Self-adjusting device for wind pressure detection of asphalt mixing plant

Abstract

The utility model relates to an asphalt mixing plant wind pressure detection self -adjusting device belongs to the technical field of asphalt mixing plant. It monitors pressure through the negative pressure gauge set up on drying cylinder and main flue, and by controller adjusts the speed of induced draft fan and inlet damper opening degree to the system negative pressure stable control in the set range. The utility model realizes the accurate control of negative pressure, avoids the dust escape caused by too small negative pressure, prevents the waste caused by the aggregate suction into the dust collector caused by too large negative pressure, effectively improves the dust removal efficiency and production environment quality.

Description

Technical Field

[0001] This utility model relates to the technical field of asphalt mixing equipment, and in particular to a self-adjusting device for detecting air pressure in an asphalt mixing plant. Background Technology

[0002] With the development of asphalt mixing plant technology, a technology has emerged that adjusts the induced draft fan damper based on whether dust is emitted from the drying drum and the main building. The feature of this technology is that the negative pressure state is judged by human vision, and the damper opening is adjusted manually to control the dust diffusion during the production process. This has led to the development of related negative pressure regulating devices, such as induced draft fans and damper assemblies.

[0003] In related technologies, operators can manually increase or decrease the opening of the induced draft fan damper by monitoring the dust emission from the drying drum and the main building in real time, thereby achieving rough control of the system's negative pressure.

[0004] However, the above manual adjustment method has the following problems:

[0005] When the negative pressure is too high, it will affect the efficiency of the volute dust collector, causing larger aggregate particles to be sucked into the bag dust collector, resulting in a waste of resources.

[0006] When the negative pressure is too low, due to operational negligence or untimely adjustment, it is easy for dust to rise everywhere in the mixing plant, polluting the environment and reducing production efficiency. Utility Model Content

[0007] In response to the shortcomings of the existing production technology, the applicant provides an asphalt mixing plant air pressure detection and self-adjusting device, which enables the induced draft fan to adjust to the corresponding speed by comparing the feedback signal from the main flue negative pressure gauge with the set flue negative pressure.

[0008] The technical solution adopted in this utility model is as follows:

[0009] A self-adjusting device for detecting wind pressure in an asphalt mixing plant, comprising:

[0010] The drying drum has a burner installed at its inlet end;

[0011] The volute dust collector is connected to the discharge end of the drying cylinder via a pipe;

[0012] The main flue is connected to the outlet of the volute dust collector;

[0013] An induced draft fan, installed on the main flue, is used to provide suction power;

[0014] A bag filter is installed on the main flue downstream of the induced draft fan;

[0015] Also includes:

[0016] A negative pressure gauge for the drying cylinder is installed on the drying cylinder to detect the negative pressure value inside the drying cylinder;

[0017] A main flue negative pressure gauge is installed on the main flue upstream of the induced draft fan to detect the negative pressure value of the main flue.

[0018] An electrically adjustable damper with a servo mechanism is installed on the pipe connecting the drying cylinder and the volute dust collector;

[0019] The controller is electrically connected to the negative pressure gauge of the drying cylinder, the negative pressure gauge of the main flue, the induced draft fan, and the electric regulating damper, respectively.

[0020] The controller is configured to: control the opening of the electric regulating damper according to the feedback signal of the negative pressure gauge of the drying cylinder to adjust the negative pressure inside the drying cylinder to a first set value; and control the rotation speed of the induced draft fan according to the feedback signal of the negative pressure gauge of the main flue to adjust the negative pressure of the main flue to a second set value.

[0021] As a further improvement to the above technical solution:

[0022] In one embodiment, the induced draft fan is a variable frequency induced draft fan.

[0023] In one embodiment, the device further includes a vibrating screen dust extraction pipe and a main building dust extraction pipe connected to the main flue.

[0024] In one embodiment, the device further includes a dust extraction pipe for discharging white material from the mixing tank, which is connected to the main flue and is equipped with a control valve.

[0025] In one embodiment, the controller is further configured to, in vacuum mode, control the electrically adjustable damper to close to a preset opening and control the induced draft fan to adjust the negative pressure of the main flue to a third set value.

[0026] In one embodiment, the preset opening is 20% of the full opening of the electrically adjustable damper.

[0027] In one embodiment, the first set value is -100Pa.

[0028] In one embodiment, the second setting value is -800 Pa, and the third setting value is -2000 Pa.

[0029] In one embodiment, an exhaust pipe is also connected to the end of the main flue.

[0030] In one embodiment, the detection end of the negative pressure gauge of the drying cylinder extends directly into the cylinder body of the drying cylinder.

[0031] The beneficial effects of this utility model are as follows:

[0032] This utility model has a compact structure. By setting a negative pressure gauge to collect pressure data in real time, and driving the electric regulating damper and the variable frequency induced draft fan with the controller to make coordinated adjustments, it can instantly respond to negative pressure disturbances caused by changes in aggregate moisture content and fluctuations in burner blower volume, and continuously stabilize the system pressure at the optimal set value. This not only avoids the problems of delayed response and poor accuracy caused by relying on manual observation and manual adjustment in traditional methods, but also completely avoids the problems of "ash emission" or "over-suction" caused by human negligence or untimely adjustment.

