A rotary furnace operation monitoring system and method

Abstract

The present invention discloses a rotary kiln operation monitoring system and method. The system includes a rotary kiln (7) disposed between the tertiary air main pipe (3) and the cement decomposition furnace (9). A tertiary air branch pipe (2) is provided on the tertiary air main pipe (3). The tertiary air branch pipe (2) is connected to the mixed feeding chamber (6) through a raw material feeding pipe (4). The mixed feeding chamber (6) is connected to the rotary kiln (7). A tertiary air branch pipe temperature sensor and a tertiary air branch pipe pressure sensor are provided on the tertiary air branch pipe (2). A rotary kiln current sensor and a rotary kiln rotation speed sensor are provided on the rotary kiln (7). The tertiary air branch pipe temperature sensor, the tertiary air branch pipe pressure sensor, the rotary kiln current sensor, and the rotary kiln rotation speed sensor are all connected to the distributed control system DCS through a transmission medium. The present invention ensures the normal operation of the rotary kiln system and improves the efficiency of the rotary kiln (7) in disposing of solid waste.

Description

Technical Field

[0001] The present invention relates to the technical field of co - disposal in cement kilns, and particularly to a rotary furnace operation monitoring system and method. Background Art

[0002] A cement rotary kiln belongs to building materials equipment and is a type of lime kiln. Rotary kilns can be divided into cement rotary kilns, metallurgical and chemical rotary kilns, and lime rotary kilns according to the materials to be processed. A cement rotary kiln is the main equipment for dry and wet production lines of cement clinker.

[0003] Rotary kilns are widely used in industries such as metallurgy, chemical industry, building refractory materials, and environmental sanitation. The rotary kiln consists of components such as a cylinder body, a supporting device, a supporting device with a retaining wheel, a driving device, a movable kiln head, a kiln tail sealing device, and a coal injection pipe device. The kiln body of the rotary kiln is inclined at a certain angle to the horizontal. The entire kiln body is supported by a supporting wheel device, and there is a retaining wheel device for controlling the up - and - down movement of the kiln body. In addition to the main drive in the drive system, an auxiliary drive device is also provided to enable the kiln body to rotate when the main power supply is interrupted, preventing the kiln body from bending and deforming. The kiln head and kiln tail sealing devices adopt advanced technologies to ensure the reliability of the seal.

[0004] The cement rotary kiln operates at a heavy load, low speed, and variable speed under high - temperature conditions. The maintenance of its accessory equipment and the control level of the thermal system are related to the safety and efficiency of the rotary kiln operation. The key points for maintaining the drive device are the lubrication of the equipment, the operating state, dynamic detection, and the meshing accuracy of the large and small gears. The installation accuracy of the supporting device determines whether the rotary kiln can operate safely and reliably. During operation, attention should be paid to reasonably controlling the load distribution of each supporting wheel, the arrangement form of the supporting wheels, the up - and - down pressure and time of the hydraulic retaining wheel, the force on the supporting wheels, and the clearance between the tyre and the backing plate. The quality of the sealing device directly affects the thermal system and operating cost of the rotary kiln. Strengthening the collation and analysis of daily maintenance data of the rotary kiln is beneficial to the equipment management work.

[0005] An inclined rotary combustion device for efficiently disposing of solid waste, abbreviated as a rotary furnace, combines the high - temperature environment in the cement clinker production process to carry out harmless treatment of various solid wastes and achieve resource recovery and utilization. The high - temperature tertiary air introduced into the cement kiln system quickly ignites and stably burns the solid waste in this inclined rotary combustion furnace. Utilizing the characteristics of high temperature, rich oxygen, long residence time, and large turbulence of this thermal device and the cement kiln system, it ensures that the organic pollutants generated during the combustion process of the solid waste are completely decomposed and burned out. The generated ash slag enters the rotary kiln and is solidified into the cement clinker minerals after high - temperature calcination. The generated tail gas is treated by the flue gas purification device for cement clinker production, thus achieving clean emission.

