CN217210271U

CN217210271U - Pellet reduction system for preventing pellet burst

Info

Publication number: CN217210271U
Application number: CN202220011678.XU
Authority: CN
Inventors: 郑富强; 胡兵; 刘臣; 师本敬; 王兆才; 张震
Original assignee: Zhongye Changtian International Engineering Co Ltd
Current assignee: Zhongye Changtian International Engineering Co Ltd
Priority date: 2022-01-04
Filing date: 2022-01-04
Publication date: 2022-08-16
Anticipated expiration: 2032-01-04

Abstract

The utility model discloses a pellet reduction system for preventing pellet burst. The utility model discloses divide the coal-based rotary kiln into the drying zone in proper order, the preheating section, reduction calcination section and slow cold stage, and through specific air current circulation design, redistribute the hot-blast back that mixes with the high temperature of reduction calcination section of the main vapor bearing of rotary kiln tail exhaust, full play preheats and the utilization potentiality of complementary energy, improve the outside vapor pressure of pelletizing at drying zone initial stage, slow down moisture desorption speed in the green pellet, when realizing green pellet rapid draing, prevent again that the pelletizing from bursting, reach the purpose that improves rotary kiln drying efficiency.

Description

Pellet reduction system for preventing pellet burst

Technical Field

The utility model relates to a pelletizing reduction technology, concretely relates to prevent pelletizing reduction system of pelletizing burst belongs to iron-bearing pelletizing reduction technical field.

Background

Direct Reduced Iron (DRI) is a supplement to scrap steel in short-run steelmaking processes and an ideal feedstock for smelting high-quality special steel. In recent years, the production of direct reduced iron has rapidly progressed worldwide. Because of the shortage of iron ore resources and natural gas, the development of the direct reduction process in China is slow, and research and practice hotspots are also focused on the coal-based direct reduction process to produce direct reduced iron or metallic iron by adopting non-coking coal. In the existing coal-based direct reduction process, oxidized pellets or cold-bonded pellets are generally used as raw materials to react in a rotary kiln to produce DRI. In the direct reduction process of the coal-based rotary kiln, the charging materials need 6 to 8 hours from entering the kiln to discharging the products, the production period is longer, and the production efficiency is low. The productivity of the direct reduction process of the rotary kiln, i.e. the amount of products produced by the rotary kiln per unit time, is generally related to the size and structure of the kiln, the conditions of raw materials and fuel, the temperature and temperature distribution in the kiln, the atmosphere and the charge amount, etc., and the reduction speed of the pellets is a fundamental factor affecting the production cycle and production efficiency of the direct reduction.

In order to improve the reduction speed of direct reduction, researchers and practitioners propose some technical measures, and some measures are proposed in the aspects of kiln body design (such as CN110229939A, a two-section rotary kiln method non-coke iron-making device), pellet batching (such as CN106591572A, a method for strengthening preparation and reduction of carbon-added pellets in iron ore), and the like, but the practicability of industrial application is poor, the method is still mostly stopped at the experimental stage at present, and the method is not popularized and applied yet.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects of the prior art, the utility model provides a pellet reduction system for preventing pellets from bursting. For realizing the low temperature fast reduction of coal-based rotary kiln, the utility model discloses divide the coal-based rotary kiln into the drying section in proper order, preheat the section, reduction roasting section and slow cold stage, and through specific air current circulation design, redistribute after mixing the hot-blast with the main moisture steam of rotary kiln tail exhaust and the high temperature hot-blast of reduction roasting section, full play preheats and the utilization potentiality of complementary energy, improve the outside vapor pressure of pelletizing at drying section initial stage, slow down moisture desorption speed in the green pellet, when realizing green pellet fast drying, prevent again that the pelletizing from bursting, reach the purpose that improves rotary kiln drying efficiency.

In order to achieve the above object, the present invention adopts the following technical solutions:

according to a first embodiment of the present invention, there is provided a pellet reduction system for preventing bursting of pellets.

A pellet reduction system for preventing pellet bursting includes a rotary kiln. According to the trend of the materials, the rotary kiln is sequentially provided with a drying section, a preheating section, a reduction roasting section and a slow cooling section. And the kiln tail air outlet of the rotary kiln is communicated with the air inlet of the first air mixing chamber through a first pipeline. And the air outlet at the top of the reduction roasting section is communicated with the air inlet of the first air mixing chamber through a second pipeline. The air outlet of the air mixing chamber is communicated with the air inlet at the bottom of the drying section at the initial stage through a third pipeline. The length of the rotary kiln is 0.5 to 800m, preferably 1 to 500m, more preferably 3 to 200 m.

Preferably, the air outlet at the top of the later stage of the drying section is communicated with the air inlet of the second air mixing chamber through a fourth pipeline. And the air outlet at the top of the reduction roasting section is communicated with the air inlet of the second air mixing chamber through a fifth pipeline. And an air outlet of the second air mixing chamber is communicated with a bottom air inlet at the middle and later stages of the drying section through a sixth pipeline.

Preferably, the system further comprises a melting furnace. The feed inlet of the melting furnace is connected with the discharge outlet of the rotary kiln through a clinker conveying device.

Preferably, the first pipeline is sequentially provided with a first flow regulating valve and a first fan. And the second pipeline is sequentially provided with a second flow regulating valve and a second fan. And the third pipeline is sequentially provided with a third flow regulating valve and a third fan.

Preferably, the fourth pipeline is sequentially provided with a fourth flow regulating valve and a fourth fan. And the fifth pipeline is sequentially provided with a fifth flow regulating valve and a fifth fan. And the sixth pipeline is sequentially provided with a sixth flow regulating valve and a sixth fan.

Preferably, the fifth conduit is a bypass conduit of the second conduit upstream of the second flow regulating valve.

Preferably, a multi-tube precipitator is optionally (optionally shown with or without) also provided on the second conduit upstream of the point where the fifth conduit joins the second conduit.

Preferably, the system further comprises a first material temperature detection device. The first material temperature detection device is arranged in the reduction roasting section.

Preferably, the system further comprises a second material temperature detection device. The second material temperature detection device is arranged in the middle and later periods of the drying section.

