Simulation device for pellet drying preheating system and burst temperature detection

Abstract

The utility model discloses a simulation device for pellet drying preheating schedule and burst temperature detection, and belongs to the technical field of iron ore pellets. The simulation device comprises a control cabinet system and a heat preservation furnace body which are connected through a heat-resistant pipeline, a computer, a frequency conversion Roots blower, a temperature controller and a flow controller are integrated in the control cabinet system, and the frequency conversion Roots blower, the temperature controller and the flow controller are in communication connection with the computer. The other end extends into the heat preservation furnace body and is divided into three branches which are connected in parallel; the high-temperature radiant tube and the crucible are arranged in the heat-resistant pipeline, the high-temperature radiant tube is used for generating heat, and the crucible is used for containing green pellets. The variable-frequency Roots blower is controlled through the computer and the flow controller, forward rotation and reverse rotation of the flow of the variable-frequency Roots blower are set, and therefore the pellet drying system is simulated, the temperature and the flow can be accurately and rapidly controlled, green pellet bursting temperature can be detected through multiple static and dynamic methods, the automation degree of the device is high, and the detection efficiency is greatly improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of iron ore pellets, and more specifically relates to a pellet drying preheating system and a simulation device for bursting temperature detection. Background Art

[0002] Iron ore pellets are high-quality raw materials / furnace materials for blast furnace ironmaking, direct reduction and smelting reduction processes. Compared with the sintering process, the pelletizing process has great advantages in terms of processing costs, energy consumption and pollutant emissions. In recent years, with the increasing requirements for energy conservation and emission reduction, there is a broad space for the further development of iron ore pellets.

[0003] The bursting temperature of green balls is one of the important indicators of pellet production. During the drying process of green balls, the water in the balls evaporates continuously through internal diffusion and surface gasification. If the internal vapor pressure is too high, the green balls may burst, deteriorating the air permeability of the ball layer, and ultimately leading to reduced yield, uneven quality of finished balls, and even kiln ringing. At present, the determination of green ball bursting temperature mostly refers to the dynamic detection method of AC Company in the United States. Based on this method, different scholars have designed different detection devices. However, these devices often detect the number of bursts of pellets at a certain constant temperature, ignoring the influence of the drying system on the bursting temperature of pellets, which is very different from the actual production (especially the chain grate-rotary kiln and belt roasting machine processes), and there are also disadvantages such as difficulty in cooling, poor precision, and low efficiency.

[0004] For example, Chinese patent applications No. 200910084434.3 and No. 201320050825.5 both designed a device for measuring the bursting temperature of pellets. The first patent application used exhaust gas combustion to dry the raw pellets, which caused problems such as difficulty in controlling temperature and flow rate. The second patent application used a resistance furnace to heat the corundum balls for heat storage, and then used the corundum balls to heat the cold air, which caused problems such as difficulty in heating and cooling (especially cooling), low experimental efficiency, and easy blockage of the pipeline. More importantly, the measuring devices provided in the above two applications ignored the important influence of the pellet drying system on the measurement of the bursting temperature of pellets, which would cause large errors in the test results. Utility Model Content

[0005] 1. Problem to be solved

[0006] In view of the deficiencies raised in the above-mentioned background technology, the utility model provides a simulation device for pellet drying preheating system and bursting temperature detection. By simulating the quality status of the green pellet drying process during exhaust drying and blast drying in actual production, combined with a tubular furnace and roasting pellet strength detection equipment, a complete set of pellet production process can be simulated, which can more systematically observe the law of pellet strength change and is also more conducive to guiding pellet production.