[0006] However, for the rotary furnace system, there is currently no corresponding operation monitoring plan to ensure its normal operation and reduce the impact on the operation of the cement kiln system. Summary of the Invention

[0007] To solve the above problems, on the one hand, the present invention provides a rotary kiln operation monitoring system, including a rotary kiln, which is arranged between the tertiary air main pipe and the cement decomposition furnace. A tertiary air branch pipe is arranged on the tertiary air main pipe. The tertiary air branch pipe is connected to a mixed feeding chamber through a raw material feeding pipe. The mixed feeding chamber is connected to the rotary kiln. A cement rotary kiln is arranged at the lower end of the cement decomposition furnace. A tertiary air branch pipe temperature sensor and a tertiary air branch pipe pressure sensor are arranged on the tertiary air branch pipe. A rotary kiln current sensor and a rotary kiln rotation speed sensor are arranged on the rotary kiln. The tertiary air branch pipe temperature sensor, the tertiary air branch pipe pressure sensor, the rotary kiln current sensor and the rotary kiln rotation speed sensor are all connected to a distributed control system DCS through a transmission medium.

[0008] Specifically, a tertiary air branch pipe gate valve is further arranged on the tertiary air branch pipe, and the tertiary air branch pipe gate valve is connected to the distributed control system DCS.

[0009] Specifically, a double pipe reamer feeding pipe is arranged on the mixed feeding chamber, and a pneumatic gate valve is arranged on the double pipe reamer feeding pipe. The pneumatic gate valve is connected to the distributed control system DCS.

[0010] Specifically, a feeding port temperature sensor and a feeding port pressure sensor are arranged on the raw material feeding pipe. The feeding port temperature sensor and the feeding port pressure sensor are both connected to the distributed control system DCS.

[0011] Specifically, a mixed feeding chamber temperature sensor and a mixed feeding chamber pressure sensor are arranged on the mixed feeding chamber. The mixed feeding chamber temperature sensor and the mixed feeding chamber pressure sensor are both connected to the distributed control system DCS.

[0012] Specifically, a rotary kiln discharge temperature sensor, a rotary kiln outlet gas temperature sensor and a rotary kiln discharge pressure sensor are further arranged on the rotary kiln. The rotary kiln discharge temperature sensor, the rotary kiln outlet gas temperature sensor and the rotary kiln discharge pressure sensor are all connected to the distributed control system DCS.

[0013] Specifically, the transmission medium includes wired transmission or wireless transmission.

[0014] On the other hand, the present invention provides a rotary kiln operation monitoring method, including the following steps:

[0015] S1: Obtain the temperature of the tertiary air branch pipe entering the rotary kiln and the temperature of the rotary kiln entering the cement decomposition furnace, so as to judge the temperature change generated by the heat absorption of the solid waste in the rotary kiln and the heat release of incineration.

[0016] S2: Obtain the pressure of the tertiary air branch pipe entering the cyclone furnace and the pressure of the cyclone furnace entering the cement decomposition furnace, which is used to judge the change of the ventilation resistance in the cyclone furnace;

[0017] S3: Obtain the pressure of the mixed feeding chamber. If the pressure exceeds the preset threshold, the pneumatic slide gate valve will be interlocked and closed through the distributed control system DCS to protect the safety of the upstream feeding equipment;

[0018] S4: Obtain the temperature of the mixed feeding chamber, which is used to judge the moisture content of the material entering the cyclone furnace, and adjust the amount of raw meal entering the cyclone furnace through the distributed control system DCS.

[0019] The beneficial effects of the present invention are as follows: on the one hand, it ensures the normal operation of the cyclone furnace system and improves the efficiency of the cyclone furnace in disposing of solid waste; on the other hand, it provides a monitoring basis for the associated operation and process adjustment of the cyclone furnace and the cement kiln firing system, and improves the overall operation level of the cyclone furnace system and the cement kiln firing system. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0021] Figure 1 It is a schematic structural diagram of the present invention;

[0022] Figure 2 It is a monitoring flow chart of the present invention;

[0023] In the figure, 1 - tertiary air branch pipe slide gate, 2 - tertiary air branch pipe, 3 - tertiary air main pipe, 4 - raw meal feeding pipe, 5 - pneumatic slide gate valve, 6 - mixed feeding chamber, 7 - cyclone furnace, 8 - cement rotary kiln, 9 - cement decomposition furnace. Detailed Embodiment

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0026] It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it is not necessary to further define and explain it in subsequent drawings.