Preferably, the system further comprises a metallization ratio detection device. The metallization ratio detection device is arranged in the preheating section.

Preferably, the system further comprises a burner and a fuel delivery pipeline. The burner is arranged in the reduction roasting section and communicated with the fuel conveying pipeline. And a combustion-supporting air pipe is communicated with the fuel conveying pipeline outside the rotary kiln.

Preferably, a plurality of burners are arranged in the reduction roasting section, and the burners are all communicated with the fuel conveying pipeline.

Preferably, the rotary kiln further comprises a kiln body air duct mechanism, an annular rotary slide rail and a rotary slide mechanism. The annular rotary slide rail is sleeved outside the rotary kiln and supported by the support. The wheel end of the rotary sliding mechanism is connected with the annular rotary sliding rail, the other end of the rotary sliding mechanism is connected with the outer end of the kiln body air duct mechanism, and the inner end of the kiln body air duct mechanism is connected to the kiln wall. Namely, the rotary kiln and the kiln body air duct mechanism can simultaneously rotate on the annular rotary slide rail through the rotary slide mechanism.

Preferably, a plurality of annular rotary sliding rails are arranged outside the rotary kiln. Any one annular rotary slide rail is connected with the rotary kiln through a plurality of rotary slide mechanisms and a plurality of kiln body air duct mechanisms.

Preferably, the kiln body air duct mechanism comprises an air inlet connecting piece, a stop valve, a pull rod and an air inlet. An air inlet channel is formed in the rotary kiln body. One end of the baffle valve extends into the air inlet channel, and the other end of the baffle valve is communicated with the air inlet connecting piece. The air inlet is arranged on the air inlet connecting piece. The one end that the rotary kiln was kept away from to the air inlet connecting piece is connected with the one end of pull rod, and the other end of pull rod is connected with rotary sliding mechanism.

Preferably, the rotary sliding mechanism comprises a rotary wheel seat, a lateral rotary wheel and a vertical rotary wheel. The rotary wheel seat is of a concave groove type structure and is meshed with the two side edge parts of the annular rotary sliding rail. And lateral rotating wheels are arranged on the rotating wheel seats on the side surfaces of the annular rotating slide rails. Vertical rotating wheels are arranged on the rotating wheel seats on the outer bottom surfaces of the annular rotating slide rails. The rotary wheel seat can rotate and slide on the annular rotary sliding rail through the lateral rotary wheel and the vertical rotary wheel.

Preferably, the rotary kiln further comprises a horizontal sliding mechanism. The horizontal sliding mechanism comprises a horizontal wheel seat, a horizontal pulley and a horizontal rail. The horizontal rail is a groove-shaped rail arranged at the upper end of the bracket. The bottom end of the horizontal wheel seat is arranged in the horizontal track through the horizontal pulley. The top end of the horizontal wheel seat is connected with the annular rotary sliding rail.

Preferably, the system further comprises a swing mechanism. The slewing mechanism comprises a slewing motor and a large gear ring. The inner ring of the large gear ring is fixed on the outer wall of the rotary kiln, and the outer ring of the large gear ring is meshed and connected with a transmission gear of the rotary motor.

According to a second embodiment of the present invention, there is provided a method for pellet reduction using the pellet reduction system for preventing pellet burst of the first embodiment.

A pellet reduction method for preventing pellet decrepitation, the method comprising the steps of:

1) according to the trend of materials, green balls enter a rotary kiln from the kiln tail, and are subjected to reduction treatment sequentially through a drying section, a preheating section, a reduction roasting section and a slow cooling section to obtain clinker.

2) Mixing hot air output by the kiln tail of the rotary kiln with hot air output by the reduction roasting section to obtain mixed wet hot air, and then conveying the mixed wet hot air to the drying section to participate in the drying treatment of the pellets at the initial stage. And adjusting the extraction amount of hot air in the reduction roasting section and the extraction amount of hot air at the tail of the rotary kiln according to the real-time temperature change of the materials in the reduction roasting section.

Preferably, the temperature of the mixed wet hot air is 350-500 ℃, preferably 400-450 ℃.

Preferably, the method further comprises:

3) and mixing the hot air output at the later stage of the drying section with the hot air output from the reduction roasting section to obtain mixed dry hot air, and then conveying the mixed dry hot air to the drying section to participate in the drying treatment of the pellets at the initial stage. And adjusting the extraction amount of hot air in the later stage of the drying section and the extraction amount of hot air in the reduction roasting section according to the real-time temperature change of the material in the later stage of the drying section.

Preferably, the temperature of the mixed dry hot air is 350-500 ℃, preferably 400-450 ℃.

Preferably, the method further comprises:

4) and conveying the clinker generated in the rotary kiln to a melting furnace for deep reduction treatment.

Preferably, in the step 2), the adjusting of the extraction amount of the hot air in the reduction roasting section and the extraction amount of the kiln tail hot air of the rotary kiln according to the real-time temperature change of the material in the reduction roasting section is specifically as follows: the set temperature of the material in the reduction roasting section is set to be T1 +/-C1 (the range of C1 is 0-50 ℃) and DEG C. Detecting the real-time temperature of the material in the reduction roasting section at T2 and DEG C in real time. Then:

and when T2 > (T1 +/-C1), increasing the extraction amount of hot air in the reduction roasting section and the extraction amount of hot air at the tail of the rotary kiln until the real-time temperature of the material in the reduction roasting section returns to the preset temperature (T1 +/-C1).

When T2 ∈ (T1. + -. C1), the current process conditions were maintained unchanged.

When T2 < (T1 +/-C1), the extraction amount of hot air in the reduction roasting section and the extraction amount of hot air at the tail of the rotary kiln are reduced until the real-time temperature of the material in the reduction roasting section returns to the preset temperature (T1 +/-C1).

