Automatic powder sampler and sampling method

Abstract

The application discloses a kind of powder automatic sampler and sampling method, the powder automatic sampler is connected with sampling lumen, including telescopic sampler with the side wall communication of sampling lumen, telescopic sampler includes sampling device shell, telescopic baffle, telescopic baffle includes front baffle, rear baffle, bottom connecting piece connecting front baffle and rear baffle, bottom connecting piece is equipped with sampling spoon, bottom connecting piece is opened with discharging hole, sampling spoon is connected with one end of telescopic connecting rod, the other end of telescopic connecting rod is connected with cylinder after being drawn out of telescopic sampler, and the discharging port is opened on telescopic sampler and is connected with sample collection box, cylinder is connected with gas source through gas source pipe, electromagnetic valve is equipped on gas source pipe, electromagnetic valve is connected with controller through electric wire.The sampling device of the application achieves real-time, timing sampling, guarantees the real-time of material quality, particle size detection, simultaneously will not cause inhaled large amount of air, impurity, will not hinder, blockage to the discharging conveying.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of sampling, in particular to a kind of powder automatic sampler and sampling method, more particularly to a kind of PVA powder sampler and sampling method special for screw conveyor discharge port. BACKGROUND

[0002] In the process of further crushing and conveying PVA (polyvinyl alcohol) products to finished product bin, the whole process is vacuum closed conveying, the powder is conveyed to the conveying pipeline by screw conveyor after crushing, and is conveyed to the finished product bin by negative pressure. The quality inspection and analysis of the powder are generally carried out by installing a sampler at the outlet of the finished product bin, which has the disadvantages of large analysis result lag, inability to timely switch to an accident bin or adjust the process when the quality problem or particle size distribution is uneven, and reduced loss.

[0003] Due to the complex structure of the whole process of conveying the crushed finished product by screw conveyor, it is necessary to maintain a closed vacuum environment. Currently, the samplers on the market cannot be normally installed. The quality inspection and analysis of the powder are generally carried out by installing a sampler at the outlet of the finished product bin after conveying to the finished product bin or manually sampling. Moreover, the screw conveyor discharge port has a complex structure and is tubular with a small internal space. Most ordinary powder samplers cannot be installed. A few samplers that can be installed will cause problems of blocking and hindering the discharge port of the conveyor due to structural problems, affecting the overall conveying effect. At the same time, the whole conveying process after crushing is vacuum negative pressure conveying, which requires a sealing effect. After the installation of a traditional sampler, air and impurities will be sucked in due to the opening, affecting the vacuum degree of conveying and the quality of the product. SUMMARY

[0004] In view of the disadvantages of the existing samplers, the present application provides a sampler that can be installed in the structure matching screw conveyor discharge port to achieve real-time and timed sampling, further ensure the real-time nature of material quality and particle size detection, and ensure the use in a vacuum feeding environment without sucking in a large amount of air and impurities, without blocking and hindering the discharge, so as to avoid affecting the conveying efficiency.

[0005] According to the first embodiment of the present application, a powder automatic sampler is provided, which is connected with a sampling tube cavity arranged on a material conveying system (such as fixedly connected between the discharge port of the screw conveyor and the conveying pipeline), and includes a telescopic sampler in communication with the sampling tube cavity. The telescopic sampler includes a sampling device shell, a telescopic baffle arranged in the sampling device shell, a sampling spoon sliding the telescopic baffle and extending into the sampling tube cavity for sampling, the sampling spoon is connected with a telescopic connecting rod, one end of the telescopic connecting rod away from the sampling spoon is connected with a pneumatic element controlling the telescopic connecting rod after penetrating out of the sampling device shell, the pneumatic element is connected with a gas source through a gas source pipe, a gas control valve is arranged on the gas source pipe, and the gas control valve is connected with a controller.

[0006] Further, the sampling tube cavity is a flange type tube cavity, which can be freely customized according to the upper end discharge port type and the conveying pipeline type after discharging, for example, can be any one of a cylindrical structure, a square structure, and a cone structure, which includes an upper connecting flange connected with the discharge port of the screw conveyor, a lower connecting flange connected with the conveying pipeline, and an intermediate cylinder connected between the upper connecting flange and the lower connecting flange, for example, integrally formed, and the material of the sampling tube cavity can be any one of stainless steel, carbon steel, and transparent glass steel, preferably transparent glass steel, which facilitates real-time observation of the discharging condition by the inspection personnel.

[0007] Further, the sampling device shell is a rectangular hollow structure with an open front end and a closed rear end, the open front end is connected with the side wall (i.e. the intermediate cylinder) of the sampling tube cavity, the whole sampling device shell is integrally connected with the sampling tube cavity, or the sampling device shell is divided into a left side part and a right side part (the shapes of the left side part and the right side part are consistent), the left side part is integrally connected with the sampling tube cavity, the left side part and the right side part are connected through a butt flange, a first flange plate is fixed on the end of the left side part away from the sampling tube cavity along the outer edge of the left side part, a second flange plate is fixed on the end of the right side part corresponding to the left side part along the outer edge of the right side part, the first flange plate and the second flange plate are connected through bolts, and a gasket is arranged between the first flange plate and the second flange plate to ensure the sealing effect of the butt flange, the connection mode of the sampling device shell provided with the butt flange facilitates the disassembly of the telescopic sampler for daily maintenance and repair; a stop plate is arranged on the top wall of the inner cavity of the front end of the sampling device shell to prevent the telescopic baffle from penetrating out of the sampling device shell (the distance between the stop plate and the front opening is preferably such that the discharge hole stays inside the sampling device shell when the telescopic baffle is extended), the height of the stop plate can resist the rear baffle, but the sampling spoon can pass through smoothly; the rear end wall plate of the sampling device shell is provided with an opening (preferably an opening with an embedded rubber ring to ensure the sealing of the telescopic sampler when the telescopic connecting rod slides) for the telescopic connecting rod to penetrate through; a blowhole is opened on the sampling device shell to connect with a blowpipe for blowing the inner cavity of the telescopic sampler, and the material of the sampling device shell can be stainless steel plate, for example, with a thickness of 3-5 mm.

