On-line monitoring system for oxygen content in industrial kiln

Abstract

The utility model discloses an industrial kiln oxygen content on -line monitoring system, including hot -blast unit and monitoring unit, and hot -blast unit includes hot -blast pipeline and electric valve, and the air source end of hot -blast pipeline is connected with hot -blast source and its air outlet is connected with kiln inner chamber, and monitoring unit includes high temperature oxygen sensor, on -line oxygen analyzer and control unit, and the temperature signal output end of high temperature oxygen sensor, oxygen content signal output end all are connected with the signal input end of on -line oxygen analyzer, and the output of on -line oxygen analyzer is connected with the input of control unit, and the output of control unit is connected with the input of electric valve, the utility model discloses installing a high temperature oxygen sensor in kiln inner chamber, utilizes high temperature oxygen sensor real -time monitoring kiln inner chamber's temperature and atmosphere, adjusts the opening of electric valve according to the oxygen content of detected, and then adjusts the hot -blast flow of entering kiln, realizes the dynamic regulation of kiln internal atmosphere, improves the high -precision control of kiln inner chamber atmosphere, improves the qualified rate of product.

Description

Technical Field

[0001] This utility model relates to industrial kilns, and more particularly to an online monitoring system for oxygen content in industrial kilns. Background Technology

[0002] In the production of ceramics, refractory materials, and carbon products, firing in kilns is typically required. The quality of the fired products depends primarily on factors such as temperature, atmosphere, and pressure within the kiln, with the atmosphere being a key factor affecting firing quality. In actual production, improper control of the firing atmosphere often leads to defects in the finished products, such as color differences, dimensional discrepancies, deformation, cracking, and insufficient hardness, increasing production costs.

[0003] Taking a ceramic mold firing trolley furnace as an example: During the firing process, some products require a reducing atmosphere, while others require an oxidizing atmosphere. Furthermore, the required excess air coefficient for combustion varies at each firing stage. If the firing atmosphere in the furnace does not meet the process requirements, it will affect the quality of the fired products. Therefore, it is necessary to constantly monitor the atmosphere inside the furnace during firing. Traditional atmosphere monitoring relies on manual observation of the flame color through the kiln's observation port, periodic sampling from inside the furnace for offline oxygen content analysis, and manual adjustments based on the results to ensure that the air-fuel ratio coefficient during combustion is within the required range. However, manual flame observation and offline detection have inherent discrepancies, making it impossible to obtain the actual situation of the atmosphere inside the furnace in a timely manner, resulting in significant errors. Summary of the Invention

[0004] In view of this, the present invention proposes an online monitoring system for oxygen content in industrial kilns.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The industrial kiln oxygen content online monitoring system of this utility model includes a hot air unit and a monitoring unit. The hot air unit includes a hot air duct communicating with the kiln cavity and an electric valve installed on the hot air duct. The air source end of the hot air duct is connected to a hot air source and its air outlet is connected to the kiln cavity. The monitoring unit includes a high-temperature oxygen sensor, an online oxygen analyzer and a control unit. The high-temperature oxygen sensor is a direct-insertion oxygen sensor that is sealed and inserted into the kiln wall of the kiln, and its probe is located in the kiln cavity. The temperature signal output terminal and oxygen content signal output terminal of the high-temperature oxygen sensor are both connected to the signal input terminal of the online oxygen analyzer. The air pump of the online oxygen analyzer is connected to the high-temperature oxygen sensor through a reference gas guide pipe. The output terminal of the online oxygen analyzer is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the input terminal of the electric valve. The beneficial effects are: This invention installs a high-temperature oxygen sensor inside the kiln cavity, which monitors the temperature and atmosphere inside the kiln cavity in real time. Based on the detected atmosphere, the opening degree of the electric valve can be adjusted to regulate the flow rate of hot air entering the kiln cavity, thereby achieving dynamic regulation of the atmosphere inside the kiln, improving the high-precision control of the kiln cavity atmosphere, and ultimately increasing the product qualification rate.

[0006] Preferably, the electric valve is an airflow regulating valve; the hot air duct includes a main pipe and a bypass branch, the electric valve is installed on the main pipe, and a first valve is installed on the main pipe at both ends of the electric valve. The first valve is a normally open manual valve; a second valve is installed on the bypass branch, and the second valve is a normally closed manual valve. The beneficial effect is that the hot air supply of this utility model is divided into one channel. When the electric valve malfunctions, the first valve can be closed and the second valve opened, allowing hot air to be supplied through the bypass pipe, ensuring that the oxygen content inside the kiln is within the required range, thereby ensuring the firing quality of the products and improving the pass rate.

[0007] Preferably, the control unit includes a controller and an alarm. The output terminal of the online oxygen analyzer is connected to the input terminal of the controller, and the signal output terminal of the controller is connected to the signal input terminal of the alarm. The controller of this invention can send an alarm signal to the alarm, prompting staff to check the operation of the hot air ducts or manually adjust the hot air supply to ensure the atmosphere inside the kiln.

[0008] Preferably, the monitoring unit further includes an instrument box, in which the online oxygen analyzer is installed. This invention protects the analyzer by installing the online oxygen analyzer inside the instrument box. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of this utility model.

[0010] Figure 2 This is a circuit block diagram of this utility model. Detailed Implementation

[0011] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific operation processes. However, the protection scope of this utility model is not limited to the following embodiments.