Preferably, in the step 3), the adjusting of the extraction amount of the hot air in the later stage of the drying section and the extraction amount of the hot air in the reduction roasting section according to the real-time temperature change of the material in the later stage of the drying section is specifically as follows: the set temperature of the material at the later stage of the drying section is T3 +/-C2 (the range of C2 is 0-50 ℃) and DEG C. And detecting the real-time temperature of the material at the later stage of the drying section at T4 and DEG C in real time. Then:

when T4 > (T3 +/-C2), the extraction amount of hot air in the later stage of the drying section and the extraction amount of hot air in the reduction roasting section are increased until the real-time temperature of the materials in the later stage of the drying section returns to the preset temperature (T3 +/-C2).

When T4 ∈ (T3. + -. C2), the current process conditions were maintained unchanged.

When T4 < (T3 +/-C2), the extraction amount of hot air in the later stage of the drying section and the extraction amount of hot air in the reduction roasting section are reduced until the real-time temperature of the materials in the later stage of the drying section returns to the preset temperature (T3 +/-C2).

Preferably, the green pellets are obtained by mixing iron-containing ore powder with a reducing agent and then pelletizing. Wherein: the iron-containing mineral powder is selected from one or more of hematite powder, magnetite powder, limonite powder, siderite powder and goethite powder. The reducing agent is selected from one or more of lignite, bituminous coal, anthracite and coke.

The utility model discloses in, to among the coal-based rotary kiln direct reduction technology of prior art, the furnace charge need 6-8h from going into the kiln to the product kiln of drawing out, and production cycle is longer, production efficiency is low to the rotary kiln of prior art is pelletizing burst rate higher in pelletizing drying process, easily takes place the ring formation phenomenon at the high temperature section. The productivity of a typical rotary kiln direct reduction process is generally related to the size and configuration of the kiln, the feedstock and fuel conditions, the temperature and temperature distribution within the kiln, the atmosphere and the amount of charge. The utility model discloses divide dry section, preheating section, reduction calcination section and slow cooling section in proper order with coal-based rotary kiln according to the trend of material. The key to realizing the low-temperature rapid reduction of the coal-based rotary kiln is to improve the main reaction rate of each section in the kiln. In addition, one of the main reasons for the ring formation of the rotary kiln for reducing and roasting the iron ore pellets is that the amount of pellet powder in the kiln is large, the pellet powder is easy to melt at a high-temperature section to cause ring formation, and the powder in the kiln is mainly caused by the burst of part of green pellets in the drying process and the abrasion of the pellets when the pellets rotate in the kiln. Therefore, the method accelerates the moisture removal of the drying section of the coal-based rotary kiln and ensures the pellet strength of the drying section, is one of the keys for realizing high efficiency and high yield of the coal-based rotary kiln and is also the key for inhibiting ring formation in the kiln. In addition, the heat transfer mode of high-temperature gas and materials in the rotary kiln mainly adopts radiation heat transfer, and the convection heat transfer of the hot gas and the materials can be enhanced by feeding the high-temperature hot gas from the lower part of the material layer of the drying section, so that the heat transfer efficiency is improved. The material temperature of the drying section is raised in a convection heat transfer mode, so that when the material is dried, the upward flowing gas quickly brings the water vapor dried out of the material away from the material layer, and the quick drying is realized. The purposes of saving energy, reducing emission and improving production efficiency are achieved.

The utility model discloses in, generally because the material contains a large amount of moisture when adding from the rotary kiln tail, at the material along with the kiln body rotates and constantly to the in-process that kiln head high temperature district removed, the material of moisture is dry in the dry section dehydration gradually in the kiln. When the pellets run to the kiln head, water in the pellets forms steam under the action of temperature, the external vapor pressure of the pellets is small, the internal vapor pressure is large, and the water is diffused and removed from the inside of the pellets to the outside. The burst temperature of the iron ore green pellets is about 250-500 ℃ generally, and the tail temperature of the rotary kiln is about 300 ℃ generally, so that once the green pellets containing a large amount of moisture enter the kiln in the drying process, the green pellets enter a drying section at about 300 ℃, the moisture in the green pellets is quickly changed into water vapor, the vapor pressure outside the green pellets is small, the vapor in the pellets quickly escapes, the pellets are easy to burst when the pellet strength is insufficient, a large amount of powder is generated, and the ring formation risk in the kiln is increased. The utility model discloses an increase the outside vapor pressure of pelletizing at the pelletizing moisture desorption initial stage, slow down moisture desorption speed in the green ball. Furthermore, the drying temperature is increased in the middle and later periods of moisture removal in the green pellets, so that the green pellets can be quickly dried, the pellets are prevented from bursting, and the aim of improving the drying efficiency of the rotary kiln is fulfilled. For the materials of which the powder is put into the kiln, the moisture removal is enhanced by high-temperature steam in the early drying stage, and the drying temperature is increased in the later drying stage, so that the rapid drying of the materials can be realized.

The utility model discloses in, general rotary kiln tail exhaust gas temperature is about 300 ℃ to contain a large amount of vapor, the gaseous about up to 1200 ℃ of reduction roasting section kiln interior. The utility model discloses a high temperature gas about 1200 ℃ with reduction roasting section is behind the multicell dust remover dust fall, obtains mixing damp and hot wind with kiln tail 300 ℃ about the waste gas of vapor in mixing the gas device mixing again, makes and mixes damp and hot wind temperature and be less than 500 ℃, then sends into its bed of material lower part from dry initial stage through the air exhauster, carries out the drying with high temperature vapor to the material. The technical scheme mainly has the following functions: firstly, high-temperature gas in a reduction roasting section is utilized to increase the temperature in the early drying stage; secondly, neutralizing the temperature of high-temperature gas in a roasting section by utilizing the tail gas of the rotary kiln with lower temperature; thirdly, returning the water vapor in the tail gas of the rotary kiln to a material layer at the initial drying stage to increase the vapor pressure of the material layer and prevent the pellets from bursting; fourthly, the mixed hot air is fed from the lower part of the material layer at the initial drying stage to strengthen the convection heat transfer. The vapor pressure outside the pellets is increased at the initial stage of the drying section, the rapid escape of moisture inside the pellets is effectively inhibited, the pellets are prevented from bursting, and the ring formation risk of the rotary kiln is greatly reduced.

