An on-line detection platform and detection method for pulverized coal quality in a wind-powder pipe for optical detection

Abstract

An on-line coal quality detection platform and detection method for a pulverized coal pipe used in optical detection, belonging to the technical field of automatic detection equipment for coal-fired power plants. The present invention solves the problems of incomplete functions of the existing coal quality optical on-line detection platform and great influence on the measurement accuracy. The lower part of the sampling pipe is inserted into the upper part of the upper air seat and communicated with the pneumatic butterfly valve through the upper air seat. A pair of opposed light detectors are fixedly installed on both sides of the lower base, and the outlet ends of two third air inlet holes are arranged opposite to each other. The temperature measuring device is fixedly inserted on a side wall of the base for detecting and adjusting the temperature in the cavity to be detected, and the temperature measuring device is threadedly connected to the base. The pneumatic butterfly valve serves as an isolation switch device between the powder extraction cavity and the cavity to be detected, and can timely connect and isolate the powder extraction cavity and the cavity to be detected. During external detection, by closing the pneumatic butterfly valve, it is convenient for the sample in the cavity to be detected to be in a relatively isolated state, which is beneficial to improving the detection accuracy.

Description

Technical Field

[0001] The present invention relates to an on-line detection platform and detection method for pulverized coal quality in a wind-powder pipe for optical detection, belonging to the technical field of automatic detection equipment for coal-fired power plants. Background Art

[0002] The quality of the pulverized coal entering the furnace of a power plant is related to the safety of the power plant operation. In the prior art, the method for detecting the coal quality is generally through optical detection technology. However, most of the existing on-line sampling devices for the wind-powder pipe applicable to the optical detection technology have the following problems:

[0003] First, the powder sampling speed is slow and the timeliness is poor;

[0004] Second, it is impossible to directly judge whether the sampling and sample discharging are successful, and the compliance of the sample with the main pipeline is poor (that is, the consistency between the measured sample and the pulverized coal flowing in the main pipeline within a time range close to this moment is poor. In the best case, at the same moment, the measured sample and the sample in the pipeline are materials of the same batch).

[0005] Third, during the sampling process, the sample is severely adsorbed and adhered to the wall, affecting the sample renewal, and the compliance of the sample with the main pipeline is poor;

[0006] Fourth, there is no static isolation between the sample to be measured and the main pipeline, and it will be disturbed by external factors such as air flow, affecting the operation of the external detector;

[0007] Fifth, there is no physical isolation between the sampling cavity and the main pipeline. During the maintenance and replacement of key devices such as the optical lens at the bottom, it is easy to cause air-powder leakage in the main pipeline and contaminate the equipment;

[0008] Sixth, when the sampling device is working, it is impossible to view the internal situation of the cavity in real time, and the sampling device is in a black box state.

[0009] Therefore, there is an urgent need for an on-line detection platform and detection method for pulverized coal quality in a wind-powder pipe applicable to optical detection to solve the above problems existing in the existing on-line sampling device. Summary of the Invention

[0010] The present invention is to solve the above technical problems, and further provides an on-line detection platform and detection method for pulverized coal quality in a wind-powder pipe for optical detection.

[0011] The technical solution adopted by the present invention to solve the above technical problems is:

[0012] An on-line detection platform for pulverized coal quality in a wind-powder pipe for optical detection includes a sampling pipe, an upper air seat, an upper base, a pneumatic butterfly valve, a base, a lower base, an optical lens, a temperature measuring device, and a pair of opposed light detectors, wherein the upper base, the pneumatic butterfly valve, the base, and the lower base are connected in sequence from top to bottom.

[0013] The upper air seat is installed inside the upper base and a uniform air cavity is formed between the upper air seat and the upper base. A number of uniform air holes are provided along the circumference of the lower part of the upper air seat. A first air inlet hole is provided on the upper base, and the first air inlet hole is communicated with the number of uniform air holes through the uniform air cavity.

[0014] The lower part of the sampling tube is inserted into the upper part of the upper air seat and is communicated with the pneumatic butterfly valve through the upper air seat.

[0015] A detection through hole is vertically provided inside the lower base. The optical lens is located directly below the detection through hole and is fixedly sealed with the lower base. The top end of the detection through hole is communicated with the pneumatic butterfly valve through the base. The inside of the base and the detection through hole of the lower base form a cavity to be detected.

[0016] Two second air inlet holes are oppositely provided on the lower base. A group of opposed light detectors are fixedly installed on both sides of the lower base and correspondingly detect the inside of the detection through hole above the optical lens through the two second air inlet holes.

