CN221649169U - System for preparing powdery high-quality active lime by suspension roasting - Google Patents

Abstract

The present invention provides a system for suspended roasting of powdered high-quality active lime, comprising a suspended preheating roasting unit, a suspended cooling unit and a connecting pipeline, which is suitable for roasting fine limestone powder into powdered active lime. First, the limestone powder enters a multi-stage series cyclone separator for preheating, and then is roasted at high temperature in a decomposition furnace in the suspended roasting system, and the limestone is decomposed into active lime powder and CO ₂ . The active lime powder is then aged in an aging furnace, so that part of the undecomposed raw limestone continues to be decomposed in the aging furnace, thereby further improving the product quality, and finally is cooled by the suspended cooling unit and transported to a finished product warehouse for storage.

Description

A system for preparing high-quality active lime in powder form by suspended roasting

Technical Field

The invention belongs to the technical field of powdered lime production, and in particular relates to a system for preparing powdered high-quality active lime by suspended roasting.

Background Art

Activity refers to the reaction speed of lime hydration and is an important indicator for evaluating lime quality. Lime with high activity has active chemical properties and stronger reaction ability. It has stronger desulfurization, dephosphorization and adsorption capabilities and requires less usage. At the same time, as a strong alkaline oxide, the reduction in the amount of lime also minimizes the erosion of lime equipment. Traditional lime production processes often use block limestone roasting, which is generally small in scale, long in roasting time, high in system energy consumption, unstable in product quality, and has disadvantages such as under-burning and over-burning, making it difficult to obtain high-quality active lime. At the same time, the existing roasted powdered lime production system also has some technical problems, mainly high energy consumption, poor system stability, high temperature in the decomposition furnace, and difficulty in producing high-quality active lime, which need to be solved urgently.

Summary of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a system for preparing powdered high-quality active lime by suspended roasting, so as to significantly improve the activity of the product, reduce system energy consumption, and improve system stability.

In order to achieve the above object, the technical solution adopted by the present invention is:

A system for preparing powdered high-quality active lime by suspended roasting comprises a suspended preheating roasting unit and a suspended cooling unit. The suspended preheating roasting unit comprises a cyclone separator, a roasting subsystem and an aging furnace.

The cyclone separators have n stages in total, which are used to suspend and preheat the limestone raw materials, and use the last stage cyclone separator to perform gas-solid separation, where n≥3; the arrangement of multi-stage cyclone separators is already relatively common, and corresponding row and column distribution can be adopted according to needs and actual engineering practice.

The roasting subsystem consists of a decomposition furnace and a mixing chamber. The top of the mixing chamber is connected to the bottom of the decomposition furnace. The upper part of the side wall of the mixing chamber is provided with a feed port, and the lower part of the side wall is provided with a burner. The preheated limestone raw material enters the mixing chamber and is fully mixed with the fuel sprayed from the burner. Driven by the rising hot gas, it enters the decomposition furnace for the roasting and is decomposed into active calcium oxide powder and _CO2 gas.

The aging furnace is connected to the discharge port of the last stage cyclone separator to age the material obtained by gas-solid separation;

The suspension cooling unit includes a fluidized cooler connected to the outlet of the aging furnace to suspend and cool the aged material to obtain powdered high-quality active lime.

In an embodiment of the present invention, the roasting subsystem is connected in series between the n-1 stage cyclone separator and the n stage cyclone separator, the discharge port of the n-1 stage cyclone separator outputs the preheated limestone raw material and is connected to the feed port of the mixing chamber, and the air inlet of the n stage cyclone separator is connected to the outlet of the decomposition furnace to perform gas-solid separation.

In an embodiment of the present invention, the decomposition furnace is a tubular decomposition furnace with a conical bottom and a straight cylinder at the top; the mixing chamber has a conical bottom and a straight cylinder at the top; there are multiple feed ports, which are symmetrically distributed in the same section or different sections; the burner is a raw material and fuel mixed combustion burner, and there are multiple burners. The fuel enters symmetrically from the bottom and top of the mixing chamber in multiple ways, and the input amount is adjustable.

