Accurate temperature measurement system for treating low-calorific-value industrial waste salt by rotary kiln

Abstract

The utility model discloses an accurate temperature measurement system for treating low-calorific-value industrial waste salt by a rotary kiln, and relates to the field of thermotechnical measurement. The system comprises a temperature measuring device, a wireless signal transmitting module, a power supply, a wireless signal receiving module and an upper computer. The temperature measuring device comprises an armored thermocouple, a fixing device of the armored thermocouple and a signal transmitter. The signal transmitter transmits the temperature signal into a 4-20 mA current signal and transmits the 4-20 mA current signal to the wireless signal transmitting module through a wire. And the wireless signal transmitting module communicates with the wireless signal receiving module based on a Zigbee communication protocol. The wireless signal receiving module communicates with an upper computer based on a Modbus RTU communication protocol and displays the collected temperature value through upper computer configuration software. The system can be expanded and comprises a plurality of wireless signal transmitting modules. The system is flexible in sensor arrangement, stable in signal, high in anti-interference performance and low in investment cost, the temperature of the low-heating-value industrial waste salt material in the rotary kiln can be accurately measured and displayed in real time, the treatment effect is guaranteed, and the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of thermal measurement, and in particular to a precise temperature measurement system for rotary kiln processing low-calorific-value industrial waste salt. Background Technology

[0002] Rotary kiln heating and carbonization is the primary method for removing organic matter from low-calorific-value industrial waste salt. The kiln temperature (typically 300-600℃) is one of the most crucial process parameters. It needs to be controlled within a specific temperature range based on the type of organic matter in the waste salt. Excessive temperature can cause the waste salt to melt, leading to salt particle agglomeration, slag adhesion to the walls, and ring formation within the kiln, thus affecting production efficiency. Conversely, insufficient temperature will prevent the rapid decomposition and carbonization of the organic matter. Along the axial direction of the rotary kiln, the organic matter in the waste salt undergoes complex oxidation-reduction reactions with the combustion flue gas, resulting in complex temperature variations. Therefore, it is necessary to develop a temperature measurement system capable of accurately, reliably, and in real-time measuring the temperature of the waste salt within the rotary kiln to monitor and control the kiln temperature. Clearly, traditional methods of temperature measurement only at the kiln head and tail are insufficient to meet the requirements.

[0003] The rotation of the rotary kiln body poses a significant challenge to the accurate measurement of axial kiln temperature. Currently, there are two main methods: indirect and direct measurement. Indirect measurement primarily involves using an infrared thermometer outside the rotary kiln to measure the outer shell temperature. Based on the kiln wall thickness, the internal temperature is calculated. However, this method is not accurate, and the internal temperature does not perfectly match the material temperature. Direct measurement involves creating temperature sensing holes in the kiln body and inserting thermocouples to accurately measure the material temperature inside the kiln. However, this method presents two difficulties: firstly, preventing material accumulation and blockage in the sensing holes can lead to inaccurate measurements. Patent ZL202020884776.5 discloses a sleeve-type material removal device in a wireless temperature measurement system for rotary kilns, but its structure is complex and its cost is high. Another challenge is the reliable, real-time transmission of the measured temperature signal. Currently, there are two main methods. One is the slip ring method, where the signal line is connected to a slip ring around the kiln body. The slip ring contacts a stationary device fixed to the kiln support base, and the temperature signal is then transmitted to the host computer system via a cable. However, after long-term operation, the slip ring and the stationary device experience increased wear, leading to poor contact and unstable signal transmission. The second method is wireless transmission. Patent ZL202323207256.3 discloses a rotary kiln wireless temperature measurement system. This system sets up several wireless temperature sensors on the rotary kiln body and uses the IEEE 802.11ax communication protocol (WiFi 6) to manage the wireless temperature sensors and communicate with the wireless management platform. However, WiFi 6 has weak anti-interference capabilities, and the heat radiation generated by the rotary kiln can seriously affect the reliability of communication between the wireless temperature sensors, the wireless multi-functional gateway, and the wireless management platform. Furthermore, WiFi 6 has high power consumption, requiring high-capacity batteries, which increases the cost. Utility Model Content