[0017] Two third air inlet holes are further provided on the lower base, and the air outlet ends of the two third air inlet holes are oppositely arranged.

[0018] The temperature measuring device is fixedly inserted on a side wall of the base for detecting and adjusting the temperature inside the cavity to be detected. The temperature measuring device is threadedly connected with the base.

[0019] Further, two symmetrically arranged semi-flange structures are processed on the upper part of the upper air seat. The two semi-flange structures are inserted into the upper base and are arranged to hold the sampling tube tightly.

[0020] Further, the top end of the sampling tube is obliquely arranged. An upper liner is coaxially inserted inside the sampling tube, and both ends of the inner wall of the upper liner are in a horn-shaped structure.

[0021] Further, a base inner liner is installed inside the base with an interference fit. The base inner liner is in a cylindrical structure and an outer edge is processed at its bottom end. The base inner liner is fixedly installed on the lower base through the outer edge, and a detection hole is provided on the side wall of the base inner liner.

[0022] Further, an observation window is installed on a side surface of the base adjacent to the temperature measuring device.

[0023] Further, a fourth air inlet hole is provided on the base, and the fourth air inlet hole is oppositely arranged with the temperature measuring device.

[0024] Further, the number of the first air inlet holes is two. The air outlet ends of the two first air inlet holes are oppositely arranged. The two first air inlet holes are parallel to each other and are arranged in a staggered manner.

[0025] Further, the two third air inlet holes are parallel to each other and are arranged in a staggered manner.

[0026] Further, a set of opposed light detectors are fixedly mounted on the lower base through two auxiliary seats, and each auxiliary seat is provided with an L-shaped through hole. The two second air inlets communicate with an external air source through the two L-shaped through holes respectively.

[0027] A detection method for the above-mentioned online coal quality detection platform of a pulverized coal pipe for optical detection includes the following steps:

[0028] Step 1: Perform ash cleaning operation in the cavity:

[0029] In the initial state, the pneumatic butterfly valve is closed. Compressed air enters the air distribution cavity through the first air inlet on the upper base, and then is discharged through the annularly arranged air distribution holes on the upper air seat. The accumulated pulverized coal above the pneumatic butterfly valve is preliminarily purged by gas injection. Set the purging time. After the purging is over, open the pneumatic butterfly valve, and then introduce compressed air into the first air inlet. Part of the air flow purges the upper surface of the optical lens and the entire cavity to be detected through the third air inlet on the lower base. Set the purging time. After the purging is over, introduce compressed air into the L-shaped through hole on the auxiliary seat and the second air inlet on the lower base to purge the upper surface of the optical lens and the entire cavity to be detected until the opposed light detector feeds back a non-blocking signal.

[0030] Step 2: Powder sampling operation:

[0031] The pulverized coal pipe and the air pipe work simultaneously. The pulverized coal flow impacts the inclined mouth at the top of the sampling pipe, and part of the solid pulverized coal falls into the sampling pipe under the action of gravity. At this time, open the pneumatic butterfly valve, and the pulverized coal then falls onto the upper surface of the optical lens. After the opposed light detector detects an opaque object, it sends a signal indicating that the pulverized coal has been obtained. Close the pneumatic butterfly valve to isolate the obtained pulverized coal from the pulverized coal pipe and the air pipe. The objective lens of the optical analysis instrument is placed on the outer lower surface of the optical lens, and starts to irradiate and scan the pulverized coal through the optical lens to obtain the required optical signal. During this process, the temperature situation in the cavity to be detected is detected by the temperature measuring device and temperature compensation is performed for the optical analysis.

[0032] Step 3: Powder discharging operation:

[0033] After the detection is completed, compressed air enters the annular air distribution cavity through the first air inlet and is discharged through a number of annularly arranged air distribution holes. The accumulated pulverized coal above the pneumatic butterfly valve is preliminarily purged by gas injection. Set the purging time. After the purging is over, open the pneumatic butterfly valve, and then turn on the compressed air. Part of the air flow purges the upper surface of the optical lens and the entire cavity to be detected through the third air inlet on the lower base, and the other part purges the inner surface of the observation window and the entire cavity to be detected through the fourth air inlet on the base. Set the purging time. After the purging is over, turn on the compressed air. The air flow purges the upper surface of the optical lens and the entire cavity to be detected through the L-shaped through hole and the second air inlet until the opposed light detector feeds back a non-opaque object signal. Then close the pneumatic butterfly valve.