[0008] Further, the telescopic baffle comprises a front baffle for sealing the opening at the front end of the sampling device shell, a rear baffle, and a bottom connecting piece connecting the front baffle and the rear baffle. The telescopic baffle slides along the bottom wall of the inner cavity of the sampling device shell under the driving of the sampling spoon. The front baffle is, for example, vertically connected to the front end of the bottom connecting piece. The rear baffle is, for example, vertically connected to the rear end of the bottom connecting piece. The front baffle, the rear baffle, and the bottom connecting piece are preferably integrally formed. The inner side of the front baffle, for example, protrudes towards the rear baffle to form a chamfer (the angle may, for example, be 30-45 degrees, and a chamfer cavity is provided at the edge of the inner opening at the front end of the sampling device shell to cooperate with the chamfer). Or the shape of the front baffle is the same as the size and shape of the opening at the front end of the sampling device shell, for example, a rectangular baffle structure, so that the front baffle completely fits the opening at the front end of the sampling device shell to form a seal. The width of the front baffle is slightly larger than the width of the bottom connecting piece (the bottom connecting piece is connected to the middle of the front baffle, and the difference in width between the front baffle and the bottom connecting piece is twice the thickness of the wall of the sampling device shell). The distance between the bottom edge of the bottom connecting piece and the front baffle is consistent with the thickness of the sampling device shell, so that the front baffle can seal the opening at the front end of the sampling device shell. The width of the front baffle may, for example, be 80-120 mm, preferably about 100 mm. The height may, for example, be 40-60 mm, preferably about 50 mm. The thickness of the front baffle may, for example, be 1-3 mm, preferably about 2 mm. A rubber gasket is fixed (for example, bonded) to the inner surface of the front baffle for sealing the opening at the front end of the sampling device shell. The width of the bottom connecting piece is consistent with the width of the inner cavity of the sampling device shell. The thickness of the bottom connecting piece may, for example, be 1-3 mm, preferably about 2 mm. The length may, for example, be 230-300 mm, preferably about 230 mm. The rear baffle is a baffle of any shape. The width of the rear baffle is smaller than the width of the inner cavity of the sampling device shell, for example, 10-30 mm smaller. The height is smaller than the height of the inner cavity of the sampling device shell, for example, 5-20 mm smaller. The thickness may, for example, be 1-3 mm, preferably about 2 mm. The rear baffle may, for example, be triangular, rectangular, or the like. The rear baffle is preferably rectangular. The telescopic baffle may, for example, be made of stainless steel.

[0009] Further, a discharge hole is provided on the bottom connecting piece, preferably at a position close to the rear baffle. For example, the center of the discharge hole is 55-75 mm away from the rear baffle. The diameter of the discharge hole may, for example, be 70-110 mm, preferably about 70 mm.

[0010] Further, the sampling spoon is a hollow three-dimensional structure that is permeable from top to bottom, such as a hollow cube structure, a cuboid structure or a hollow cylinder structure with top and bottom surfaces removed, and is made of, for example, stainless steel. The front end of the sampling spoon is preferably provided with a forward protruding taper, and the protruding distance is, for example, 1-3 mm, preferably about 2 mm. The protruding point is preferably directly opposite the center of the front baffle. The width of the sampling spoon is, for example, the same as the width of the inner cavity of the sampling device shell, and the height is less than the height of the inner cavity of the sampling device shell, for example, 10-30 mm less. The length is, for example, 80-120 mm, preferably about 100 mm. The rear end of the sampling spoon is connected to the telescopic connecting rod (for example, can be welded). Under the driving of the telescopic connecting rod, the sampling spoon slides between the front baffle and the rear baffle along the bottom connecting piece. When the telescopic connecting rod is extended, the sampling spoon is pushed to slide forward until it stops against the front baffle. The telescopic connecting rod continues to extend, pushing the front baffle and the entire telescopic baffle to slide forward, and the sampling spoon reaches the sampling tube cavity for sampling (the length of the bottom connecting piece is preferably greater than the sum of the length of the sampling spoon and the diameter of the discharge hole. When the sampling device shell is integrally connected with the sampling tube cavity, the distance from the front end of the front baffle to the opening of the sampling device shell is preferably equal to the length of the sampling spoon). After sampling is completed, the telescopic connecting rod is shortened, and the sampling spoon with the sample slides backward until it stops against the rear baffle. The telescopic connecting rod continues to shorten, pushing the rear baffle and the entire telescopic baffle to slide backward into the sampling device shell. Further, the telescopic connecting rod can be single or double. The telescopic connecting rod passes through the rear baffle (when the telescopic connecting rod is single, a hole is opened in the rear baffle for the telescopic connecting rod to pass through; when the telescopic connecting rod is double, the telescopic connecting rod passes through both sides of the rear baffle, and the distance between the two telescopic connecting rods is greater than the width of the rear baffle) and is connected to the pneumatic element outside the rear end wall of the sampling device shell.

[0011] Further, the telescopic sampler is provided with a discharge opening connected to the sample collection box. Preferably, the discharge opening of the telescopic sampler is opened on the bottom plate of the sampling device shell, preferably close to the rear end wall of the sampling device shell. For example, the center of the discharge opening is 85-105 mm away from the rear end wall, preferably 105 mm. The discharge opening is, for example, a circular hole, and the hole diameter is, for example, 70-110 mm, preferably 70 mm, and is preferably the same size as the discharge hole on the bottom connecting piece.