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a precise temperature measurement system for rotary kilns processing low-calorific-value industrial waste salt. The system aims to measure the axial material temperature within the kiln in real-time and accurately during the processing of low-calorific-value industrial waste salt, while improving the stability and reliability of temperature signal transmission and reducing equipment investment costs. Therefore, the technical solution adopted by this invention is as follows:

[0005] A precise temperature measurement system for treating low-calorific-value industrial waste salt in a rotary kiln comprises the following components: a temperature measuring device, a wireless signal transmitting module, a power supply, a wireless signal receiving module, and a host computer. Multiple temperature measuring devices are arranged axially on the rotary kiln body. Each device consists of an armored thermocouple and its fixing device, and a signal transmitter. The signal transmitter is connected to the armored thermocouple, converting the temperature signal into a 4-20mA current signal. This 4-20mA current signal is then transmitted to the wireless signal transmitting module via a wire. The integrated A / D converter within the wireless signal transmitting module converts the current signal into a digital signal and communicates with the wireless signal receiving module based on the Zigbee communication protocol. Communication between the wireless signal receiving module and the host computer is based on the Modbus RTU communication protocol. The acquired temperature values ​​are displayed using the host computer's configuration software. Multiple temperature measuring devices are connected to the wireless signal transmitting module via wires, and one or more wireless signal transmitting modules and the wireless signal receiving module form a data transmission network.

[0006] In the above scheme, the outer shell of the armored thermocouple is made of high-temperature resistant stainless steel or ceramic. It is inserted into the interior through the through hole of the rotary kiln body. The end of the through hole is shaped like an enlarged trumpet, with a depth of not less than 1.5 cm and an flaring angle of not less than 45°. The end of the armored thermocouple protrudes from the trumpet but does not protrude from the inner wall of the kiln body, remaining 0.5-1.0 cm away from the inner wall of the kiln body. The space between the armored thermocouple and the through hole of the kiln body is filled with heat insulation cotton or heat insulation pad.

[0007] In the above scheme, one end of the armored thermocouple fixing device is fixedly connected to the rotary kiln body, and the other end is connected to the armored thermocouple by thread or flange connection.

[0008] In the above scheme, the wireless signal transmitting module and the power supply are both placed in the distribution box. The distribution box is fixedly installed on the rotary kiln body and rotates with the rotary kiln. A heat insulation and heat dissipation device is provided between the distribution box and the rotary kiln body.

[0009] In the above scheme, a wire support is fixedly connected to the rotary kiln body to prevent the wire from contacting the rotary kiln body.

[0010] Compared with the prior art, the beneficial effects of this utility model are:

[0011] 1) The thermocouple is in direct contact with the waste salt material in the rotary kiln, and the end of the kiln body through hole is made into a funnel shape to avoid material accumulation, and can accurately and in real time measure the material temperature.

[0012] 2) The thermocouple and signal transmitter are integrated into one device, avoiding the attenuation and interference of temperature signal during long-distance transmission; this utility model converts the temperature signal into a 4-20mA current signal and transmits it to the wireless signal transmission module through a wire. Compared with voltage signals and wireless transmission methods, it has stronger anti-attenuation and anti-thermal radiation interference capabilities, which makes the signal transmission more stable and reliable.

[0013] 3) Multiple temperature measurement devices are connected to a single wireless signal transmission module via wires, reducing the wireless signal transmission path. This not only lowers the probability of interference from thermal radiation and enhances the stability and reliability of signal transmission, but also simplifies the network and reduces equipment investment costs.

[0014] 4) Utilizing wireless temperature data transmission avoids the instability issues caused by poor contact in slip ring systems. Furthermore, the Zigbee communication protocol provides stronger anti-interference capabilities than WiFi 6 and Bluetooth, resulting in more stable and reliable signal transmission. Additionally, Zigbee devices consume significantly less power than WiFi 6 devices, approximately 1 / 10 or even less, thus requiring less battery capacity and consequently reducing device cost.