[0034] The present invention has the following effects compared with the prior art:

[0035] By providing an opposed light detector, the detection platform has the function of detecting whether the pulverized coal is taken and discharged in place, which is beneficial to ensuring the authenticity of the sample.

[0036] Before detection, by providing an opposed light detector, it can be detected whether a sample of the required thickness has accumulated in the cavity to be detected; after detection, by providing an opposed light detector, it can be verified whether the detected sample in the cavity to be detected has been completely cleaned.

[0037] The pneumatic butterfly valve, as a disconnection device between the powder sampling cavity and the cavity to be detected, can timely connect and isolate the powder sampling cavity and the cavity to be detected. During external detection, by closing the pneumatic butterfly valve, it is convenient for the sample in the cavity to be detected to be in a relatively isolated state, which is beneficial to improving the detection accuracy.

[0038] In addition, when the pneumatic butterfly valve is in the closed state, it can achieve complete isolation between the cavity to be detected and the main pipeline, so as to facilitate the maintenance and replacement of key components such as optical lenses inside the cavity to be detected.

[0039] Through the on-line detection platform of the present invention, rapid sampling can be achieved. At the same time, through the setting of the pneumatic butterfly valve, rapid sample discharge can be achieved, and the accuracy of the sample can be ensured. The sample detection environment is isolated and anti-interference. Each component structure in the entire on-line detection platform is respectively connected by bolts, which is convenient for disassembly, installation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a first three-dimensional structure schematic diagram of the on-line detection platform of the present invention;

[0041] Figure 2 It is a second three-dimensional structure schematic diagram of the on-line detection platform of the present invention;

[0042] Figure 3 It is a third three-dimensional structure schematic diagram of the on-line detection platform of the present invention;

[0043] Figure 4 It is a fourth three-dimensional structure schematic diagram of the on-line detection platform of the present invention;

[0044] Figure 5 It is a main sectional view schematic diagram of the on-line detection platform of the present invention;

[0045] Figure 6 It is a three-dimensional structure schematic diagram of the sampling pipe;

[0046] Figure 7 It is a first three-dimensional structure schematic diagram of the upper lining pipe;

[0047] Figure 8 It is a second three-dimensional structure schematic diagram of the upper lining pipe;

[0048] Figure 9 The fifth three-dimensional structural schematic diagram of the on-line detection platform of the present invention (the sampling tube, the upper lining tube and the upper base are not shown);

[0049] Figure 10 The three-dimensional structural schematic diagram of the pneumatic butterfly valve;

[0050] Figure 11 The perspective schematic diagram of the upper base;

[0051] Figure 12 The three-dimensional structural schematic diagram of the base;

[0052] Figure 13 The first three-dimensional structural schematic diagram of the inner lining of the base;

[0053] Figure 14 The second three-dimensional structural schematic diagram of the inner lining of the base;

[0054] Figure 15 The perspective schematic diagram of the lower base;

[0055] Figure 16 The three-dimensional structural schematic diagram of the upper air seat.

[0056] In the figure:

[0057] 1. Sampling tube; 2. Upper air seat; 2-1. Air distribution hole; 3. Upper base; 3-1. First air inlet hole; 4. Pneumatic butterfly valve; 5. Base; 5-1. Fourth air inlet hole; 6. Lower base; 6-1. Detection through hole; 6-2. Second air inlet hole; 6-3. Third air inlet hole; 7. Optical lens; 8. Temperature measuring device; 9. Opposite light detector; 10. Upper lining tube; 11. Inner lining of the base; 11-1. Detection hole; 12. Observation window; 13. Auxiliary seat; 13-1. L-shaped through hole; 14. Air distribution cavity. Specific embodiments

[0058] Specific embodiment 1: In combination with Figures 1 to 16 Describe this embodiment, and make a further detailed description of the present invention. It can be understood that the specific embodiments described here are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0059] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0061] In the description of this embodiment, the orientation or positional relationship such as "up", "down", "left", and "right" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0062] An on-line coal quality detection platform for optical detection of a pulverized coal pipeline, comprising a sampling pipe 1, an upper air seat 2, an upper base 3, a pneumatic butterfly valve 4, a base 5, a lower base 6, an optical lens 7, a temperature measuring device 8, and a pair of opposed light detectors 9. Among them, the upper base 3, the pneumatic butterfly valve 4, the base 5, and the lower base 6 are connected in sequence from top to bottom.

