A method for taking mixed materials in layers for a sintering machine and a layered sampling device

Abstract

A method for taking mixed materials from a sintering machine in layers and a layered sampling device belong to the technical field of sintering machines. The layered taking method comprises the following steps: during normal material distribution, the ignition furnace nozzle is closed to ensure that the mixed materials on 2 to 3 trolleys are not ignited; a layered sampling device is placed after the unignited trolley comes out of a heat preservation cover; the layered sampling device is pressed into the bottom of the mixed material layer; the machine is stopped and the trolley on which the layered taking device is placed is lifted, and an empty trolley is replaced for machine conversion and sintering production; layered sampling is performed to detect and analyze the particle size, carbon content and chemical composition; the layered sampling device is formed by stacking and sleeve-connecting a base tube and a plurality of sleeves. The beneficial effects of the present invention are that the layered sampling device has a simple overall structure and a low manufacturing cost. The sampling method using the sampling device has a small impact on the sintering production process, reduces the number of sintering machine shutdowns, has a small impact on the original distribution state of the mixed materials, more truly reflects the original distribution state of the sintering machine mixed materials, and improves the reliability of the layered sampling detection results.

Description

Technical Field

[0001] The invention relates to the technical field of sintering machines, and in particular to a method for taking mixed materials in layers for a sintering machine and a layered sampling device. Background Art

[0002] With the development of large-scale sintering systems and ultra-thick bed sintering technology, the granulation capacity of the sintering system and the reasonable segregation level of the distribution equipment directly determine the cold and hot permeability of the mixture on the sintering machine trolley, which directly affects the output and quality of the sintered ore. The most ideal distribution method should make the mixture coarser from top to bottom along the height of the material layer, and reduce the carbon content, which is conducive to increasing the permeability of the material layer and improving the quality of the sintered ore. Therefore, studying the distribution strength, moisture, chemical composition, carbon segregation, etc. of the mixture on the sintering machine trolley is of great practical significance for guiding the optimization of the sintering production process and improving the sintering production capacity.

[0003] The existing mixed material sampling method requires stopping the sintering machine before sampling, placing the sampling device, and then performing the material distribution operation. After the material distribution is completed, the sintering machine needs to be stopped again to take out the sampling device and then perform the layered sampling operation. Although the problem of layered sampling is solved, the sintering machine is stopped many times, which affects the continuity of sintering, and the process of taking out the sampling device may cause material leakage, thereby affecting the reliability of the layered sampling test results. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for stratified sampling of a sintering machine mixture and a stratified sampling device, wherein the stratified sampling device has a simple overall structure and low manufacturing cost. The sampling method using the sampling device has little impact on the sintering production process, reduces the number of sintering machine shutdowns, has little impact on the original distribution state of the mixture, more truly reflects the original distribution state of the sintering machine mixture, and improves the reliability of the stratified sampling detection results.

[0005] To achieve the above object, the technical solution adopted by the present invention to solve the technical problem is: the method for taking mixed materials of the sintering machine in layers comprises the following steps:

[0006] 1) For normal material distribution of the sintering machine trolley, close the ignition furnace nozzle for a period of time after material distribution to ensure that the mixed material of 2 to 3 sintering machine trolleys is not ignited;

[0007] 2) After the unignited sintering machine trolley is out of the heat preservation cover, multiple layered sampling devices are placed flatly at different positions on the material surface;

[0008] 3) A heavy object with a flat bottom is lifted by a crane and placed on the stratified sampling device. After the crane unloads the force, the stratified sampling device is pressed into the bottom of the mixed material layer by the heavy object, and the crane lifts away the heavy object;

[0009] 4) The unignited sintering machine trolley on which the stratified sampling device is placed is turned to a position for replacing the sintering machine trolley, the sintering machine is stopped, and the entire sintering machine trolley is hoisted out;

[0010] 5) Clean up the scattered materials on the sintering machine, replace an empty sintering machine trolley, and then switch the machine for sintering production;

[0011] 6) Take layered samples of the mixed material in the layered sampling device that has been hoisted onto the trolley;

[0012] 7) The particle size, carbon content and chemical composition of the mixed materials taken out from each layer at different positions of the sintering machine trolley are tested and analyzed, and then the segregation effects of the distribution in the horizontal and vertical directions are compared respectively.

