touches the bottom, that is, when the gravity measurement value change is greater than the threshold value, it is considered that the conical weight 14 reaches the upper surface position of the jig bed thickness;

[0034] T13 measurement device limiting module: one end of the limiting rod 10 is fixed on the connecting piece 11 connected with the electric screw 8, and the other end is suspended between the upper limit switch 6 and the lower limit switch 7, and the position of the conical weight 14 when the limiting rod 10 just touches the upper limit switch 6 is taken as the base point; by adjusting the connecting rod 13, the height of the conical weight 14 is changed, so that the limiting rod 10 just touches the lower limit switch 7 when the conical weight 14 just touches the jig screen, and the distance between the upper limit switch 6 and the lower limit switch 7 is the maximum stroke H, H is 100mm;

[0035] T14 measurement device detection module: the stepping motor 5 moves to drive the electric screw 8 to rotate, and the stroke h of the conical weight 14 is calculated according to the incremental rotation number N of the electric screw 8 and the pitch p, wherein the incremental rotation number N = down rotation number - up rotation number, h = N x p, and the bed thickness L = H - h = H - N x p, when the conical weight 14 is at the base point position, the incremental rotation number N = 0.

[0036] In this embodiment, p = 1mm, the weight of the measurement unit and the limiting unit is 3.5kg, the threshold value is 0.4kg, in a certain measurement, when the gravity measurement value change exceeds the threshold value, N = 68, and the bed thickness L = H - h = 100 - 68 * 1 = 32(mm)

[0037] Example 2: The present application is applied to the jig bed thickness online detection of tin ore tin ore recovery. The pulp concentration is about 25%, the selected ore tin grade is about 0.8%, the jig model is LTA70 / 2, the concentrate is obtained, and the concentrate SnO2 grade is required to be 45%, and the concentrate is directly used as the product.

[0038] The hardware selection of the embodiment is as follows: the controller 1 is a PLC touch screen integrated machine, the model of which is MM-40MR-12MT-700-FX-B; the signal amplification conditioner 2 has the specifications of input signal 0-15 mV, output 4-20 mA, and power supply 24 VDC; the weighing sensor 3 is a cantilever type weighing sensor, and the measurement range is 0-15 kg; the stepper motor controller 4 has the specifications of DM422, and the power supply is 24 VDC; the stepper motor 5 has the model of 23HS5628S-1204, 40 lead, and the power supply is 24 VDC; the upper limit switch 6 is a micro switch, the model of which is V-15-1C25; the lower limit switch 7 is a micro switch, the model of which is V-15-1C25; the electric screw rod 8 has a diameter of 10 mm and a pitch of 1 mm; the nut piece 9 has a diameter of 35 mm and a thickness of 5 mm; the limiting rod 10 has a length of 250 mm, the connecting piece 11 has a diameter of 30 mm and a thickness of 5 mm; the sleeve 12 has an outer diameter of 25 mm, and the lower surface is a screw hole with a diameter of 8 mm; the connecting rod 13 has a diameter of 10 mm, and the upper end is an M8 screw; the conical weight 14 has a lower surface diameter of 130 mm and a height of 130 mm; the inner rack 15 has the specifications of length*height=200 mm*200 mm; the outer rack 16 has the specifications of length*height=280 mm*180 mm; and the case has the specifications of 500 mm*600 mm*300 mm.

[0039] The bed layer thickness online detection device provided in the embodiment has the same structure as that of embodiment 1.

[0040] The bed layer thickness online detection method of the embodiment is composed of four method modules, i.e., a component motion control and bed layer thickness detection module, a measurement device weight measurement module, a measurement device limiting module, and a measurement device detection module, and the technical solutions of the technical modules are the same as those of embodiment 1.

[0041] In the embodiment, p=3 mm, the weight of the measurement unit and the limiting unit is 10.5 kg, the threshold value is 0.4 kg, in a certain measurement, when the gravity measurement value change exceeds the threshold value, N=58, and the bed layer thickness L=H-h=500-58*3=326 (mm).