[0063] The upper air seat 2 is inserted into the upper base 3 and a uniform air cavity 14 is formed between the upper air seat 2 and the upper base 3. A plurality of uniform air holes 2-1 are formed in the lower part of the upper air seat 2 along its circumferential direction. A first air inlet hole 3-1 is formed in the upper base 3, and the first air inlet hole 3-1 is communicated with the plurality of uniform air holes 2-1 through the uniform air cavity 14.

[0064] The lower part of the sampling pipe 1 is inserted into the upper part of the upper air seat 2 and is communicated with the pneumatic butterfly valve 4 through the upper air seat 2.

[0065] A detection through-hole 6-1 is vertically formed in the lower base 6. The optical lens 7 is located directly below the detection through-hole 6-1 and is fixedly and sealingly connected to the lower base 6. The top end of the detection through-hole 6-1 communicates with the pneumatic butterfly valve 4 through the base 5. The interior of the base 5 and the detection through-hole 6-1 of the lower base 6 form a cavity to be inspected.

[0066] Two second air inlet holes 6-2 are oppositely formed on the lower base 6. A set of opposed light detectors 9 are fixedly installed on both sides of the lower base 6, and correspondingly detect the interior of the detection through-hole 6-1 above the optical lens 7 through the two second air inlet holes 6-2.

[0067] Two third air inlet holes 6-3 are further formed on the lower base 6, and the air outlet ends of the two third air inlet holes 6-3 are oppositely arranged.

[0068] The temperature measuring device 8 is fixedly inserted into a side wall of the base 5 for detecting and adjusting the temperature in the cavity to be inspected. The temperature measuring device 8 is threadedly connected to the base 5.

[0069] The base 5, the pneumatic butterfly valve 4 and the upper base 3 are sequentially fixedly connected by a plurality of bolts from bottom to top. The number of bolts can be four and they are evenly distributed along the circumference of the upper base 3. In order to facilitate the installation of the bolts, ear plates can be fixedly arranged on the outer side of the pneumatic butterfly valve 4. Figures 1 to 4 Only one set of bolts is shown in the figure.

[0070] During the use process, the sampling tube 1 is inserted into the protective sleeve below the pulverized coal and air pipeline, and is flange-connected to the protective sleeve through the tops of the plurality of bolts. At this time, the sampling tube 1 has extended into the pulverized coal and air pipeline and protrudes from the lower inner wall. The top end of the sampling tube 1 is of an inclined structure, and it is ensured that the inclined opening at the top of the sampling tube 1 is in the windward direction.

[0071] The lower base 6 is fixedly installed below the base 5. The interior of the base 5 and the detection through-hole 6-1 of the lower base 6 form a cavity to be inspected.

[0072] By providing two third air inlet holes 6-3, purging of the upper surface of the optical lens 7 and the interior of the cavity to be inspected is realized.

[0073] A set of opposed light detectors 9 are coaxially arranged. By providing the opposed light detectors 9, the detection platform has the function of detecting whether the pulverized coal is taken and discharged in place, which is beneficial to ensuring the authenticity of the sample.

[0074] Before detection, by providing the opposed light detectors 9, it can be detected whether a sample of the required thickness has accumulated in the cavity to be inspected; after detection, by providing the opposed light detectors 9, it is verified whether the inspected sample in the cavity to be inspected has been thoroughly cleaned.

[0075] By setting the second air inlet hole 6-2, it is not only possible to detect whether there are any obstacles on the optical lens 7 and inside the cavity to be detected through the opposed light detector 9, but also possible to blow the upper surface of the optical lens 7 and the inside of the cavity to be detected by introducing air flow into the second air inlet hole 6-2.

[0076] Specifically, by introducing air flow into the second air inlet hole 6-2 to blow the upper surface of the optical lens 7 and the inside of the cavity to be detected, and then detecting whether there are any obstacles on the optical lens 7 and inside the cavity to be detected through a set of opposed light detectors 9 and two corresponding second air inlet holes 6-2 are provided, the opposed light detector 9 provides real-time feedback on the signal of the presence / absence of obstacles.

[0077] When the pneumatic butterfly valve 4 is in the open state, the sampling pipe 1, the upper air seat 2, the pneumatic butterfly valve 4 and the base 5 are arranged vertically and communicatively. When the pneumatic butterfly valve 4 is in the closed state, the sampling pipe 1 and the upper air seat 2 form a powder sampling cavity.

[0078] The pneumatic butterfly valve 4, the base and the upper base are all fixedly connected by bolts.