[0013] Furthermore, in the step 1), the time for closing the ignition furnace nozzle after placing the material is 2 minutes to 3 minutes.

[0014] Furthermore, in the step 2), a plurality of the layered sampling devices are evenly distributed on the material surface of the center line of the unfired sintering machine trolley in the width direction.

[0015] Furthermore, the heavy object in step 3) is set as a turnover box for conveying grate bars, and the weight of the turnover box is 1 t to 3 t.

[0016] A layered sampling device used in the method for layered sampling of sintering machine mixed materials comprises a base tube and a sleeve. A plurality of sleeves can be detachably sleeved on the top of the base tube in sequence. The sleeve is provided with a positioning sleeve ear to prevent the plurality of stacked sleeves from sliding up and down.

[0017] Furthermore, the positioning sleeve ear is configured as a strip steel plate structure, and a plurality of the positioning sleeve ears are welded circumferentially at one end of the sleeve, and the positioning sleeve ears extend outward by 40 mm to 80 mm along the length direction of the sleeve.

[0018] Furthermore, the base tube and the sleeve are both cut from a circular steel pipe of equal length, the circular steel pipe has a diameter of 300mm to 450mm, a wall thickness of 3mm to 5mm, and the length of the base tube and the sleeve is 200mm to 400mm.

[0019] Furthermore, the lower portion of the base tube is configured as a tapered inserting portion, and the edge of the tapered inserting portion has a smooth transition.

[0020] Furthermore, one end of the base tube and the sleeve is provided with an annular groove, and the other end of the sleeve is provided with an annular protrusion which is connected to the annular groove by snapping.

[0021] Furthermore, the number of the sleeves is 2 to 5.

[0022] The beneficial effects of the present invention are:

[0023] 1. The stratified sampling method of the present invention performs normal material distribution on the sintering machine trolley. It is only necessary to close the furnace nozzle after the material distribution to ensure that the mixed materials of 2 to 3 sintering machine trolleys are not ignited. The stratified sampling device is placed after the unignited sintering machine trolley comes out of the heat preservation cover. Compared with the prior art, it is not necessary to place the sampling device on the sintering machine trolley before material distribution to force the sintering machine to stop, thereby reducing the number of stoppages and the failure rate; a heavy object is hoisted and placed on the stratified sampling device and the stratified sampling device is pressed into the bottom layer of the mixed material, and then the sintering machine trolley with the stratified sampling device is hoisted out after the machine is stopped, and an empty sintering machine trolley is replaced for sintering production, and stratified sampling is performed in the stratified sampling device that has been hoisted out. Compared with the prior art, this sampling method does not need to take out the sampling device as a whole, has less impact on the original distribution state of the mixed material, more truly reflects the original distribution state of the sintering machine mixed material, and improves the reliability of the stratified sampling detection result.

[0024] 2. The stratified sampling device involved in the present invention is composed of a base tube and a plurality of sleeves stacked together. The positioning sleeve ears arranged on the sleeves play a role in positioning the sleeves and preventing them from sliding. The number of stacked sleeves can be selected according to the thickness of the mixed material. The stratified sampling device has a simple overall structure and can be formed by cutting a circular steel pipe. It has low manufacturing cost, strong versatility, and convenient stratified material collection.

[0025] In summary, the stratified sampling device involved in the present invention has a simple overall structure and low manufacturing cost. The sampling method using the sampling device has little impact on the sintering production process, reduces the number of sintering machine shutdowns, has little impact on the original distribution state of the mixture, and more truly reflects the original distribution state of the sintering machine mixture, thereby improving the reliability of the stratified sampling detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The following is a brief description of the contents expressed in the drawings of the present specification and the marks in the drawings:

[0027] Figure 1 It is a structural schematic diagram of the stratified sampling device in the present invention;

[0028] Figure 2 for Figure 1 A schematic diagram of the structure of the middle base tube;

[0029] Figure 3 for Figure 1 A schematic diagram of the structure of the middle sleeve;

[0030] Figure 4 The particle size distribution law of the material layer at position 1 of the sintering machine trolley in the present invention;

[0031] Figure 5The particle size distribution law of the material layer at position 2 of the sintering machine trolley in the present invention;