[0012] The distance between the discharge hole on the bottom connecting piece and the front baffle is preferably the same as the distance between the front end opening of the sampling device shell and the discharge opening.

[0013] Further, the pneumatic element is a cylinder, the telescopic connecting rod is connected with a buffer piston arranged in the cylinder, the buffer piston has a left cylinder chamber on the left side and a right cylinder chamber on the right side, the cylinder has a first retraction air port on the left end and a first extension air port on the right end, and the buffer piston moves leftward and rightward to push the telescopic connecting rod to extend and retract. The cylinder is selected from standard fittings, for example, and can be cylindrical or cuboid in shape. The volume of the cylinder is, for example, 1-2L, preferably 1L. The telescopic stroke of the cylinder is, for example, 230-300mm, preferably 230mm.

[0014] Further, the gas source pipe comprises a retraction air pipe connected with the first retraction air port of the cylinder and an extension air pipe connected with the first extension air port of the cylinder, the extension air pipe is provided with a tee joint, and the branch port of the tee joint is connected with the blowing pipe and the blowing hole. The gas enters the inner cavity of the sampling device through the tee joint and the blowing pipe, and the inner cavity of the sampling device and the telescopic baffle are blown.

[0015] Further, the gas control valve is an electromagnetic valve. Preferably, the electromagnetic valve is a two-position five-way electromagnetic valve. The model of the electromagnetic valve is, for example, 4V-310, and the brand is, for example, Yadea. The electromagnetic valve comprises a second retraction air port connected with the retraction air pipe, a second extension air port connected with the extension air pipe, a total air inlet connected with the gas source (the gas source is always connected with the air), a first air outlet and a second air outlet for discharging the gas in the cylinder, a valve core for switching the flow direction of the gas arranged in the electromagnetic valve, a piston arranged on the valve core, a coil arranged in the electromagnetic valve for controlling the valve core to move in parallel, and a flow channel of the gas in the electromagnetic valve. In the initial state, the gas source supplies the gas to the left cylinder chamber through the total air inlet and the second retraction air port (the cylinder wall can withstand the gas pressure in the cylinder), the buffer piston is at the rightmost end, and the sampling spoon is in the retracted state. When the electromagnetic valve is in the energized state, the electromagnetic valve is actuated, the coil controls the valve core to move, the second retraction air port and the first air outlet are connected, the gas in the left cylinder chamber enters the retraction air pipe and is discharged from the connected second retraction air port and first air outlet (the pressure in the left cylinder chamber decreases), the total air inlet and the second extension air port are connected, the gas enters the extension air pipe, is distributed through the tee joint, part of the gas enters the inner cavity of the sampling device shell through the blowing pipe to blow, and the other part of the gas reaches the right cylinder chamber to push the buffer piston to move leftward, the telescopic connecting rod extends, and the sampling spoon is pushed out to the sampling pipe cavity to sample instantaneously. When the electromagnetic valve is de-energized, the coil controls the valve core to reset, the electromagnetic valve is in the initial state, the second extension air port and the second air outlet are connected, the gas in the right cylinder chamber enters the extension air pipe and is discharged from the connected second extension air port and second air outlet (the pressure in the right cylinder chamber decreases), the total air inlet and the second retraction air port are connected, the gas enters the retraction air pipe to reach the left cylinder chamber, the buffer piston is pushed to move rightward, the telescopic connecting rod shortens, the sampling spoon is brought back instantaneously, and the powder in the sampling spoon flows to the sample collection box through the discharging port.

[0016] Further, the controller can be any one of PLC, intelligent controller, DCS, etc., and the controller is connected with the electromagnetic valve through wire or wireless. The controller sends a command to make the electromagnetic valve powered on or powered off through timing or remote control. The first timer module and the second timer module are programmed in the controller. The first timer module controls the sampling period, for example, sampling is performed once every 15-45 minutes, preferably about 30 minutes. The second timer module controls the sampling time, for example, the sampling time is set to 2-10 seconds, preferably about 5 seconds. When the first timer module finishes timing, the controller outputs a signal to make the electromagnetic valve coil powered on, and at the same time, the second timer module starts timing. The sampling spoon is pushed out to the sampling lumen for sampling. When the second timer module finishes timing, the controller outputs a signal to make the electromagnetic valve coil powered off, and the telescopic connecting rod is retracted, and the sampling spoon is brought back.

[0017] According to the second embodiment of the present application, a sampling method of the automatic powder sampler is provided, and the method comprises:

[0018] (1) Before starting sampling, the front baffle of the telescopic baffle blocks the front end opening of the sampling device shell. The discharge hole, the sampling spoon, and the opening of the discharge port are in a coincident state. The electromagnetic valve is in an initial state. The first timer module (controlling the sampling period, for example, sampling is performed once every 15-45 minutes, preferably about 30 minutes) and the second timer module (controlling the sampling time, for example, the sampling time is set to 2-10 seconds, preferably about 5 seconds, and the telescopic connecting rod is in an extended state during the sampling time) are programmed in the controller. After the controller receives a sampling command (remote manual or the first timer module finishes timing), the controller outputs a signal to make the electromagnetic valve coil powered on, and at the same time, the second timer module starts timing. The gas in the left cylinder chamber is discharged through the telescopic air pipe. The gas enters the telescopic air pipe. A part of the gas enters the telescopic sampler inner cavity to perform a blow on the telescopic sampler inner cavity and the telescopic baffle. Another part of the gas enters the right cylinder chamber to push the buffer piston to move leftward. The telescopic connecting rod is extended to push the sampling spoon to reach the sampling lumen instantaneously, and the powder falls to the sampling spoon.