[0079] The upper air seat 2 penetrates into the upper base 3 from bottom to top, and its bottom is fixedly connected to the upper base 3 by a fastening bolt.

[0080] The lower base 6 and the base 5 are fixedly connected by bolts.

[0081] The optical lens 7 is fixed to the bottom of the lower base 6 through a gland, a sealing ring and screws.

[0082] The inner wall of the detection through hole 6-1 has a horn-shaped structure to form a diversion groove, which is convenient for ash cleaning operation inside the cavity.

[0083] The pneumatic butterfly valve 4 serves as an isolation switch device between the powder sampling cavity and the cavity to be detected, and can timely connect and isolate the powder sampling cavity and the cavity to be detected. During external detection, by closing the pneumatic butterfly valve 4, it is convenient for the sample inside the cavity to be detected to be in a relatively isolated state, which is beneficial to improving the detection accuracy.

[0084] In addition, when the pneumatic butterfly valve 4 is in the closed state, it is possible to completely isolate the cavity to be detected from the main pipeline, so as to facilitate the maintenance and replacement of key components such as the optical lens 7 inside the cavity to be detected.

[0085] Through the online detection platform of the present invention, rapid sampling can be achieved. At the same time, through the setting of the pneumatic butterfly valve 4, rapid sample discharge can be achieved, and the accuracy of the sample can be guaranteed, so that the sample detection environment is isolated and anti-interference. Each component structure in the entire online detection platform is respectively connected by bolts, which is convenient for disassembly, installation and maintenance.

[0086] The online detection platform described in the present invention has no electrical components above 24 volts, and has better safety.

[0087] The upper part of the upper gas seat 2 is processed with two symmetrically arranged semi-flange structures. The two semi-flange structures are inserted into the upper base 3 and are arranged to hold the sampling tube 1 tightly. With such a design, it is convenient to fix the lower part of the sampling tube 1. The two symmetrically arranged semi-flange structures act as elastic pieces. The lower part of the sampling tube 1 is inserted between the two semi-flange structures, and the requirement for the matching dimension between the sampling tube 1 and the upper base 3 is smaller. Fixing bolts are respectively inserted through both sides of the upper base 3 and are pressed against the two semi-flange structures on the upper gas seat 2 to ensure the tight holding between the semi-flange structure and the sampling tube 1. To ensure the fixing effect, the number of fixing bolts can be four arranged in pairs symmetrically.

[0088] The top end of the sampling tube 1 is obliquely arranged. An upper liner 10 is coaxially inserted inside the sampling tube 1. The inner wall ends of the upper liner 10 are in a flared structure. With such a design, the obliquely arranged top end of the sampling tube 1 forms an inclined opening, forming an extended collection structure that can actively obtain samples, which is beneficial to quickly obtain samples. The inner wall ends of the upper liner 10 are in a flared structure, and its inner wall forms a low surface energy structure (that is, the inner wall of the upper liner 10 is provided with a surface coating, such as a Teflon coating or other non-stick material coatings), making it difficult for samples to adsorb. At the same time, the lower part of the inner wall of the upper liner 10 is arranged in a flared structure, and the air equalizing holes 2-1, as near-wall air holes, discharge airflows to blow and clean the lower inner wall of the upper liner 10 key points.

[0089] A base inner liner 11 is installed in the base 5 with an interference fit. The base inner liner 11 is in a cylindrical structure and its bottom end is processed with an outer edge. The base inner liner 11 is fixedly installed on the lower base 6 through the outer edge. Detection holes 11-1 are opened on the side wall of the base inner liner 11. With such a design, the base inner liner 11 and the outer edge are coaxially arranged. The inner cavity of the base inner liner 11 is part of the cavity to be inspected. The temperature measuring device 8 and the fourth air inlet are both arranged corresponding to the detection holes 11-1, which is convenient for measuring and controlling the temperature inside the cavity to be inspected, and at the same time is convenient for external airflows to enter the cavity to be inspected through the fourth air inlet.

[0090] An observation window 12 is installed on one side surface of the base 5 adjacent to the temperature measuring device 8. With such a design, it is convenient to observe the inside of the cavity to be inspected, which is convenient for problem analysis. At the same time, the observation window 12 is a detachable structure, which is convenient for device maintenance. The observation window 12 is preferably installed close to the temperature measuring device 8. The observation window 12 is fixed on one side surface of the base 5 through a gland, a sealing ring and screws.