The utility model discloses in, the utility model discloses accessible on-line monitoring material temperature, charge level gas composition and material metallization rate judge that material reduction reaction carries out the condition in the rotary kiln, and then through the circulation gas flow who adjusts the distribution of temperature field in the kiln and let in the bed of material, realize the control to material reduction reaction and temperature. The gas components of the charge level can be measured by an online smoke component detection device, and the material metallization rate can be monitored online by a material metallization rate measurement technology based on conductivity. In general: firstly, establishing a reference relation between a thermal regulation system for quickly reducing the material at a low temperature, material layer atmosphere and material metallization rate according to the characteristics of the material and a reducing agent, and determining a necessary heating rate, a temperature interval and a duration range of each main reduction reaction section, a material layer atmosphere and a material surface gas composition range of each reduction reaction section, and a relation between the conductivity and the metallization rate of the material of each reduction reaction section in the material reduction process as a reference requirement for subsequently regulating and controlling the material reduction process in the rotary kiln. Secondly, in the running process of the rotary kiln, the temperature, the material surface waste gas component and the material metallization rate of different sections in the rotary kiln are monitored in real time through temperature monitoring devices, material surface gas component content monitoring devices and material metallization rate monitoring devices distributed on the rotary kiln, and then the redistribution quantity of the circulating gas is adjusted according to data information monitored in real time.

The utility model discloses in, mix the hot-blast and the hot-blast of reduction roasting section output of rotary kiln tail output and obtain mixed damp and hot-blast, then will mix damp and hot-blast and carry to the drying process that participates in the pelletizing to the drying section initial stage. And adjusting the extraction amount of hot air in the reduction roasting section and/or the extraction amount of hot air at the kiln tail of the rotary kiln according to the real-time temperature change of the materials in the reduction roasting section. The specific control mode is as follows: the set temperature of the material in the reduction roasting section is set to be T1 +/-C1 (the range of C1 is 0-50 ℃) and DEG C. And detecting the real-time temperature of the material in the reduction roasting section at T2 and DEG C in real time. Then:

The utility model discloses in, the moisture has been removed some in the pelletizing after drying section initial stage is handled, improves drying temperature in drying section middle and later stage and does not worry the pelletizing and burst in order to accelerate drying rate. The steam content is few in rotary kiln drying section later stage gas, consequently the utility model discloses a high-temperature gas about 1200 ℃ of section of will reducing roasting is behind the multicell dust remover dust fall, obtains mixed dry hot air with the hot-blast gas mixing in the gas mixing device in drying section later stage, and the temperature of mixed dry hot air is less than 500 ℃, then sends into its lower part of the bed of material from the drying section middle and later stage through the air exhauster, carries out the drying with the high-temperature gas who does not take steam to the material. The technical scheme has the main effects that firstly, the high-temperature gas in the roasting section is utilized to increase the drying temperature in the middle and later periods of the drying section and increase the drying speed; secondly, the high-temperature gas temperature of the reduction roasting section is neutralized by the gas at the later stage of the low-temperature drying section; thirdly, mixed gas is fed from the lower part of the material layer in the middle and later drying stages, and convection heat transfer is enhanced. The steam dried out from the material is quickly carried away by the upward flowing gas, so that the quick drying is realized.

The utility model discloses in, mix the hot-blast and the hot-blast dry hot-blast of reduction roasting section output of drying section later stage output and obtain mixed dry hot-blast, then will mix dry hot-blast and carry to the drying process that the drying section initial stage participated in the pelletizing. And adjusting the extraction amount of hot air in the later stage of the drying section and the extraction amount of hot air in the reduction roasting section according to the real-time temperature change of the material in the later stage of the drying section. The specific control mode is as follows: the set temperature of the material at the later stage of the drying section is T3 +/-C2 (the range of C2 is 0-50 ℃) and DEG C. And detecting the real-time temperature of the material at the later stage of the drying section at T4 and DEG C in real time. Then:

In the utility model, in the process of reducing iron oxide, iron element is gradually reduced from high valence to low valence. When the temperature is more than 570 ℃, the reduction order of the iron oxide is Fe ₂ O ₃ →Fe ₃ O ₄ → FexO → Fe. Wherein, the difficulty of FexO → Fe is the largest, the preheating section of the iron-bearing pellet ore in the rotary kiln is reduced by Fe ₂ O ₃ →Fe ₃ O ₄ → FexO, then introducing coal gas (CO, H) into the rotary kiln in the reduction roasting section and the slow cooling section ₂ Mixed gas) to make the iron-bearing pellets undergo the direct reduction reaction in the furnace, the Fe crystal grains in the raw material are primarily aggregated and grown to form the direct reduced iron after the gas-based direct reduction, the iron-bearing material (clinker) treated by the rotary kiln generally also contains a considerable amount of iron oxide (generally FexO), the clinker containing FexO can be placed in a melting furnace (generally a vertical electric furnace) for melting, air and coal powder are continuously introduced in the melting process, firstly, a combustion reaction is carried out in an oxidation zone (an upper layer area in the furnace) to provide heat for a reduction reaction of iron oxide, the reduction reaction of the iron oxide is carried out in a reduction zone (a lower layer area in the furnace), C in the coal and the iron oxide are carried out a deep reduction reaction in the reduction zone, CO is generated in the reaction process, the reaction product coal ash, gangue and a solvent react to form slag which exists in a slag layer, and molten iron is settled and flows out from a front furnace. The incompletely reacted mixed gas contains CO (about 21%), and CO as main components ₂ (about 25%), H ₂ (about 4%), N ₂ (about 48%), H ₂ O (about 2%), and the gas can be led out for reforming.

In the present invention, the first pipe has a pipe diameter of 0.1 to 10m, preferably 0.3 to 8m, more preferably 0.5 to 5m, still more preferably 0.8 to 4m, such as 1m, 1.2m, 1.5m, 2m, 2.5m, 3m, 3.5m, etc. The kiln diameter of the rotary kiln body is 0.5 to 80m, preferably 1 to 50m, more preferably 2 to 30m, still more preferably 3 to 20m, such as 5m, 8m, 10m, 12m, 15m, 18m, 20m, etc. The length of the kiln body of the rotary kiln is 0.5-800m, preferably 1-500m, more preferably 3-200m, still more preferably 5-100m, such as 8m, 10m, 15m, 20m, 25m, 30m, 35m, 40m, 45m, 50m, 55m, 60m, 65m, 70m, 75m, 80m, 85m, 90m, 95m, 100m, etc.