[0019] (2) the second timer module timing ends, sampling is completed, the surrounding powder is blown away by the blowing gas flow, the controller sends a signal to make the electromagnetic valve coil power off, the gas in the right cylinder chamber is discharged from the extension air pipe, the gas enters the left cylinder chamber through the retraction air pipe, the buffer piston is pushed to move to the right, the sampling spoon loaded with the sample slides back into the sampling device shell instantaneously, returns to the initial state, the front baffle of the telescopic baffle blocks the front end opening of the sampling device shell, the discharge hole, the sampling spoon and the discharge opening are completely coincided in position, the powder in the sampling spoon flows to the sample collection box through the discharge opening, one sampling is completed, the first timer module and the second timer module are reset, the first timer module starts timing again, and the second timer module waits for timing; when the first timer module completes timing again, the second sampling is started, and the above steps are repeated.

[0020] The beneficial effects of the present application are:

[0021] The powder automatic sampler of the present application can be directly installed at the discharge opening of the screw conveyor, and can realize the timed and real-time collection of the PVA powder at the discharge opening of the screw conveyor, further ensures the real-time performance of the material quality and particle size detection, timely adjusts and switches the accident bin, the unique telescopic sampling structure does not occupy the narrow tubular discharge space, does not hinder and block the discharge and conveying, so as to avoid affecting the conveying efficiency, the unique sealing structure can be completely applied to the vacuum conveying pipeline, does not cause a large amount of air and impurities to be sucked in, and does not pollute the powder or reduce the conveying vacuum pressure, cooperates with the convenient and practical back blowing structure, can ensure that the sampling tube cavity is swept in real time, prevents the telescopic rod of the sampler from being stuck due to heating and accumulation of the powder, and reduces the maintenance amount, the sampling tube cavity is transparent tempered glass structure, equivalent to the discharge window, convenient for the inspection personnel to observe the discharge condition, and the telescopic sampler and the sampling tube cavity can be flange connected, convenient for disassembly and maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a whole structure schematic view of a powder automatic sampler of the present application;

[0023] Figure 2 It is a schematic view of a sampling state;

[0024] Figure 3 It is a schematic view of a sampling state two;

[0025] Figure 4 It is a schematic view of a sampling state three;

[0026] Figure 5 It is a schematic view of the cooperation of the chamfer and the chamfer cavity;

[0027] Figure 6 It is a schematic view of the electromagnetic valve power-on state;

[0028] Figure 7 The schematic diagram of the electromagnetic valve in power-off state.

[0029] Reference signs:

[0030] 1-sampling tube cavity; 1-1-upper connecting flange; 1-2-lower connecting flange; 1-3-intermediate cylinder;

[0031] 2-telescopic sampler;

[0032] 2-1-telescopic baffle; 2-1-1-front baffle; 2-1-1-1-chamfer; 2-1-2-rear baffle; 2-1-3-bottom connecting piece; 2-1-4-discharge hole;

[0033] 2-2-sampling device housing; 2-2-1-rear end wall plate of the sampling device housing; 2-2-2-first flange piece; 2-2-3-second flange piece; 2-2-4-chamfer cavity;

[0034] 2-3-telescopic connecting rod;

[0035] 3-butting flange; 4-sampling spoon;

[0036] 5-electromagnetic valve; 5-1-second retraction air port; 5-2-second extension air port; 5-3-total air inlet; 5-4-first air outlet; 5-5-second air outlet; 5-6-valve core; 5-7-coil; 5-8-piston;

[0037] 6-cylinder; 6-1-first retraction air port; 6-2-first extension air port;

[0038] 7-controller; 8-three-way joint; 9-purging hole;

[0039] 10-air source pipe; 10-1-retraction air pipe; 10-2-extension air pipe;

[0040] 11-discharge port; 12-sample collection box; 13-wire; 14-purging pipe. DETAILED DESCRIPTION

[0041] The present application will be further described below in conjunction with the drawings and examples.

[0042] In the present application, the orientations "front, rear, left, right" are taken as the reference base with the placement position in the drawings.

[0043] As Figures 1-7As shown, the powder automatic sampler of the present application is connected to the sampling cavity 1 between the discharge port of the screw conveyor and the conveying pipeline, and comprises a telescopic sampler 2 in communication with the side wall of the sampling cavity 1, the telescopic sampler 2 comprising a sampling device housing 2-2 in communication with the sampling cavity 1, a telescopic baffle 2-1 arranged in the sampling device housing 2-2 and sliding along the bottom wall of the inner cavity of the sampling device housing 2-2, the telescopic baffle 2-1 comprising a front baffle 2-1-1 for blocking the front end opening of the sampling device housing 2-2, a rear baffle 2-1-2, and a bottom connecting piece 2-1-3 connecting the front baffle and the rear baffle, the bottom connecting piece 2-1-3 being provided with a sampling spoon 4 sliding along the bottom connecting piece and driving the telescopic baffle to slide and sampling into the sampling cavity 1, the bottom connecting piece being provided with a discharging hole 2-1-4, the sampling spoon 4 being connected to one end of a telescopic connecting rod 2-3, the other end of the telescopic connecting rod 2-3 being connected to a pneumatic element after passing out of the sampling device housing 2-2, the telescopic sampler 2 being provided with a discharge port 11 connected to a sample collection box 12, the pneumatic element being connected to a gas source through a gas source pipe 10, the gas source pipe 10 being provided with a gas control valve controlling the inflow and outflow of gas, the gas control valve being connected to a controller 7 through an electric wire 13 or wirelessly.

[0044] The sampling cavity 1 is a flange type cavity, and the sampling cavity 1 can be freely customized according to the style of the upper end discharge port and the style of the conveying pipeline after discharging, for example, can be any one of a cylindrical structure, a square structure, and a cone structure, and comprises an upper connecting flange 1-1 connected to the discharge port of the screw conveyor, a lower connecting flange 1-2 connected to the conveying pipeline, and an intermediate cylinder 1-3 connected between the upper connecting flange and the lower connecting flange, for example, integrally formed, and the material of the sampling cavity 1 can be any one of stainless steel, carbon steel, and transparent glass steel, and preferably transparent glass steel, which facilitates real-time observation of the discharging condition by the inspection personnel.

