CN113877697B - Melt impact crushing and granulating system and method - Google Patents

Abstract

The invention provides a melt impact crushing granulation system and method, including a power transmission assembly, an impact crushing granulation assembly, and a particle collection assembly; the particle collection assembly includes a cylindrical particle collection device, and the inner wall of the particle collection device is surrounded by The formed area is the working chamber of the system; the impact crushing and granulating assembly is arranged in the working chamber, including a rotating shaft and an impact member installed on the rotating shaft; the impact member has a protruding structure for melt impact ; The power transmission assembly is arranged outside the working chamber and is used to connect with the rotating shaft to drive the rotation of the striking member. The invention provides the melt impact crushing and granulation system, which relates to a new type of dry granulation production technology-melt impact crushing and granulation technology, which utilizes the fluid properties of the melt to impact the melt with high-speed moving impactors. It is a granulation technology that impacts, deforms and spreads, and then breaks and splashes.

Description

A melt impact crushing granulation system and method

technical field

The invention belongs to the technical field of granulation production and waste heat recovery, and in particular relates to a melt impact crushing granulation system and method.

Background technique

The granulation production process has a very common demand in production and life. For example, granules are more durable and convenient to use than decoctions, and are more quickly absorbed than tablets; fertilizers are easy to store, transport and use after granulation, which helps It can improve the efficiency of fertilization; molten iron can be made into granules instead of ingots, which can reduce the feeding and production costs for subsequent use; metallurgical slag can be used to produce slag pellets for the production of cement and road pads. Taking the metallurgical industry as an example, according to data from the National Bureau of Statistics of China, China’s pig iron production has reached 808 million tons in 2019, and its by-product blast furnace slag has an annual output of 250 million tons. The contained waste heat resources are equivalent to 14 million tons of standard coal, accounting for about 30% of the waste heat generated by iron and steel plants. While bringing about heavy pressure on energy conservation and emission reduction, it also has considerable prospects for waste heat recovery and resource utilization.

At present, the granulation treatment methods mainly used in the metallurgical industry are divided into two categories: water quenching method and dry treatment method. The water quenching method uses the pressurized water jet to directly impact the high-temperature melt. While breaking the high-temperature melt into fine particles, it is rapidly cooled to a low temperature and solidified from the outside to the inside. Under the action of surface tension, it tends to solidify into Spherical granule, after dehydration treatment, the granulated product can be obtained. Therefore, the method is simple in technology and low in cost, and is widely used in the industry. However, the temperature of the particles obtained by the water quenching method is low, and waste heat is seriously wasted. The water quenching process needs to consume a lot of water, and the sulfur in the high-temperature melt reacts with water to generate acid mist, and the heavy metals contained in some melts, such as nickel and chromium, are easy to enter the water, and the generated sewage is recycled during actual production The utilization rate is low and difficult to handle, which seriously consumes water resources and pollutes the ecological environment, and cannot meet the needs of energy conservation and emission reduction.

Dry treatment methods mainly include air quenching method, extrusion crushing method and centrifugal granulation method. The comparative advantage is that it does not consume water resources and does not require drying treatment, but it also has its own defects. The difference between the wind quenching method and the water quenching method is that the working medium is replaced by air, and the high-pressure air jet is used to crush and cool the high-temperature melt. Wind energy consumption is high, and it has limited control over the particle size of production. The extrusion crushing method is to pour the solid raw material fragments into the cracks of the crushed parts such as rollers and tooth chains, and use the continuous extrusion force generated by the crushed parts to destroy the solid structure, so that the raw materials are gradually crushed into particles. In addition to the normal metallurgical production process, this method is also suitable for the treatment of waste metallurgical slag accumulated over the years, but the energy consumption of the continuous operation of the supply machine is high, and the degree of control over the granulation effect of the particles decreases with the loss of the broken parts. It is easy to generate dust and pollute the working environment. The centrifugal granulation method is a method of crushing and granulating by using the centrifugal force and the instability of the moving fluid. The high-temperature melt is poured on the rotating parts such as the turntable, the inclined wall rotor, and the perforated rotor. Under the action of the rotating centrifugal force and friction , the melt will spread out on the rotating part to form a liquid film, and after reaching the edge of the rotating part, it will be thrown into the air along the tangential direction, and the gradually increasing degree of fluid instability will break the liquid film into a liquid column and then break into particles. The investment and operation cost is low, the operation process is simple, and the degree of automation is high, but the liquid film rotation drawing will generate cotton-like objects, and the circumferential spread of the liquid film makes the position of the transmission mechanism limited to the bottom of the turntable in the granulation chamber, depending on the actual situation. Sometimes it is necessary to install an additional water wall near the transmission mechanism to maintain long-term continuous production.

