Biomass powder online moisture detection device

Abstract

This utility model discloses an online moisture detection device for biomass powder, installed on the lower outer wall of the horizontal section of the air-powder pipe in a biomass powder production system. It includes a mounting base, the upper end of which is fixed to the outer wall of the air-powder pipe; a waist-shaped hole connected to the inner cavity of the air-powder pipe on the mounting base; an outer shell, detachably connected to the bottom surface of the mounting base; the inner cavity of the outer shell communicating with the waist-shaped hole; and an electrode plate fixed inside the outer shell. The electrode plate is electrically connected to a DC or AC power supply of a control cabinet via leads. This utility model indirectly calculates the moisture content of the biomass powder by measuring the resistance and capacitance values ​​between the electrode plate and the biomass powder, achieving online detection. Furthermore, it employs both resistance and capacitance detection modes for mutual verification, eliminating detection errors and ensuring the accuracy of the results.

Description

Technical Field

[0001] This utility model relates to the field of biomass co-firing technology in coal-fired boilers, and more specifically to an online moisture detection device for biomass powder. Background Technology

[0002] Biomass co-firing is an effective measure to reduce carbon emissions from coal-fired boilers. For coal-fired boilers, 1 ton of standard coal has a calorific value of 7000 kcal, corresponding to CO2 emissions of 2.6 tons. If 1 ton of biomass with a calorific value of 3500 kcal is co-firing, it is equivalent to saving 0.5 tons of standard coal and reducing CO2 emissions by 1.3 tons. In the process of co-firing biomass, accurate measurement of the biomass mass is essential.

[0003] In biomass milling systems with drying functions, two calculation methods—heat balance calculation and curve interpolation—can continuously and reliably measure the amount of biomass blended in. The moisture content of the biomass powder is an indispensable parameter in both methods. To ensure the accuracy of the calculation results, the moisture content of the biomass powder needs to be obtained precisely and in real-time during the metering process.

[0004] Therefore, how to provide a device that can detect the moisture content of biomass powder online in real time is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the present invention provides an online moisture detection device for biomass powder. The biomass powder in the air-powder pipe enters the outer shell, and the moisture content of the biomass powder is indirectly calculated by measuring the capacitance or resistance value between the electrode plate and the biomass powder. Furthermore, the results can be mutually verified through both capacitive and resistive detection modes, thereby eliminating detection errors.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An online moisture detection device for biomass flour is installed on the lower outer wall of the horizontal section of the air-powder pipe in a biomass flour milling system, comprising:

[0008] Mounting base, the upper end of which is fixed to the outer wall of the air-powder pipe; the mounting base is provided with an oblong hole that communicates with the inner cavity of the air-powder pipe;

[0009] The housing is detachably connected to the bottom surface of the mounting base; the inner cavity of the housing communicates with the oblong hole.

[0010] The electrode plate is fixed inside the housing; the electrode plate is electrically connected to the DC or AC power supply of the control cabinet via leads.

[0011] The beneficial effects of this utility model are that the biomass powder in the air-powder pipe enters the outer shell, the electrode plate can measure the resistance value when connected to a DC power supply, and can measure the capacitance value when connected to an AC power supply. By measuring the resistance or capacitance value between the electrode plate and the biomass powder, the moisture content of the biomass powder can be indirectly calculated, thus realizing online moisture detection of biomass.

[0012] Preferably, the device further includes an insulating liner, which is located inside the outer shell and its outer wall is pressed against the inner wall of the outer shell; the electrode plate is fixed in the insulating liner, and the inner cavity of the insulating liner communicates with the oblong hole. By using the insulating liner as an isolation pad between the electrode plate and the outer shell, the resistance or capacitance between the electrode plate and the outer shell is eliminated, thereby ensuring the accuracy of the detection results.

[0013] Preferably, the inner wall of the insulating liner has an electrode groove, and the electrode plate is embedded in the electrode groove. This ensures the stability of the electrode plate installation.

