Belt type roasting machine with spiral air inlet coal injection mechanism

Abstract

The utility model discloses a belt type roasting machine with a spiral air inlet coal injection mechanism, which can utilize idle space above a hot air cover of the belt type roasting machine to design an existing secondary hot air pipeline into a pipeline structure with a spiral self-rotating pipe section on the premise of not occupying extra space. A plurality of pulverized coal injection mechanisms and arc excitation devices are arranged on the pipeline in a matched mode, pulverized coal injection and combustion are directly achieved in the spiral air inlet branch pipe so that qualified hot air for roasting can be obtained, and on the premise that the quality of roasted products is not reduced, the quality of the roasted products can be improved. According to the belt type roasting device, the breakthrough that cheap pulverized coal replaces expensive coal gas to serve as roasting heat supply fuel is achieved, the defects that an existing belt type roasting device is high in process cost and limited in process suitability are overcome, a new development approach is provided for the belt type roasting process in steel pellet production, and the belt type roasting device has the advantages of being low in energy consumption cost, not occupying extra space and the like.

Description

Technical Field

[0001] The utility model relates to steel metallurgy production equipment, in particular to a grate-kiln with a spiral air inlet and coal injection mechanism, belonging to the technical field of steel metallurgy production. Background Art

[0002] Oxidized pellets are an important type of furnace charge for blast furnace smelting. Currently, the processes for producing oxidized pellets on the market mainly include three categories: grate-kiln, traveling grate-rotary kiln, and shaft furnace pelletizing process. Among them, the shaft furnace pelletizing process has been gradually phased out, with a market share of less than 5%; while the grate-kiln process has become the mainstream of the future pellet market by virtue of its advantages such as small floor area, good equipment integrity, and advanced energy consumption and emission indicators.

[0003] In the current trend of the steel market, vigorously developing low-cost pelletizing processes is the key to the future upgrading and transformation of the steel industry. Currently, as the mainstream pellet process, the grate-kiln is restricted by equipment technology and can only use high-calorific-value gas (natural gas or coke oven gas) as fuel, resulting in the following problems: 1) High process cost: Since the grate-kiln process currently has to use high-calorific-value gas, and the price of this part of high-calorific-value gas is very high, the process cost of producing pellets by the entire grate-kiln remains high; 2) Limited process suitability: It is uneconomical and unrealistic for many steel enterprises to specially introduce a high-cost gas pipeline to build a grate-kiln pellet production line, which in turn leads to the inability to select the grate-kiln process. Content of the Utility Model

[0004] Aiming at the problems of high production cost and limited application existing in the existing grate-kiln process using high-calorific-value gas as fuel in the prior art, the utility model provides a grate-kiln with a spiral air inlet and coal injection mechanism. Without occupying additional space, by utilizing the idle space above the hot air hood of the grate-kiln, the existing secondary hot air pipeline is designed into a pipeline structure with a spiral self-rotating pipe section, and a plurality of pulverized coal injection mechanisms and arc excitation devices are arranged on the pipeline. The pulverized coal is directly injected and burned in the spiral air inlet branch pipe to obtain qualified hot air for roasting. Through the design of the spiral self-rotating pipe section, the purpose of using cheap pulverized coal as the heating fuel for roasting is achieved, with the advantages of low energy consumption cost and no additional space occupation.

[0005] To achieve the above technical purpose, the technical solution adopted by the utility model is as follows:

[0006] A grate-kiln with a spiral air inlet and coal injection mechanism, the grate-kiln includes a drying section, a suction drying section, a preheating section, a roasting section, a first cooling section, a second cooling section connected in series in sequence, and a hot air hood covering above each section.

[0007] The spiral air inlet and coal injection mechanism includes a main hot air conveying pipe, a spiral air inlet branch pipe, and a pulverized coal injection mechanism.

[0008] Among them: The air inlet end of the main hot air conveying pipe is connected to the exhaust port at the top of the first cooling section, its exhaust end is connected to the upper end of the spiral air inlet branch pipe, and the lower end of the spiral air inlet branch pipe is connected to the air inlet of the roasting section. The spiral air inlet branch pipe has a spiral pipe section structure designed to spiral downwards, and a plurality of pulverized coal injection mechanisms are connected to the spiral air inlet branch pipe at intervals from top to bottom. An arc excitation device is provided in a supporting manner on the spiral air inlet branch pipe downstream of each pulverized coal injection mechanism.

[0009] In a preferred embodiment of the present invention, the lower part of the spiral air inlet branch pipe is bent upwards to form a bent air outlet pipe section. The air outlet end of the bent air outlet pipe section is higher than its air inlet end, and the air outlet end of the bent air outlet pipe section is connected to the side air inlet of the hot air hood above the roasting section.

[0010] In a preferred embodiment of the present invention, an ash outlet is opened on the lower side wall of the lowest end of the bent air outlet pipe section, and a weighing ash hopper is connected and arranged below the ash outlet. Preferably, an ear plate extends horizontally outwards at the upper hopper wall of the weighing ash hopper. The ear plate is connected to the outer wall on the lower side of the bent air outlet pipe section through an elastic weighing connecting piece.

[0011] In a preferred embodiment of the present invention, a first telescopic baffle and a second telescopic baffle are further arranged in the bent air outlet pipe section. The first telescopic baffle is vertically arranged on the upper inner wall of the pipe cavity of the bent air outlet pipe section through a first driving motor, and the second telescopic baffle is vertically arranged on the lower inner wall of the pipe cavity of the bent air outlet pipe section through a second driving motor. The vertical heights of the first telescopic baffle and the second telescopic baffle are respectively driven by the first driving motor and the second driving motor. Preferably, along the axial direction of the bent air outlet pipe section, a plurality of first telescopic baffles and a plurality of second telescopic baffles are arranged at intervals in an alternating manner.