[0027] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0028] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the term "connection" 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 invention can be understood according to specific circumstances.

[0029] The following will describe in detail some embodiments of the present invention with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0030] Embodiment 1:

[0031] Refer to Figure 1 , a rotary kiln operation monitoring system, including a rotary kiln 7, the rotary kiln 7 is arranged between the tertiary air main pipe 3 and the cement decomposition furnace 9, a tertiary air branch pipe 2 is arranged on the tertiary air main pipe 3, the tertiary air branch pipe 2 is connected to the mixing feeding chamber 6 through a raw material feeding pipe 4, the mixing feeding chamber 6 is connected to the rotary kiln 7, a cement rotary kiln 8 is arranged at the lower end of the cement decomposition furnace 9, a tertiary air branch pipe temperature sensor and a tertiary air branch pipe pressure sensor are arranged on the tertiary air branch pipe 2, a rotary kiln current sensor and a rotary kiln speed sensor are arranged on the rotary kiln 7, and the tertiary air branch pipe temperature sensor, the tertiary air branch pipe pressure sensor, the rotary kiln current sensor and the rotary kiln speed sensor are all connected to the distributed control system DCS through a transmission medium.

[0032] Further, in this embodiment, a damper for the tertiary air branch pipe 1 is also provided on the tertiary air branch pipe 2, and the damper for the tertiary air branch pipe 1 is connected to the distributed control system DCS.

[0033] Further, in this embodiment, a double-screw feeder pipe is provided on the mixed feeding chamber 6, and a pneumatic damper valve 5 is provided on the double-screw feeder pipe. The pneumatic damper valve 5 is connected to the distributed control system DCS.

[0034] Further, in this embodiment, a feed inlet temperature sensor and a feed inlet pressure sensor are provided on the raw material feed pipe 4, and both the feed inlet temperature sensor and the feed inlet pressure sensor are connected to the distributed control system DCS.

[0035] Further, in this embodiment, a mixed feeding chamber temperature sensor and a mixed feeding chamber pressure sensor are provided on the mixed feeding chamber 6, and both the mixed feeding chamber temperature sensor and the mixed feeding chamber pressure sensor are connected to the distributed control system DCS.

[0036] Further, in this embodiment, a cyclone furnace discharge temperature sensor, a cyclone furnace outlet gas temperature sensor, and a cyclone furnace discharge pressure sensor are also provided on the cyclone furnace 7. The cyclone furnace discharge temperature sensor, the cyclone furnace outlet gas temperature sensor, and the cyclone furnace discharge pressure sensor are all connected to the distributed control system DCS.

[0037] Further, in this embodiment, the transmission medium includes wired transmission or wireless transmission.

[0038] The cyclone furnace 7 uses the high-temperature tertiary air in cement production to rapidly dry and ignite the fed solid waste, achieving stable combustion. The generated waste gas enters the cement decomposition furnace 9 for continued combustion and decomposition, and the generated ash slag enters the cement decomposition furnace 9 and then enters the cement rotary kiln 8 for continuous calcination and solidification. Compared with various existing solid waste disposal devices (such as gasifiers, mechanical biological methods, hot plate furnaces, stepped furnaces, grate furnaces, etc.), the cyclone furnace 7 has unique advantages such as a relatively simple system, small floor area, less investment, stable and reliable operation, low operating costs, strong solid waste adaptability, and high burnout rate. Utilizing the high-temperature environment of the cement rotary kiln system can avoid secondary pollution. At the same time, the heat in domestic waste can also replace part of the coal consumption for utilization. Through high-temperature incineration and high-temperature sintering of cement clinker mineralization, the purpose of decomposing, degrading, eliminating, inerting, and stabilizing the toxic characteristics of domestic waste can be achieved. The cyclone furnace 7 for disposing of combustible waste has unique advantages such as waste resource utilization, good and thorough disposal effect, no secondary pollution, environmental protection, guaranteed product quality, utilization of existing industrial facilities, no additional land occupation, less investment, and low operating costs.

[0039] The distributed control system (DCS) can achieve the group program control of motors, as well as the acquisition, processing, display and regulation of process variables; it greatly improves labor productivity and the management and operation level of the factory. The cement process is a production process for handling solid and powdered materials. The thermal process changes caused by air, coal and materials are complex, and there are many uncontrollable factors. From the perspective of process control, it is a process with a long residence time, large time constants, many external interferences, and complex mutual interference relationships.