[0014] Preferably, the insulating liner is made of one or two materials selected from ceramic and polytetrafluoroethylene, and has an operating temperature greater than 160°C. Using insulating materials for the insulating liner eliminates resistance or capacitance between the electrode plate and the outer shell, while also meeting the high-temperature operating requirements of the biomass pulverizing system.

[0015] Preferably, the system further includes a purge connection pipe, one end of which is fixed to the outer wall of the housing, and the other end is connected to a purge air duct; the insulating liner has a purge hole that connects to the inner cavity of the purge connection pipe. The purge air in the purge air duct can enter the housing through the purge connection pipe, thereby back-blowing the biomass powder inside the housing into the powder duct, ensuring the periodic detection of the moisture content of the biomass powder.

[0016] Preferably, a solenoid valve is fixed on the purge duct, and the solenoid valve is electrically connected to the control cabinet. The solenoid valve controls the purge air entering the purge duct, thereby controlling the purge cycle and realizing periodic moisture detection.

[0017] Preferably, the upper surface of the mounting base is an arc surface, and the radius of the arc surface is adapted to the radius of the air-powder pipe; the arc surface is welded and fixed to the outer wall surface of the air-powder pipe. Welding the arc surface to the outer wall surface of the air-powder pipe ensures its sealing performance.

[0018] Preferably, a flange is fixed to the upper end of the mounting base; the bottom surface of the mounting base has a threaded hole corresponding to the through hole on the flange, and the threaded end of the bolt is screwed into the through hole and the threaded hole in sequence to bolt the flange to the bottom surface of the mounting base. The outer shell and the mounting base are connected by bolts, which facilitates the disassembly of the outer shell, thereby meeting the requirements for replacing the insulating liner and electrode plate and cleaning the inside of the outer shell.

[0019] Preferably, there are two electrode plates, and the two electrode plates are connected to the DC power supply or AC power supply. Biomass powder is filled into the insulating liner through oblong holes. The moisture content is calculated by measuring the resistance or capacitance of the biomass powder between the two electrode plates. The two electrode plates can be connected to different power supplies to perform both resistance and capacitance detection modes. By verifying each other using these two detection modes, detection errors can be eliminated.

[0020] Preferably, the control cabinet is equipped with a control system that can control the connection and disconnection between the lead wire and the DC power supply or the AC power supply.

[0021] As can be seen from the above technical solution, compared with the prior art, this utility model discloses an online moisture detection device for biomass powder. It indirectly calculates the moisture content of biomass powder by measuring the resistance and capacitance values ​​between the electrode plate and the biomass powder, thereby achieving online detection. Furthermore, it uses both resistance and capacitance detection modes for mutual verification to eliminate detection errors and ensure the accuracy of the results. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 A schematic diagram of the detection device provided by this utility model;

[0024] Figure 2 A cross-sectional view of the outer shell provided for this utility model;

[0025] Figure 3 A schematic diagram of the mounting base structure provided by this utility model;

[0026] Figure 4 A schematic diagram of the outer shell structure provided for this utility model;

[0027] Figure 5 A schematic diagram of the insulating liner structure provided by this utility model;

[0028] Figure 6 A schematic diagram of the electrode plate structure provided by this utility model.