[0007] 2. Technical solution

[0008] In order to solve the above problems, the technical solution adopted by the utility model is as follows:

[0009] The utility model provides a simulation device for pellet drying preheating system and burst temperature detection, including a control cabinet system and a heat preservation furnace, wherein the control cabinet system is provided with a computer, and a variable frequency Roots blower, a temperature controller and a flow controller which are respectively communicated and connected with the computer, and is used to realize automatic control of the work of the variable frequency Roots blower, the temperature controller and the flow controller, specifically:

[0010] The air outlet of the variable frequency Roots blower is connected to one end of the heat-resistant pipe, the other end of the heat-resistant pipe extends into the insulation furnace and is divided into three branches connected in parallel, a vortex flowmeter is installed on the heat-resistant pipe outside the insulation furnace, and the vortex flowmeter is communicatively connected with the flow controller to control the flow rate and wind speed of the variable frequency Roots blower for blowing or exhausting air;

[0011] The three branches of the heat-resistant pipeline are the first branch, the second branch and the third branch. The first branch is provided with a PLC remote-controlled electric valve, and the pipeline connected to the second branch is also provided with a PLC remote-controlled electric valve for switching the direction of the blown gas through the pellet layer. The second branch is provided with a high-temperature radiation tube for generating heat or heating cold air, and the high-temperature radiation tube is connected to the temperature controller; the third branch is provided with a crucible for holding green pellets.

[0012] Through the above-mentioned device structure design, the quality of the green ball drying process during exhaust drying and blast drying in actual production can be better simulated. Combined with the roasting pellet strength detection equipment, the change law of pellet strength under different production conditions can be systematically observed, which is conducive to guiding pellet production.

[0013] As a further optimization of the utility model, temperature-controlled thermocouples are installed at both ends of the crucible, and the temperature-controlled thermocouples are communicatively connected to the temperature controller, which is convenient for detecting the temperature of the pellets during exhaust drying and blast drying, and also convenient for accurately controlling the drying temperature.

[0014] As a further optimization of the utility model, a hole is opened on the pipeline of the second branch and is located 190 to 210 mm below the high-temperature radiation tube. An extension pipe is connected and extends to the outside of the insulation furnace. A PLC remote-controlled electric valve is provided on the extension pipe for exhausting air during exhaust drying.

[0015] As a further optimization of the utility model, the upper end of the pipeline of the third branch extends outside the insulation furnace and is provided with a PLC remote-controlled electric valve, and the lower end of the pipeline also extends outside the insulation furnace and is provided with a manual stop valve, which can regularly discharge the powder accumulated in the pipeline due to the bursting of the pellets.

[0016] As a further optimization of the present invention, a spherical joint is provided between the pipelines of the third branch and the second branch to facilitate translation of the pipelines.

[0017] As a further optimization of the utility model, the top of the crucible is sealed and connected to the pipeline by bolts and rubber pads, which is easy to install and disassemble, and can ensure the sealing of the installation. In addition, the bottom of the crucible is provided with grate bars, which are made of heat-resistant steel bars welded side by side, so as to facilitate the placement of the green balls to be tested.

[0018] As a further optimization of the utility model, the heat-resistant pipe material is selected from any one of 1Cr18Ni9Ti (321), 1Cr23Ni13 (309), 0Cr25Ni20 (310S), and 1Cr25Ni20Si2 (314), which has good high-temperature strength and oxidation resistance.

[0019] As a further optimization of the utility model, the insulation furnace is filled with high-temperature refractory materials, which have high-temperature resistance and heat preservation properties.

[0020] 3. Beneficial effects

[0021] Compared with the prior art, the beneficial effects of the utility model are:

[0022] (1) The simulation device of the utility model can better simulate the quality conditions of the raw ball drying process of exhaust drying and blast drying in actual production by optimizing the design of its overall structure. Combined with the tubular furnace and the roasting pellet strength detection equipment, it can simulate a complete set of pellet production process, which can not only observe the law of pellet strength change more systematically, but also has high detection efficiency, small error and high accuracy, which is more conducive to guiding the stable production of enterprises.