[0045] The sampling device shell 2-2 is a front-end open, rear-end closed rectangular hollow structure, the open front end is communicated with the side wall of the sampling tube cavity 1 (i.e. the middle cylinder 1-3), the sampling device shell 2-2 is integrally connected with the sampling tube cavity 1, or the sampling device shell 2-2 is divided into a left side part and a right side part (the shapes of the left side part and the right side part are consistent), the left side part is integrally connected with the sampling tube cavity 1, for example, the left side part and the right side part are connected through the butt flange 3, the end of the left side part away from the sampling tube cavity 1 is fixed with the first flange plate 2-2-2 along the outer edge of the left side part, the end corresponding to the left side part of the right side part is fixed with the second flange plate 2-2-3 along the outer edge of the right side part, the first flange plate 2-2-2 and the second flange plate 2-2-3 are connected through bolts, and a gasket is arranged between the first flange plate and the second flange plate to ensure the sealing effect of the butt flange, the connection mode of the sampling device shell provided with the butt flange connection facilitates the disassembly of the telescopic sampler, so that daily maintenance and repair can be carried out; a stop plate for preventing the rear baffle of the telescopic baffle from penetrating out of the sampling device shell is arranged on the top wall of the inner cavity of the front end of the sampling device shell (the distance between the stop plate and the front end opening is preferably such that the discharge hole stays in the sampling device shell when the telescopic baffle is extended), the height of the stop plate can resist the rear baffle, but the sampling spoon can pass through smoothly; the rear end wall plate 2-2-1 of the sampling device shell is provided with an opening (preferably an inner rubber ring is arranged after the opening to ensure the sealing property of the telescopic sampler when the telescopic connecting rod 2-3 slides) for the telescopic connecting rod 2-3 to penetrate; the sampling device shell 2-2 is provided with a blowing hole 9 connected with a blowing pipe 14 for blowing the inner cavity of the telescopic sampler 2.

[0046] The front baffle 2-1-1 is connected to the front end of the bottom connecting piece 2-1-3, for example, the rear baffle 2-1-2 is connected to the rear end of the bottom connecting piece 2-1-3, for example, the front baffle 2-1-1, the rear baffle 2-1-2 and the bottom connecting piece 2-1-3 are preferably integrally formed, for example, Figure 5As shown, the inner side of the front baffle, for example, protrudes in the direction of the rear baffle to form a chamfer 2-1-1-1 (the angle may be 30-45 degrees, for example, and a chamfer cavity 2-2-4 is provided on the inner opening edge of the front end of the sampling device shell to match the chamfer); or the shape of the front baffle 2-1-1 is the same as the size and shape of the front end opening of the sampling device shell 2-2, which may be a rectangular flap structure, for example, so that the front baffle completely fits the front end opening of the sampling device shell 2-2 to form a seal, the width of the front baffle 2-1-1 is slightly larger than the width of the bottom connecting piece 2-1-3, the bottom connecting piece 2-1-3 is connected to the middle of the front baffle 2-1-1, the width difference between the front baffle 2-1-1 and the bottom connecting piece 2-1-3 is twice the thickness of the sampling device shell 2-2, the distance between the bottom connecting piece 2-1-3 and the bottom edge of the front baffle 2-1-1 is consistent with the thickness of the sampling device shell 2-2, so that the front baffle 2-1-1 can block the front end opening of the sampling device shell 2-2, the width of the front baffle 2-1-1 may be 80-120mm, for example, preferably about 100mm, the height may be 40-60mm, for example, preferably about 50mm, the thickness of the front baffle 2-1-1 may be 1-3mm, for example, preferably about 2mm, a rubber gasket is fixed (e.g. bonded) to the inner surface of the front baffle 2-1-1 for sealing the front end opening of the sampling device shell 2-2, the width of the bottom connecting piece 2-1-3 is consistent with the width of the inner cavity of the sampling device shell 2-2, the thickness of the bottom connecting piece 2-1-3 may be 1-3mm, for example, preferably about 2mm, the length may be 230-300mm, for example, preferably about 230mm, the rear baffle 2-1-2 may be any shape of baffle, the width of the rear baffle 2-1-2 is smaller than the width of the inner cavity of the sampling device shell, for example, 10-30mm smaller, the height is smaller than the height of the inner cavity of the sampling device shell, for example, 5-20mm smaller, the thickness may be 1-3mm, for example, preferably about 2mm, the rear baffle 2-1-2 may be triangular, rectangular, etc., and the rear baffle is preferably rectangular.

[0047] The discharge hole 2-1-4 is preferably provided on the bottom connecting piece 2-1-3 near the rear baffle 2-1-2, for example, the center of the discharge hole 2-1-4 is 120-200mm from the rear baffle, the diameter of the discharge hole may be 70-110mm, for example, preferably about 70mm.