Compared with the prior art, the utility model discloses a beneficial technological effect as follows:

1: the utility model discloses take out the high-temperature gas that overflows in the reduction roasting section bed of material, mix in the gas mixing device with the tail gas that the rotary kiln drying section contains steam after the multicell dust remover dust fall. The temperature of the mixed gas is lower than 500 ℃, then the mixed gas is sent from the lower part of the material layer at the initial drying stage through the exhaust fan, and the materials at the initial drying stage are dried by high-temperature steam, so that the external vapor pressure of the pellets is increased, the moisture removal rate in the green pellets is slowed down, the green pellets are prevented from bursting while being rapidly dried, and the aim of improving the drying efficiency of the rotary kiln is fulfilled.

2: the utility model discloses still take the high-temperature gas of reduction roasting section out and through the multi-tube dust remover dust fall after, do not contain the gaseous mixing in gas mixing device of steam with the drying section later stage, then send into its bed of material lower part from dry middle and later stages through the air exhauster, carry out the drying with the high-temperature gas who does not take steam to the material. The drying temperature is increased in the middle and later period of the moisture removal in the ball. The temperature of drying section material is risen through the mode of convection heat transfer, realizes the effective utilization of waste heat for when the material is dry, the material layer is still can be taken away from with the vapor of drying out in the material to the gas of upflow, further realizes quick drying.

Drawings

FIG. 1 is a schematic view of the single-airflow circulation pellet reduction system of the present invention.

Fig. 2 is a schematic diagram of the pellet reduction system of the present invention with double air circulation.

Fig. 3 is a schematic view of the whole structure of the pellet reduction system of the present invention.

Fig. 4 is a schematic structural view of the rotary kiln of the present invention.

Fig. 5 is a sectional view of the rotary kiln a-a of the present invention.

Fig. 6 is a perspective view of a view of the rotary kiln a-a of the present invention.

Reference numerals are as follows: 1: a rotary kiln; 101: a drying section; 102: a preheating section; 103: a reduction roasting section; 104: a slow cooling section; 105: burning a nozzle; 106: a fuel delivery conduit; 107: a combustion-supporting air duct; 108: a first air mixing chamber; 109: a second air mixing chamber; 2: melting and separating furnace; 201: a clinker conveying device; 3: a multi-tube dust collector; 4: a material temperature detection device; 5: a CO concentration detection device; 6: metallization ratio detection means; 7: a kiln body air duct mechanism; 701: an air inlet connecting piece; 702: a stop valve; 703: a pull rod; 704: an air inlet; 705: an air inlet channel; 8: an annular rotary slide rail; 801: a support; 9: a rotary slide mechanism; 901: rotating the wheel seat; 902: a lateral rotating wheel; 903: a vertical rotating wheel; 10: a horizontal sliding mechanism; 1001: a horizontal wheel seat; 1002: a horizontal pulley; 1003: a horizontal rail; 11: a swing mechanism; 1101: a rotary motor; 1102: a large gear ring; l1: a first pipe; l2: a second conduit; l3: a third pipeline; l4: a fourth conduit; l5: a fifth pipeline; l6: a sixth pipeline; m1: a first flow regulating valve; m2: a second flow regulating valve; m3: a third flow rate regulating valve; m4: a fourth flow regulating valve; m5: a fifth flow regulating valve; m6: a sixth flow regulating valve; f1: a first fan; f2: a second fan; f3: a third fan; f4: a fourth fan; f5: a fifth fan; f6: and a sixth fan.

Detailed Description

The technical solution of the present invention is illustrated below, and the claimed invention includes but is not limited to the following embodiments.

A pellet reduction system for preventing pellet burst includes a rotary kiln 1. According to the trend of materials, the rotary kiln 1 is sequentially provided with a drying section 101, a preheating section 102, a reduction roasting section 103 and a slow cooling section 104. The kiln tail air outlet of the rotary kiln 1 is communicated with the air inlet of the first air mixing chamber 108 through a first pipeline L1. The air outlet at the top of the reduction roasting section 103 is communicated with the air inlet of the first air mixing chamber 108 through a second pipeline L2. The air outlet of the air mixing chamber 108 is communicated with the air inlet at the bottom of the drying section 101 at the initial stage through a third pipeline L3. The length of the rotary kiln 1 is 0.5 to 800m, preferably 1 to 500m, more preferably 3 to 200 m.

Preferably, the top air outlet of the later stage of the drying section 101 is communicated with the air inlet of the second air mixing chamber 109 through a fourth pipeline L4. The air outlet at the top of the reduction roasting section 103 is communicated with the air inlet of the second air mixing chamber 109 through a fifth pipeline L5. The air outlet of the second air mixing chamber 109 is communicated with the bottom air inlet of the middle and later stages of the drying section 101 through a sixth pipeline L6.

Preferably, the system further comprises a melting furnace 2. The feed inlet of the melting furnace 2 is connected with the discharge outlet of the rotary kiln 1 through a clinker conveying device 201.

Preferably, the first pipeline L1 is provided with a first flow regulating valve M1 and a first fan F1 in sequence. And the second pipeline L2 is sequentially provided with a second flow regulating valve M2 and a second fan F2. And the third pipeline L3 is sequentially provided with a third flow regulating valve M3 and a third fan F3.

Preferably, the fourth pipeline L4 is sequentially provided with a fourth flow regulating valve M4 and a fourth fan F4. And a fifth flow regulating valve M5 and a fifth fan F5 are sequentially arranged on the fifth pipeline L5. And a sixth flow regulating valve M6 and a sixth fan F6 are sequentially arranged on the sixth pipeline L6.

Preferably, the fifth pipeline L5 is a bypass pipeline of the second pipeline L2 located upstream of the second flow rate adjustment valve M2.