[0023] (2) The utility model provides a simulation device that can fully simulate the bursting temperature and drying preheating system of actual production. The temperature and flow control of the entire device are accurate and fast, with a high degree of automation and greatly improved detection efficiency. It can realize static and dynamic detection of green ball bursting temperature in multiple ways with high accuracy and can meet various detection needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the pellet drying preheating system and the simulation device for bursting temperature detection of the utility model;

[0025] Figure 2 It is a front view of the crucible of the utility model;

[0026] Figure 3 It is a top view of the crucible of the utility model;

[0027] In the figure:

[0028] 100. Control cabinet system; 101. Computer; 102. Variable frequency Roots blower; 103. Ammeter; 104. Voltmeter; 105. Temperature controller; 106. Flow controller; 107. Switch;

[0029] 200. Insulation furnace; 201. Vortex flowmeter; 202. Heat-resistant pipe; 203. PLC remote-controlled electric valve; 204. Ball joint; 205. High-temperature radiation tube; 206. Crucible; 2061. Grate; 207. Temperature-control thermocouple; 208. Manual stop valve; 209. First branch; 210. Second branch; 211. Third branch. DETAILED DESCRIPTION

[0030] It should be noted that it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0031] The utility model is further described below in conjunction with specific embodiments.

[0032] Example 1

[0033] like Figure 1 As shown, a simulation device for pellet drying preheating system and burst temperature detection in this embodiment includes a control cabinet system 100 and a holding furnace 200. The control cabinet system 100 integrates a computer 101, a switch 107, an ammeter 103, a voltmeter 104, and a variable frequency Roots blower 102, a temperature controller 105 and a flow controller 106 which are respectively communicated and connected to the computer 101. The switch 107 controls the power on and off of the entire control cabinet system 100. The ammeter 103 and the voltmeter 104 are used to measure the high-temperature radiation tube 205 in real time, so as to facilitate the temperature in the holding furnace 200, and further realize the regulation of the wind temperature during pellet drying.

[0034] The simulation device of the utility model can completely simulate the actual production process by setting the process parameters of different drying and preheating systems in the computer 101, including the setting of the heating rate, the blast / exhaust time, the blast / exhaust drying temperature, the blast / exhaust time, the preheating temperature, the preheating time and the wind speed / flow rate. At the same time, the variable frequency Roots blower 102 can realize the forward and reverse rotation of the set flow rate through the computer 101 and the flow controller 106, thereby simulating the drying system (blast drying and exhaust drying), and can simulate the actual production process of pellets. Specifically:

[0035] The variable frequency Roots blower 102 is installed in the control cabinet system 100, and its air outlet end is connected to one end of the heat-resistant pipe 202, and the other end of the heat-resistant pipe 202 extends into the insulation furnace 200 and is divided into three branches connected in parallel. The connection between the control cabinet system 100 and the insulation furnace 200 is realized through the heat-resistant pipe 202. A vortex flowmeter 201 is installed on the heat-resistant pipe 202 located outside the insulation furnace 200, and the vortex flowmeter 201 is connected to the flow controller 106 for communication. The control cabinet system 100 automatically controls the flow controller 106 through the computer 101, and the flow controller 106 is used to control the flow rate and wind speed of the variable frequency Roots blower 102 for blowing or exhausting.

[0036] In this embodiment, in order to better simulate the different states in the actual production process of pelletizing, the heat-resistant pipe 202 extending into the insulation furnace 200 is divided into three parallel branches. Specifically, Figure 1 As shown, the three branches are respectively a first branch 209, a second branch 210 and a third branch 211. The first branch 209 is mainly used to control the air blowing during the drying of the pellets. In order to realize automatic control, a PLC remote-controlled electric valve 203 is provided on the pipeline of the first branch 209, and a PLC remote-controlled electric valve 203 is also provided on the pipeline connecting the first branch 209 and the second branch 210, which is used to switch the direction of the blown gas passing through the pellet material layer.