In an embodiment of the present invention, the aging furnace body is composed of a first straight tube portion, a first cone portion, a second straight tube portion, and a second cone portion connected in sequence from top to bottom; wherein, the first cone portion and the second cone portion are both structures that are wide at the top and narrow at the bottom, the volume of the first straight tube portion is much larger than that of the other portions, and the inner side walls of the second cone portion are evenly distributed with a plurality of inflation boxes, and the side walls of the second straight tube portion are connected to the material legs. A first air distribution device is arranged in the aging furnace, and the first air distribution device is located above the inflation box and below the material legs.

In an embodiment of the present invention, the top end of the first straight pipe portion is the raw material inlet of the aging furnace, the material leg is an inverted hook structure, the part connected to the second straight pipe portion is a discharge straight pipe, a second air distribution device is arranged at the junction of the discharge straight pipe of the inverted hook structure and the vertical pipe, a high-temperature regulating valve is arranged on the discharge straight pipe, and the material leg and the inflation box are both connected to the air outlet of the Roots blower.

In an embodiment of the present invention, the fluidized bed cooler has a total of m stages, m≥3, and a cooling cyclone separator is arranged between each stage of the fluidized bed cooler and the next stage of the fluidized bed cooler along the material flow direction, the outlet of the last stage of the fluidized bed cooler is connected to the last stage of the cooling cyclone separator, the outlet of the last stage of the cooling cyclone separator receives the dust collector, and the outlet of the dust collector has a dust collecting fan; wherein the feed inlet of the first stage of the fluidized bed cooler is the inlet of the suspension cooling unit, and the air outlet of the first stage of the cooling cyclone separator is connected to the bottom of the mixing chamber to provide air for the suspension preheating roasting unit.

In an embodiment of the present invention, the dust collecting fan outlet is connected to the air supply fan, the air supply fan outlet is connected to a certain level of fluidized bed cooler in the middle, and the air supply fan inlet is provided with a branch pipe connected to the atmosphere, and a cold air regulating valve is provided on the branch pipe.

In the embodiment of the present invention, each stage of the fluidized cooler is provided with a corresponding fluidizing fan, wherein the inlet of the first-stage fluidizing fan is connected to the outlet pipe of the second-stage cooling cyclone separator.

Compared with the prior art, the system of the present invention is composed of a suspension preheating roasting unit, a suspension cooling unit and connecting pipes, and has the following advantages:

1. Some of the undecomposed limestone powder is further decomposed in the aging furnace, and the activity of the finished lime is higher.

2. The system has suspended preheating, suspended roasting and suspended cooling, with low heat consumption.

3. A mixing chamber is set at the bottom of the decomposition furnace, which makes heat exchange more efficient and the temperature field in the decomposition furnace more uniform, effectively avoiding the formation of coking and scaling due to local high temperature in the furnace when using pulverized coal fuel, and making the system more stable.

4. The suspension cooling unit makes full use of the waste heat of suspension cooling to further reduce the energy consumption of the system.

5. The fluidizing air of the first-stage fluidized cooler adopts the hot air separated by the second-stage cooling cyclone, which avoids the mixing of cold air, increases the air temperature entering the decomposition furnace, and reduces the roasting energy consumption.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions implemented in the present invention, the following will briefly introduce the drawings in the description of the embodiments. It should be understood that the drawings only show some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

FIG1 is a schematic diagram of the overall structure of the present invention.

FIG. 2 is a schematic diagram of the structure of the roasting subsystem of the present invention.

FIG. 3 is a schematic diagram of the structure of an aging furnace according to the present invention.

In the figure: high temperature fan 1, primary cyclone separator 2, secondary cyclone separator 3, tertiary cyclone separator 4, fourth stage cyclone separator 5, decomposition furnace 6, mixing chamber 7, fifth stage cyclone separator 8, aging furnace 9, material leg 91, second air distribution device 92, charging box 93, first air distribution device 94, primary cooling cyclone separator 10, primary fluidized cooler 11, secondary cooling cyclone separator 12, secondary fluidized cooler 13, tertiary fluidized cooler 14, tertiary cooling cyclone separator 15, dust collector 16, dust collecting fan 17, chain conveyor 18, burner 19, high temperature regulating valve 20, cold air regulating valve 21, primary cooling fluidized fan 22, secondary fluidized fan 23, tertiary fluidized fan 24, air supply fan 25, Roots blower 26.