Preferably, a multi-manifold dust collector 3 is optionally further provided on the second conduit L2 upstream of the position where the fifth conduit L5 is connected to the second conduit L2.

Preferably, the system further comprises a first material temperature detection device 4. The first material temperature detection device 4 is arranged in the reduction roasting section 103.

Preferably, the system further comprises a second material temperature detection device 5. The second material temperature detection device 5 is provided in the middle and later stages of the drying section 101.

Preferably, the system further comprises a metallization ratio detection device 6. The metallization ratio detection device 6 is arranged in the preheating section 102.

Preferably, the system further comprises a burner 105 and a fuel delivery conduit 106. The burner 105 is arranged in the reduction roasting section 103 and is communicated with a fuel conveying pipeline 106. Outside the rotary kiln 1, a combustion-supporting air duct 107 is also connected to the fuel delivery duct 106.

Preferably, a plurality of burners 105 are arranged in the reduction roasting section 103, and all of the burners 105 are communicated with a fuel conveying pipeline 106.

Preferably, the rotary kiln 1 further comprises a kiln body air duct mechanism 7, an annular rotary slide rail 8 and a rotary slide mechanism 9. The annular rotary slide rail 8 is sleeved outside the rotary kiln 1 and supported by a support 801. The wheel end of the rotary sliding mechanism 9 is connected with the annular rotary sliding rail 8, the other end of the rotary sliding mechanism is connected with the outer end of the kiln body air duct mechanism 7, and the inner end of the kiln body air duct mechanism 7 is connected to the kiln wall. Namely, the rotary kiln 1 and the kiln body air duct mechanism 7 can simultaneously rotate on the annular rotary slide rail 8 through the rotary slide mechanism 9.

Preferably, a plurality of annular rotary slide rails 8 are arranged outside the rotary kiln 1. Any one of the annular rotary slide rails 8 is connected with the rotary kiln 1 through a plurality of rotary slide mechanisms 9 and a plurality of kiln body air duct mechanisms 7.

Preferably, the kiln body air duct mechanism 7 comprises an air inlet connector 701, a stop valve 702, a pull rod 703 and an air inlet 704. An air inlet channel 705 is arranged on the kiln body of the rotary kiln 1. One end of the baffle valve 702 extends into the air inlet channel 705, and the other end thereof is communicated with the air inlet connector 701. The air inlet 704 is formed in the air inlet connector 701. One end of the air inlet connecting piece 701 far away from the rotary kiln 1 is connected with one end of a pull rod 703, and the other end of the pull rod 703 is connected with a rotary sliding mechanism 9.

Preferably, the rotary sliding mechanism 9 includes a rotary wheel base 901, a lateral rotary wheel 902, and a vertical rotary wheel 903. The rotary wheel seat 901 is of a concave groove-shaped structure and is engaged with two side edge portions of the annular rotary slide rail 8. The rotating wheel seats 901 on the side surfaces of the annular rotating slide rail 8 are all provided with lateral rotating wheels 902. Vertical rotating wheels 903 are arranged on the rotating wheel seats 901 on the outer bottom surfaces of the annular rotating slide rails 8. The rotating wheel base 901 can rotate and slide on the annular rotating slide rail 8 through the lateral rotating wheel 902 and the vertical rotating wheel 903.

Preferably, the rotary kiln 1 further includes a horizontal sliding mechanism 10. The horizontal sliding mechanism 10 includes a horizontal wheel base 1001, a horizontal pulley 1002, and a horizontal rail 1003. The horizontal rail 1003 is a groove-shaped rail arranged at the upper end of the bracket 801. The bottom end of the horizontal wheel base 1001 is mounted in a horizontal rail 1003 by a horizontal pulley 1002. The top end of the horizontal wheel seat 1001 is connected with the annular rotary slide rail 8.

Preferably, the system further comprises a swing mechanism 11. The swing mechanism 11 includes a swing motor 1101 and a ring gear 1102. The inner ring of the large gear ring 1102 is fixed on the outer wall of the rotary kiln 1, and the outer ring of the large gear ring 1102 is meshed with a transmission gear of the rotary motor 1101.

Example 1

As shown in fig. 1, a pellet reduction system for preventing bursting of pellets includes a rotary kiln 1. According to the trend of materials, the rotary kiln 1 is sequentially provided with a drying section 101, a preheating section 102, a reduction roasting section 103 and a slow cooling section 104. The kiln tail air outlet of the rotary kiln 1 is communicated with the air inlet of the first air mixing chamber 108 through a first pipeline L1. The air outlet at the top of the reduction roasting section 103 is communicated with the air inlet of the first air mixing chamber 108 through a second pipeline L2. The air outlet of the air mixing chamber 108 is communicated with the bottom air inlet at the early stage of the drying section 101 through a third pipeline L3. The length of the rotary kiln 1 is 10 m.

Example 2

Example 1 is repeated, as shown in fig. 2, except that the top air outlet of the latter stage of the drying section 101 is communicated with the air inlet of the second air-mixing chamber 109 through a fourth duct L4. The air outlet at the top of the reduction roasting section 103 is communicated with the air inlet of the second air mixing chamber 109 through a fifth pipeline L5. The air outlet of the second air mixing chamber 109 is communicated with the bottom air inlet of the middle and later stages of the drying section 101 through a sixth pipeline L6.

Example 3

Example 2 was repeated except that the system also included a melting furnace 2. The feed inlet of the melting furnace 2 is connected with the discharge outlet of the rotary kiln 1 through a clinker conveying device 201.

Example 4

Example 3 is repeated, as shown in fig. 3, except that the first pipeline L1 is provided with a first flow rate adjusting valve M1 and a first fan F1 in this order. And the second pipeline L2 is sequentially provided with a second flow regulating valve M2 and a second fan F2. And the third pipeline L3 is sequentially provided with a third flow regulating valve M3 and a third fan F3.

Example 5

Example 4 is repeated except that the fourth flow control valve M4 and the fourth fan F4 are sequentially provided on the fourth line L4. And a fifth flow regulating valve M5 and a fifth fan F5 are sequentially arranged on the fifth pipeline L5. And a sixth flow regulating valve M6 and a sixth fan F6 are sequentially arranged on the sixth pipeline L6.