On the whole, we need a granulation production technology with low pollution and low cost, simple operation process, good granulation effect, efficient recovery of waste heat, flexible layout and easy maintenance. This technology can be applied to various industries with similar granulation production requirements. industry, not limited to applications within the metallurgical industry.

Contents of the invention

Aiming at the existing problems in the existing granulation production technology, the present invention provides a melt impact crushing granulation system and method, which relates to a new type of dry granulation production technology-melt impact crushing granulation technology, which utilizes the The granulation technology that impacts the melt with high-speed moving impactors, deforms and spreads, and then breaks and splashes.

The technical solution adopted by the present invention to solve the technical problem is: a melt impact crushing granulation system, including a power transmission component, an impact crushing granulation component and a particle collection component;

The particle collection assembly includes a cylindrical particle collection device, and the area surrounded by the inner wall of the particle collection device is the working chamber of the system;

The impact crushing and granulation assembly is arranged in the working chamber, including a rotating shaft and an impact member installed on the rotating shaft; the impact member has a protruding structure for melt impact;

The power transmission assembly is arranged outside the working chamber and is used for connecting with the rotating shaft to drive the rotation of the striking member.

Further, the power transmission assembly is a shaft transmission assembly or a gear transmission assembly; the shaft transmission assembly includes a drive motor that provides rotational power, with the motor shaft as the rotation shaft, or the motor shaft is connected to rotate through a flange and a coupling Shaft; the gear transmission assembly includes a drive motor that provides rotational power, and a transmission gear mounted on the motor shaft, the transmission gear is connected to the rotating shaft; the transmission gear is a bevel gear or a cylindrical gear.

Further, the upper half of the inner wall of the particle collection device is a vertical wall, and the lower part is an inclined wall, and the particle outlet of the inclined wall is provided with waste heat recovery equipment such as a particle collection tank or material conveying equipment or a waste heat boiler.

Further, the gear transmission assembly can adjust the position and direction of the drive motor and the upper and lower limits of the transmission speed by changing the type and parameters of the transmission gear.

Further, the impact member is a bevel gear or a cylindrical gear or a finned drum.

Further, when the impactor is a bevel gear, the tooth width is 1.5 to 10 times the diameter of the melt flow, and the indexing cone angle is 15° to 75°;

When the impactor is a cylindrical gear, the tooth height is 2 to 15 times the diameter of the melt flow, the tooth pitch is 2 to 15 times the diameter of the melt flow, and the tooth width is 1 to 10 times the diameter of the melt flow;

When the impact member is a drum with fins, the fins are arranged along the circumference of the drum, the thickness of the fins along the circumference of the drum is 0.5 to 5 times the diameter of the melt flow, and the fins are arranged along the circumference of the drum. The radial length of the drum is 1.5 to 10 times the diameter of the melt flow, and the length of the fins along the axial direction of the drum is 1 to 10 times the diameter of the melt flow.