[0091] A fourth air inlet hole 5-1 is opened on the base 5, and the fourth air inlet hole 5-1 is arranged opposite to the temperature measuring device 8. With such a design, an external air source is connected through the fourth air inlet hole 5-1 to blow the inner surface of the observation window 12 and the entire cavity to be inspected.

[0092] The number of the first air inlets 3-1 is two. The air outlet ends of the two first air inlets 3-1 are arranged oppositely. The two first air inlets 3-1 are parallel to each other and arranged in a staggered manner. With such a design, the air flows discharged from the two first air inlets 3-1 form an upward swirling flow, thereby making the purging effect better.

[0093] The two third air inlets 6-3 are parallel to each other and arranged in a staggered manner. With such a design, the air flows discharged from the two third air inlets 6-3 form an upward swirling flow, and the cleaning of the cavity to be detected is more thorough.

[0094] A group of opposed light detectors 9 are fixedly installed on the lower base 6 through two auxiliary seats 13 respectively. An L-shaped through hole 13-1 is formed in each auxiliary seat 13. The two second air inlets 6-2 communicate with an external air source through the two L-shaped through holes 13-1 respectively. With such a design, it is convenient to introduce air flow into the second air inlets 6-2. The auxiliary seat 13 is fixedly connected with the lower base 6 by bolts. The opposed light detector 9 is installed on the auxiliary seat 13 by means of threads.

[0095] A detection method for the above on-line detection platform of pulverized coal quality in a wind-powder pipe for optical detection comprises the following steps:

[0096] Step 1, perform ash cleaning operation in the cavity:

[0097] In the initial state, the pneumatic butterfly valve 4 is closed. Compressed air enters the air distribution cavity 14 through the first air inlets 3-1 on the upper base 3, and then is discharged through the annularly arranged air distribution holes 2-1 on the upper air seat 2, so as to perform preliminary purging and cleaning on the accumulated pulverized coal above the pneumatic butterfly valve 4 by using gas injection. Set the purging time. After the purging is completed, open the pneumatic butterfly valve 4, and then introduce compressed air into the first air inlets 3-1. A part of the air flow purges the upper surface of the optical lens 7 and the whole cavity to be detected through the third air inlets 6-3 on the lower base 6. Set the purging time. After the purging is completed, introduce air into the L-shaped through holes 13-1 on the auxiliary seats 13 and the second air inlets 6-2 on the lower base 6 to purge the upper surface of the optical lens 7 and the whole cavity to be detected until the opposed light detector 9 feeds back a non-blocking signal.

[0098] With such a design, most of the samples are blown away after being purged through the first air inlets for the first time, but some samples will be blown into the second air inlets. Moreover, the channels corresponding to the second air inlets and the passages above the corresponding lenses are key parts and most need to be kept clean. Therefore, after the first purge through the first air inlets, a second purge is performed through the second air inlets to ensure the cleanliness of the upper surface of the optical lens and the whole cavity to be detected.

[0099] Step 2, perform powder sampling operation:

[0100] When the air-coal powder pipes work simultaneously, the coal powder flow impacts the inclined mouth at the top end of the sampling pipe 1. Part of the solid coal powder falls into the sampling pipe 1 under the action of gravity. At this time, the pneumatic butterfly valve 4 is opened, and the coal powder then falls onto the upper surface of the optical lens 7. After the opposed light detector 9 detects the light-blocking object, it sends the signal that the coal powder has been obtained. The pneumatic butterfly valve 4 is closed to isolate the obtained coal powder from the air-coal powder pipes. The objective lens of the optical analysis instrument is placed on the outer lower surface of the optical lens 7, and it starts to irradiate and scan the coal powder through the optical lens 7 to obtain the required optical signal. During this process, the temperature situation in the cavity to be detected is detected by the temperature measuring device 8 and temperature compensation is carried out for the optical analysis.

[0101] Step 3: Powder discharging operation:

[0102] After the detection is completed, compressed air enters the annular air distribution cavity 14 through the first air inlet hole 3-1, and is discharged through a number of annularly arranged air distribution holes 2-1. The accumulated coal powder above the pneumatic butterfly valve 4 is preliminarily purged by gas jetting. Set the purging time. When the purging is over, the pneumatic butterfly valve 4 is opened, and then compressed air is turned on. Part of the air flow purges the upper surface of the optical lens 7 and the entire cavity to be detected through the third air inlet hole 6-3 on the lower base 6, and the other part purges the inner surface of the observation window 12 and the entire cavity to be detected through the fourth air inlet hole 5-1 on the base 5. Set the purging time. When the purging is over, compressed air is turned on, and the air flow purges the upper surface of the optical lens 7 and the entire cavity to be detected through the L-shaped through hole 13-1 and the second air inlet hole 6-2 until the opposed light detector 9 feeds back a signal without an obstruction. Then the pneumatic butterfly valve 4 is closed. The opening and closing of the pneumatic butterfly valve 4 are fed back by a positioner matched with the valve.