Example 6

Example 5 was repeated except that the fifth conduit L5 was a bypass conduit of the second conduit L2 upstream of the second flow control valve M2.

Example 7

Example 6 was repeated except that a multi-manifold dust collector 3 was optionally further provided on the second line L2 upstream of the position where the fifth line L5 was connected to the second line L2.

Example 8

Example 7 is repeated except that the system further comprises a first material temperature detecting means 4. The first material temperature detection device 4 is arranged in the reduction roasting section 103.

Example 9

Example 8 is repeated except that the system further comprises a second material temperature detecting means 5. The second material temperature detection device 5 is provided in the middle and later stages of the drying section 101.

Example 10

Example 9 is repeated except that the system further comprises metallization ratio detection means 6. The metallization ratio detection device 6 is arranged in the preheating section 102.

Example 11

Example 10 is repeated except that the system further comprises a burner 105 and a fuel delivery conduit 106. The burner 105 is arranged in the reduction roasting section 103 and is communicated with a fuel conveying pipeline 106. Outside the rotary kiln 1, a combustion-supporting air duct 107 is also connected to the fuel delivery duct 106.

Example 12

Example 11 was repeated except that a plurality of burners 105 were provided in the reduction roasting section 103, and the plurality of burners 105 were each communicated with the fuel feed pipe 106.

Example 13

Example 12 was repeated except that the length of the rotary kiln 1 was 15 m.

Example 14

Example 13 was repeated except that the length of the rotary kiln 1 was 20 m.

Example 15

Example 14 was repeated except that the length of the rotary kiln 1 was 40 m.

Example 16

Example 15 is repeated, as shown in fig. 4, except that the rotary kiln 1 further comprises a kiln body air duct mechanism 7, an annular rotary slide rail 8 and a rotary slide mechanism 9. The annular rotary slide rail 8 is sleeved outside the rotary kiln 1 and supported by a support 801. The wheel end of the rotary sliding mechanism 9 is connected with the annular rotary sliding rail 8, the other end of the rotary sliding mechanism is connected with the outer end of the kiln body air duct mechanism 7, and the inner end of the kiln body air duct mechanism 7 is connected to the kiln wall. Namely, the rotary kiln 1 and the kiln body air duct mechanism 7 can simultaneously rotate on the annular rotary slide rail 8 through the rotary slide mechanism 9.

Example 17

Example 16 is repeated except that the exterior of the rotary kiln 1 is provided with a plurality of endless rotary slide rails 8. Any one of the annular rotary slide rails 8 is connected with the rotary kiln 1 through a plurality of rotary slide mechanisms 9 and a plurality of kiln body air duct mechanisms 7.

Example 18

Embodiment 17 is repeated, as shown in fig. 5, except that the kiln body air duct mechanism 7 comprises an air inlet connector 701, a stop valve 702, a pull rod 703 and an air inlet 704. An air inlet channel 705 is arranged on the kiln body of the rotary kiln 1. One end of the baffle valve 702 extends into the air inlet channel 705, and the other end thereof is communicated with the air inlet connector 701. The air inlet 704 is formed in the air inlet connector 701. One end of the air inlet connecting piece 701 far away from the rotary kiln 1 is connected with one end of a pull rod 703, and the other end of the pull rod 703 is connected with a rotary sliding mechanism 9.

Example 19

Embodiment 18 is repeated except that the rotary slide mechanism 9 comprises a rotary wheel base 901, a lateral rotary wheel 902 and a vertical rotary wheel 903. The rotary wheel seat 901 is of a concave groove-shaped structure and is engaged with two side edge portions of the annular rotary slide rail 8. The rotating wheel seats 901 on the side surfaces of the annular rotating slide rail 8 are all provided with lateral rotating wheels 902. Vertical rotating wheels 903 are arranged on the rotating wheel seats 901 on the outer bottom surfaces of the annular rotating slide rails 8. The rotary wheel seat 901 can slide on the annular rotary slide rail 8 in a rotating way through a lateral rotary wheel 902 and a vertical rotary wheel 903.

Example 20

Example 19 was repeated except that the rotary kiln 1 further included a horizontal sliding mechanism 10. The horizontal sliding mechanism 10 includes a horizontal wheel base 1001, a horizontal pulley 1002, and a horizontal rail 1003. The horizontal rail 1003 is a groove-shaped rail arranged at the upper end of the bracket 801. The bottom end of the horizontal wheel base 1001 is mounted in a horizontal rail 1003 by a horizontal pulley 1002. The top end of the horizontal wheel seat 1001 is connected with the annular rotary slide rail 8.

Example 21

Embodiment 20 is repeated except that the system further comprises a slewing mechanism 11. The swing mechanism 11 includes a swing motor 1101 and a ring gear 1102. The inner ring of the large gear ring 1102 is fixed on the outer wall of the rotary kiln 1, and the outer ring of the large gear ring 1102 is meshed with a transmission gear of the rotary motor 1101.

Claims

1. A pellet reduction system for preventing pellet bursting is characterized in that: the system comprises a rotary kiln (1); according to the trend of materials, the rotary kiln (1) is sequentially provided with a drying section (101), a preheating section (102), a reduction roasting section (103) and a slow cooling section (104); an air outlet at the tail of the rotary kiln (1) is communicated with an air inlet of a first air mixing chamber (108) through a first pipeline (L1); the air outlet at the top of the reduction roasting section (103) is communicated with the air inlet of the first air mixing chamber (108) through a second pipeline (L2); an air outlet of the first air mixing chamber (108) is communicated with an air inlet at the bottom of the drying section (101) in the initial stage through a third pipeline (L3); the length of the rotary kiln (1) is 0.5-800 m.

2. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the length of the rotary kiln (1) is 1-500 m.

3. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the length of the rotary kiln (1) is 3-200 m.

4. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the air outlet at the top of the later stage of the drying section (101) is communicated with the air inlet of the second air mixing chamber (109) through a fourth pipeline (L4); the air outlet at the top of the reduction roasting section (103) is communicated with the air inlet of the second air mixing chamber (109) through a fifth pipeline (L5); the air outlet of the second air mixing chamber (109) is communicated with the bottom air inlet of the middle and later stages of the drying section (101) through a sixth pipeline (L6).

5. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the system also comprises a melting furnace (2); the feed inlet of the melting furnace (2) is connected with the discharge outlet of the rotary kiln (1) through a clinker conveying device (201).

6. The pellet reduction system for preventing pellet popping as claimed in claim 4, wherein: a first flow regulating valve (M1) and a first fan (F1) are sequentially arranged on the first pipeline (L1); a second flow regulating valve (M2) and a second fan (F2) are sequentially arranged on the second pipeline (L2); and the third pipeline (L3) is sequentially provided with a third flow regulating valve (M3) and a third fan (F3).

7. The pellet reduction system for preventing pellet popping as claimed in claim 6, wherein: a fourth flow regulating valve (M4) and a fourth fan (F4) are sequentially arranged on the fourth pipeline (L4); a fifth flow regulating valve (M5) and a fifth fan (F5) are sequentially arranged on the fifth pipeline (L5); and the sixth pipeline (L6) is sequentially provided with a sixth flow regulating valve (M6) and a sixth fan (F6).

8. The pellet reduction system for preventing pellet popping as claimed in claim 7, wherein: the fifth conduit (L5) is a bypass conduit of the second conduit (L2) upstream of the second flow regulating valve (M2); and/or

A multi-tube dust collector (3) is optionally further provided on the second pipeline (L2) upstream of the position where the fifth pipeline (L5) is connected to the second pipeline (L2).

9. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the system also comprises a first material temperature detection device (4); the first material temperature detection device (4) is arranged in the reduction roasting section (103).

10. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the system also comprises a second material temperature detection device (5); the second material temperature detection device (5) is arranged in the middle and later periods of the drying section (101).

11. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the system also comprises a metallization ratio detection device (6); the metallization ratio detection device (6) is arranged in the preheating section (102).

12. The pellet reduction system for preventing pellet popping as claimed in claim 1, wherein: the system also comprises a burner (105) and a fuel conveying pipeline (106); the burner (105) is arranged in the reduction roasting section (103) and is communicated with a fuel conveying pipeline (106); outside the rotary kiln (1), a combustion-supporting air pipe (107) is also communicated with the fuel conveying pipeline (106).

13. The pellet reduction system for preventing pellet popping as claimed in claim 12, wherein: a plurality of burners (105) are arranged in the reduction roasting section (103), and the plurality of burners (105) are all communicated with a fuel conveying pipeline (106).

14. The pellet reduction system for preventing pellet popping as claimed in any one of claims 1-13, wherein: the rotary kiln (1) also comprises a kiln body air duct mechanism (7), an annular rotary slide rail (8) and a rotary sliding mechanism (9); the annular rotary slide rail (8) is sleeved outside the rotary kiln (1) and is supported by a support (801); the wheel end of the rotary sliding mechanism (9) is connected with the annular rotary sliding rail (8), the other end of the rotary sliding mechanism is connected with the outer end of the kiln body air duct mechanism (7), and the inner end of the kiln body air duct mechanism (7) is connected to the kiln wall; namely, the rotary kiln (1) and the kiln body air duct mechanism (7) can simultaneously rotate on the annular rotary slide rail (8) through the rotary slide mechanism (9).

15. The pellet reduction system for preventing pellet popping as claimed in claim 14, wherein: a plurality of annular rotary slide rails (8) are arranged outside the rotary kiln (1); any one annular rotary slide rail (8) is connected with the rotary kiln (1) through a plurality of rotary slide mechanisms (9) and a plurality of kiln body air duct mechanisms (7).

16. The pellet reduction system for preventing pellet popping as claimed in claim 14, wherein: the kiln body air duct mechanism (7) comprises an air inlet connecting piece (701), a stop valve (702), a pull rod (703) and an air inlet (704); an air inlet channel (705) is formed in the kiln body of the rotary kiln (1); one end of the baffle valve (702) extends into the air inlet channel (705), and the other end of the baffle valve is communicated with the air inlet connecting piece (701); the air inlet (704) is arranged on the air inlet connecting piece (701); one end of the air inlet connecting piece (701) far away from the rotary kiln (1) is connected with one end of a pull rod (703), and the other end of the pull rod (703) is connected with a rotary sliding mechanism (9); and/or

The rotary sliding mechanism (9) comprises a rotary wheel seat (901), a lateral rotary wheel (902) and a vertical rotary wheel (903); the rotary wheel seat (901) is of a concave groove-shaped structure and is occluded at the two side edge parts of the annular rotary slide rail (8); lateral rotating wheels (902) are arranged on the rotating wheel seats (901) on the side surfaces of the annular rotating slide rails (8); vertical rotating wheels (903) are arranged on the rotating wheel seats (901) on the outer bottom surface of the annular rotating slide rail (8); the rotary wheel seat (901) can rotate and slide on the annular rotary slide rail (8) through a lateral rotary wheel (902) and a vertical rotary wheel (903).

17. The pellet reduction system for preventing pellet popping as claimed in claim 16, wherein: the rotary kiln (1) also comprises a horizontal sliding mechanism (10); the horizontal sliding mechanism (10) comprises a horizontal wheel seat (1001), a horizontal pulley (1002) and a horizontal rail (1003); the horizontal rail (1003) is a groove-shaped rail arranged at the upper end of the bracket (801); the bottom end of the horizontal wheel seat (1001) is installed in a horizontal rail (1003) through a horizontal pulley (1002); the top end of the horizontal wheel seat (1001) is connected with an annular rotary slide rail (8).

18. The pellet reduction system for preventing pellet popping as claimed in claim 17, wherein: the system further comprises a swing mechanism (11); the slewing mechanism (11) comprises a slewing motor (1101) and a large gear ring (1102); the inner ring of the large gear ring (1102) is fixed on the outer wall of the rotary kiln (1), and the outer ring of the large gear ring (1102) is meshed and connected with a transmission gear of the rotary motor (1101).