DETAILED DESCRIPTION

In order to make the above-mentioned objects, features and advantages of the present invention more understandable, the present invention is further described in detail below in conjunction with the accompanying drawings. For the convenience of describing the basic structure of the present invention, the accompanying drawings only illustrate the relevant parts of the present invention rather than all of them.

In the traditional lime preparation process, lump limestone is used as raw material and cooled directly after roasting. Not only does the roasting time take a long time, but the activity of the resulting product is often not high. In order to improve the activity, the existing technology often makes improvements to the roasting process, mainly increasing the time and temperature, but the effect is minimal and leads to increased energy consumption. More importantly, it is easy to cause under-burning and over-burning.

To this end, the present application provides a system for preparing powdered high-quality active lime by suspended roasting. The roasting environment is not substantially adjusted, but an aging step is added after roasting to increase the decomposition rate of limestone, thereby finally obtaining high-quality active lime. The complete process steps of the present invention can be described as follows:

Step 1: After the limestone raw material enters the system, it is subjected to multiple suspension heat exchange and gas-solid separation, and the limestone raw material is suspended and preheated to 780°C to 820°C. The material is heated by suspension preheating, so that the material reaches the required temperature for decomposition as soon as possible, shortens the decomposition time of the material in the decomposition furnace, and reduces the energy consumption of the system. The limestone raw material of the present invention is powdery, and its recommended feed fineness is ≤0.5mm, which meets the requirements of suspension and heat exchange rate. In the suspended state, the powdery material has a large gas-solid contact area, rapid convection heat exchange, and high efficiency.

Step 2: The preheated limestone raw material is roasted at a high temperature of 880-930°C to obtain active calcium oxide powder (mixed with some incompletely decomposed limestone powder) and _CO2 gas, and gas-solid separation is performed.

Step 3, aging the material obtained by gas-solid separation for 3 to 20 minutes, so that part of the incompletely decomposed limestone powder continues to decompose, and the activity of the obtained lime can be further improved by aging. Aging is a key step of the present invention, which is essentially different from the traditional direct cooling after roasting. The specific duration of aging can be adjusted according to the properties of the material obtained after roasting. The aging furnace can obtain a high limestone decomposition rate while controlling the appropriate furnace temperature, thereby reducing the energy consumption of the system.

Step 4, suspending and cooling the aged calcium oxide powder to obtain powdered high-quality active lime. As above, the present invention not only improves the cooling effect through suspension cooling, but also has lower energy consumption.

In another aspect of the present invention, a system for preparing powdered high-quality active lime by suspension roasting is provided to implement the above method. Referring to FIG1 , the system of the present invention mainly includes a suspension preheating roasting unit 100 and a suspension cooling unit 200, and includes some necessary connecting pipes. According to the attached drawings, the arrangement and docking of these connecting pipes are not difficult for those skilled in the art.

The suspension preheating and roasting unit 100 realizes suspension preheating, suspension roasting and aging, which mainly includes a cyclone separator, a roasting subsystem and an aging furnace 9. There are n levels of cyclone separators, which are used for suspension preheating of limestone raw materials. The air inlet of the first-stage cyclone separator is the feed inlet of the suspension preheating and roasting unit 100. The last-stage cyclone separator performs gas-solid separation on the product of the roasting subsystem to obtain active calcium oxide powder and some undecomposed limestone powder, where n≥3. The roasting subsystem performs the aforementioned roasting step, and roasts the preheated limestone raw material to decompose it into active calcium oxide powder and _CO2 gas. The aging furnace 9 is a key component, which is connected to the discharge port of the last-stage cyclone separator, so that the material obtained by gas-solid separation completes the aging step therein. The outlet of the aging furnace 9 is the outlet of the suspension preheating and roasting unit 100. Through the aging furnace 9, some of the incompletely decomposed limestone powder continues to decompose, further increasing the CaO content in the lime, and obtaining a high-activity product.

The suspension cooling unit 200 includes a fluidized cooler connected to the outlet of the aging furnace 9 to suspend and cool the aged material to obtain powdered high-quality active lime.