[0012] It should be noted that in the description of this utility model, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0013] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0014] like Figure 1-2 As shown, this utility model proposes an online oxygen content monitoring system for industrial kilns, including a hot air unit and a monitoring unit. The hot air unit includes a hot air duct connected to the inner cavity of the kiln 1 and an electric valve 2 installed on the hot air duct. One end of the hot air duct is connected to a hot air source, and the other end is connected to the inner cavity of the kiln 1 to introduce hot air into the inner cavity of the kiln 1. The monitoring unit includes a high-temperature oxygen sensor 3, an online oxygen analyzer, and a control unit. The high-temperature oxygen sensor 3 is a direct-insertion oxygen sensor that is sealed and inserted into the kiln wall of the kiln 1. Its probe is located in the inner cavity of the kiln 1 and is used to acquire the temperature signal and oxygen concentration signal of the inner cavity of the kiln 1. The temperature signal output terminal and the oxygen content signal output terminal of the high-temperature oxygen sensor 3 are both connected to the signal input terminal of the online oxygen analyzer. The air pump of the online oxygen analyzer is connected to the high-temperature oxygen sensor 3 through a reference gas guide pipe 4. The output terminal of the online oxygen analyzer is connected to the input terminal of the control unit. The output terminal of the control unit is connected to the input terminal of the electric valve 2. The control unit controls the opening and closing and the degree of opening of the electric valve 2 (preferably a hot air regulating butterfly valve).

[0015] In actual operation, the air pump introduces reference gas (dry air) into the high-temperature oxygen sensor 3 through the reference gas guide pipe 4. The high-temperature oxygen sensor 3 acquires the temperature and oxygen content signals of the inner cavity of the kiln 1 in real time, and transmits the acquired temperature and oxygen content signals to the online oxygen analyzer. The online oxygen analyzer analyzes the temperature and oxygen content signals and displays them on its own display screen. The online oxygen analyzer transmits the acquired oxygen content information to the control unit. The control unit adjusts the opening of the electric valve 2 according to the received oxygen content information. By adjusting the flow rate of hot air entering the inner cavity of the kiln 1, the internal atmosphere of the kiln 1 is dynamically adjusted, thereby improving the high-precision control of the atmosphere inside the kiln 1 and thus improving the product qualification rate.

[0016] In this invention, the control unit includes a controller and an alarm. The output terminal of the online oxygen analyzer is connected to the input terminal of the controller, and the signal output terminal of the controller is connected to the signal input terminal of the alarm. The hot air duct includes a main pipe 5 and a bypass branch 6. An electric valve 2 is installed on the main pipe 5, with two first valves 7 located at either end of the electric valve 2. Both first valves 7 are normally open manual valves. A second valve 8 is installed on the bypass branch 6; the second valve 8 is normally closed manual valve. During operation, the controller controls the opening of the electric valve 2 based on the received oxygen content information within the kiln 1, adjusting the oxygen content of the kiln 1 by regulating the hot air intake. When the oxygen content in the kiln 1 exceeds a preset time without adjustment (electric valve 2 malfunction), an alarm sounds, the first valve 7 closes, and the second valve 8 opens, disconnecting the connection between the main pipe 5 and the kiln 1. Hot air is then supplied to the kiln 1 via the bypass branch 6. The opening of the second valve 8 is adjusted to regulate the hot air intake of the kiln 1, thereby regulating the oxygen content until it is within the required range, thus ensuring the firing quality of the products and improving the pass rate.

[0017] Combination Figure 1 It can be seen that the monitoring unit of this utility model also includes an instrument box 9, in which the online oxygen analyzer is installed. Installing the online oxygen analyzer in the instrument box 9 can protect the online oxygen analyzer. The monitoring unit also includes a control cabinet 10, in which the control unit is installed to protect the control unit.

[0018] It should be noted that the controller of this utility model can be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), and a state machine, etc. It can also be a PLC, or an industrial control computer with computer attributes and characteristics. Of course, the controller can also be equipped with a wireless communication module to realize the connection with a remote terminal and receive control commands from the remote terminal.

[0019] Finally, it should be emphasized that the above description is merely a preferred embodiment of this utility model and is not intended to limit this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An online monitoring system for oxygen content in industrial kilns, characterized in that: The system includes a hot air unit and a monitoring unit. The hot air unit includes a hot air duct that communicates with the inner cavity of the kiln and an electric valve installed on the hot air duct. The air source end of the hot air duct is connected to a hot air source, and its air outlet is connected to the inner cavity of the kiln. The monitoring unit includes a high-temperature oxygen sensor, an online oxygen analyzer, and a control unit. The high-temperature oxygen sensor is a direct-insertion oxygen sensor that is sealed and inserted into the kiln wall of the kiln, and its probe is located in the inner cavity of the kiln. The temperature signal output terminal and oxygen content signal output terminal of the high-temperature oxygen sensor are both connected to the signal input terminal of the online oxygen analyzer. The gas pump of the online oxygen analyzer is connected to the high-temperature oxygen sensor through a reference gas guide tube. The output terminal of the online oxygen analyzer is connected to the input terminal of the control unit. The output terminal of the control unit is connected to the input terminal of the electric valve.

2. The online monitoring system for oxygen content in industrial kilns according to claim 1, characterized in that: The electric valve is an air volume regulating valve; the hot air duct includes a main pipe and a bypass branch, the electric valve is installed on the main pipe, and a first valve is installed on the main pipe at both ends of the electric valve. The first valve is a normally open manual valve; a second valve is installed on the bypass branch. The second valve is a normally closed manual valve.

3. The online monitoring system for oxygen content in industrial kilns according to claim 2, characterized in that: The control unit includes a controller and an alarm. The output terminal of the online oxygen analyzer is connected to the input terminal of the controller, and the signal output terminal of the controller is connected to the signal input terminal of the alarm.

4. The online monitoring system for oxygen content in industrial kilns according to claim 1, characterized in that: The monitoring unit also includes an instrument box, in which the online oxygen analyzer is installed.

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