[0048] The sampling spoon 4 is a hollow three-dimensional structure that is permeable from top to bottom, for example, it can be a hollow cube structure, a cuboid structure or a hollow cylinder structure with the top and bottom surfaces removed. The front end of the sampling spoon 4 is preferably provided with a forward protruding taper, for example, the forward protruding distance can be 1-3 mm, preferably about 2 mm. The protruding point is preferably directly opposite the center position of the front baffle 2-1-1. The width of the sampling spoon 4 can be consistent with or slightly smaller than the inner cavity width of the sampling device shell 2-2. The height of the sampling spoon 4 is smaller than the inner cavity height of the sampling device shell, for example, 10-30 mm smaller. The length of the sampling spoon 4 can be 80-120 mm, preferably about 100 mm. The size of the sampling spoon 4 is set to meet the sampling needs and ensure smooth reciprocating movement in the inner cavity of the sampling device shell. The rear end of the sampling spoon 4 is connected to the telescopic connecting rod 2-3 (for example, it can be welded). Under the driving of the telescopic connecting rod 2-3, the sampling spoon 4 slides between the front baffle 2-1-1 and the rear baffle 2-1-2 along the bottom connecting piece 2-1-3. When the telescopic connecting rod 2-3 is extended, the sampling spoon 4 is pushed to slide forward until it stops against the front baffle 2-1-1. The telescopic connecting rod 2-3 continues to extend, the sampling spoon 4 pushes the front baffle and then drives the entire telescopic baffle 2-1 to slide forward, and the sampling spoon 4 reaches the sampling tube cavity 1 for sampling (the length of the bottom connecting piece is preferably greater than the sum of the length of the sampling spoon and the diameter of the discharge hole, and the distance from the front end of the sampling device shell to the front baffle is just the length of the sampling spoon). After sampling is completed, the telescopic connecting rod 2-3 is shortened, and the sampling spoon 4 with the sample slides backward until it stops against the rear baffle 2-1-2. The telescopic connecting rod 2-3 continues to shorten, the sampling spoon pushes the rear baffle and then drives the entire telescopic baffle to slide backward into the inner cavity of the sampling device shell 2-2.

[0049] The telescopic connecting rod 2-3 can be single or double. The telescopic connecting rod 2-3 passes through the rear baffle 2-1-2 (when the telescopic connecting rod 2-3 is single, a hole is opened on the rear baffle 2-1-2 for the telescopic connecting rod 2-3 to pass through; when the telescopic connecting rod 2-3 is double, the telescopic connecting rod 2-3 passes through both sides of the rear baffle 2-1-2, and the distance between the two telescopic connecting rods is slightly greater than the width of the rear baffle) and then passes out of the rear end wall plate 2-2-1 of the sampling device shell 2-2 and is connected to the air cylinder.

[0050] The discharge port 11 of the telescopic sampler is opened on the bottom plate of the sampling device shell, preferably near the rear end wall plate 2-2-1 of the sampling device shell. For example, the center of the discharge port is 85-105 mm away from the rear end wall plate, preferably 105 mm. The discharge port is, for example, a circular hole with a diameter of, for example, 70-110 mm, preferably 70 mm, which is preferably consistent with the size of the discharge hole on the bottom connecting piece.

[0051] The distance between the discharge hole on the bottom connecting piece and the front baffle and the distance between the front end opening of the sampling device shell and the discharge port are preferably consistent.

[0052] The pneumatic element is a cylinder 6, the telescopic connecting rod is connected with a buffer piston arranged in the cylinder, the left side of the buffer piston is a left cylinder chamber, the right side is a right cylinder chamber, the left end of the cylinder 6 is provided with a first retraction air port 6-1, the right end is provided with a first extension air port 6-2, the buffer piston moves left and right to push the telescopic connecting rod to extend or retract, the cylinder 6 is selected from a standard accessory, for example, the cylinder 6 can be cylindrical or cuboid, the volume of the cylinder can be 1-2L, preferably 1L, and the telescopic stroke of the cylinder can be 230-300mm, preferably 230mm. The reason for such arrangement is that the traditional sampler has requirements on the material density flowing through the structure of the discharge port (i.e. the sampling tube cavity) where it is located. When the discharge density is low, the sampling amount will be insufficient or the negative pressure pumping force needs to be increased to meet the sampling requirements. However, the powder automatic sampler of the present application can control the stroke of the cylinder to make the telescopic connecting rod drive the sampling spoon to extend into different positions in the sampling tube cavity for sampling, which is not limited by the material density flowing through the sampling tube cavity.

[0053] The gas control valve is an electromagnetic valve 5, the gas source pipe between the cylinder 6 and the electromagnetic valve 5 includes a retraction air pipe 10-1 connected with the first retraction air port 6-1 of the cylinder and an extension air pipe 10-2 connected with the first extension air port 6-2 of the cylinder, the extension air pipe 10-2 is provided with a three-way joint 8, the branch port of the three-way joint 8 is connected with a blow pipe 14 and a blow hole 9, the gas enters the inner cavity of the sampling device shell 2-2 through the three-way joint 8 and the blow pipe 14 to blow the inner cavity of the sampling device shell and the telescopic baffle.