Further, when the impactor is a bevel gear, the method for determining the lower limit of the bevel gear speed is as follows: Assume that the falling speed of the melt flow when it reaches the impact point in actual operation is U, the number of bevel gear teeth is z ₁ , and the indexing cone angle δ , and the average tooth height of the impact area with the melt flow is h, then the bevel gear speed n should satisfy:

以避免熔体流未经撞击破碎便在锥齿轮上堆积；That is: the speed n of the bevel gear should be greater than

In order to avoid the accumulation of the melt flow on the bevel gear without being impacted and broken;

When the impact member is a cylindrical gear, the method for determining the lower limit of the rotational speed of the cylindrical gear is as follows: assuming that the falling speed of the melt flow when it reaches the impact point in actual operation is U, the number of teeth of the cylindrical gear is z ₂ , and the tooth width is b, then the cylindrical gear Speed n should meet:

以避免熔体流未经撞击破碎便越过撞击区；That is: the speed n of the cylindrical gear should be greater than

To prevent the melt flow from crossing the impact zone without being broken by impact;

When the impact member is a drum with fins, the method for determining the lower limit of the rotating speed of the drum is as follows: assuming that the falling speed of the melt flow when it reaches the impact point in actual operation is U, and the number of fins on the drum is z _3. The length of the fins along the axial direction of the drum is L, then the speed n of the bevel gear should satisfy:

以避免熔体流未经撞击破碎便越过撞击区。That is: the rotational speed n of the drum should be greater than

In order to prevent the melt stream from crossing the impact zone without being broken by impact.

Further, the particle collection device and the power transmission assembly are provided with water-cooling and air-cooling equipment to maintain operation, and indirectly cool the impact crushing and granulating assembly.

Further, the melt can be arranged with multiple melt flows along the circumference and radial direction of the impactor according to the requirements of the processing capacity, and the movement path of each melt flow should pass within the range where the protrusion structure of the impactor is located. The surface of the melt stream is slightly cooled before impact but still maintains fluid properties.

Another aspect of the present invention provides a granulation method based on the above system, which includes: the melt flows out of the launder into the working chamber of the system, and when the melt moves to the range where the protruding structure of the impact member is located, the impact member moves at 150- Rotating at a speed of 2000 rpm, its high-speed moving protruding structure impacts and breaks the melt flow into molten droplets with a diameter of less than 10mm. The molten droplets are rapidly cooled into particles during the splashing process, and the particles hit the inner wall of the particle collection component. The rebound falls, rolls down the sloped inner wall of the lower half and is collected.

The principle of the granulation technology used in the present invention is that after the moving fluid collides with the solid, the fluid structure is deformed under the action of an external force, and the structural instability develops accordingly, leading to fluid fragmentation.

Compared with prior art, the beneficial effect of the present invention is:

In the melt impact crushing granulation system and the impact crushing granulation method using the granulation system of the present invention, relying on the principle of fluid impact instability and crushing, the raw material is impacted and crushed when it is in a molten state, so that it can be granulated into Spherical particles, the crushing process is rapid, reducing the probability of wire drawing, good granulation effect, simple operation process, low energy consumption, and environmental friendliness. At the same time, it provides convenience for waste heat recovery, significantly reduces production and operation costs, and enhances industry competition. force.

Description of drawings

Figure 1 is a schematic diagram of the system structure of melt impact crushing and granulation;

Fig. 2 is a schematic diagram of the structure of the impactor cylindrical gear;

Fig. 3 is a structural schematic diagram of a drum with fins on the impact member;

Fig. 4 is a schematic diagram of the structure of the bevel gear in the gear transmission assembly;

Fig. 5 is a schematic structural diagram of a cylindrical gear in a gear transmission assembly;

Among them, 1—drive motor; 2—coupling; 3—rotating shaft; 4—bevel gear; 5—particle collection device; 6—launder; 7—cooling water tank; 8—water wall; 9—cylindrical gear; 10 —Rotating cylinder; 11—bevel gear transmission; 12—cylindrical gear transmission.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Referring to Figures 1, 2, and 3, the present invention provides a granulation system for melt impact crushing, including a power transmission assembly, an impact crushing granulation assembly, and a particle collection assembly; the particle collection assembly includes cylindrical particles Collecting device 5, the area surrounded by the inner wall of the particle collecting device is the working chamber of the system; the impact crushing and granulating assembly is arranged in the working chamber, including a rotating shaft 3 and an impact member installed on the rotating shaft, the The power transmission assembly is arranged outside the working chamber, which is used to connect with the rotating shaft to drive the rotation of the impactor; the melt is introduced into the working chamber of the system through the launder 6, and the diameter of each melt flow is 20mm, and the falling speed is 3m/ s.

