Continuous sample injector for trace solid powder

Abstract

The invention relates to a trace solid powder continuous sample injector which comprises a cylindrical shell and a spiral feeding mechanism, the cylindrical shell is provided with a feeding port and a discharging port, the spiral feeding mechanism is installed in the cylindrical shell and connected with a driving motor, and an ultrasonic transducer is arranged in a screw of the spiral feeding mechanism. The device is simple in structure, powder adhesion can be effectively prevented through ultrasonic vibration, and the sampling precision is improved.

Description

Technical Field

[0001] The invention belongs to the field of analytical instruments, and in particular relates to a continuous sample feeder for trace solid powder. Background Art

[0002] In the pyrolysis and combustion research of solid powders such as biomass and coal powder, stable and controllable powder feeding is crucial for experimental repeatability and data accuracy. The feeding speed of the continuous feeder for trace solid powder is very small, usually 1-100 mg / min. However, the existing powder feeders have the following problems in practical applications: (1) The powder is easy to adhere to the conveying mechanism or the tube wall during the injection process, resulting in uneven injection and affecting the reliability of the experimental results; (2) When conveying solid powders such as biomass and coal powder, the traditional spiral feeding mechanism is prone to blockage or unstable conveying due to electrostatic effects, hygroscopicity or inter-particle forces; (3) The existing anti-adhesion technology mainly relies on external vibration devices or carrier gas purges, but the anti-adhesion effect on highly hygroscopic and fine particle powders is limited. Summary of the invention

[0003] The purpose of the present invention is to provide a continuous sample feeder for micro solid powder to solve the above problems. To this end, the technical solution adopted by the present invention is as follows:

[0004] According to an embodiment of the present invention, a continuous sample feeder for trace solid powder is provided, which may include a cylindrical shell and a spiral feeding mechanism, wherein the cylindrical shell is provided with a feeding port and a discharging port, and the spiral feeding mechanism is installed in the cylindrical shell and connected to a driving motor, and is characterized in that an ultrasonic transducer is built into the screw of the spiral feeding mechanism.

[0005] In one embodiment, the operating frequency of the ultrasonic transducer is 20kHz-100kHz.

[0006] In one embodiment, the screw rod is a hollow structure, and the ultrasonic transducer is installed in the cavity of the screw rod and fixedly connected to the screw rod.

[0007] In one embodiment, the continuous sampler for trace solid powder may further include a carrier gas purge unit, one end of the cavity of the screw is fluidically connected to the carrier gas purge unit, and the other end is closed, and a blowing hole is provided on the screw, and the blowing hole is connected to the cavity of the screw.

[0008] In one embodiment, the number of the blowing holes in each circle is 1 to 5.

[0009] In one embodiment, the diameter of the blowing hole is 0.5-1 mm.

[0010] In one embodiment, the cylindrical housing is placed horizontally, and the feed inlet and the discharge outlet are located at the upper left and lower right of the cylindrical housing, respectively.

[0011] In one embodiment, a gate valve is installed at the feed inlet, and the gate valve is used to control the powder feed rate.

[0012] In one embodiment, the drive motor is a servo motor.

[0013] In one embodiment, the spiral feeding mechanism is a single-screw conveying structure.

[0014] In one embodiment, the solid powder includes biomass and pulverized coal.

[0015] The present invention adopts the above technical solutions, and the beneficial effects are as follows.

[0016] (1) Effectively prevent powder adhesion: The ultrasonic transducer integrated in the center of the screw applies uniform vibration to the powder, reduces the adhesion between particles, and improves the conveying stability.

[0017] (2) Improve the injection accuracy: The spiral feeding mechanism combines ultrasonic vibration and carrier gas purging to achieve a highly controllable powder injection volume, meeting the experimental requirements of pyrolysis and combustion research.

[0018] (3) Simplify the structural design: Compared with the external vibration device, this device integrates the ultrasonic transducer inside the screw to achieve a compact design, reduce energy consumption, and improve the reliability of the equipment.