[0040] In view of the operating characteristics of the rotary kiln system, the present invention sets up the operating monitoring items for the main equipment of the rotary kiln system, which can provide reliable monitoring means for the safe operation of the rotary kiln system equipment. Combining the technological correlation characteristics of the rotary kiln system and the cement kiln firing system, the process parameter monitoring set can provide the monitoring elements of key information for the joint operation of the rotary kiln system and the cement kiln firing system. All the parameter data information obtained by the present invention is connected to the DCS control system in the cement plant. Through the PLC control program setting, it has the conditions of automatic and intelligent control. The DCS control system is the abbreviation of the distributed control system, and its main feature is its centralized management and decentralized control. DCS usually uses several controllers (process stations) to control numerous control points in a production process. The controllers are connected through a network and can exchange data. The operation is carried out by a computer operation station, which is connected to the controller through a network to collect production data and convey operation instructions. At present, the DCS control system has extremely wide applications in various industries such as cement, power, metallurgy, petrochemical, etc.

[0041] The monitoring method of the present invention includes the operation monitoring of the main equipment and the process operation monitoring.

[0042] Specifically, the operation monitoring of the main equipment includes:

[0043] S1: Obtain the current (or torque), speed and stator temperature of the drive motor of the rotary kiln 7 to monitor the operating speed, load, material filling rate in the rotary kiln 7 and incineration temperature of the rotary kiln 7. The selection of the monitoring instrument is formulated according to the equipment requirements.

[0044] S2: Obtain the bearing temperature and vibration value of the transmission reduction gear to monitor the operating conditions and force stability of the transmission reduction gear of the rotary kiln; the bearing temperature of the reduction gear ≤ 65°C, and the vibration value of the bearing seat ≤ 2 mm / s.

[0045] S3: Obtain the temperature of the supporting device's idler bearing bush to monitor the force and lubrication conditions of the idler wheel, and the bearing temperature ≤ 65°C.

[0046] S4: Obtain the working pressure and displacement indication of the thrust control device to monitor the downward thrust and the upward and downward thrust of the rotary kiln 7.

[0047] S5: Obtain the temperature scanner of the rotary kiln 7 cylinder to monitor the integrity of the refractory material in the rotary kiln 7 and the temperature distribution inside the furnace during incineration;

[0048] S6: Obtain the given and feedback values of the tertiary air valve actuator entering the rotary kiln 7 to adjust and display the proportion of the tertiary air entering the rotary kiln 7.

[0049] Specifically, refer to Figure 2 , the process operation monitoring includes:

[0050] S1: Obtain the temperature of the tertiary air branch pipe 2 entering the rotary kiln 7 and the temperature of the rotary kiln 2 entering the cement decomposition furnace 9 to judge the temperature change caused by the heat absorption of the solid waste in the rotary kiln 7 and the heat release during incineration;

[0051] S2: Obtain the pressure of the tertiary air branch pipe 2 entering the rotary kiln 7 and the pressure of the rotary kiln 7 entering the cement decomposition furnace 9 to judge the change of the ventilation resistance in the rotary kiln 7;

[0052] S3: Obtain the pressure of the mixed feeding chamber 6. If the pressure exceeds the preset threshold, the pneumatic gate valve 5 will be interlocked and closed through the distributed control system DCS to protect the safety of the upstream feeding equipment;

[0053] S4: Obtain the temperature of the mixed feeding chamber 6 to judge the moisture content of the material entering the rotary kiln 7, and adjust the raw material amount entering the rotary kiln 7 through the distributed control system DCS.

[0054] Specifically, the preset threshold of the pressure of the mixed feeding chamber 6 is -2000 - 0 Pa; the preset threshold of the temperature of the mixed feeding chamber 6 is 0 - 1200 degrees Celsius. When the temperature of the mixed feeding chamber 6 exceeds 1200 degrees Celsius, the raw material amount entering the rotary kiln 7 will be increased.