The above system provides basic equipment support for implementing the method of the present invention. The components involved can adopt existing components. However, in order to achieve better results, the present invention further makes one or more of the following improvements, which can be combined arbitrarily.

In one embodiment of the present invention, as shown in FIG2 , the roasting subsystem is composed of a decomposition furnace 6 and a mixing chamber 7, and the top of the mixing chamber 7 is connected to the bottom of the decomposition furnace 6, and this connection can be a direct connection. There is a feed port at the lower part of the side wall of the mixing chamber 7, and the feed port is also the feed port of the roasting subsystem; the burners 19 are arranged in four ways in a high and low position cross arrangement on the mixing chamber 7, two of which are symmetrically arranged immediately below the feed port, and the other two are symmetrically arranged at the upper part of the mixing chamber 7. The preheated limestone raw material enters the mixing chamber 7, is fully mixed with the fuel sprayed from the low-level burner 19, and enters the decomposition furnace 6 driven by the rising hot gas for roasting, and is finally decomposed into active calcium oxide powder and _CO2 gas.

In one embodiment of the present invention, the roasting subsystem is connected in series between the n-1 stage cyclone separator and the n-stage cyclone separator, wherein the discharge port of the n-1 stage cyclone separator is connected to the feed port of the mixing chamber 7 to transport the preheated limestone raw material to the mixing chamber 7, and the air inlet of the n-stage cyclone separator, i.e., the last stage cyclone separator, is connected to the outlet of the decomposition furnace 6 to perform gas-solid separation.

In one embodiment of the present invention, the decomposition furnace 6 is a tubular decomposition furnace, the bottom is a cone shape with a wide top and a narrow bottom, and the top is a straight cylinder. The bottom of the mixing chamber 7 is also a cone shape with a wide top and a narrow bottom, and the top is a straight cylinder; there are multiple feed inlets in the mixing chamber 7, which are symmetrically distributed in the same section or different sections to obtain a better dispersed feeding effect, and the burner 19 is a raw material and fuel mixed burning burner, the number is also multiple, symmetrically distributed, and the fuel enters from the bottom and top of the mixing chamber 7 in multiple symmetrical ways, and the input amount is adjustable.

In one embodiment of the present invention, as shown in reference figure 3, the body of the aging furnace 9 is composed of a first straight tube portion, a first cone portion, a second straight tube portion, and a second cone portion connected in sequence from top to bottom. Among them, the first cone portion and the second cone portion are both structures that are wide at the top and narrow at the bottom, and the slopes of the two can be adjusted as necessary according to the aging requirements. The first straight tube portion is the main chamber for aging, and its volume is much larger than that of the other parts. The top of the first straight tube portion is connected to the discharge pipe of the n-stage cyclone separator. A plurality of air boxes 93 are evenly distributed on the inner side wall of the second cone portion, and the material legs 91 are connected to the side wall of the second straight tube portion. A first air distribution device 94 is provided in the aging furnace 9. The first air distribution device 94 is located above the air distribution box 93. The present embodiment adopts a circular shape.

In this embodiment, the active calcium oxide powder enters the aging furnace 9 from the top, and is retained in the aging furnace 9 for aging for 3 to 20 minutes. The residual heat of the high-temperature calcium oxide entering the aging furnace 9 is used to continue to decompose some undecomposed limestone. Under the action of the Roots blower 26, the material is fully homogenized through the gas box 93, and the heat exchange is enhanced to promote decomposition. The first air distribution device 94 supports the bed material, distributes the air evenly, and ensures that the material can be fully homogenized in the furnace. The material leg 91 is a hook-shaped structure, which can effectively isolate the furnace body and the unloading device, play a sealing role, and the heat exchange efficiency of the aging furnace 9 is higher; the horizontal section is provided with a second air distribution device 92. When unloading, the gas from the Roots blower 26 passes through the second air distribution device 92, so that the local material is in a dilute phase fluidized state, and the gas flows and is unloaded; a high-temperature regulating valve 20 is provided on the discharge straight pipe, and the unloading speed and the aging time of the material in the aging furnace are controlled by the valve.