[0029] Among them, 1-air powder pipe; 2-mounting base; 21-arc surface; 22-slender hole; 23-threaded hole; 3-outer shell; 31-flange; 4-insulating lining; 41-electrode groove; 42-purge hole; 5-electrode plate; 6-lead wire; 4-purge connection pipe. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] See appendix Figures 1 to 6 According to an embodiment of this utility model, an online moisture detection device for biomass powder is installed on the lower outer wall of the horizontal section of the air-powder pipe 1 in a biomass powdering system. The device indirectly calculates the moisture content of the biomass powder by measuring the resistance and capacitance values ​​between the electrode plate 5 and the biomass powder, thus achieving online moisture detection of the biomass powder. The device includes a mounting base 2, a housing 3, and electrode plates 5. The upper end of the mounting base 2 is fixed to the outer wall of the air-powder pipe 1. The mounting base 2 has a waist-shaped hole 22 connecting to the inner cavity of the air-powder pipe 1. The housing 3 is detachably connected to the bottom surface of the mounting base 2. The inner cavity of the housing 3 communicates with the waist-shaped hole 22. The electrode plates 5 are fixed inside the housing 3. The electrode plates 5 are electrically connected to the DC or AC power supply of the control cabinet via lead wires 6. There are two electrode plates 5, and both electrode plates 5 are connected to the DC or AC power supply. The control cabinet contains a control system that can control the connection and disconnection between the lead wires 6 and the DC or AC power supply.

[0032] To further optimize the above technical solution and prevent the detection results from being affected by the resistance and capacitance values ​​between the outer shell and the electrode plate, an insulating liner 4 is also included. The insulating liner 4 is located inside the outer shell 3 and its outer wall is pressed tightly against the inner wall of the outer shell 3. The electrode plate 5 is fixed in the insulating liner 4, and the inner cavity of the insulating liner 4 is connected to the waist-shaped hole 22.

[0033] In other specific embodiments, to ensure that the electrode plate 5 is installed securely and stably, the inner wall of the insulating liner 4 is provided with an electrode groove 41, and the electrode plate 5 is embedded in the electrode groove 41.

[0034] In this embodiment, the insulating liner 4 is made of one or more insulating materials such as ceramics and polytetrafluoroethylene, and has a service temperature greater than 160°C. While ensuring its insulation performance, it meets the high-temperature environment requirements of the biomass pulverizing system production process.

[0035] In this embodiment, the biomass powder inside the outer shell 3 can be automatically removed after the detection is completed. It also includes a purge connection pipe 7, one end of which is fixed to the outer wall of the outer shell 3 and the other end is connected to the purge air pipe. The insulating inner liner 4 is provided with a purge hole 42 that connects to the inner cavity of the purge connection pipe 7.

[0036] In some other embodiments, a solenoid valve is fixed to the purge duct, and the solenoid valve is electrically connected to the control cabinet. The solenoid valve controls the purge air to enter the insulating lining for backflushing.

[0037] To further optimize the above technical solution and ensure an effective sealed connection between the mounting base and the air-powder pipe, the upper end surface of the mounting base 2 is an arc surface 21, and the radius of the arc surface 21 is adapted to the radius of the air-powder pipe 1; the arc surface 21 is welded and fixed to the outer wall surface of the air-powder pipe 1.

[0038] To further optimize the above technical solution, facilitate the disassembly of the outer shell to replace the insulating liner or electrode plate, or facilitate the cleaning of the inner cavity of the outer shell, a flange 31 is fixed at the upper end of the mounting base 2; a threaded hole 23 corresponding to the through hole on the flange 31 is opened on the bottom surface of the mounting base 2, and the threaded end of the bolt is screwed into the through hole and the threaded hole 23 in sequence to bolt the flange 31 to the bottom surface of the mounting base 2.

[0039] The detection device provided in this embodiment has two detection modes: resistive and capacitive.

[0040] The resistance-based detection mode utilizes the negative correlation between the moisture content and resistance of biomass powder. It indirectly calculates the moisture content of the biomass powder by measuring the resistance of the powder filled between two electrode plates. The resistance-based detection mode first establishes a resistance-moisture content curve by measuring the resistance values ​​of standard biomass powder samples with different moisture contents. During moisture content detection, as the air-powder mixture flows through the oblong orifice, the biomass powder settles into the insulating liner, gradually filling the space between the two electrode plates. The control system connects the two electrode plates to a DC power supply. Based on the detected resistance value and the resistance-moisture content curve, the control system calculates the moisture content of the biomass powder in reverse. Then, the control system controls a solenoid valve to connect the purge air duct. The purge air enters the insulating liner through the purge connection pipe and purge hole, backflushing the biomass powder back into the air-powder duct. After closing the solenoid valve, the next biomass powder settling, resistance detection, moisture content calculation, and purge operation begins. By controlling the opening and closing time of the solenoid valve, online detection of the biomass powder moisture content can be achieved periodically.