Wherein, the upper half of the inner wall of the particle collection device is a vertical wall, and the lower half is an inclined wall, and the particle outlet of the inclined wall is provided with a particle collection tank, or material conveying equipment or waste heat recovery equipment. The working chamber of the particle collection device can accommodate the broken droplets that have been separated from the tooth surface and splash in it, and the inner wall of the upper part blocks the molten droplets that are rapidly cooled into particles during the splashing process, and the blocked particles fall along the lower half of the collection device. The inclined inner wall at the top rolls down and is collected, and the collected particles can be further recovered by waste heat recovery equipment. The waste heat recovery equipment can be a waste heat boiler that uses heat exchange tubes and heat exchange walls to perform water-cooled heat exchange with slag particles.

Wherein, the inner wall of the particle collection device 5 is equipped with a water wall 8 to accelerate particle cooling and recover waste heat.

Wherein, the power transmission assembly is a shaft transmission assembly or a gear transmission assembly; the shaft transmission assembly includes a drive motor that provides rotational power, and the motor shaft is used as the rotation shaft, or the motor shaft is connected to the rotation shaft through a flange and a coupling The gear transmission assembly includes a drive motor that provides rotational power, and a transmission gear mounted on the motor shaft, the transmission gear is connected to the rotating shaft; the transmission gear is a bevel gear or a cylindrical gear. The drive motor 1 is placed in the cooling water tank 7 to dissipate heat and cool to maintain operation, and indirectly cool the rotating shaft 3 and the impact member.

Wherein, the impactor is a bevel gear 4 or a cylindrical gear 9 or a drum 10 with fins, the structural diagrams are shown in Figures 1, 2 and 3, wherein the number of teeth and the number of fins are selected according to needs.

The selection of specific power transmission components and impactors in the present invention is shown in Embodiments 1, 2 and 3.

Example 1

)；In this embodiment, the impact member is a bevel gear, and the tooth surface of the bevel gear faces the direction of the melt falling; the number of teeth of the bevel gear is 30, the tooth width is 100 mm, and the indexing cone angle is 45°, and the impact area of the bevel gear is 45°. The average tooth height of the bevel gear is 50mm, and the speed of the bevel gear is 500 r/min (greater than the lower limit of the speed)

);

In this embodiment, the power transmission assembly includes a drive motor 1 and a coupling 2, the drive motor 1 provides a driving force, and the rotating shaft 3 of the impact crushing and granulation assembly is driven to rotate under the connection transmission of the coupling 2, and then Drive the bevel gear 4 as the striker on the shaft.

The working principle of the system described in this embodiment is:

Turn on the drive motor 1, and through the connection of the coupling 2, the stably rotating motor shaft drives the rotating shaft 3 of the impact crushing and granulation assembly to start rotating, and then drives the bevel gear 4 as the impactor to rotate, gradually reaching and maintaining a predetermined speed; Start to guide the flow, so that the melt flows out along the flow groove 6 and is introduced into the working chamber of the system. When the melt flow moves to the range where the teeth of the bevel gear 4 are located, the high-speed moving gear tooth surface hits the end from the side and separates A part of the melt is taken away. Due to the effect of high-speed impact, the part of the melt that is taken away is deformed on the tooth surface and spreads divergently along the tooth surface. During the spreading process, the instability of the fluid structure continues to increase until it is broken into diameters Then the broken droplet breaks away from the tooth surface of the bevel gear 4 under the action of its rebound splash and the centrifugal force of the gear rotation movement; the molten droplet obtained by the impact and crushing of the bevel gear 4 breaks away from the tooth surface, and the molten droplet breaks away from the tooth surface Splash in the working chamber of the particle collection device 5, the specific surface area suddenly increases due to the breakage of the melt flow, the molten drop cools rapidly during the splashing process, the flow viscosity of the melt increases and gradually solidifies from the shell inward, and hits the particles The inner wall of the upper half of the collecting device 5 rebounds and falls, rolls down along the inclined inner wall of the lower half of the collecting device and is collected, and finally collects particles.