[0012] In a preferred embodiment of the present invention, the pulverized coal injection mechanism includes a pulverized coal conveying pipeline and a powder spraying pipe. The pulverized coal conveying pipeline is connected to the spiral air inlet branch pipe through the powder spraying pipe, and a regulating valve is arranged on the powder spraying pipe. Preferably, the powder spraying pipe intersects the spiral air inlet branch pipe obliquely, and the injection direction of the pulverized coal is opposite to the hot air flow direction.

[0013] In a preferred embodiment of the present invention, the pulverized coal conveying pipeline is connected to the spiral air inlet branch pipe through a plurality of powder spraying pipes with regulating valves.

[0014] In a preferred embodiment of the present invention, a plurality of powder spraying pipes with regulating valves are uniformly distributed along the circumference of the spiral air inlet branch pipe in a spiral winding manner.

[0015] In a preferred embodiment of the present utility model, the arc excitation device includes a plurality of arc positive rods and a plurality of arc negative rods. The plurality of arc positive rods and the plurality of arc negative rods are arranged in pairs on the two side walls of the spiral air inlet branch pipe along the flow direction of the air flow.

[0016] In a preferred embodiment of the present utility model, a gas injection pipe is further connected to the spiral air inlet branch pipe.

[0017] In a preferred embodiment of the present utility model, a steam injection pipe is further connected to the spiral air inlet branch pipe.

[0018] In a preferred embodiment of the present utility model, along the width direction of the roasting section, a plurality of temperature measuring elements are arranged in the hot air hood above the roasting section.

[0019] In a preferred embodiment of the present utility model, a pair of spiral air inlet branch pipes are symmetrically arranged on both sides in the width direction of the hot air hood above the roasting section. Preferably, along the flow direction of the material, multiple pairs of spiral air inlet branch pipes are arranged on both sides of the hot air hood above the roasting section.

[0020] In a preferred embodiment of the present utility model, cold air pipes are connected to the bottom air inlets of the first cooling section and the second cooling section. The top air outlet of the first cooling section is connected to the main hot air conveying pipe, and a hot air conveying branch pipe is further led out from the main hot air conveying pipe and connected to the top air inlet of the preheating section. The top air outlet of the second cooling section is connected to the bottom air inlet of the drying section through the first hot air circulation pipe. The bottom air outlet of the roasting section is connected to the top air inlet of the drying section through the second hot air circulation pipe. The top air outlets of the drying section, the bottom air outlets of the drying section, and the bottom air outlets of the preheating section are all connected to the external exhaust air pipes.

[0021] In the present utility model, generally, a cooling fan blows cooling air into the cooling section through a cooling air inlet duct to cool the high-temperature materials in the cooling section. After heat exchange, hot air is formed. The hot air after heat exchange enters the roasting section through a main hot air conveying pipe and spiral air inlet branch pipes arranged above the roasting section to serve as combustion-supporting air. During this process, according to the needs of the actual working conditions, pulverized coal is sprayed into the spiral air inlet branch pipes and ignited by an arc excitation device to heat the hot air so that the temperature of the hot air finally entering the roasting section meets the roasting requirements. That is, by utilizing the idle space above the belt roasting machine and setting spiral air inlet branch pipes with a certain height, a place is provided for the injection and combustion of pulverized coal, enabling pulverized coal to replace high-quality gas as the roasting heat supply fuel without additional combustion chambers or additional site occupation, significantly reducing the production cost. Compared with high-quality gas, which is expensive and inconvenient to transport, pulverized coal has the advantages of wider distribution, easier source acquisition and transportation, and stronger practicability and economy. That is to say, the present utility model realizes the breakthrough of replacing expensive gas with cheap pulverized coal as the roasting heat supply fuel without reducing the quality of roasting products, overcomes the deficiencies of high process cost and limited process suitability of the existing belt roasting machine, and provides a new development path for the belt roasting process in iron and steel pellet production.

[0022] In the present utility model, by utilizing the idle space above the belt roasting machine, the traditional secondary air duct is designed as a spiral air inlet branch pipe structure with a certain height, and a plurality of pulverized coal injection mechanisms (including pulverized coal conveying pipes and powder spraying pipes, etc.) and supporting arc excitation devices are respectively connected to different pipe sections of the spiral air inlet branch pipes. Their function is to spray pulverized coal into different pipe sections of the spiral air inlet branch pipes, so that the pulverized coal is mixed with the secondary hot air and descends evenly, and then is ignited by the arc excitation device to increase the temperature of the secondary hot air. It should be noted that there is a preferred scheme for the arrangement of the pulverized coal injection mechanism here, that is, multiple powder spraying pipes are evenly distributed in a circumferential spiral around the spiral air inlet branch pipe, and are inclined so that the injection of pulverized coal is reverse to the air flow. By adopting this annular spiral reverse injection method, the mixing rate of pulverized coal and secondary hot air can be effectively enhanced, preventing the occurrence of uneven pulverized coal concentration, and laying a foundation for the subsequent rapid and complete combustion of pulverized coal.