[0019] (4) Suitable for various solid powders: The present invention is suitable for solid powders with different particle sizes such as biomass and pulverized coal, and can be widely applied to high-temperature analytical instruments. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of a micro solid powder continuous sampler according to an embodiment of the present invention. Detailed Embodiments

[0021] The following will describe the preferred embodiments of the present invention in detail with reference to the drawings, so as to more clearly understand the purpose, features, and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not a limitation on the scope of the present invention, but only to illustrate the essential spirit of the technical solution of the present invention.

[0022] In the following description, for the purpose of explaining various disclosed embodiments, certain specific details are set forth to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments can be practiced without one or more of these specific details. In other instances, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail so as not to unnecessarily obscure the description of the embodiments.

[0023] Unless the context requires otherwise, throughout the specification and claims, the words "comprising" and its variants, such as "including" and "having", should be understood in an open, inclusive sense, i.e., to be interpreted as "including, but not limited to".

[0024] References to "an embodiment" or "one embodiment" in the specification throughout mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in an embodiment" or "in one embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0025] As used in this specification and the appended claims, the singular forms "a" and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally used in its inclusive sense of "and / or" unless the context clearly dictates otherwise.

[0026] In the following description, for the purpose of clearly showing the structure and working mode of the present invention, many directional terms will be used for description. However, terms such as "front", "rear", "left", "right", "outer", "inner", "outward", "inward", "up", "down", etc. should be understood as convenient terms and should not be understood as limiting terms.

[0027] In addition, terms such as "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but may be slightly inclined.

[0028] In the description of the present application, it should also be noted that unless otherwise clearly specified and defined, the terms "arranged", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0029] As Figure 1 shown, a micro solid powder continuous sampler of the present invention may include a cylindrical housing 1 and a screw feeding mechanism 2. Among them, the cylindrical housing 1 is provided with a feeding port 11 and a discharging port 12. The screw feeding mechanism 2 is installed inside the cylindrical housing 1 and is drivingly connected to a driving motor (not shown). Both ends of the cylindrical housing 1 and the screw feeding mechanism 2 are sealed by a sealing ring 3 to prevent powder leakage. Among them, an ultrasonic transducer 4 is built into the screw 21 of the screw feeding mechanism 2. The ultrasonic transducer 4 can apply high-frequency uniform vibration to the conveyed powder during the conveying process, reduce the adhesion between particles, and improve the conveying stability. Compared with an external vibration device, this micro solid powder continuous sampler integrates an ultrasonic transducer inside the screw, realizing a compact design, reducing energy consumption, and improving the reliability of the equipment.

[0030] The arrangement positions of the feeding port 11 and the discharging port 12 are related to the material conveying direction of the screw feeding mechanism 2. In the shown embodiment, the cylindrical housing 1 is placed horizontally, and the feeding port 11 and the discharging port 12 are respectively located at the upper left and lower right of the cylindrical housing 1, that is, the material conveying direction of the screw feeding mechanism 2 is from left to right. This structure makes the material conveying smoother. It should be understood that the feeding port 11 and the discharging port 12 can also be respectively located at the upper right and lower left of the cylindrical housing 1. The upper part of the feeding port 11 can be set in a hopper shape for storing solid powders such as biomass or pulverized coal, and a gate valve is provided at the lower end for controlling the powder feeding amount. Preferably, the gate valve is a pneumatic gate valve. The cylindrical housing 1 can be made of materials such as stainless steel.

[0031] Preferably, the working frequency of the ultrasonic transducer 4 is 20 kHz - 100 kHz. The ultrasonic transducer is commercially available, and its structure will not be described in detail here.

[0032] In this embodiment, the screw 21 of the screw feeding mechanism 2 is of a hollow structure. The ultrasonic transducer 4 is installed in the cavity 211 of the screw 21 and is fixedly connected to the screw 21, so that the vibration can be transmitted through the screw and act on the conveyed powder. The ultrasonic transducer 4 can be fixedly installed inside the screw 21 by fixing methods well known to those skilled in the art such as screws and snap connections. The connecting wire of the ultrasonic transducer 4 can pass out from one end of the cavity 211. The number of ultrasonic transducers 4 is set according to the size of the sampler. The number of ultrasonic transducers 4 can be 1 - 3.