[0054] The gas control valve is an electromagnetic valve 5, preferably, the electromagnetic valve 5 is a two-position five-way electromagnetic valve, for example, the model of the electromagnetic valve can be 4V-310, and the brand can be Yadea. The electromagnetic valve 5 includes a second retraction air port 5-1 connected with the retraction air pipe 10-1, a second extension air port 5-2 connected with the extension air pipe, a total air inlet 5-3 connected with the gas source (the gas source is always connected), a first exhaust port 5-4 and a second exhaust port 5-5 for exhausting the gas in the cylinder, a valve core 5-6 inside the electromagnetic valve for switching the flow direction of the gas, a piston 5-8 arranged on the valve core 5-6, and a coil 5-7 arranged in the electromagnetic valve for controlling the parallel movement of the valve core 5-6 to change the flow channel of the gas in the electromagnetic valve. The electromagnetic valve 5 is a gas path switching switch. In the initial state, the gas source supplies gas to the left cylinder chamber through the total air inlet 5-3 and the second retraction air port 5-1 (the cylinder wall can withstand the gas pressure in the cylinder), the buffer piston is at the rightmost end, and the sampling spoon is in the retracted state. When the sampling spoon is extended, the gas source supplies gas to the right cylinder chamber through the total air inlet 5-3 and the second extension air port 5-2 (the cylinder wall can withstand the gas pressure in the cylinder), the buffer piston is at the leftmost end, and the sampling spoon is in the extended state. Figure 6As shown, when the electromagnetic valve 5 is in the energized state, the electromagnetic valve is in action, the coil 5-7 controls the spool 5-6 to move, the second retraction air port 5-1 and the first exhaust port 5-4 are communicated, the gas in the left cylinder chamber enters the retraction air pipe and is discharged from the communicated second retraction air port 5-1 and the first exhaust port 5-4 (the pressure in the left cylinder chamber is reduced), the total air inlet 5-3 is communicated with the second extension air port 5-2, the gas enters the extension air pipe 10-2, is distributed through the three-way pipe 8, and then part of the gas enters the inner cavity of the sampling device shell through the purge pipe 14 for purging, and the other part of the gas reaches the right cylinder chamber, pushes the buffer piston to move left, the telescopic connecting rod 2-3 is extended, and the sampling spoon 4 is instantaneously pushed out to the sampling pipe cavity 1 for sampling. Figure 7 As shown, when the electromagnetic valve is de-energized, the coil controls the spool to reset, the electromagnetic valve gas circuit is in the initial state, the second extension air port 5-2 is communicated with the second exhaust port 5-5, the gas in the right cylinder chamber enters the extension air pipe and is discharged from the communicated second extension air port 5-2 and the second exhaust port 5-5 (the pressure in the right cylinder chamber is reduced), the total air inlet 5-3 is communicated with the second retraction air port 5-1, the gas enters the retraction air pipe 10-1 and reaches the left cylinder chamber, pushes the buffer piston to move right, the telescopic connecting rod is shortened, the sampling spoon 4 is instantaneously taken back, the powder in the sampling spoon 4 flows to the sample collection box 12 through the discharge port 11, and at the same time, the front baffle completely adheres to the front end opening of the sampling device shell 2-2 to form a seal (ensuring that the vacuum pressure of the discharge port is stable, and preventing foreign matters and air from entering the conveying pipeline through the sampler discharge port), and when the gas is discharged from the extension air pipe, since very little gas is discharged from the cylinder, very little gas enters the inner cavity of the sampling device shell from the three-way pipe, and the retracted sampling spoon is not affected.

[0055] The controller 7 can be any one of a PLC, an intelligent controller, a DCS and the like. The controller 7 is used to time or remotely send instructions to make the electromagnetic valve 5 be energized or de-energized. For example, a first timer module and a second timer module are programmed in the controller 7. The first timer module is used to control the sampling period, for example, sampling is performed once every 15-45 minutes, preferably about 30 minutes. The second timer module is used to control the sampling time, that is, the residence time of the sampling spoon in the sampling pipe cavity. For example, the sampling time is set to 2-10 seconds, preferably about 5 seconds. When the first timer module finishes timing, the controller 7 outputs a signal to make the electromagnetic valve coil be energized, and at the same time, the second timer module starts timing. The sampling spoon is instantaneously pushed out to the sampling pipe cavity for sampling. When the second timer module finishes timing, the controller 7 outputs a signal to make the electromagnetic valve coil be de-energized. The telescopic connecting rod is shortened, and the sampling spoon is instantaneously taken back.

[0056] Embodiment

[0057] A sampling method of the automatic powder sampler, the method comprising:

[0058] (1) Before sampling, the front baffle 2-1-1 of the telescopic baffle seals the front end opening of the sampling device shell 2-2, the discharge hole 2-1-4, the sampling spoon 4, and the opening of the discharge port 11 are in a coincident state, the electromagnetic valve is in an initial state, the first timer module in the controller 7 controls the sampling period, sampling is performed once every 30 minutes, the second timer module in the controller 7 controls the sampling time, the sampling time is set to about 5 seconds, when the first timer module finishes timing, the controller 7 outputs a signal to make the coil 5-7 of the electromagnetic valve electrified after receiving the sampling instruction, at the same time, the second timer module starts timing, the gas in the left cylinder chamber is discharged through the telescopic air pipe 10-1, the gas enters the telescopic air pipe 10-2, a part of the gas enters the inner cavity of the telescopic sampler 2, and the inner cavity of the telescopic sampler 2 and the telescopic baffle 2-1 are swept once, and the other part of the gas enters the right cylinder chamber, and drives the buffer piston to move leftwards, the telescopic connecting rod 2-3 is stretched out, and drives the sampling spoon 4 to slide forward instantaneously to the sampling tube cavity 1, and the powder falls to the sampling spoon 4 (as shown in Figure 2 );

[0059] (2) When the second timer module finishes timing, the sampling is completed, the surrounding powder is blown away by the sweeping gas flow, the controller 7 sends a signal to make the coil 5-7 of the electromagnetic valve de-energized, the gas in the right cylinder chamber is discharged from the telescopic air pipe 10-2, the gas enters the left cylinder chamber through the telescopic air pipe 10-1, drives the buffer piston to move rightwards, the telescopic connecting rod 2-3 with the sampling spoon containing the sample slides back instantaneously into the sampling device shell 2-2 (as shown in Figure 3 ), and returns to the initial state, the front baffle 2-1-1 of the telescopic baffle seals the front end opening of the sampling device shell 2-2, the discharge hole 2-1-4, the sampling spoon 4, and the opening of the discharge port 11 are in a coincident state, the powder in the sampling spoon 4 flows to the sample collection box 12 through the discharge port 11 (as shown in Figure 4 ), and completes one sampling, at the same time, the first timer module and the second timer module are reset, the first timer module starts timing again, and the second timer module waits for timing, when the first timer module finishes timing again, the second sampling is started, and the above steps are repeated.