[0032] Figure 6 The particle size distribution law of the material layer at position 3 of the sintering machine trolley in the present invention;

[0033] The markings in the above figures are: 1. base tube, 11. conical insert, 2. sleeve, 3. positioning sleeve ear, 4. annular groove, 5. annular protrusion. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The specific implementation scheme of the present invention is: Figures 1 to 3As shown, the stratified sampling device of the present invention comprises a base tube 1 and a sleeve 2. A plurality of sleeves 2 can be detachably sleeved on the top of the base tube 1 in sequence. The base tube 1 and the sleeve 2 are both cut from a round steel pipe of equal length. The diameter of the round steel pipe is 300 mm to 450 mm, and the wall thickness is 3 mm to 5 mm. The length of the base tube 1 and the sleeve 2 is 200 mm to 400 mm. The stratified sampling device has a simple overall structure, is easy to manufacture, and has a low manufacturing cost. The number of sleeves 2 is determined by the thickness of the mixed material layer of the sintering machine. Generally, the number of sleeves 2 is 2 to 5. In order to prevent the sliding of the plurality of sleeves 2 after being sleeved, a plurality of positioning sleeve ears 3 are arranged along the circumferential direction at one end of the sleeve 2 to prevent the plurality of stacked sleeves 2 from sliding up and down. The positioning sleeve ears 3 are arranged as strip steel The plate structure is 3mm to 5mm thick, 80mm to 120mm long, and 40mm to 80mm wide. The positioning sleeve ear 3 extends outward by 40mm to 80mm along the length direction of the sleeve 2. In order to make the overall structure more stable after the stacking between the base tube 1 and the sleeve 2, one end of the base tube 1 and the sleeve 2 is provided with an annular groove 4, and the other end of the sleeve 2 is provided with an annular protrusion 5 connected to the annular groove 4 by clamping. The stacking is completed by clamping, and the circumferential positioning sleeve ear 3 plays a further positioning role. In addition, in order to reduce the resistance of the stratified sampling device entering the mixed material layer, the lower edge of the base tube 1 located at the lowest layer is polished and sharpened, so that the lower part of the base tube 1 forms a conical insertion portion 11, and the edge of the conical insertion portion 11 is smoothly transitioned.

[0037] The method for taking stratified materials from a sintering machine mixture using the stratified sampling device comprises the following steps:

[0038] 1) For normal material distribution of the sintering machine trolley, close the ignition furnace nozzle for 2min to 3min after material distribution to ensure that the mixed material of the 2nd to 3rd sintering machine trolley is not ignited;

[0039] 2) After the unfired sintering machine trolley is out of the heat preservation cover, a corresponding number of sleeves 2 are selected according to the material thickness of the mixed material and stacked on the base tube 1 to form the stratified material taking device, and multiple stratified sampling devices are evenly distributed on the material surface of the center line of the unfired sintering machine trolley in the width direction. The stratified sampling devices can be arranged on both sides and in the middle of the center line. In order to make the detection more comprehensive, more than three stratified sampling devices can also be set;

[0040] 3) Use a crane to lift a heavy object with a flat bottom and place it on the layered sampling device. The heavy object can be set as a turnover box for conveying grate bars. The weight of the turnover box is 1t to 3t. After the crane unloads the force, the layered sampling device is pressed into the bottom of the mixed material layer by the heavy object, and the crane lifts the heavy object away;

[0041] 4) Move the unignited sintering machine trolley with the layered sampling device to the position for replacing the sintering machine trolley, stop the sintering machine, and lift out the entire sintering machine trolley;

[0042] 5) Clean up the scattered materials on the sintering machine, replace an empty sintering machine trolley, and then switch the machine for sintering production;

[0043] 6) Sampling the mixture in the stratified sampling device that has been hoisted onto the trolley, that is, sampling the mixture in each layer where the sleeve 2 is located and the layer where the base tube 1 is located from top to bottom. After sampling the mixture in one layer of sleeve 2 is completed, it is disassembled and the next layer of sampling is continued until the sampling of the mixture in the base tube 1 is completed;

[0044] 7) The particle size, carbon content and chemical composition of the mixed materials taken out from each layer at different positions of the sintering machine trolley are tested and analyzed, and then the segregation effects of the distribution in the horizontal and vertical directions are compared respectively.