[0023] In the present utility model, multiple pulverized coal injection mechanisms are respectively connected to different pipe sections of the spiral air inlet branch pipe for injecting pulverized coal. According to the different combustion efficiencies of different pulverized coals, it can be selectively injected from multiple pulverized coal injection mechanisms at different height positions. Generally, the pulverized coal with a longer burnout time or a larger particle size is injected at a more forward position (i.e., closer to the upstream end of the spiral air inlet branch pipe), and vice versa. This enables the pulverized coal to burn out and allows the hot air with the highest temperature to quickly enter the roasting section when the pulverized coal burns out, effectively reducing the heat loss during the flow of the high-temperature hot air in the spiral air inlet branch pipe. Further, the pulverized coal can also be dispersed and injected through multiple pulverized coal injection mechanisms (i.e., after determining the addition amount of pulverized coal per unit time, the pulverized coal to be added is equally divided into multiple portions and injected simultaneously from multiple positions, which can make the pulverized coal burn simultaneously and contribute to improving the combustion efficiency. Compared with injecting all the pulverized coal from one position at the same time, the time required for injecting and burning out the pulverized coal can be greatly reduced. It should be noted that when the pulverized coal is injected in a multi-point manner, according to the flow direction of the air flow, the powder amounts injected at each position are equal or gradually decreasing, and are adjusted according to the actual working conditions), enabling the pulverized coal to burn out faster and better, thereby improving the utilization efficiency of the pulverized coal.

[0024] It should be noted that the idle space above the belt roasting machine is relatively limited, and it takes a certain time for the pulverized coal to be injected until it burns out. The design of the spiral air inlet branch pipe, on the one hand, significantly increases the travel of the pipeline in a limited space, which can extend the combustion time of the pulverized coal in the pipeline (especially for some pulverized coals with a slower combustion rate or large particle-sized pulverized coals mixed in, it can make them burn out before falling into the ash hopper, thereby ensuring the combustion efficiency of the pulverized coal). On the other hand, it can also reduce the downward speed of the pulverized coal, avoiding waste caused by it falling into the ash hopper before burning out or entering the roasting section and affecting the quality of the roasted product. In addition, the spiral design can also make the hot air from the first cooling section form a swirling air flow inside it, which is beneficial to further improving the mixing uniformity of the hot air and the pulverized coal. Moreover, the spiral structure has the advantage of controllable feeding speed compared with the straight pipe structure; compared with the folded pipe structure, it has the advantages of smooth downward flow of the powder material, uniform feeding speed, small erosion and wear inside the pipe, and long pipeline life.

[0025] In the present utility model, from top to bottom, a pulverized coal injection mechanism and an arc excitation device are provided at intervals of a certain length of pipe section on the spiral air inlet branch pipe. The pulverized coal injection mechanism is generally located upstream of the arc excitation device. That is, the arc excitation device heats and ignites the mixed fluid formed by the pulverized coal and the hot air injected by the upstream pulverized coal injection mechanism for each section, enabling the pulverized coal to burn out quickly in the spiral air inlet branch pipe, thereby significantly increasing the temperature of the secondary hot air and ensuring the uniformity of the temperature in the roasting section, which is helpful to improve and guarantee the quality of the roasted product.

[0026] In a preferred embodiment of the present utility model, each arc excitation device includes a plurality of pairs of alternating current arc electrodes that are evenly distributed along the air flow direction and symmetrically arranged on both side walls of the spiral air inlet branch pipe. Each pair of electrodes consists of an arc positive electrode rod and an arc negative electrode rod. Its function is to form a breakdown arc between the positive and negative electrode rods, creating a local high temperature to ignite the pulverized coal flow bundle traveling between the electrode rods, enabling the pulverized coal to flow downward in the spiral air inlet branch pipe while burning rapidly.

[0027] In the present utility model, due to the relatively high silicon content in the coal ash, it is easy to cause the pellet ore to agglomerate. To prevent the pulverized coal from entering the roasting material layer, a weighing ash hopper is provided at the lowest end of the spiral air inlet branch pipe (i.e., the lower end of the bent air outlet pipe section). The upper end of the weighing ash hopper is fixed to the outer wall of the spiral air inlet branch pipe through ear plates and weighing springs (it should be noted that a dust falling port communicating with the weighing ash hopper is provided at the lowest end of the spiral air inlet branch pipe). Its purpose is to accumulate and weigh the coal ash generated by the combustion of the pulverized coal in the spiral air inlet branch pipe under the action of gravity, thereby determining whether there is an abnormal condition where the coal ash enters the hot air hood in the roasting section or the pulverized coal is not completely burned. It should be noted that the weighing spring is a weighing spring with an elastic sealing air curtain. The material of the elastic sealing air curtain can be any non-venting soft material and does not affect the expansion and contraction of the spring. Its main function is to ensure airtightness and prevent air leakage.

[0028] In the present utility model, the lower part of the spiral air inlet branch pipe is bent upward to form a bent air outlet pipe section. The bottom end of the bent air outlet pipe section is designed to be inclined upward with a height lower than the air inlet of the hot air hood in the roasting section (i.e., the air inlet end of the bent air outlet pipe section is lower than its air outlet end); a labyrinth partition mechanism (such as a first telescopic baffle, a first driving motor, a second telescopic baffle, and a second driving motor, etc.) is additionally provided in the inclined upwardly arranged bent air outlet pipe section. The first and second telescopic baffles are respectively arranged in the front and back in the direction of the pulverized coal flow (any setting angle should be included in the protection scope of the present utility model). Its purpose is to block the pulverized coal and coal ash entrained in the secondary hot air that reaches the bottom and continues to flow to the roasting section through the bent air outlet pipe section under the action of the telescopic baffle, and make the blocked pulverized coal and coal ash sink to the weighing ash hopper below under the action of natural gravity.