In one embodiment of the present invention, there are m stages of fluidized coolers, m≥3, and a cooling cyclone separator is arranged between each stage of fluidized cooler and the next stage of fluidized cooler along the material flow direction to perform gas-solid separation on the material. The outlet of the last stage of fluidized cooler is connected to the last stage of cooling cyclone separator, and the outlet of the last stage of cooling cyclone separator receives the dust collector 16, and the outlet of the dust collector 16 is provided with a dust collecting fan 17; wherein the feed port of the first stage fluidized cooler 11 is the inlet of the suspension cooling unit 200, and the air outlet of the first stage cooling cyclone separator 10 is connected to the bottom of the mixing chamber 7, which can provide air for the suspension preheating roasting unit 100.

In one embodiment of the present invention, the outlet of the dust collecting fan 17 is connected to the air supply fan 25, and the hot air discharged from the dust collecting fan 17 is utilized, and the energy consumption of the system is further reduced, wherein the cold air regulating valve 21 is used when the hot air is insufficient. The outlet of the air supply fan 25 is connected to a certain level of fluidized cooler in the middle, and the incoming high-temperature materials are cooled, and the air is provided for the suspension preheating roasting unit 100 system. The inlet of the air supply fan 25 is provided with a branch pipe connected to the atmosphere, and the branch pipe is provided with a cold air regulating valve 21, which plays a role of supplement and standby. In one embodiment of the present invention, each level of fluidized cooler is provided with a corresponding fluidizing fan, so that the solid particles in the cooler are suspended in the air flow to form a fluidized state. The inlet of the first-level fluidizing fan 22 is connected to the outlet pipeline of the second-level cooling cyclone separator 12, and the separated gas is used as the gas source of the first-level fluidizing fan 22 to avoid the mixing of cold air, effectively increase the temperature of the gas entering the decomposition furnace, and reduce the energy consumption of the system. In the embodiment shown in Figure 1 of the present invention, n=5, m=3, that is, the suspended preheating roasting unit 100 is respectively composed of a first-stage cyclone separator 2, a second-stage cyclone separator 3, a third-stage cyclone separator 4, a fourth-stage cyclone separator 5, a decomposition furnace 6, a mixing chamber 7, a fifth-stage cyclone separator 8, and an aging furnace 9 from top to bottom, and each device is connected in sequence through pipelines; the burner 19 is installed in the mixing chamber 7, and the aging furnace 9 is connected to a high-temperature regulating valve 20 and a Roots blower 26.

The suspension cooling unit 200 is mainly composed of a primary cooling cyclone separator 10, a primary fluidizing cooler 11, a secondary cooling cyclone separator 12, a secondary fluidizing cooler 13, a tertiary fluidizing cooler 14, a tertiary cooling cyclone separator 15, a dust collector 16, a dust collecting fan 17, a chain conveyor 18, a cold air regulating valve 21, a primary fluidizing fan 22, a secondary fluidizing fan 23, a tertiary fluidizing fan 24, and an air supply fan 25.

The inlet of the first-stage cyclone separator 2 is connected to the outlet pipeline of the second-stage cyclone separator 3, and the discharge of the first-stage cyclone separator 2 is connected to the air inlet pipeline of the second-stage cyclone separator 3; the inlet 3 of the second-stage cyclone separator is connected to the outlet pipeline of the third-stage cyclone separator 4, and the discharge of the second-stage cyclone separator 3 is connected to the air inlet pipeline of the third-stage cyclone separator 4; the inlet of the third-stage cyclone separator 4 is connected to the outlet pipeline of the fourth-stage cyclone separator 5, and the discharge of the third-stage cyclone separator 4 is connected to the air inlet pipeline of the fourth-stage cyclone separator 5; the inlet of the fourth-stage cyclone separator 5 is connected to the outlet pipeline of the fifth-stage cyclone separator 8, and the discharge of the fourth-stage cyclone separator 5 is connected to the pipeline of the mixing chamber 7, and the mixing chamber 7 is connected to the decomposition furnace 6.