[0015] In summary, this invention overcomes the shortcomings of current technology, enabling accurate and real-time measurement of the axial material temperature inside the rotary kiln when processing low-calorific-value industrial waste salt, improving the stability and reliability of signal transmission, and reducing equipment investment costs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from the drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structural framework of this utility model;

[0018] The numbers in the diagram are explained as follows: 1 Temperature measuring device, 2 Wireless signal transmitting module, 3 Power supply, 4 Distribution box, 5 Wireless signal receiving module, 6 Host computer, 7 Wire support, 1-1 Signal transmitter, 1-2 Armored thermocouple, 1-3 Armored thermocouple fixing device, 1-4 Kiln body, 1-5 Refractory layer, 1-6 Insulation cotton, 1-7 Insulation sealing gasket, 1-8 Horn mouth. Detailed Implementation

[0019] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the following description is provided in conjunction with the appendix. Figure 1 The present invention will be further described in detail below with reference to specific embodiments.

[0020] This embodiment employs a precise temperature measurement system for treating low-calorific-value industrial waste salt in a rotary kiln, comprising a temperature measuring device 1, a wireless signal transmitting module 2, a power supply 3, a power distribution box 4, a wireless signal receiving module 5, and a host computer 6.

[0021] In this embodiment, several temperature measuring devices 1 are arranged axially on the rotary kiln body. In this embodiment, there are 6 temperature measuring devices 1, namely... Figure 1 T1-T6 in the middle are distributed sequentially at equal intervals to the kiln tail.

[0022] Each temperature measuring device 1 in this embodiment consists of one armored thermocouple 1-2 and its fixing device 1-3, and one signal transmitter 1-1. The armored thermocouple 1-2 and the signal transmitter 1-1 are integrated into one device. In this embodiment, a flange sleeve is used as the armored thermocouple fixing device 1-3. Alternatively, a sleeve with internal threads can be used, one end of which is either fully welded to the rotary kiln body. The armored thermocouple 1-2 passes through the flange sleeve into the rotary kiln body, or is connected to the flange sleeve through a flange or through threads.

[0023] In this embodiment, the kiln body through-hole passes through the kiln body 1-4 and the refractory layer 1-5, with the end forming an enlarged trumpet shape. The depth of the trumpet 1-8 is 1.5cm, and the flaring angle is 60°. The outer shell of the armored thermocouple 1-2 is made of high-temperature resistant stainless steel or ceramic. It is vertically inserted into the rotary kiln through the kiln body through-hole, passing through the trumpet and without its end protruding from the inner wall of the kiln, remaining 0.5-1.0cm away from the inner wall of the kiln. Insulating cotton 1-6 is filled between the armored thermocouple 1-2 and the kiln body through-hole, and an insulating sealing gasket 1-7 is provided at the bottom of the trumpet 1-8 to prevent waste salt material inside the kiln from leaking into the kiln body through-hole.

[0024] In this embodiment, the signal transmitters 1-1 of the six temperature measuring devices 1 are all connected to a signal transmitting module 2 via wires. These transmitters convert the temperature signals measured by the armored thermocouples 1-2 into 4-20mA current signals and transmit them to the corresponding input ports on the wireless signal transmitting module 2. The wires are mica-wrapped high-temperature wires, and several wire supports 7 are provided along the wire path to prevent the wires from contacting the rotary kiln body. The wire supports 7 are made of steel, welded to the kiln body, and have heat-insulating pads at the points of contact with the wires.

[0025] In this embodiment, a lithium battery (3) is used as the power source to power the wireless signal transmitting module (2), with a power supply voltage of 24VDC. Both the wireless signal transmitting module (2) and the power source (3) are installed inside the distribution box (4), protecting the internal electronic equipment from harsh environmental conditions such as wind, sun, and rain. To ensure effective wireless signal transmission, the wireless signal transmitting module (2) is equipped with an external antenna, which is led to the outside of the distribution box (4). The distribution box (4) is mounted on the rotary kiln body using a heat insulation and heat dissipation device, which includes a mounting bracket welded to the rotary kiln body with studs. The distribution box (4) is mounted on the mounting bracket, and heat insulation is provided between the distribution box (4) and the mounting bracket using heat insulation pads or insulation cotton.