[0037] A high-temperature radiation tube 205 is provided on the pipeline of the second branch 210. The high-temperature radiation tube 205 is communicatively connected to the temperature controller 105 and is used to generate heat or heat cold air. The rated working temperature of the high-temperature radiation tube 205 is 1150°C, the maximum working temperature is 1200°C, and the maximum working current is 100A. In addition, a hole is opened at 190 to 210 mm below the high-temperature radiation tube 205, and an extension tube is connected to extend outside the insulation furnace 200. The extension tube is provided with a PLC remote-controlled electric valve 203 for exhausting air during exhaust drying.

[0038] A crucible 206 for holding green pellets is provided on the pipe of the third branch 211, the upper end of the pipe of the third branch 211 extends outside the insulation furnace 200, and a PLC remote-controlled electric valve 203 is provided on the pipe outside the insulation furnace 200. The top of the crucible 206 is also outside the insulation furnace 200, and the upper, lower and bottom parts of the crucible 206 are all arranged inside the insulation furnace 200. The insulation furnace 200 is filled with high-temperature refractory materials, which have high temperature resistance and insulation properties.

[0039] More optimally, a temperature-controlling thermocouple 207 is installed 10 mm above the top and below the bottom of the crucible 206 , and the temperature-controlling thermocouple 207 is communicatively connected to the temperature controller 105 , and is used to measure and control the air temperature of the exhaust drying and the forced air drying, respectively.

[0040] The lower end of the pipeline of the third branch 211 also extends to the outside of the holding furnace 200 and is provided with a manual stop valve 208, which can regularly discharge the powder generated by the explosion of the pellets accumulated in the pipeline.

[0041] As a further improvement of this embodiment, a spherical joint 204 flange connection is provided between the pipelines of the third branch 211 and the second branch 210 to facilitate translation of the pipelines.

[0042] Example 2

[0043] like Figure 1-3 As shown, the simulation device of this embodiment has the same main structure as that of embodiment 1. The difference between this embodiment and embodiment 1 is that the top of the crucible 206 is connected to the pipeline by bolts and rubber pads, which is easy to disassemble and strictly sealed. The material of the crucible 206 is the same as that of the heat-resistant pipeline 202. In addition, Figure 2 As shown, the size of the crucible 206 of this embodiment can be selected according to actual needs. The crucible 206 used in this embodiment has an inner diameter of 50 mm and a wall thickness of 5 mm. The bottom of the crucible is made of heat-resistant steel bars with a diameter of 3 mm and a gap of 4 mm welded side by side to form a "simulated" grate bar 2061 to improve air permeability.

[0044] In addition, the size of the heat-resistant pipe 202 can be selected according to actual needs. In this embodiment, the inner diameter of the pipe is 70 mm and the wall thickness is 5 mm. The material is any one of 1Cr18Ni9Ti (321), 1Cr23Ni13 (309), 0Cr25Ni20 (310S), and 1Cr25Ni20Si2 (314), which has good high-temperature strength and oxidation resistance.

[0045] When the simulation device of the utility model is used for simulation, the pellet bursting temperature can be determined by static method and dynamic method. The specific working principle and operation are as follows:

[0046] Static method:

[0047] First, turn on the switch 107 of the control cabinet system 100 to power on the entire device. Then adjust the working current and voltage of the high-temperature radiation tube 205 to heat the body of the insulation furnace 200. After the temperature reaches the set temperature, select the blast or exhaust mode, adjust the air volume, wait for the temperature to stabilize again, and then start the burst temperature detection.

[0048] Dynamic method:

[0049] Put the green balls in the cold state, design the blast drying temperature, time and exhaust drying temperature, time, the maximum heating rate of the high temperature radiation tube is 50℃ / min, the maximum wind temperature is 600℃, and the maximum wind speed is 2.0m / s.

[0050] When the above two methods are used to determine the bursting temperature of green balls, 50 green balls of uniform size (green ball diameter is 10-12.5 mm) are selected each time and loaded into the crucible 206, and then the crucible 206 is connected to the pipeline (third branch 211) through bolts and rubber pads. After waiting for 5 minutes, the crucible 206 is taken out, the balls are poured out, and the bursting of the balls is checked.