[0103] Specific embodiment 2: Combining Figures 1 to 16 To illustrate this embodiment, the compressed air at the first air inlet hole above the pneumatic butterfly valve is turned on. The air flow is purged through the air distribution holes for 3 to 5 seconds and then closed. At the same time, the pneumatic butterfly valve is opened, the third air inlet hole and the fourth air inlet hole are opened, and purging is carried out for 3 to 5 seconds and then closed. The L-shaped through hole, the second air inlet hole and the opposed light detector are opened. When the opposed light detector feeds back that the purging is clean, the purging stops. Then a new sampling starts. When the detection feedback indicates that the powder sampling is completed, the pneumatic butterfly valve is closed. The optical detection probe outside the optical lens starts to detect until the detection is completed. Thus, a sampling and detection cycle is completed.

[0104] Other compositions and connection relationships are the same as those in Specific embodiment 1.

Claims

1. An on-line detection platform for pulverized coal quality in a wind-powder pipe for optical detection, characterized in that: It includes a sampling tube (1), an upper air seat (2), an upper base (3), a pneumatic butterfly valve (4), a base (5), a lower base (6), an optical lens (7), a temperature measuring device (8) and a set of opposed light detectors (9). Among them, the upper base (3), the pneumatic butterfly valve (4), the base (5) and the lower base (6) are connected in sequence from top to bottom. The upper air seat (2) is inserted into the upper base (3) and a uniform air cavity (14) is formed between the upper air seat (2) and the upper base (3). A number of uniform air holes (2-1) are formed along the circumference of the lower part of the upper air seat (2). A first air inlet hole (3-1) is formed on the upper base (3). The first air inlet hole (3-1) is communicated with the number of uniform air holes (2-1) through the uniform air cavity (14). The lower part of the sampling tube (1) is inserted into the upper part of the upper air seat (2) and is communicated with the pneumatic butterfly valve (4) through the upper air seat (2). A detection through hole (6-1) is vertically formed in the lower base (6). The optical lens (7) is located directly below the detection through hole (6-1) and is fixedly connected to the lower base (6) in a sealed manner. The top end of the detection through hole (6-1) is communicated with the pneumatic butterfly valve (4) through the base (5). An inspection cavity is formed between the interior of the base (5) and the detection through hole (6-1) of the lower base (6). Two second air inlet holes (6-2) are oppositely formed on the lower base (6). A set of opposed light detectors (9) are fixedly installed on both sides of the lower base (6) relatively, and the interior of the detection through hole (6-1) above the optical lens (7) is detected correspondingly through the two second air inlet holes (6-2). Two third air inlet holes (6-3) are also formed on the lower base (6), and the air outlet ends of the two third air inlet holes (6-3) are arranged relatively. The temperature measuring device (8) is fixedly inserted on a side wall of the base (5) and is used for detecting and adjusting the temperature in the inspection cavity. The temperature measuring device (8) is threadedly connected with the base (5).

2. The online detection platform for pulverized coal quality in a wind-powder pipe used for optical detection according to claim 1, wherein: Two symmetrically arranged semi-flange structures are processed on the upper part of the upper air seat (2). The two semi-flange structures are inserted into the upper base (3) and are arranged to hold the sampling tube (1) tightly.

3. The on-line detection platform for pulverized coal quality in a wind-powder pipe for optical detection according to claim 2, characterized in that: The top end of the sampling tube (1) is obliquely arranged. An upper liner (10) is coaxially inserted into the sampling tube (1). The inner wall ends of the upper liner (10) are in a horn-shaped structure.

4. An on-line coal quality detection platform for a wind and powder pipe used for optical detection according to claim 2 or 3, characterized in that: A base inner liner (11) is installed in the base (5) with an interference fit. The base inner liner (11) is in a cylindrical structure and its bottom end is processed with an outer edge. The base inner liner (11) is fixedly installed on the lower base (6) through the outer edge. A detection hole (11-1) is formed on the side wall of the base inner liner (11).