[0029] In the present utility model, a pulverized coal anti-backflow baffle is also provided in the pipe cavity of the spiral air inlet branch pipe upstream of each pulverized coal injection mechanism. The structure and setting method of the pulverized coal anti-backflow baffle are the same as those of the first telescopic baffle and / or the second telescopic baffle.

[0030] In the present utility model, several temperature measuring elements are also arranged in the hot air hood above the roasting section. The purpose is to infer whether the temperature in the roasting chamber is uniform by measuring the temperature of the elements, and further infer whether unburned pulverized coal has entered the roasting chamber and continues to burn.

[0031] In the present utility model, when the traveling grate type roasting machine described in the present utility model is used for production, the amount of pulverized coal injected is controlled by the pulverized coal injection mechanism according to the actual working conditions to ensure the stable operation of the system. Specifically: the system will first detect multiple working conditions in the current working conditions (including pellet quality, required roasting temperature, calorific value of pulverized coal, etc.), and calculate the value of pulverized coal to be injected. For example, if the amount of pulverized coal injected through the pulverized coal injection mechanism per unit time is set as W mf , Kg: then there is:

[0032] W mf = W qt ×C qt ×(T1 - T0)÷Q mf (1)

[0033] In formula (1), W qt is the mass of pellets flowing through the roasting section per unit time, Kg. C qt is the specific heat capacity of pellets, KJ / (kg·°C). T1 is the target temperature to which the pellets in the roasting section need to be heated, °C. T0 is the initial temperature of the pellets in the roasting section, °C. Q mf is the calorific value of pulverized coal, KJ / Kg.

[0034] Furthermore, when the amount of pulverized coal injected through the pulverized coal injection mechanism per unit time is W mf : the system automatically controls the regulating valve to adjust the opening of the powder injection pipe according to this calculated value. At the same time, according to the pulverized coal injection value, the length range of the pipe section of the spiral air inlet branch pipe that needs to be ignited, as well as the coal ash generation value, etc. are calculated. For example, if the length of the pipe section heated by the arc excitation device for the spiral air inlet branch pipe is set as L, m. The generated mass of coal ash is W mh , Kg. Then there is:

[0035] L = W mf ×λ×V×d (2)

[0036] W mh = W mf ×η (3)

[0037] In formulas (2)-(3), λ is the length correction coefficient, with a value range of 6.5 - 12.5 (preferably 7 - 11). V is the hot air flow velocity entering the roasting section, m / s. d is the particle size of pulverized coal, m. η is the coal ash generation coefficient, with a value range of 0.005 - 0.05.

[0038] It should be noted that the system activates the corresponding arc elements according to the calculation results of formulas (2)-(3). For example, if the calculated height L requires activating 5 pairs of AC arc electrodes, then 5 pairs of AC arc electrodes are activated; if 10 pairs of electrode rods need to be activated, then 10 pairs are activated. After determining the number of pairs of AC arc electrodes to be activated, pulverized coal is injected and burned. During this process, the system will detect whether the weight of the coal ash measured in the weighing ash hopper is equal to the calculated coal ash generation value W mh If they are equal, this adjustment ends; if not, it enters the feedback adjustment link. In the feedback adjustment link, the system will detect whether the temperature values at different positions in the hot air hood of the roasting section are evenly distributed through several temperature measuring elements arranged in the hot air hood above the roasting section: If so, it indicates that the pulverized coal has been burned out in the spiral air inlet branch pipe, but the coal ash has entered the roasting section. At this time, the system will send a signal to the labyrinth partition mechanism to increase the telescopic depth of the first telescopic baffle and the second telescopic baffle, reducing the possibility of the pulverized coal being carried into the roasting section by the secondary hot air; If the temperature is not evenly distributed, it indicates that the pulverized coal has not been burned out in the spiral air inlet branch pipe and there is secondary combustion after entering the roasting section. At this time, the system will send a signal to the arc excitation device to extend the distance range of the ignition arc area on the spiral air inlet branch pipe (i.e., increase the number of pairs of AC arc electrodes activated). After this operation, the system will continue to detect the weight of the ash powder in the weighing ash hopper and compare it with the calculated coal ash generation value. If they are still not equal, the steps of this link will be repeated until they are equal. If they are equal, the system defaults that this adjustment ends.

[0039] It should be noted that all the formulas in the present invention are obtained by the inventor through fitting based on experiments and engineering applications. All calculations are based on the values after conversion according to the specified unit conversion. The values after converting the units are substituted into the formulas for calculation (after converting the units, only the values are substituted into the formulas for calculation, and the units are not substituted. The units are only used to adjust the magnitude of the values).

[0040] In the present invention, a gas injection device (a gas injection pipe with a control regulating valve) is additionally provided on the spiral air inlet branch pipe. Its function is to provide auxiliary gas combustion when the injection amount of pulverized coal cannot be increased, so as to provide qualified high-temperature secondary hot air for the roasting section.

[0041] In the present invention, a steam injection device (a steam injection pipe with a control regulating valve) is additionally provided on the spiral air inlet branch pipe. Its function is to provide auxiliary steam injection to cause a water-gas reaction with the pulverized coal when both the injection amount of pulverized coal and the injection amount of gas cannot be increased and the pulverized coal is difficult to burn out, strengthening the burnout rate of the pulverized coal and providing qualified high-temperature secondary hot air for the roasting section.

[0042] In the present utility model, the belt grate cooler of the present utility model has functions associated with external automatic control and adjustment mechanisms, and realizes the automatic and precise control and adjustment of the belt grate cooler through the automatic control and adjustment mechanisms, thereby ensuring the stability and safety of the system operation.