[0055] On the one hand, the present invention provides a monitoring and control scheme to ensure the normal operation of the rotary kiln system and improve the efficiency of the rotary kiln in disposing solid waste; on the other hand, it provides a monitoring basis for the associated operation and process adjustment of the rotary kiln and the cement kiln firing system, and improves the overall operation level of the rotary kiln system and the cement kiln firing system.

[0056] It should be noted that for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, some steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily essential to the present application.

[0057] In addition, the terms "connected" and "arranged" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the indicated technical features. Thus, features defined with "connected" and "arranged" may explicitly or implicitly include one or more of such features. Moreover, terms such as "connected" and "arranged" are used to distinguish similar objects and need not be used to describe a particular order or sequence. It should be understood that the data used in this way may be interchangeable under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order different from those illustrated or described herein.

[0058] In the above embodiments, the basic principles, main features and advantages of the present invention have been described. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, any modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A rotary kiln operation monitoring system, including a rotary kiln (7), the rotary kiln (7) is arranged between the tertiary air main pipe (3) and the cement decomposition furnace (9), a tertiary air branch pipe (2) is arranged on the tertiary air main pipe (3), the tertiary air branch pipe (2) is connected to the mixing feeding chamber (6) through a raw material feeding pipe (4), the mixing feeding chamber (6) is connected to the rotary kiln (7), and a cement rotary kiln (8) is arranged at the lower end of the cement decomposition furnace (9). Characterized in that, A tertiary air branch pipe temperature sensor and a tertiary air branch pipe pressure sensor are arranged on the tertiary air branch pipe (2), a rotary kiln current sensor and a rotary kiln rotation speed sensor are arranged on the rotary kiln (7), and the tertiary air branch pipe temperature sensor, the tertiary air branch pipe pressure sensor, the rotary kiln current sensor and the rotary kiln rotation speed sensor are all connected to the distributed control system DCS through a transmission medium; A tertiary air branch pipe gate (1) is further arranged on the tertiary air branch pipe (2), and the tertiary air branch pipe gate (1) is connected to the distributed control system DCS; a double-tube reamer feeding pipe is arranged on the mixing feeding chamber (6), a pneumatic gate valve (5) is arranged on the double-tube reamer feeding pipe, and the pneumatic gate valve (5) is connected to the distributed control system DCS; an inlet temperature sensor and an inlet pressure sensor are arranged on the raw material feeding pipe (4), and the inlet temperature sensor and the inlet pressure sensor are both connected to the distributed control system DCS; A mixing feeding chamber temperature sensor and a mixing feeding chamber pressure sensor are arranged on the mixing feeding chamber (6), and the mixing feeding chamber temperature sensor and the mixing feeding chamber pressure sensor are both connected to the distributed control system DCS; A rotary kiln discharge temperature sensor, a rotary kiln outlet gas temperature sensor and a rotary kiln discharge pressure sensor are further arranged on the rotary kiln (7), and the rotary kiln discharge temperature sensor, the rotary kiln outlet gas temperature sensor and the rotary kiln discharge pressure sensor are all connected to the distributed control system DCS.

2. A rotary kiln operation monitoring system according to claim 1, Characterized in that, The transmission medium includes wired transmission or wireless transmission.

3. A rotary kiln operation monitoring method, implemented based on the rotary kiln operation monitoring system according to any one of claims 1 to 2, Characterized in that, Including the following steps: S1: Obtain the temperature of the tertiary air branch pipe (2) entering the rotary kiln (7) and the temperature of the rotary kiln (7) entering the cement decomposition furnace (9) to judge the temperature change generated by the heat absorption of solid waste in the rotary kiln (7) and the heat release of incineration; S2: Obtain the pressure of the tertiary air branch pipe (2) entering the rotary kiln (7) and the pressure of the rotary kiln (7) entering the cement decomposition furnace (9) to judge the change of the ventilation resistance in the rotary kiln (7); S3: Obtain the pressure of the mixing feeding chamber (6), if the pressure exceeds the preset threshold, the pneumatic gate valve (5) is interlocked and closed through the distributed control system DCS to protect the safety of the upstream feeding equipment. S4: Obtain the temperature of the mixed feeding chamber (6) to judge the moisture content of the material entering the rotary kiln (7), and adjust the amount of raw meal entering the rotary kiln (7) through the distributed control system DCS.

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