Furthermore, the preheated limestone raw material enters the mixing chamber 7 symmetrically in two ways, and the fuel is sprayed into the mixing chamber 7 symmetrically in four ways, from the bottom and top, so that the raw material and the fuel are fully mixed in the mixing chamber 7, and the heat exchange is more efficient and conducive to roasting. The fuel is input in four ways with high and low positions adjustable, and the temperature field in the decomposition furnace 6 is more uniform, which can avoid local high temperature in the furnace, resulting in coking and crusting.

The air outlet of the suspension preheating roasting unit 100 is connected through a pipeline through the primary cyclone separator 2 and the high-temperature fan 1, the aging furnace 9 is connected to the primary fluidized cooler 11 in the suspension cooling unit 200 through a pipeline, and the mixing chamber 7 is connected to the primary cooling cyclone separator 10 in the suspension cooling unit 200 through a pipeline. The system feeds the air inlet of the primary cyclone separator 2 to the air outlet of the secondary cyclone separator 3. A waste heat power generation device is provided between the primary cyclone separator 2 and the high-temperature fan 1, and the residual hot gas can be used for drying raw materials and fuels.

As shown in FIG1 , the specific preheating and roasting process in this embodiment is as follows: the raw material enters the first-stage cyclone separator 2 and enters the air inlet to the second-stage cyclone separator 3 and the air outlet connecting pipe, and exchanges gas-solid heat with the rising hot gas to preheat the raw material; at the same time, the raw material enters the first-stage cyclone separator 2 for gas-solid separation under the drive of the rising hot gas, and the hot gas is discharged through the air outlet pipe of the first-stage cyclone separator 2 under the action of the high-temperature fan 1. After separation, the raw material enters the second-stage cyclone separator 3 through the heavy hammer flip lock air valve on the bottom connecting pipe of the first-stage cyclone separator 2 and enters the air inlet to the third-stage cyclone separator 4 and the air outlet connecting pipe, and performs gas-solid heat exchange again; the raw material enters the second-stage cyclone separator 3 again under the drive of the rising gas for gas-solid separation; and so on, the raw material enters the third-stage cyclone separator 4 and the fourth-stage cyclone separator 5 in sequence, and finally the preheated high-temperature raw material enters the mixing chamber 7 to be fully mixed with the injected fuel, and enters the decomposition furnace 6 for high-temperature roasting under the drive of the rising hot gas, and decomposes into high-quality active calcium oxide powder and _CO2 gas. The calcium oxide powder enters the five-stage cyclone separator 8 for gas-solid separation, and enters the aging furnace 9 through the heavy hammer flip-over air lock valve for aging for 3 to 20 minutes to allow some undecomposed limestone powder to continue to decompose. The hot gas flows from bottom to top under the action of the high-temperature fan 1 and is discharged through the outlet pipe of the first-stage cyclone separator 2.

The inlet 10 of the first-stage cooling cyclone separator is connected to the outlet pipeline of the first-stage fluidized cooler 11, the discharge of the first-stage cooling cyclone separator 10 is connected to the pipeline of the second-stage fluidized cooler 13, the inlet of the second-stage cooling cyclone separator 12 is connected to the pipeline of the second-stage fluidized cooler 13, the discharge of the second-stage cooling cyclone separator 12 is connected to the pipeline of the tertiary fluidized cooler 14, the outlet of the second-stage cooling cyclone separator 12 is connected to the first-stage fluidized cooler pipe 11, the tertiary fluidized cooler 14 is connected to the inlet pipeline of the tertiary cooling cyclone separator 15, and the outlet of the tertiary cooling cyclone separator 15 is connected to the dust collector 16 and the dust collecting fan 17 pipeline.

Furthermore, the primary fluidized cooler 11, the secondary fluidized cooler 13 and the tertiary fluidized cooler 14 are provided with corresponding primary fluidized fans 22, secondary fluidized fans 23 and tertiary fluidized fans 24, and the bottom of the fluidized cooler is provided with an emergency discharge port. The inlet of the primary fluidized fan 22 is connected to the outlet pipe of the secondary cooling cyclone separator 12, and the inlet of the secondary fluidized fan 23 and the tertiary fluidized fan 24 is connected to the atmosphere.

Furthermore, the three-stage cooling cyclone separator 15 discharge, the dust collector 16 discharge and each fluidized cooler emergency discharge are connected to the chain conveyor 18 pipeline.