[0043] In the present utility model, in a preferred embodiment, the diameter of the main hot air conveying pipe is 5 - 300 cm, preferably 8 - 200 cm, and more preferably 10 - 100 cm. The diameter of the spiral air inlet branch pipe is 1 - 200 cm, preferably 3 - 150 cm, and more preferably 5 - 80 cm. The diameter of the pipe in the pulverized coal injection mechanism is 5 - 100 cm, preferably 8 - 80 cm, and more preferably 10 - 50 cm. The angle of the spiral pipe section on the spiral air inlet branch pipe inclined downward in a spiral shape is 10 - 80°, preferably 15 - 70°, and more preferably 20 - 60°. The thickness of the hot air hood is 0.1 - 80 cm, preferably 0.5 - 50 cm, and more preferably 1 - 30 cm.

[0044] Compared with the prior art, the beneficial technical effects of the present utility model are as follows:

[0045] 1: Without occupying additional space, the present utility model utilizes the idle space above the hot air hood of the belt grate cooler, designs the existing secondary hot air pipe into a pipe structure with a spiral self-rotating pipe section, and is equipped with a plurality of pulverized coal injection mechanisms and arc excitation devices on this pipe. The pulverized coal is directly injected and burned in the spiral air inlet branch pipe to obtain qualified hot air for roasting. Through the design of the spiral self-rotating pipe section, the purpose of using cheap pulverized coal as the heating fuel for roasting is achieved, which has the advantages of low energy consumption cost and no additional occupation of space.

[0046] 2: Without reducing the quality of the roasted product, the present utility model realizes the breakthrough of using cheap pulverized coal instead of expensive gas as the heating fuel for roasting, overcomes the deficiencies of high process cost and limited process suitability of the existing belt grate cooler, and provides a new development path for the belt grate roasting process in iron and steel pellet production.

[0047] 3: The belt grate cooler of the present utility model can be implemented without occupying additional space, has low investment and operation costs, a simple overall structure, and stable and reliable operation, and has excellent practical application value in the future market. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic cross-sectional structure diagram of the roasting section of the present utility model in the horizontal direction.

[0049] Figure 2 It is a schematic cross-sectional structure diagram of the belt grate cooler of the present utility model in the longitudinal direction.

[0050] Figure 3 This is a schematic structural diagram of the pulverized coal injection mechanism of the present utility model.

[0051] Figure 4 This is a schematic structural diagram of the pulverized coal injection mechanism of the present utility model having multiple powder injection pipes.

[0052] Figure 5 This is a schematic cross-sectional structural diagram of the pulverized coal injection mechanism of the present utility model having multiple powder injection pipes.

[0053] Figure 6 This is a schematic structural diagram of the arc excitation device of the present utility model.

[0054] Figure 7 This is an enlarged schematic diagram of the structure and connection mode of the weighing ash hopper of the present utility model.

[0055] Figure 8 This is an enlarged schematic diagram of the structure and connection mode of the telescopic baffle of the present utility model.

[0056] Reference numerals: 1: drying section; 2: draining section; 3: preheating section; 4: roasting section; 401: second hot air circulation pipeline; 5: first cooling section; 6: second cooling section; 601: first hot air circulation pipeline; 7: main hot air conveying pipe; 701: hot air conveying branch pipe; 8: spiral air inlet branch pipe; 801: bent air outlet pipe section; 802: weighing ash hopper; 803: ear plate; 804: elastic weighing connecting piece; 805: first telescopic baffle; 806: second telescopic baffle; 807: first driving motor; 808: second driving motor; 809: gas injection pipeline; 810: steam injection pipeline; 9: pulverized coal injection mechanism; 901: pulverized coal conveying pipeline; 902: powder injection pipe; 903: regulating valve; 10: arc excitation device; 1001: arc positive electrode rod; 1002: arc negative electrode rod; 11: hot air hood; 1101: temperature measuring element. Detailed implementation manners

[0057] The technical solutions of the present utility model will be illustrated by way of examples below. The scope of protection claimed by the present utility model includes but is not limited to the following embodiments.

[0058] A belt grate cooler with a spiral air inlet and pulverized coal injection mechanism, the belt grate cooler includes a drying section 1, a draining section 2, a preheating section 3, a roasting section 4, a first cooling section 5, a second cooling section 6 connected in series in sequence, and a hot air hood 11 covering above each section.

[0059] The spiral air inlet and pulverized coal injection mechanism includes a main hot air conveying pipe 7, a spiral air inlet branch pipe 8, and a pulverized coal injection mechanism 9.

[0060] Wherein: The air inlet end of the main hot air conveying pipe 7 is communicated with the exhaust port at the top of the first-stage cooling section 5, and its exhaust end is communicated with the upper end of the spiral air inlet branch pipe 8. The lower end of the spiral air inlet branch pipe 8 is communicated with the air inlet of the roasting section 4. The spiral air inlet branch pipe 8 has a spiral pipe section structure designed to spiral downwards, and a plurality of pulverized coal injection mechanisms 9 are connected to the spiral air inlet branch pipe 8 at intervals from top to bottom. Arc excitation devices 10 are arranged in a supporting manner on the spiral air inlet branch pipe 8 downstream of each pulverized coal injection mechanism 9.

[0061] In a preferred embodiment of the present utility model, the lower part of the spiral air inlet branch pipe 8 is bent upwards to form a bent air outlet pipe section 801. The air outlet end of the bent air outlet pipe section 801 is higher than its air inlet end, and the air outlet end of the bent air outlet pipe section 801 is communicated with the side air inlet of the hot air hood 11 above the roasting section 4.