[0026] In this embodiment, multiple temperature measuring devices are connected to one wireless signal transmitting module via wires. One or more wireless signal transmitting modules and the wireless signal receiving module form a wireless data transmission network. This embodiment also includes multiple wire supports on the rotary kiln body. These supports can be triangular or needle-shaped, with the wires passing through holes at the top of the supports to prevent direct contact between the wires and the rotary kiln body. The wire supports are made of heat-insulating materials or have a good heat dissipation structure to prevent high-temperature damage to the wires.

[0027] In this embodiment, the wireless signal transmitting module 2 integrates an A / D converter, which can convert the 4-20mA current signal transmitted by the wire into a digital signal, and communicate with the wireless signal receiving module 5 via network based on the Zigbee communication protocol.

[0028] In this embodiment, the wireless signal receiving module 5 communicates the received digital signals with the host computer 6 via the Modbus RTU protocol. The host computer 6 converts the acquired digital signals into temperature values ​​and displays them through configuration software, thereby assisting in the control of the temperature of the waste salt material in the rotary kiln, ensuring the removal effect of organic matter in the waste salt, and improving production efficiency.

[0029] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A precise temperature measurement system for treating low-calorific-value industrial waste salt in a rotary kiln, characterized in that, The system includes temperature measuring devices, a wireless signal transmitting module, a power supply, a wireless signal receiving module, and a host computer. Multiple temperature measuring devices are arranged axially on the rotary kiln body. Each temperature measuring device consists of an armored thermocouple and its fixing device, and a signal transmitter. The signal transmitter is connected to the armored thermocouple and transmits a 4-20mA current signal to the wireless signal transmitting module via a wire. The integrated A / D converter in the wireless signal transmitting module converts the current signal into a digital signal and communicates with the wireless signal receiving module based on the Zigbee communication protocol. Communication between the wireless signal receiving module and the host computer is based on the Modbus RTU communication protocol. The acquired temperature values ​​are displayed through the host computer's configuration software. Multiple temperature measuring devices are connected to the wireless signal transmitting module via wires, and the wireless signal transmitting and receiving modules form a data transmission network. The outer shell of the armored thermocouple is made of high-temperature resistant stainless steel or ceramic. It is inserted into the rotary kiln through a through-hole in the kiln body. The end of the through-hole is shaped like an enlarged trumpet, and the end of the armored thermocouple protrudes through the trumpet without protruding from the inner wall of the kiln.

2. The precise temperature measurement system for rotary kiln treatment of low-calorific-value industrial waste salt as described in claim 1, characterized in that, The depth of the flared opening is not less than 1.5 cm, and the flaring angle is not less than 45°; the end of the armored thermocouple is 0.5-1.0 cm away from the inner wall of the kiln, and the space between the armored thermocouple and the kiln through hole is filled with heat insulation cotton or heat insulation pad.

3. The precise temperature measurement system for rotary kiln treatment of low-calorific-value industrial waste salt as described in claim 2, characterized in that, One end of the armored thermocouple fixing device is fixedly connected to the rotary kiln body, and the other end is connected to the armored thermocouple by thread or flange.

4. The precise temperature measurement system for rotary kiln treatment of low-calorific-value industrial waste salt as described in claim 1, characterized in that, The wireless signal transmitting module and power supply are both placed in the distribution box. The distribution box is fixedly installed on the rotary kiln body and rotates with the rotary kiln. A heat insulation and heat dissipation device is provided between the distribution box and the rotary kiln body.

5. The precise temperature measurement system for rotary kiln treatment of low-calorific-value industrial waste salt as described in claim 1, characterized in that, A wire support is fixedly connected to the rotary kiln body to prevent the wires from coming into contact with the kiln body.

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