[0041] The capacitive detection mode utilizes the physical property that "the dielectric constant of water is much higher than that of most dry materials" to indirectly estimate the moisture content by measuring the capacitance value of the material. The capacitive detection mode first requires establishing a capacitance-moisture content curve by measuring the capacitance values ​​of standard biomass powder samples with different moisture contents. During moisture content detection, the control system connects the two electrode plates to an AC power supply, and the control system measures the capacitance value; the remaining steps are the same as in the resistance detection mode.

[0042] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0043] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An online moisture detection device for biomass flour, installed on the lower outer wall of the horizontal section of the air-powder pipe (1) in a biomass flour milling system, characterized in that, include: Mounting base (2), the upper end of which is fixed to the outer wall of the air powder pipe (1); the mounting base (2) is provided with a waist-shaped hole (22) that communicates with the inner cavity of the air powder pipe (1); The outer casing (3) is detachably connected to the bottom surface of the mounting base (2); the inner cavity of the outer casing (3) communicates with the waist-shaped hole (22); Electrode plate (5), which is fixed inside the outer casing (3); the electrode plate (5) is electrically connected to the DC or AC power supply of the control cabinet via lead wire (6).

2. The online moisture detection device for biomass powder according to claim 1, characterized in that, It also includes an insulating liner (4), which is located inside the outer shell (3) and its outer wall is pressed against the inner wall of the outer shell (3); the electrode plate (5) is fixed in the insulating liner (4), and the inner cavity of the insulating liner (4) is connected to the waist-shaped hole (22).

3. The online moisture detection device for biomass powder according to claim 2, characterized in that, The inner wall of the insulating liner (4) is provided with an electrode groove (41), and the electrode plate (5) is embedded in the electrode groove (41).

4. The online moisture detection device for biomass powder according to claim 2, characterized in that, The insulating liner (4) is made of one or two of the following materials: ceramic and polytetrafluoroethylene, and has a service temperature greater than 160°C.

5. The online moisture detection device for biomass powder according to claim 3, characterized in that, It also includes a purge connection pipe (7), one end of which is fixed to the outer wall of the outer shell (3), and the other end is connected to the purge air pipe; the insulating liner (4) is provided with a purge hole (42) that connects to the inner cavity of the purge connection pipe (7).

6. The online moisture detection device for biomass powder according to claim 5, characterized in that, A solenoid valve is fixed on the purging duct, and the solenoid valve is electrically connected to the control cabinet.

7. The online moisture detection device for biomass powder according to claim 1, characterized in that, The upper surface of the mounting base (2) is an arc surface (21), and the radius of the arc surface (21) is adapted to the radius of the air-powder pipe (1); the arc surface (21) is welded and fixed to the outer wall surface of the air-powder pipe (1).

8. The online moisture detection device for biomass powder according to claim 1, characterized in that, The upper end of the mounting base (2) is fixed with a flange (31); the bottom surface of the mounting base (2) is provided with a threaded hole (23) corresponding to the through hole on the flange (31), and the threaded end of the bolt is screwed into the through hole and the threaded hole (23) in sequence to bolt the flange (31) to the bottom surface of the mounting base (2).

9. The online moisture detection device for biomass powder according to claim 1, characterized in that, The number of electrode plates (5) is two, and the two electrode plates (5) are connected to the DC power supply or AC power supply.

10. An online moisture detection device for biomass powder according to any one of claims 1 to 8, characterized in that, The control cabinet is equipped with a control system, which can control the connection and disconnection between the lead (6) and the DC power supply or the AC power supply.

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