[0062] In a preferred embodiment of the present utility model, an ash outlet is opened on the lower side wall of the lowest end of the bent air outlet pipe section 801, and a weighing ash hopper 802 is communicated and arranged below the ash outlet. Preferably, an ear plate 803 extends horizontally outwards at the upper hopper wall of the weighing ash hopper 802. The ear plate 803 is connected to the outer wall on the lower side of the bent air outlet pipe section 801 through an elastic weighing connecting piece 804.

[0063] In a preferred embodiment of the present utility model, a first telescopic baffle 805 and a second telescopic baffle 806 are further arranged in the bent air outlet pipe section 801. The first telescopic baffle 805 is vertically arranged on the upper inner wall of the pipe cavity of the bent air outlet pipe section 801 through a first driving motor 807, and the second telescopic baffle 806 is vertically arranged on the lower inner wall of the pipe cavity of the bent air outlet pipe section 801 through a second driving motor 808. The vertical heights of the first telescopic baffle 805 and the second telescopic baffle 806 are respectively driven by the first driving motor 807 and the second driving motor 808. Preferably, along the axial direction of the bent air outlet pipe section 801, a plurality of first telescopic baffles 805 and a plurality of second telescopic baffles 806 are alternately arranged at intervals.

[0064] In a preferred embodiment of the present utility model, the pulverized coal injection mechanism 9 includes a pulverized coal conveying pipeline 901 and a powder spraying pipe 902. The pulverized coal conveying pipeline 901 is communicated with the spiral air inlet branch pipe 8 through the powder spraying pipe 902, and a regulating valve 903 is arranged on the powder spraying pipe 902. Preferably, the powder spraying pipe 902 intersects the spiral air inlet branch pipe 8 obliquely, and the spraying direction of the pulverized coal is opposite to the hot air flow direction.

[0065] In a preferred embodiment of the present utility model, the pulverized coal conveying pipeline 901 is communicated with the spiral air inlet branch pipe 8 through a plurality of powder spraying pipes 902 with regulating valves 903.

[0066] In a preferred embodiment of the present utility model, a plurality of powder spraying pipes 902 with regulating valves 903 are uniformly distributed along the circumferential direction of the spiral air inlet branch pipe 8 in a spiral surrounding manner.

[0067] In a preferred embodiment of the present utility model, the arc excitation device 10 includes a plurality of arc positive rods 1001 and a plurality of arc negative rods 1002. The plurality of arc positive rods 1001 and the plurality of arc negative rods 1002 are arranged in pairs on both side walls of the spiral air inlet branch pipe 8 along the air flow direction.

[0068] In a preferred embodiment of the present utility model, a gas injection pipe 809 is further connected to the spiral air inlet branch pipe 8.

[0069] In a preferred embodiment of the present utility model, a steam injection pipe 810 is further connected to the spiral air inlet branch pipe 8.

[0070] In a preferred embodiment of the present utility model, along the width direction of the roasting section 4, a plurality of temperature measuring elements 1101 are arranged in the hot air hood 11 above the roasting section 4.

[0071] In a preferred embodiment of the present utility model, a pair of spiral air inlet branch pipes 8 are symmetrically arranged on both sides in the width direction of the hot air hood 11 above the roasting section 4. Preferably, along the material flow direction, a plurality of pairs of spiral air inlet branch pipes 8 are arranged on both sides of the hot air hood 11 above the roasting section 4.

[0072] In a preferred embodiment of the present utility model, the bottom air inlets of the first cooling section 5 and the second cooling section 6 are both connected with cold air pipes. The top air outlet of the first cooling section 5 is connected to the hot air conveying main pipe 7, and a hot air conveying branch pipe 701 is led out from the hot air conveying main pipe 7 and connected to the top air inlet of the preheating section 3. The top air outlet of the second cooling section 6 is connected to the bottom air inlet of the drying section 1 through the first hot air circulation pipe 601. The bottom air outlet of the roasting section 4 is connected to the top air inlet of the drying section 2 through the second hot air circulation pipe 401. The top air outlets of the drying section 1, the bottom air outlets of the drying section 2, and the bottom air outlets of the preheating section 3 are all connected with external exhaust air pipes.

[0073] Example 1

[0074] As Figure 1-8 shown, a belt grate type roasting machine with a spiral air inlet coal spraying mechanism, the belt grate type roasting machine includes a drying section 1, a drying section 2, a preheating section 3, a roasting section 4, a first cooling section 5, a second cooling section 6, and a hot air hood 11 covering above each section, which are connected in series in sequence.

[0075] The spiral air inlet coal spraying mechanism includes a hot air conveying main pipe 7, a spiral air inlet branch pipe 8, and a pulverized coal injection mechanism 9.

[0076] Wherein: The air inlet end of the main hot air conveying pipe 7 is connected to the exhaust port at the top of the first-stage cooling section 5, and its exhaust end is connected to the upper end of the spiral air inlet branch pipe 8. The lower end of the spiral air inlet branch pipe 8 is connected to the air inlet of the roasting section 4. The spiral air inlet branch pipe 8 has a spiral pipe section structure designed to spiral downwards from top to bottom, and a plurality of pulverized coal injection mechanisms 9 are connected to the spiral air inlet branch pipe 8 at intervals from top to bottom. An arc excitation device 10 is provided in a supporting manner on the spiral air inlet branch pipe 8 downstream of each pulverized coal injection mechanism 9.