5. An on-line coal quality detection platform for a wind and powder pipe used for optical detection according to claim 4, characterized in that: An observation window (12) is installed on a side surface of the base (5) adjacent to the temperature measuring device (8).

6. An on-line detection platform for pulverized coal quality in a wind-powder pipe used for optical detection according to claim 2, 3 or 5, characterized in that: A fourth air inlet hole (5-1) is formed on the base (5), and the fourth air inlet hole (5-1) is arranged relatively to the temperature measuring device (8).

7. An on-line detection platform for pulverized coal quality in a wind-powder pipe for optical detection according to claim 6, characterized in that: The number of the first air inlet holes (3-1) is two. The air outlet ends of the two first air inlet holes (3-1) are arranged relatively. The two first air inlet holes (3-1) are parallel to each other and are arranged in a staggered manner.

8. An on-line coal quality detection platform for a wind and powder pipe used for optical detection according to claim 2, 3 or 5, characterized in that: The two third air inlet holes (6-3) are parallel to each other and are arranged in a staggered manner.

9. An on-line coal quality detection platform for a wind and powder pipe used in optical detection according to claim 6, characterized in that: A set of opposed light detectors (9) are fixedly mounted on the lower base (6) through two auxiliary bases (13), and an L-shaped through hole (13-1) is provided on each auxiliary base (13). The two second air inlet holes (6-2) are communicated with an external air source through the two L-shaped through holes (13-1).

10. A detection method for the online detection platform of pulverized coal quality in a wind-powder pipe for optical detection according to any one of the above claims 1 to 9, characterized in that: The method includes the following steps: Step 1: Perform ash cleaning operation in the cavity: In the initial state, the pneumatic butterfly valve (4) is closed. Compressed air enters the air distribution cavity (14) through the first air inlet hole (3-1) on the upper base (3), and then is discharged through the annularly arranged air distribution holes (2-1) on the upper air seat (2), and the accumulated pulverized coal above the pneumatic butterfly valve (4) is preliminarily purged and cleaned by gas injection; set the purging time. After the purging is completed, open the pneumatic butterfly valve (4), and then introduce compressed air into the first air inlet hole (3-1). A part of the air flow purges the upper surface of the optical lens (7) and the entire cavity to be inspected through the third air inlet hole (6-3) on the lower base (6). Set the purging time. After the purging is completed, introduce compressed air into the L-shaped through hole (13-1) on the auxiliary base (13) and the second air inlet hole (6-2) on the lower base (6) to purge the upper surface of the optical lens (7) and the entire cavity to be inspected until the opposed light detector (9) feeds back a non-blocking signal. Step 2: Powder sampling operation: The air powder pipe works simultaneously. The pulverized coal flow impacts the inclined mouth at the top of the sampling pipe (1), and part of the solid pulverized coal falls into the sampling pipe (1) under the action of gravity. At this time, open the pneumatic butterfly valve (4), and the pulverized coal then falls onto the upper surface of the optical lens (7); after the opposed light detector (9) detects an opaque object, it sends a signal indicating that the pulverized coal has been obtained; close the pneumatic butterfly valve (4) to isolate the obtained pulverized coal from the air powder pipe. The objective lens of the optical analysis instrument is placed on the outer lower surface of the optical lens (7), and starts to irradiate and scan the pulverized coal through the optical lens (7) to obtain the required optical signal; during this process, the temperature situation in the cavity to be inspected is detected by the temperature measuring device (8) and temperature compensation is performed on the optical analysis. Step 3: Powder discharging operation: After the detection is completed, compressed air enters the annular air distribution cavity (14) through the first air inlet hole (3-1) and is discharged through the annularly arranged plurality of air distribution holes (2-1), and the accumulated pulverized coal above the pneumatic butterfly valve (4) is preliminarily purged and cleaned by gas injection; Set the purging time. After the purging is completed, open the pneumatic butterfly valve (4), and then turn on the compressed air. A part of the air flow purges the upper surface of the optical lens (7) and the entire cavity to be inspected through the third air inlet hole (6-3) on the lower base (6), and the other part purges the inner surface of the observation window (12) and the entire cavity to be inspected through the fourth air inlet hole (5-1) on the base (5); set the purging time. After the purging is completed, turn on the compressed air, and the air flow passes through the L-shaped through hole (13-1) and the second air inlet hole (6-2) to purge the upper surface of the optical lens (7) and the entire cavity to be inspected until the opposed light detector (9) feeds back a non-opaque object signal; then close the pneumatic butterfly valve (4).

Images