[0033] This utility model also has the following advantages:

[0034] This invention firstly maintains the optimal negative pressure of the drying drum itself at the outlet of the drying drum through an electric damper to ensure drying efficiency; secondly, it maintains the optimal negative pressure of the entire main flue system through a variable frequency induced draft fan in the main flue. This ensures that the volute dust collector can operate under its designed optimal negative pressure conditions, thereby efficiently separating larger aggregate particles and effectively preventing these valuable materials from being sucked into the bag filter dust collector. At the same time, it can also meet the dust suction negative pressure requirements of the vibrating screen, main building, and other parts, thus optimizing the dust removal effect and resource recovery.

[0035] This invention switches to a preset "dust suction mode" during the "white material release" stage. In this mode, the controller instructs the damper to close to a specific opening (ensuring strong dust suction while allowing residual air to cool the drying cylinder), and at the same time significantly increases the speed of the induced draft fan to generate extremely strong negative pressure to collect high-concentration dust. This special handling capability solves the problem of the biggest dust problem at the end of production and further improves environmental protection performance. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0037] Figure 2 for Figure 1 Top view.

[0038] Figure 3 for Figure 2 BB-direction sectional view.

[0039] The components include: 1. Burner; 2. Drying drum negative pressure gauge; 3. Drying drum; 4. Volute dust collector; 5. Electric regulating damper; 6. Main flue; 7. Vibrating screen dust suction pipe; 8. Main building dust suction pipe; 9. Mixing cylinder white material discharge dust suction pipe; 10. Main flue negative pressure gauge; 11. Bag dust collector; 12. Exhaust stack; 13. Exhaust fan. Detailed Implementation

[0040] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0041] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0044] It should be understood that although the terms "first," "second," etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0045] Furthermore, the accompanying drawings are not drawn to a 1:1 scale, and the relative dimensions of the components are shown in the drawings only as examples and not necessarily to actual scale.

[0046] like Figures 1-3 The accompanying drawing shows a structural diagram of an asphalt mixing plant wind pressure detection self-adjusting device according to an embodiment of the present invention; for ease of description, the drawing only shows the structure related to the embodiment of the present invention.

[0047] This application provides a self-adjusting device for detecting wind pressure in an asphalt mixing plant, which achieves negative pressure regulation through negative pressure gauge detection and feedback control.

[0048] In some embodiments, the burner 1 is disposed at the inlet end of the drying cylinder 3 for heating and drying the aggregate inside the cylinder;

[0049] The discharge end of the drying drum 3 is connected to the volute dust collector 4 through a pipe, and an electric regulating damper 5 with a servo mechanism is installed on the pipe.

[0050] The outlet of the volute dust collector 4 is connected to the main flue 6;

[0051] An induced draft fan 13 and a bag filter 11 are sequentially installed on the main flue 6, and the purified gas is finally discharged by the exhaust stack 12.

[0052] In addition, the main flue 6 is also connected to the vibrating screen dust suction pipe 7, the main building dust suction pipe 8, and the mixing tank white material discharge dust suction pipe 9, which are used to collect dust generated in other parts of the mixing building.

[0053] Among them, the dust suction pipe 9 for discharging white material from the mixing tank is equipped with a control valve (not marked separately in the figure), which is used to open the branch when needed.

[0054] In some embodiments, a drying cylinder negative pressure gauge 2 is installed on the cylinder body of the drying cylinder 3, with its detection end extending directly into the inside of the cylinder body, for real-time detection of the negative pressure value inside the drying cylinder 3.

[0055] A main flue negative pressure gauge 10 is installed on the main flue 6, and located upstream of the inlet of the induced draft fan 13, to detect the total negative pressure value of the main flue 6 in real time.

[0056] A controller (not shown in the figure, usually a PLC or industrial computer control system) is electrically connected to the electrical control system of the drying drum negative pressure gauge 2, the main flue negative pressure gauge 10, the electric regulating damper 5, and the induced draft fan 13 via signal lines.

[0057] In some embodiments, the controller is programmed to achieve two-level cooperative control:

[0058] The first-level control targets the drying cylinder 3: the controller receives the feedback signal from the negative pressure gauge 2 of the drying cylinder and compares it with a preset first setpoint (e.g., -100Pa). If a deviation exists, the controller outputs a control signal to drive the servo mechanism of the electric regulating damper 5, adjusting the damper's opening to change the airflow resistance through the drying cylinder 3, ultimately maintaining the negative pressure inside the drying cylinder 3 stably at the optimal first setpoint. This control effectively addresses the interference caused by changes in aggregate moisture content or variations in the burner 1's airflow on the negative pressure of the drying cylinder 3, ensuring drying efficiency and preventing ash emission from the cylinder.