[0060] Obviously, the above embodiments are only examples for clearly illustrating, but not limitation to the embodiments. Other different forms of changes or variations can be made on the basis of the above description for those of ordinary skill in the art. All the embodiments do not need to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A powder automatic sampler, which is connected to a sampling tube cavity (1) between the discharge port of a screw conveyor and the conveying pipeline, characterized in that, It includes a telescopic sampler (2) in communication with the sampling tube cavity (1), the telescopic sampler (2) includes a sampling device shell (2-2), a telescopic baffle (2-1) arranged in the sampling device shell (2-2), a sampling spoon (4) driving the telescopic baffle (2-1) to slide and sampling into the sampling tube cavity (1), the telescopic baffle (2-1) includes a front baffle (2-1-1) for blocking the front end opening of the telescopic sampling device shell (2-2), a rear baffle (2-1-2), and a bottom connecting piece (2-1-3) connecting the front baffle and the rear baffle, the front baffle (2-1-1) is connected to the front end of the bottom connecting piece (2-1-3), the rear baffle (2-1-2) is connected to the rear end of the bottom connecting piece (2-1-3), the shape of the front baffle (2-1-1) is the same as the size and shape of the front end opening of the sampling device shell (2-2), for blocking the front end opening of the sampling device shell, the sampling spoon (4) is connected with a telescopic connecting rod (2-3), one end of the telescopic connecting rod (2-3) away from the sampling spoon (4) penetrates out of the sampling device shell (2-2) and is connected with a pneumatic element controlling the telescopic connecting rod, the pneumatic element is connected with a gas source through a gas source pipe (10), a gas control valve is arranged on the gas source pipe (10), the gas control valve is connected with a controller (7), the sampling device shell (2-2) is a hollow rectangular structure with a front end opening and a rear end closed, the front end opening is integrally connected with the side wall of the sampling tube cavity (1), and the whole sampling device shell (2-2) is integrally connected with the sampling tube cavity (1).

2. The automatic powder sampler of claim 1, wherein, The sampling tube cavity (1) is a flange type tube cavity, the sampling tube cavity (1) is any one of a cylindrical structure, a square structure and a cone structure, which includes an upper connecting flange (1-1) connected with a discharge port of a screw conveyor, a lower connecting flange (1-2) connected with a conveying pipeline, and an intermediate cylinder (1-3) connected between the upper connecting flange and the lower connecting flange, the material of the sampling tube cavity (1) is any one of stainless steel, carbon steel and transparent glass steel.

3. The automatic powder sampler of claim 1, wherein, The sampling device shell (2-2) is divided into a left side portion and a right side portion, the left side portion and the right side portion are connected through a butt flange (3), the butt flange (3) includes a first flange piece (2-2-2) and a second flange piece (2-2-3), and a gasket is arranged between the first flange piece (2-2-2) and the second flange piece (2-2-3); a rear end wall plate (2-2-1) of the sampling device shell is provided with an opening for the telescopic connecting rod (2-3) to penetrate through; a blowhole (9) is arranged on the sampling device shell (2-2) and connected with a blowing pipe (14), for blowing the inner cavity of the telescopic sampler (2).

4. The automatic powder sampler of claim 1, wherein, A discharging hole (2-1-4) is arranged on the bottom connecting piece, and the discharging hole (2-1-4) is arranged at a position close to the rear baffle (2-1-2) of the bottom connecting piece (2-1-3).

5. The automatic powder sampler of claim 1, wherein, The sampling spoon (4) is a hollow three-dimensional structure which is permeable from top to bottom. The front end of the sampling spoon (4) is set as a cone which protrudes forward. The width of the sampling spoon (4) is consistent with the width of the inner cavity of the sampling device shell (2-2), and the height of the sampling spoon (4) is less than the height of the inner cavity of the sampling device shell. The rear end of the sampling spoon (4) is connected with the telescopic connecting rod (2-3).

6. The automatic powder sampler of claim 5, wherein, The telescopic connecting rod (2-3) is single or double. The telescopic connecting rod (2-3) passes through the rear end wall plate (2-2-1) of the sampling device shell (2-2) after crossing the rear baffle (2-1-2) and is connected with the pneumatic element.

7. The automatic powder sampler of claim 1, wherein, The telescopic sampler (2) is provided with a discharging port (11) which is connected with a sample collection box (12). The discharging port (11) of the telescopic sampler is arranged on the bottom wall of the sampling device shell.

8. The automatic powder sampler of claim 3, wherein, The pneumatic element is a pneumatic cylinder (6). The telescopic connecting rod is connected with a buffer piston arranged in the pneumatic cylinder. The left side of the buffer piston is a left cylinder chamber, and the right side is a right cylinder chamber. The left end of the pneumatic cylinder (6) is provided with a first retraction air port (6-1), and the right end is provided with a first extension air port (6-2).

9. The automatic powder sampler of claim 8, wherein, The gas source pipe (10) includes a retraction air pipe (10-1) connected with the first retraction air port (6-1) of the pneumatic cylinder (6) and an extension air pipe (10-2) connected with the first extension air port (6-2) of the pneumatic cylinder. The extension air pipe (10-2) is provided with a tee joint (8). The branch port of the tee joint (8) is connected with a blowing hole (9) through a blowing pipe (14). The gas enters the inner cavity of the sampling device shell (2-2) through the tee joint (8) and the blowing pipe (14) to blow the inner cavity of the sampling device shell and the telescopic baffle.

10. The automatic powder sampler of claim 1, wherein, The controller (7) is any one of a PLC, an intelligent controller and a DCS. The controller (7) includes a programmed first timer module for controlling the sampling period and a programmed second timer module for controlling the sampling time.

11. The automatic powder sampler of claim 1, wherein, The gas control valve is an electromagnetic valve. The controller is connected with the electromagnetic valve through wires or wireless. The electromagnetic valve is powered on or powered off by the controller timing or remote instruction.

Images