Furthermore, the outlet of the dust collecting fan 17 is connected to the air supply fan 25 pipeline, and the inlet of the air supply fan 25 is provided with a branch pipe connected to the atmosphere, and a cold air regulating valve 21 is provided on the branch pipe.

Furthermore, the air used in the suspension preheating roasting unit 100 is supplied by the air supply fan 25 of the secondary fluidized bed cooler 13 .

Furthermore, the three-stage fluidized bed cooler 14 is provided with two air inlets communicating with the atmosphere.

Furthermore, a heavy hammer flap air lock valve is provided on the bottom discharge pipe of the cyclone separator.

Furthermore, the feed fineness of the raw material is ≤0.5 mm.

As shown in FIG1 , the suspension cooling process in this embodiment is as follows:

The calcium oxide powder is discharged from the aging furnace 9 into the primary fluidized cooler 11 for cooling, and driven by the airflow, enters the primary cooling cyclone separator 10 for gas-solid separation. After separation, the calcium oxide powder enters the secondary fluidized cooler 13 for cooling, and the gas enters the mixing chamber 7 from the air outlet of the cyclone separator 11, and is used as combustion-supporting air for the fuel combustion of the suspended preheating roasting unit 100. The calcium oxide powder entering the secondary fluidized cooler 13 enters the secondary cooling cyclone separator 12 for gas-solid separation under the drive of the airflow, and after separation, the calcium oxide powder enters the tertiary fluidized cooler 14 for cooling, and the gas after separation enters the primary fluidized cooler 11, and is used as the air for the primary fluidized cooler 11. The suspension cooling unit 200 is powered by the air supply fan 25, and the wind source comes from the cooling hot air discharged by the dust collection fan 17, which makes full use of the cooling waste heat, avoids the mixing of too much cold air, increases the air temperature entering the decomposition furnace, and further reduces the system energy consumption. The cold air regulating valve 21 is used when the cooling hot air is insufficient.

The three-stage fluidized cooler 14 is provided with two air inlets connected to the atmosphere, which are used as air for the three-stage cooling of the finished product. The calcium oxide powder entering the three-stage fluidized cooler 14 enters the three-stage cooling cyclone separator 15 for gas-solid separation under the action of the dust collecting fan 17, and the gas is purified by the dust collector 16 and discharged from the chimney. The calcium oxide finished products collected by the three-stage cooling cyclone separator 15 and the dust collector 16 are finally transported to the finished product warehouse for storage through the chain conveyor 18.

In summary, the present invention provides a system for suspended roasting of powdered high-quality active lime, the powdered lime produced by the invention has higher activity, the raw materials and fuel are mixed more evenly during roasting, the roasting temperature is easier to control, and local high temperature is avoided to cause coking and scaling in the decomposition furnace. Through reasonable design of the system, the production of high-quality active lime can be ensured, and at the same time, the energy consumption of the system is further reduced, and the system is more stable.

In addition, the above description is only the technical principle and embodiment of the present invention. The present invention is not limited to the specific embodiment described. This solution can be used for the light burning of coal gangue, carbide slag, magnesite, and dolomite, and can also be used in other light burning systems that require suspended preheating. For those skilled in the art, it is possible to modify the technical solution of the embodiment or replace some of the technical features therein with equivalents without departing from the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims (8)