[0042] Embodiment 3: The present application is applied to the bed layer thickness online detection of a jig for coal mine material recovery. The ore pulp concentration is about 25%, the maximum particle size of the selected ore is 35 mm, the jig model is JC1616-2, the refined ore is obtained, the sulfur content of the refined ore is required to be 1.5%, the ash content is required to be 20.5%, and the refined ore is directly used as a product.

[0043] The hardware selection of the embodiment is as follows: the controller 1 is a PLC touch screen integrated machine, the model is MM-40MR-12MT-700-FX-B, and the manufacturer is Zhongda excellent control; the signal amplification conditioner 2 has the specifications of input signal 0-15 mV, output 4-20 mA, and power supply 24 VDC; the weighing sensor 3 is a cantilever type weighing sensor, and the measurement range is 0-15 kg; the stepper motor controller 4 has the specifications of DM422, and the power supply is 24 VDC; the stepper motor 5 has the model of 23HS5628S-1204, 40 lead, and the power supply is 24 VDC; the upper limit switch 6 is a micro switch, the model is V-15-1C25; the lower limit switch 7 is a micro switch, the model is V-15-1C25; the electric screw rod 8 has a diameter of 18 mm and a pitch of 10 mm; the nut piece 9 has a diameter of 200 mm and a thickness of 15 mm; the limiting rod 10 has a length of 500 mm, the connecting piece 11 has a diameter of 30 mm and a thickness of 15 mm; the sleeve 12 has an outer diameter of 120 mm, and the lower part is a screw hole with a diameter of 18 mm; the connecting rod 13 has a diameter of 18 mm, and the upper end is an M18 screw; the conical weight 14 has a diameter of 100 mm at the lower part and a height of 80 mm; the inner rack 15 has the specifications of length*height=1150 mm*1150 mm; the outer rack 16 has the specifications of length*height=1800 mm*1800 mm; and the case has the specifications of 500 mm*600 mm*300 mm.

[0044] The bed layer thickness online detection device provided in the embodiment has the same structure as that of embodiment 1.

[0045] The bed layer thickness online detection method of the embodiment is composed of four method modules, i.e., a component motion control and bed layer thickness detection module, a measurement device weight measurement module, a measurement device limiting module, and a measurement device detection module, and the technical solutions of the technical modules are the same as those of embodiment 1.

[0046] In the embodiment, p=2.5 mm, the weight of the measurement unit and the limiting unit is 13.3 kg, the threshold value is 0.43 kg, in a certain measurement, when the gravity measurement value change exceeds the threshold value, N=60, and the bed layer thickness L=H-h=600-60*2.5=450 (mm).