[0077] Example 2

[0078] Repeat Example 1, except that the lower part of the spiral air inlet branch pipe 8 is bent upwards to form a bent air outlet pipe section 801. The air outlet end of the bent air outlet pipe section 801 is higher than its air inlet end, and the air outlet end of the bent air outlet pipe section 801 is connected to the side air inlet of the hot air hood 11 above the roasting section 4.

[0079] Example 3

[0080] Repeat Example 2, except that an ash outlet is provided on the lower side wall of the lowest end of the bent air outlet pipe section 801, and a weighing ash hopper 802 is connected and provided below the ash outlet.

[0081] Example 4

[0082] Repeat Example 3, except that an ear plate 803 extends horizontally outwards at the upper hopper wall of the weighing ash hopper 802. The ear plate 803 is connected to the outer wall on the lower side of the bent air outlet pipe section 801 through an elastic weighing connecting member 804.

[0083] Example 5

[0084] Repeat Example 4, except that a first telescopic baffle 805 and a second telescopic baffle 806 are further provided in the bent air outlet pipe section 801. The first telescopic baffle 805 is vertically arranged on the upper inner wall of the pipe cavity of the bent air outlet pipe section 801 through a first driving motor 807, and the second telescopic baffle 806 is vertically arranged on the lower inner wall of the pipe cavity of the bent air outlet pipe section 801 through a second driving motor 808. The vertical heights of the first telescopic baffle 805 and the second telescopic baffle 806 are respectively driven by the first driving motor 807 and the second driving motor 808.

[0085] Example 6

[0086] Repeat Example 5, except that along the axial direction of the bent air outlet pipe section 801, a plurality of first telescopic baffles 805 and a plurality of second telescopic baffles 806 are alternately arranged at intervals.

[0087] Example 7

[0088] Repeat Example 6, except that the pulverized coal injection mechanism 9 includes a pulverized coal conveying pipeline 901 and a powder injection pipe 902. The pulverized coal conveying pipeline 901 is connected to the spiral air inlet branch pipe 8 through the powder injection pipe 902, and a regulating valve 903 is provided on the powder injection pipe 902.

[0089] Example 8

[0090] Repeat Example 7, except that the powder injection pipe 902 intersects the spiral air inlet branch pipe 8 obliquely, and the injection direction of the pulverized coal is opposite to the hot air flow direction.

[0091] Example 9

[0092] Repeat Example 8, except that the pulverized coal conveying pipeline 901 is connected to the spiral air inlet branch pipe 8 through multiple powder injection pipes 902 each with a regulating valve 903.

[0093] Example 10

[0094] Repeat Example 9, except that multiple powder injection pipes 902 each with a regulating valve 903 are uniformly arranged in a spiral around the circumferential direction of the spiral air inlet branch pipe 8.

[0095] Example 11

[0096] Repeat Example 10, except that the arc excitation device 10 includes a plurality of arc positive rods 1001 and a plurality of arc negative rods 1002. The plurality of arc positive rods 1001 and the plurality of arc negative rods 1002 are arranged in pairs on both side walls of the spiral air inlet branch pipe 8 along the air flow direction.

[0097] Example 12

[0098] Repeat Example 11, except that a gas injection pipeline 809 is further connected to the spiral air inlet branch pipe 8.

[0099] Example 13

[0100] Repeat Example 12, except that a water vapor injection pipeline 810 is further connected to the spiral air inlet branch pipe 8.

[0101] Example 14

[0102] Repeat Example 13, except that along the width direction of the roasting section 4, a plurality of temperature measuring elements 1101 are provided in the hot air hood 11 above the roasting section 4.

[0103] Example 15

[0104] Repeat Example 14, except that a pair of spiral air inlet branch pipes 8 are symmetrically arranged on both sides in the width direction of the hot air hood 11 above the roasting section 4. Along the material flow direction, multiple pairs of spiral air inlet branch pipes 8 are provided on both sides of the hot air hood 11 above the roasting section 4.

[0105] Example 16

[0106] Repeat Example 15, except that cold air pipes are connected to the bottom air inlets of both the first cooling section 5 and the second cooling section 6. The top air outlet of the first cooling section 5 is connected to the main hot air conveying pipe 7, and a hot air conveying branch pipe 701 is also led out from the main hot air conveying pipe 7 and connected to the top air inlet of the preheating section 3. The top air outlet of the second cooling section 6 is connected to the bottom air inlet of the drum drying section 1 through the first hot air circulation pipe 601. The bottom air outlet of the roasting section 4 is connected to the top air inlet of the draining section 2 through the second hot air circulation pipe 401. Exhaust air pipes are connected to the top air outlets of the drum drying section 1, the bottom air outlets of the draining section 2, and the bottom air outlets of the preheating section 3.

Claims

1. A belt grate with a spiral air inlet and coal injection mechanism. The belt grate includes a drying section (1), a suction drying section (2), a preheating section (3), a roasting section (4), a first cooling section (5), a second cooling section (6) connected in series in sequence, and a hot air hood (11) covering above each section; it is characterized in that: The spiral air inlet coal injection mechanism includes a main hot air conveying pipe (7), a spiral air inlet branch pipe (8), and a pulverized coal injection mechanism (9); Among them: The air inlet end of the main hot air conveying pipe (7) is connected to the exhaust port at the top of the first cooling section (5), and its exhaust end is connected to the upper end of the spiral air inlet branch pipe (8). The lower end of the spiral air inlet branch pipe (8) is connected to the air inlet of the roasting section (4); The spiral air inlet branch pipe (8) has a spiral pipe section structure designed to spiral downwards, and a plurality of pulverized coal injection mechanisms (9) are connected to the spiral air inlet branch pipe (8) at intervals from top to bottom; An arc excitation device (10) is provided in a supporting manner on the spiral air inlet branch pipe (8) downstream of each pulverized coal injection mechanism (9).