1. A system for preparing powdered high-quality active lime by suspended roasting, characterized in that it comprises a suspended preheating roasting unit (100) and a suspended cooling unit (200), wherein the suspended preheating roasting unit (100) comprises a cyclone separator, a roasting subsystem and an aging furnace (9); The cyclone separator has n stages in total, the limestone raw material is suspended and preheated, and the gas-solid separation is performed by the last stage cyclone separator, wherein n≥3; The roasting subsystem is composed of a decomposition furnace (6) and a mixing chamber (7). The top of the mixing chamber (7) is connected to the bottom of the decomposition furnace (6). The upper part of the side wall of the mixing chamber (7) is provided with a feed port, and the lower part of the side wall is provided with a burner (19). The preheated limestone raw material enters the mixing chamber (7) and is fully mixed with the fuel sprayed from the burner (19). Driven by the rising hot gas, the limestone enters the decomposition furnace (6) for roasting and is decomposed into active calcium oxide powder and _CO2 gas. The aging furnace (9) is connected to the discharge port of the last stage cyclone separator to age the material obtained by gas-solid separation; The suspension cooling unit (200) comprises a fluidized cooler connected to the outlet of the aging furnace (9) to suspend and cool the aged material to obtain powdered high-quality active lime. 2. The system for preparing powdered high-quality active lime by suspended roasting according to claim 1 is characterized in that the roasting subsystem is connected in series between the n-1 stage cyclone separator and the n stage cyclone separator, the discharge port of the n-1 stage cyclone separator outputs the preheated limestone raw material and is connected to the feed port of the mixing chamber (7), and the air inlet of the n stage cyclone separator is connected to the outlet of the decomposition furnace (6) to perform gas-solid separation. 3. The system for preparing powdered high-quality active lime by suspended roasting according to claim 1 or 2 is characterized in that the decomposition furnace (6) is a tubular decomposition furnace with a conical bottom and a straight cylinder at the top; the mixing chamber (7) has a conical bottom and a straight cylinder at the top; there are multiple feed inlets, which are symmetrically distributed in the same cross section or different cross sections; the burner (19) is a raw material and fuel mixed burning burner, and there are multiple burners, and the fuel enters the mixing chamber (7) symmetrically from multiple paths at the bottom and top, and the input amount is adjustable. 4. The system for preparing powdered high-quality active lime by suspended roasting according to claim 1 is characterized in that the furnace body of the aging furnace (9) is composed of a first straight tube portion, a first cone portion, a second straight tube portion, and a second cone portion connected in sequence from top to bottom; wherein the first cone portion and the second cone portion are both structures that are wide at the top and narrow at the bottom, the volume of the first straight tube portion is much larger than that of the other portions, a plurality of air charging boxes (93) are evenly distributed on the inner side wall of the second cone portion, the side wall of the second straight tube portion is connected to the material leg (91), and a first air distribution device (94) is arranged in the aging furnace (9), and the first air distribution device (94) is located above the air charging box (93) and below the material leg (91). 5. The system for preparing powdered high-quality active lime by suspended roasting according to claim 4 is characterized in that the top of the first straight pipe portion is the raw material inlet of the aging furnace (9), the material leg (91) is an inverted hook structure, and the part connected to the second straight pipe portion is a discharge straight pipe, and a second air distribution device (92) is arranged at the junction of the discharge straight pipe of the inverted hook structure and the vertical pipe, a high-temperature regulating valve (20) is arranged on the discharge straight pipe, and the material leg (91) and the charging box (93) are both connected to the air outlet of the Roots blower (26). 6. According to the system for preparing powdered high-quality active lime by suspended roasting as claimed in claim 1, it is characterized in that the fluidized cooler has a total of m stages, m≥3, and a cooling cyclone separator is arranged between each stage of the fluidized cooler and the next stage of the fluidized cooler along the material flow direction, the outlet of the last stage of the fluidized cooler is connected to the last stage of the cooling cyclone separator, the outlet of the last stage of the cooling cyclone separator receives the dust collector (16), and the outlet of the dust collector (16) is provided with a dust collecting fan (17); wherein the feed inlet of the first stage of the fluidized cooler (11) is the inlet of the suspended cooling unit (200), and the air outlet of the first stage of the cooling cyclone separator (10) is connected to the bottom of the mixing chamber (7) to provide air for the suspended preheating roasting unit (100). 7. The system for preparing powdered high-quality active lime by suspended roasting according to claim 6 is characterized in that the outlet of the dust collecting fan (17) is connected to the air supply fan (25), the outlet of the air supply fan (25) is connected to a certain level of fluidized bed cooler in the middle, and the inlet of the air supply fan (25) is provided with a branch pipe connected to the atmosphere, and a cold air regulating valve (21) is provided on the branch pipe. 8. The system for preparing powdered high-quality active lime by suspended roasting according to claim 6, characterized in that each stage of fluidized cooler is provided with a corresponding fluidizing fan, wherein the inlet of the first-stage fluidizing fan (22) is connected to the outlet pipe of the second-stage cooling cyclone separator (12).