[0045] Example: The above stratified sampling method was applied to a sintering plant at 300m 2 The sintering machine is implemented. The single-section trolley of the sintering machine has a specification of 4m×1.5mm, a machine speed of about 1.7m / min, a mixed material layer thickness of 850mm (including a 50mm bottom material layer), and a base tube and sleeve height of 200mm. Therefore, the number of sleeves of the sampling device is designed to be 3, and the round steel pipe specification is φ380mm×3.5mm.

[0046] The specific stratified sampling process is as follows: 1. Before sampling, the sintering machine trolley is normally laid. After laying, the ignition furnace nozzle is closed for 2min to 3min. From the material surface, it can be seen that the mixed materials of 2 to 3 trolleys have not been ignited; 2. After the unignited trolley comes out of the insulation cover, the above-mentioned stratified sampling device is placed flat on the material surface, and the specific landing point is close to the center line of the material surface of the unignited section along the forward direction of the trolley. In order to ensure the integrity of the sample taken, the stratified sampling device is especially placed on the center line of the width direction of the middle section of the unignited section trolley. In order to compare whether the mixed material is evenly laid along the width direction of the sintering machine trolley at the same time, Place three stratified sampling devices evenly in the width direction of the sintering machine trolley, that is, place a stratified sampling device at both ends and in the middle of the sintering machine trolley in the width direction; 3. Use a crane to lift the conveying grate bar turnover box used for on-site maintenance and place it on the upper end of the stratified sampling device. After the crane unloads the force, the stratified sampling device is pressed into the bottom of the mixed material layer, and the crane lifts the conveying grate bar turnover box; 4. Turn the unignited sintering machine trolley with the stratified sampling device to the position for replacing the sintering machine trolley, stop the sintering machine, lift out the entire trolley, clean up the scattered materials on the sintering machine, replace it with an empty sintering machine trolley, and then turn the machine over for sintering production.

[0047] The mixed materials in the layered sampling device at three positions along the width direction of the sintering machine trolley were sampled in four layers on site, and the particle size, carbon content, chemical composition, etc. of the mixed materials taken out from each layer were tested and analyzed. Figures 4 to 6 As shown in Table 1, Position 1 and Position 3 are edge positions along the width direction of the sintering machine trolley, and Position 2 is the middle position along the width direction of the sintering machine trolley.

[0048] in Figures 4 to 6 They are the particle size distribution laws of the material layer at different positions. Figures 4 to 6 The average particle size of the mixture at three positions on the width direction of the sintering machine trolley and the content of +3mm (>3mm) particle size increase from the upper part of the material layer to the lower part of the material layer, and the content of -0.5mm (<0.5mm) particle size decreases from the upper part of the material layer to the lower part of the material layer. The particle size distribution law meets the particle size distribution requirement that the mixture becomes coarser from top to bottom along the material layer height. However, the average values ​​of the average particle size of the mixture at the above three positions are 2.832mm, 3.293mm and 3.595mm respectively. The ideal distribution state is that the average particle size at the three positions is equal, and the normal range of segregation is between -0.1mm and 0.1mm, indicating that there is a large segregation in the horizontal distribution of the sintering mixture. It is necessary to carefully observe the installation position, wear degree and operation state of the round roller and the nine rollers to find out the cause of the segregation of the mixture in the horizontal direction.

[0049] Table 1 is a table of chemical composition distribution of the mixture at different positions of the material layer. It can be seen from Table 1 that there is no obvious regularity in the distribution of total carbon content (TC) of different material layers at various positions, while the sintering distribution fuel requirement is that the carbon content of the mixture decreases from top to bottom along the material layer height. This distribution pattern does not match the sintering distribution fuel requirement. It is necessary to further find out the reasons for the unreasonable fuel distribution to improve the fuel distribution of the material layer; there is no obvious regularity in the distribution of total iron (TFe), ferrous oxide (FeO) and alkalinity (the ratio between CaO and SiO2), which meets the requirements of homogeneous sintering with uniform distribution of quality and chemical composition, and is beneficial to the quality and composition stability of the sintered ore. However, since there is no obvious regularity in the distribution of total carbon content (TC), it does not meet the requirements of uniform heat sintering. The two need to be balanced and improved according to actual conditions.