[0051] The number of green ball bursts is 2 (less than 5%) as the green ball burst temperature indicator. If the number of green balls burst is more than 2, the temperature displayed on the control cabinet must be lowered and measured again until the number of bursts is 2. If the number of green balls burst is less than 2, the temperature displayed on the control cabinet must be increased and measured again until the number of bursts is 2.

[0052] The above-mentioned simulation device which can fully simulate the bursting temperature and drying preheating system of actual production is used for measurement. The temperature and flow control of the whole device are accurate and fast, with a high degree of automation, and the experimental efficiency is greatly improved.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A simulation device for pellet drying preheating system and burst temperature detection, characterized in that: The invention comprises a control cabinet system (100) and a heat preservation furnace (200), wherein the control cabinet system (100) is provided with a computer (101), and a variable frequency Roots blower (102), a temperature controller (105) and a flow controller (106) which are respectively communicatively connected to the computer (101), wherein: The air outlet of the variable frequency Roots blower (102) is connected to one end of a heat-resistant pipe (202); the other end of the heat-resistant pipe (202) extends into the heat-insulating furnace (200) and is divided into three branches connected in parallel; a vortex flowmeter (201) is installed on the heat-resistant pipe (202) outside the heat-insulating furnace (200); the vortex flowmeter (201) is in communication connection with a flow controller (106) and is used to control the flow rate and wind speed of the variable frequency Roots blower (102) for blowing or exhausting air; The three branches of the heat-resistant pipeline (202) are a first branch (209), a second branch (210) and a third branch (211). The first branch (209) is provided with a PLC remote-controlled electric valve (203), and the pipeline connected to the second branch (210) is also provided with a PLC remote-controlled electric valve (203) for switching the direction of the gas blown through the pellet layer. The second branch (210) is provided with a high-temperature radiation tube (205) for generating heat or heating cold air, and the high-temperature radiation tube (205) is communicatively connected to the temperature controller (105); the third branch (211) is provided with a crucible (206) for holding green pellets.

2. The simulation device for pellet drying preheating system and burst temperature detection according to claim 1 is characterized in that: Temperature-controlling thermocouples (207) are installed at both upper and lower ends of the crucible (206), and the temperature-controlling thermocouples (207) are communicatively connected to the temperature controller (105).

3. The simulation device for pellet drying preheating system and burst temperature detection according to claim 1, characterized in that: A hole is opened on the pipeline of the second branch (210) at 190 to 210 mm below the high-temperature radiation tube (205), and an extension pipe is connected to extend to the outside of the insulation furnace (200). The extension pipe is provided with a PLC remote-controlled electric valve (203) for exhausting air during exhaust drying.

4. The simulation device for pellet drying preheating system and burst temperature detection according to claim 1 is characterized in that: The upper end of the pipeline of the third branch (211) extends to the outside of the insulation furnace (200) and is provided with a PLC remote-controlled electric valve (203), and the lower end of the pipeline also extends to the outside of the insulation furnace (200) and is provided with a manual stop valve (208).

5. The simulation device for pellet drying preheating system and burst temperature detection according to claim 4 is characterized in that: A spherical joint (204) is provided between the pipelines of the third branch (211) and the second branch (210).

6. A simulation device for pellet drying preheating system and burst temperature detection according to any one of claims 1 to 5, characterized in that: The top of the crucible (206) is sealedly connected to the pipeline via bolts and rubber pads, and the bottom of the crucible (206) is provided with grate bars (2061).

7. A simulation device for pellet drying preheating system and burst temperature detection according to any one of claims 1 to 5, characterized in that: The heat-resistant pipe (202) is made of any one of 1Cr18Ni9Ti (321), 1Cr23Ni13 (309), 0Cr25Ni20 (310S), and 1Cr25Ni20Si2 (314).

8. A simulation device for pellet drying preheating system and burst temperature detection according to any one of claims 1 to 5, characterized in that: The insulation furnace (200) is filled with high-temperature refractory material.

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