2. The traveling grate machine according to claim 1, wherein: The lower part of the spiral air inlet branch pipe (8) is bent upwards to form a bent air outlet pipe section (801). The air outlet end of the bent air outlet pipe section (801) is higher than its air inlet end, and the air outlet end of the bent air outlet pipe section (801) is connected to the side air inlet of the hot air hood (11) above the roasting section (4).

3. The traveling grate machine according to claim 2, wherein: An ash outlet is opened on the lower side wall of the lowest end of the bent air outlet pipe section (801), and a weighing ash hopper (802) is connected and provided below the ash outlet.

4. The traveling grate machine according to claim 3, characterized in that: An ear plate (803) extends horizontally outwards at the upper hopper wall of the weighing ash hopper (802); The ear plate (803) is connected to the outer wall on the lower side of the bent air outlet pipe section (801) through an elastic weighing connecting piece (804).

5. The traveling grate machine according to claim 2, characterized in that: A first telescopic baffle (805) and a second telescopic baffle (806) are also provided in the bent air outlet pipe section (801); The first telescopic baffle (805) is vertically arranged on the upper inner wall of the pipe cavity of the bent air outlet pipe section (801) through a first driving motor (807), and the second telescopic baffle (806) is vertically arranged on the lower inner wall of the pipe cavity of the bent air outlet pipe section (801) through a second driving motor (808); The vertical heights of the first telescopic baffle (805) and the second telescopic baffle (806) are respectively driven by the first driving motor (807) and the second driving motor (808).

6. The traveling grate machine according to claim 5, wherein: Along the axial direction of the bent air outlet pipe section (801), a number of first telescopic baffles (805) and a number of second telescopic baffles (806) are arranged in an alternating and spaced manner in sequence.

7. The traveling grate machine according to any one of claims 1-6, characterized in that: The pulverized coal injection mechanism (9) includes a pulverized coal conveying pipeline (901) and a powder spraying pipe (902); The pulverized coal conveying pipeline (901) is connected to the spiral air inlet branch pipe (8) through the powder spraying pipe (902), and a regulating valve (903) is provided on the powder spraying pipe (902).

8. The traveling grate machine according to claim 7, wherein: The powder spraying pipe (902) intersects the spiral air inlet branch pipe (8) obliquely, and the spraying direction of the pulverized coal is opposite to the hot air flow direction.

9. The traveling grate machine according to claim 7, characterized in that: The pulverized coal conveying pipeline (901) is connected to the spiral air inlet branch pipe (8) through multiple powder spraying pipes (902) with regulating valves (903).

10. The traveling grate roaster according to claim 9, characterized in that: Multiple powder spraying pipes (902) with regulating valves (903) are evenly distributed along the circumference of the spiral air inlet branch pipe (8) in a spiral winding manner.

11. The traveling grate machine according to any one of claims 1-6, 8-10, characterized in that: The arc excitation device (10) includes a plurality of arc positive rods (1001) and a plurality of arc negative rods (1002); the plurality of arc positive rods (1001) and the plurality of arc negative rods (1002) are arranged in pairs on the two side walls of the spiral air inlet branch pipe (8) along the flow direction of the air flow.

12. The traveling grate machine according to any one of claims 1-6, 8-10, characterized in that: A gas injection pipe (809) is further connected to the spiral air inlet branch pipe (8); and / or A steam injection pipe (810) is further connected to the spiral air inlet branch pipe (8).

13. The traveling grate machine according to claim 7, characterized in that: A gas injection pipe (809) is further connected to the spiral air inlet branch pipe (8); and / or A steam injection pipe (810) is further connected to the spiral air inlet branch pipe (8).

14. The traveling grate machine according to claim 11, wherein: A gas injection pipe (809) is further connected to the spiral air inlet branch pipe (8); and / or A steam injection pipe (810) is further connected to the spiral air inlet branch pipe (8).

15. The traveling grate roaster according to any one of claims 1-6, 8-10, 13-14, characterized in that: Along the width direction of the roasting section (4), a plurality of temperature measuring elements (1101) are arranged in the hot air hood (11) above the roasting section (4).

16. The traveling grate machine according to any one of claims 1-6, 8-10, 13-14, characterized in that: A pair of spiral air inlet branch pipes (8) are symmetrically arranged on both sides in the width direction of the hot air hood (11) above the roasting section (4).

17. The traveling grate machine according to claim 16, wherein: Along the flow direction of the material, a plurality of pairs of spiral air inlet branch pipes (8) are arranged on both sides of the hot air hood (11) above the roasting section (4).

18. The traveling grate machine according to any one of claims 1-6, 8-10, 13-14, and 17, characterized in that: Cold air pipes are connected to the bottom air inlets of the first cooling section (5) and the second cooling section (6); the top air outlet of the first cooling section (5) is connected to the main hot air conveying pipe (7), and a hot air conveying branch pipe (701) is led out from the main hot air conveying pipe (7) and connected to the top air inlet of the preheating section (3); the top air outlet of the second cooling section (6) is connected to the bottom air inlet of the drying section (1) through the first hot air circulation pipe (601); the bottom air outlet of the roasting section (4) is connected to the top air inlet of the extraction drying section (2) through the second hot air circulation pipe (401); the top air outlets of the drying section (1), the bottom air outlets of the extraction drying section (2) and the bottom air outlets of the preheating section (3) are all connected with external exhaust air pipes.

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