Example 2

)。The impact member described in this embodiment is a cylindrical gear, which is arranged in such a way that the end face of the cylindrical gear faces upwards (the end face of the cylindrical gear faces the falling direction of the melt), and the melt falls between the teeth gaps, and then the tooth surface hits the melt from the side; The number of teeth of the cylindrical gear is 30, the tooth height is 100mm, the tooth pitch is 100mm, and the tooth width is 100mm.

).

The power transmission assembly described in this embodiment is a gear transmission assembly, which is used to adjust the position and direction of the drive motor and the upper and lower limits of the transmission speed. The gear transmission assembly includes a drive motor that provides rotational power, and is installed on the motor shaft The transmission gear, the transmission gear is connected to the rotating shaft; the transmission gear is a bevel gear, as shown in Figure 4, the bevel gear transmission 11 is adopted, and the vertically arranged motor can be changed without changing the position of the impactor Arranged horizontally, it can still drive the impactor to rotate; at the same time, the gear transmission ratio affects the range of the output speed, and the upper and lower limits of the transmission speed can be adjusted.

The remaining settings of the system in this embodiment are the same as those in Embodiment 1, and the working principle of this embodiment is the same as that in Embodiment 1 except that the settings of impactors and power transmission components are different.

Example 3

)。In this embodiment, the impactor is a drum with fins, and the installation method is that the end face of the drum faces upwards (the end face of the drum faces the direction where the melt falls). Impact the melt, there are 6 fins on the drum, the thickness of the fins along the circumference of the drum is 30mm, the length of the fins along the radial direction of the drum is 100mm, and the length of the fins along the axial direction of the drum is 100mm , the rotational speed of the rotor with fins during work is 1000 rpm (greater than the lower limit of rotational speed

).

The power transmission assembly described in this embodiment is a gear transmission assembly, which is used to adjust the position and direction of the drive motor and the upper and lower limits of the transmission speed. The gear transmission assembly includes a drive motor that provides rotational power, and is installed on the motor shaft The transmission gear, the transmission gear is connected to the rotating shaft; the transmission gear is a cylindrical gear, as shown in Figure 5, using a cylindrical gear transmission 12, the motor can be arranged on the impactor side without changing the position of the impactor Azimuth, at the same time, the gear transmission ratio affects the range of the output speed, and the upper and lower limits of the transmission speed can be adjusted.

In the present invention, the various impactors and transmission modes mentioned above can be selected and combined according to the actual situation. The remaining settings of the system in this embodiment are the same as in Embodiment 1. The working principle of this embodiment, except for the impactor and the power transmission component settings Except being different, all the other are identical with embodiment 1.

The above technical solutions have set forth the technical ideas of the present invention, and cannot limit the protection scope of the present invention. Any changes and modifications made to the above technical solutions according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall belong to The scope of protection of the technical solution of the present invention.

Claims (8)

1. A melt impact crushing granulation system, characterized in that: comprising a power transmission assembly, an impact crushing granulation assembly and a particle collection assembly; The particle collection assembly includes a cylindrical particle collection device, and the area surrounded by the inner wall of the particle collection device is the working chamber of the system; The impact crushing and granulation assembly is arranged in the working chamber, including a rotating shaft and an impact member installed on the rotating shaft; the impact member has a protruding structure for melt impact; The power transmission assembly is arranged outside the working chamber, and is used for connecting with the rotating shaft to drive the rotation of the striking member; The impact member is a bevel gear or a cylindrical gear or a finned drum; When the impact member is a bevel gear, the method for determining the lower limit of the bevel gear speed is as follows: Assume that the falling speed of the melt flow when it reaches the impact point in actual operation is U, the number of bevel gear teeth is z ₁ , the indexing cone angle δ, and the melt flow The average tooth height in the impact area of the flow is h, then the bevel gear speed n should satisfy:

That is: the speed n of the bevel gear should be greater than

rpm to avoid accumulation of the melt stream on the bevel gear without being crushed by impact; When the impact member is a cylindrical gear, the method for determining the lower limit of the rotational speed of the cylindrical gear is as follows: assuming that the falling speed of the melt flow when it reaches the impact point in actual operation is U, the number of teeth of the cylindrical gear is z ₂ , and the tooth width is b, then the cylindrical gear Speed n should meet:

That is: the speed n of the cylindrical gear should be greater than

RPM to avoid the melt flow passing the impact zone without being crushed by the impact; When the impact member is a drum with fins, the method for determining the lower limit of the rotating speed of the drum is as follows: assuming that the falling speed of the melt flow when it reaches the impact point in actual operation is U, and the number of fins on the drum is z _3. The length of the fins along the axial direction of the drum is L, then the speed n of the bevel gear should satisfy:

That is: the rotational speed n of the drum should be greater than

rpm to prevent the melt stream from crossing the impact zone without being broken by the impact. 2. A melt impact crushing and granulation system according to claim 1, characterized in that: the power transmission assembly is a shaft transmission assembly or a gear transmission assembly; the shaft transmission assembly includes a drive motor that provides rotational power , the motor shaft is used as the rotating shaft, or the motor shaft is connected to the rotating shaft through a flange and a coupling; the gear transmission assembly includes a driving motor that provides rotational power, and a transmission gear installed on the motor shaft, and the transmission gear is connected to The rotating shaft, the transmission gear is a bevel gear or a cylindrical gear. 3. A melt impact crushing granulation system according to claim 1, characterized in that: the upper half of the inner wall of the particle collection device is a vertical wall, the lower half is an inclined wall, and the particle outlet of the inclined wall is There is a particle collection tank or material conveying equipment or waste heat recovery equipment at the place. 4. A melt impact crushing and granulation system according to claim 2, characterized in that: the gear transmission assembly adjusts the position and direction of the drive motor and the upper transmission speed by changing the type and parameters of the transmission gear. lower limit. 5. A melt impact crushing granulation system according to claim 1, characterized in that: When the impactor is a bevel gear, the tooth width is 1.5 to 10 times the diameter of the melt flow, and the indexing cone angle is 15° to 75°; When the impactor is a cylindrical gear, the tooth height is 2 to 15 times the diameter of the melt flow, the tooth pitch is 2 to 15 times the diameter of the melt flow, and the tooth width is 1 to 10 times the diameter of the melt flow; When the impact member is a drum with fins, the fins are arranged along the circumference of the drum, the thickness of the fins along the circumference of the drum is 0.5 to 5 times the diameter of the melt flow, and the fins are arranged along the circumference of the drum. The radial length of the drum is 1.5 to 10 times the diameter of the melt flow, and the length of the fins along the axial direction of the drum is 1 to 10 times the diameter of the melt flow. 6. A melt impact crushing and granulation system according to claim 1, characterized in that: the particle collection device and the power transmission assembly are equipped with water cooling and air cooling equipment to maintain operation, and indirectly cool the impact crushing granulation components. 7. A melt impact crushing and granulation system according to claim 1, characterized in that: the melt can arrange multiple melt flows along the circumference and radial direction of the impactor according to the demand of processing capacity, and each melt flow The movement path of the body flow should pass through the range where the protruding structure of the impact member is located. 8. A granulation method based on the system according to any one of claims 1 to 7, characterized in that it includes: the melt flows out from the launder into the working chamber of the system, and moves to the location where the protruding structure of the impactor is located. When within the range, the impactor rotates at a speed of 150-2000 rpm, and its high-speed moving protruding structure impacts and breaks the melt flow into droplets with a diameter of less than 10mm, and the droplets are rapidly cooled into particles during the splashing process. After hitting the inner wall of the particle collection assembly, the particles rebound and fall, roll down along the inclined inner wall of the lower half and be collected.

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