[0033] In this embodiment, the screw feeding mechanism 2 is a single-screw conveying structure, and its main body can be processed from materials such as stainless steel. Preferably, the driving motor of the screw feeding mechanism 2 is a servo motor, and the sampling rate can be accurately controlled by programming.

[0034] In a specific embodiment, the micro solid powder continuous sampler may further include a carrier gas purging unit (not shown), which is used to provide gas flow assistance during the powder transportation process to further reduce powder adhesion. Specifically, one end of the cavity 211 of the screw 21 of the spiral feeding mechanism 2 is in fluid communication with the carrier gas purging unit, and the other end is closed, and this closed end is the end connected to the driving motor. That is, one end of the cavity 211 is the air inlet 212, which is connected to the fan of the carrier gas purging unit through a pipeline. The gas used in the carrier gas purging unit can be an inert gas such as nitrogen (N2). There are air blowing holes 23 provided on the screw 21, and the air blowing holes 23 are in communication with the cavity of the screw 21. Therefore, the gas can blow the powder through the air blowing holes 23 to reduce powder adhesion. The air blowing holes 23 are provided on the screw 21 between two adjacent spiral blades 22. The number of air blowing holes 23 in each turn can be 1 - 5, which is set according to the actual situation. The aperture of the air blowing holes 23 can be 0.5 - 1 mm.

[0035] The micro solid powder continuous sampler of the present invention has the following advantages:

[0036] (1) Effectively prevent powder adhesion: The ultrasonic transducer integrated in the center of the screw applies uniform vibration to the powder, reduces the adhesion between particles, and improves the transportation stability.

[0037] (2) Improve the sampling accuracy: The spiral feeding mechanism combines ultrasonic vibration and carrier gas purging to achieve a highly controllable powder sampling amount, meeting the experimental requirements of pyrolysis and combustion research.

[0038] (3) Simplify the structural design: Compared with the external vibration device, this method integrates the ultrasonic transducer inside the screw to achieve a compact design, reduce energy consumption, and improve the reliability of the equipment.

[0039] (4) Applicable to various solid powders: The present invention is applicable to solid powders with different particle sizes such as biomass and coal powder, and can be widely used in high-temperature analytical instruments.

[0040] The preferred embodiments of the present invention have been described in detail above. However, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention. These equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A micro solid powder continuous sampler, comprising a cylindrical shell and a spiral feeding mechanism. The cylindrical shell is provided with a feeding port and a discharging port. The spiral feeding mechanism is installed inside the cylindrical shell and connected to a driving motor, characterized in that, An ultrasonic transducer is built into the screw of the spiral feeding mechanism.

2. The micro solid powder continuous sampler according to claim 1, wherein The operating frequency of the ultrasonic transducer is 20 kHz - 100 kHz.

3. The micro solid powder continuous sampler according to claim 1, wherein The screw is of a hollow structure, and the ultrasonic transducer is installed in the cavity of the screw and fixedly connected to the screw.

4. The micro solid powder continuous sampler according to claim 3, characterized in that, It further includes a carrier gas purging unit. One end of the cavity of the screw is in fluid communication with the carrier gas purging unit, and the other end is closed. And there are air blowing holes provided on the screw, and the air blowing holes are in communication with the cavity of the screw.

5. The micro solid powder continuous sampler according to claim 4, characterized in that, The number of the air blowing holes per turn is 1 - 5.

6. The micro solid powder continuous sampler according to claim 4, characterized in that, The aperture of the air blowing holes is 0.5 - 1 mm.

7. The micro solid powder continuous sampler according to claim 1, characterized in that, The cylindrical shell is placed horizontally, and the feeding port and the discharging port are respectively located at the upper left and the lower right of the cylindrical shell.

8. The micro solid powder continuous sampler according to claim 1, characterized in that The driving motor is a servo motor.

9. The continuous sampler for trace solid powder according to claim 1, wherein, The spiral feeding mechanism is a single-screw conveying structure.

10. The micro solid powder continuous sampler according to claim 1, characterized in that, The solid powder includes biomass and pulverized coal.

Images