[0047] The above only describes the preferred embodiments of the present application, and it should be noted that, for ordinary skilled persons in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A detection method of an on-line detection device for bed thickness of a jigging machine, characterized by, The bed layer thickness on-line detection device of the jigging machine comprises a stroke measurement unit, a weight measurement unit, a limiting unit, a control unit and a frame; The stroke measurement unit is used for measuring the stroke of the conical weight (14), the weight measurement unit is used for measuring the weight of the stroke measurement unit, the limiting unit is used for limiting the stroke of the conical weight (14), the control unit is used for data acquisition, component control and calculation, and the frame is used for component fixation and overall support of the entire detection device; the jigging machine bed layer thickness detection method adopts a periodic detection mode; the controller (1) controls the movement of the stepping motor (5) through the stepping motor controller (4), and calculates the stroke of the conical weight according to the number of rotations of the electric screw rod (8); meanwhile, the weight change of the stroke measurement unit is detected by the weighing sensor (3); when the conical weight contacts the bed layer and the gravity data change exceeds the threshold value, it is considered that the upper surface position of the bed layer is reached, thereby calculating the bed layer thickness; the limiting unit comprises an upper limiting switch (6), a lower limiting switch (7) and a limiting rod (10); the upper limiting switch (6) and the lower limiting switch (7) are both installed inside the inner frame (15), and the upper limiting switch (6) is installed at the top of the inner frame (15), and the lower limiting switch (7) is installed at the bottom of the inner frame (15); one end of the limiting rod (10) is fixed on the connecting sheet (11) connected with the electric screw rod (8), and the other end is suspended between the upper limiting switch (6) and the lower limiting switch (7) for triggering the upper limiting switch (6) or the lower limiting switch (7), thereby limiting the conical weight (14); The stroke measurement unit comprises a stepping motor (5), an electric screw rod (8), a nut sheet (9), a connecting sheet (11), a sleeve (12), a connecting rod (13), a conical weight (14) and an inner frame (15); the stepping motor (5) is fixed on the inner frame (15), the output end of the stepping motor (5) is connected with the electric screw rod (8), the electric screw rod (8) is connected with the sleeve (12) through the nut sheet (9) and the connecting sheet (11), one end of the connecting rod (13) extends into the sleeve (12), and the other end of the connecting rod (13) is installed with the conical weight (14); The weight measurement unit comprises a weighing sensor (3); one end of the weighing sensor (3) is fixed on the outer top of the inner frame (15), and the other end of the weighing sensor (3) is fixed on the outer frame (16), which is the frame; The control unit comprises a controller (1), a signal amplification conditioner (2), a stepping motor controller (4) and a case (17); the controller (1), the signal amplification conditioner (2) and the stepping motor controller (4) are all installed in the case (17), and the signal amplification conditioner (2) and the stepping motor controller (4) are respectively electrically connected with the controller (1); the stepping motor controller (4) is electrically connected with the stepping motor (5); the upper limiting switch (6) and the lower limiting switch (7) are respectively electrically connected with the controller (1); and the weighing sensor (3) is electrically connected with the signal amplification conditioner (2). The detection method of the jig bed layer thickness on-line detection device comprises four technical modules, and is specifically as follows: The T11 component motion control and bed layer thickness detection module: the controller (1) controls the stepping motor (5) to move through the stepping motor controller (4), and calculates the stroke of the conical weight (14) according to the rotation number of the electric screw rod (8), and the weight change of the stroke measurement unit is detected by the weighing sensor (3), when the conical weight (14) is lowered to contact the bed layer, and the gravity data change amount exceeds the threshold value, it is considered that the upper surface position of the bed layer is reached, and the bed layer thickness is calculated; after the measurement is completed, the controller (1) controls the stepping motor (5) to move through the stepping motor controller (4), so that the conical weight (14) returns to the upper limit position, and waits for the detection of the next cycle; The T12 measurement device weight measurement module: the weight change of the stroke measurement unit is detected by the weighing sensor (3), according to the change of the upward force given by water and the bed layer when the conical weight (14) is lowered, the gravity measurement value changes accordingly, and whether the conical weight (14) touches the bottom is judged according to the change, that is, when the gravity measurement value change is greater than the threshold value, it is considered that the conical weight (14) reaches the upper surface position of the jig bed layer thickness; The T13 measurement device limiting module: one end of the limiting rod (10) is fixed on the connecting sheet (11) connected with the electric screw rod (8), and the other end is suspended between the upper limit switch (6) and the lower limit switch (7), and the position of the conical weight (14) when the limiting rod (10) just touches the upper limit switch (6) is taken as the base point; the height of the conical weight (14) is changed by adjusting the connecting rod (13), so that the limiting rod (10) just touches the lower limit switch (7) when the conical weight (14) just touches the jig screen, and the distance between the upper limit switch (6) and the lower limit switch (7) is the maximum stroke H; The T14 measurement device detection module: the stepping motor (5) moves to drive the electric screw rod (8) to rotate, and the stroke h of the conical weight (14) is calculated according to the incremental rotation number N and the pitch p of the electric screw rod (8), wherein the incremental rotation number N = down rotation number - up rotation number, h = N x p, and the bed layer thickness L = H - h = H - N x p, when the conical weight (14) is at the base point position, the incremental rotation number N = 0.

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