[0050] Table 1

[0051]

[0052] In summary, the stratified sampling device involved in the present invention has a simple overall structure and low manufacturing cost. The sampling method using the sampling device has little impact on the sintering production process, reduces the number of sintering machine shutdowns, has little impact on the original distribution state of the mixture, and more truly reflects the original distribution state of the sintering machine mixture, thereby improving the reliability of the stratified sampling detection results.

[0053] The above description is only used to illustrate some principles of the present invention. This specification is not intended to limit the present invention to the specific structure and application scope shown and described. Therefore, all corresponding modifications and equivalents that may be used belong to the patent scope applied for by the present invention.

Claims

1. A method for taking mixed materials from a sintering machine in layers, characterized in that: The following steps are involved: 1) For normal material distribution of the sintering machine trolley, close the ignition furnace nozzle for a period of time after material distribution to ensure that the mixed material of 2 to 3 sintering machine trolleys is not ignited; 2) After the unignited sintering machine trolley is out of the heat preservation cover, multiple layered sampling devices are placed flatly at different positions on the material surface; 3) A heavy object with a flat bottom is lifted by a crane and placed on the stratified sampling device. After the crane unloads the force, the stratified sampling device is pressed into the bottom of the mixed material layer by the heavy object, and the crane lifts away the heavy object; 4) The unignited sintering machine trolley with the stratified sampling device is turned to the position for replacing the sintering machine trolley, the sintering machine is stopped, and the entire sintering machine trolley is lifted out; 5) Clean up the scattered materials on the sintering machine, replace an empty sintering machine trolley, and then switch the machine for sintering production; 6) Take layered samples of the mixed material in the layered sampling device that has been hoisted onto the trolley; 7) The particle size, carbon content and chemical composition of the mixture taken out from each layer at different positions of the sintering machine trolley are tested and analyzed, and then the segregation effects of the mixture in the horizontal and vertical directions are compared respectively.

2. The method for taking mixed material from a sintering machine in layers according to claim 1, characterized in that: In the step 1), the time for closing the ignition furnace nozzle after placing the material is 2 minutes to 3 minutes.

3. The method for taking mixed material from a sintering machine in layers according to claim 1, characterized in that: In the step 2), the plurality of layered sampling devices are evenly distributed on the material surface of the center line of the unfired sintering machine trolley in the width direction.

4. The method for taking mixed material from a sintering machine in layers according to claim 1, characterized in that: The heavy object in step 3) is set as a turnover box for conveying grate bars, and the weight of the turnover box is 1 t to 3 t.

5. A layered sampling device used in the method for layered sampling of sintering machine mixed material according to any one of claims 1 to 4, characterized in that: The invention comprises a base tube (1) and a sleeve (2); a plurality of sleeves (2) are detachably sleeved on the top of the base tube (1); a positioning sleeve ear (3) is provided on the sleeve (2) to prevent the plurality of stacked sleeves (2) from sliding up and down; the positioning sleeve ear (3) is configured as a strip steel plate structure; a plurality of the positioning sleeve ears (3) are welded to one end of the sleeve (2) along the circumferential direction; and an annular groove (4) is provided on one end of each of the base tube (1) and the sleeve (2).

6. The stratified sampling device according to claim 5, characterized in that: The positioning sleeve ear (3) extends outward by 40 mm to 80 mm along the length direction of the sleeve (2).

7. The stratified sampling device according to claim 5, characterized in that: The base tube (1) and the sleeve (2) are both cut from a circular steel tube of equal length; the circular steel tube has a diameter of 300 mm to 450 mm and a wall thickness of 3 mm to 5 mm; the base tube (1) and the sleeve (2) have a length of 200 mm to 400 mm.

8. The stratified sampling device according to claim 7, characterized in that: The lower part of the base tube (1) is arranged as a conical inserting portion (11), and the edge of the conical inserting portion (11) has a smooth transition.

9. The stratified sampling device according to claim 7, characterized in that: The other end of the sleeve (2) is provided with an annular protrusion (5) which is clamped and connected to the annular clamping groove (4).

10. The stratified sampling device according to claim 5, characterized in that: The number of the sleeves (2) is 2 to 5.

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