[0059] The second-level control targets the entire main flue system: the controller receives feedback signals from the main flue negative pressure gauge 10 and compares them with a preset second setpoint (e.g., -800Pa). If a deviation exists, the controller outputs a control signal to adjust the speed of the induced draft fan 13 (preferably, the induced draft fan 13 is a variable frequency fan, with speed adjusted by changing the frequency), thereby changing the total air volume of the system and precisely maintaining the negative pressure of the main flue 6 at the second setpoint. This control ensures that the volute dust collector 4 can efficiently separate larger aggregate particles under optimal negative pressure conditions, preventing them from being sucked into the bag filter 11 and wasting them. It also provides sufficient negative pressure for the vibrating screen suction pipe 7 and the main building suction pipe 8, preventing dust from escaping from these areas.

[0060] In addition, the controller has a preset special working mode—dust suction mode, which is suitable for high dust conditions when "discharging white material" is performed at the end of production. When switching to this mode, the controller executes a preset program: first, it controls the electric regulating damper 5 to close to a preset opening degree (e.g., 20% of full opening). This retains a small amount of airflow for cooling the high-temperature drying drum 3, while significantly increasing the airflow speed in the duct.

[0061] Simultaneously, the controller switches the set target of the main flue negative pressure gauge 10 to a higher third set value (e.g., -2000Pa) and controls the induced draft fan 13 to run at high speed to generate extremely strong negative pressure. At this time, the operator opens the valve on the dust suction pipe 9 for discharging white material from the mixing tank, which can efficiently remove a large amount of dust generated during the material discharge process.

[0062] In summary, this utility model has a reasonable structure. Through the specific structural settings and control logic described above, it constructs an intelligent and efficient automatic negative pressure adjustment system, fundamentally solving the defects of traditional manual adjustment methods.

[0063] This utility model has a reasonable structure. By setting a negative pressure gauge to collect pressure data in real time, and driving the electric regulating damper and the variable frequency induced draft fan with the controller to make coordinated adjustments, it can respond to negative pressure disturbances caused by changes in aggregate moisture content, fluctuations in burner blower volume, etc., and continuously stabilize the system pressure at the optimal set value.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The embodiments described above merely illustrate the implementation of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A self-adjusting device for detecting air pressure in an asphalt mixing plant, characterized in that, include: The drying cylinder (3) has a burner (1) installed at its inlet end; The volute dust collector (4) is connected to the discharge end of the drying cylinder (3) via a pipe; The main flue (6) is connected to the outlet of the volute dust collector (4); An induced draft fan (13) is installed on the main flue (6) to provide suction power; A bag filter (11) is installed on the main flue (6) downstream of the induced draft fan (13); Also includes: A negative pressure gauge (2) for drying cylinder is installed on the drying cylinder (3) to detect the negative pressure value inside the drying cylinder (3); A main flue negative pressure gauge (10) is installed on the main flue (6) upstream of the induced draft fan (13) to detect the negative pressure value of the main flue (6); An electric regulating damper (5) with a servo mechanism is installed on the pipe connecting the drying cylinder (3) and the volute dust collector (4); The controller is electrically connected to the drying cylinder negative pressure gauge (2), the main flue negative pressure gauge (10), the induced draft fan (13), and the electric regulating damper (5), respectively. The controller is configured to: control the opening of the electric regulating damper (5) according to the feedback signal of the drying cylinder negative pressure gauge (2) to adjust the negative pressure inside the drying cylinder (3) to a first set value; and control the rotation speed of the induced draft fan (13) according to the feedback signal of the main flue negative pressure gauge (10) to adjust the negative pressure of the main flue (6) to a second set value.

2. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 1, characterized in that: The induced draft fan (13) is a variable frequency induced draft fan.

3. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 1, characterized in that: The device also includes a vibrating screen dust collection pipe (7) and a main building dust collection pipe (8) connected to the main flue (6).

4. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 1, characterized in that: The device also includes a mixing cylinder discharge dust suction pipe (9) connected to the main flue (6), and a control valve is provided on the mixing cylinder discharge dust suction pipe (9).

5. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 1, characterized in that: The controller is also configured to, in vacuum mode, control the electric regulating damper (5) to close to a preset opening, and control the induced draft fan (13) to adjust the negative pressure of the main flue (6) to a third set value.

6. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 5, characterized in that: The preset opening degree is 20% of the full opening degree of the electric regulating damper (5).

7. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 1, characterized in that: The first setting value is -100Pa.

8. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 5, characterized in that: The second setting value is -800Pa, and the third setting value is -2000Pa.

9. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 1, characterized in that: The main flue (6) is also connected to an exhaust pipe (12) at its end.

10. The self-adjusting device for detecting air pressure in an asphalt mixing plant according to claim 1, characterized in that: The detection end of the negative pressure gauge (2) of the drying cylinder extends directly into the cylinder body of the drying cylinder (3).

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