Fuzhou Artificial Panel Factory is the first factory in China to introduce the complete set of medium density fiberboard equipment in the United States. US-made rubberized cyclone
The separator is mounted above the metering silo between the applicator and the paving machine and is the throat of the production line. For a long time, the separator has often been blocked and cannot be adapted to normal production. We have made several minor changes, but they have not improved their blockage. Later, through repeated observations and tests, the following major improvements were made and succeeded.
1 situation before improvement
The cyclone separator functions to separate the wood fibers from the mixed gas stream and feed them into a metering chamber. It works under negative pressure (Fig. 1). When the mixed airflow enters the separator to make the spiral downward movement, the material is deflected toward the inner wall of the cone under the action of centrifugal force. Due to the action of gravity and the movement of the airflow, the lower end of the cone The discharge opening is discharged. Because the wood fiber is light in weight and easy to agglomerate, when the output is increased, some wood fibers form an ash ring under the entrainment of the rising inner vortex, and circle at the intersection of the cone and the ash storage box, as the thickness of the ash ring increases. Large, the fiber drop is hindered, eventually leading to blockage, and the fiber flies out of the exhaust port.
2 debugging
The main factors affecting the performance of the cyclone separator are: inlet wind speed, mixed concentration, chip slack ratio, fiber shape, water content and initial viscosity of the glue. The fibers in the separator are mainly separated from the air by the action of centrifugal force, which is proportional to the square of the tangential velocity of the material.
Increasing the inlet wind speed can speed up the rotary motion of the airflow in the separator, and the centrifugal force of the material is increased, thereby improving the separation efficiency and the processing capability. In reality, however, the damper of the separator fan can be adjusted to a small amount. Increasing the wind speed, the airflow creates a strong eddy current in the separator, preventing the material from reaching the inner wall of the separator housing. At the same time, due to excessive centrifugal force, the material rebounds, causing the fibers to float at the bottom of the cone, eventually causing blockage. When the wind speed is reduced, the air flow in the system is insufficient, which may cause the air supply pipe to be blocked. The commissioning proved that adjusting the air delivery system could not improve the clogging of the separator.
3 analysis and improvement of the program
According to the data, the cyclone separator is basically designed according to the American long cone cyclone separator, and the taper is small and the cone is long. Compared with the domestic cone type cyclone separator, the structure type is the same, but in the structural size, it has the characteristics of long cone length and small discharge opening.
In general, the shape of the cyclone separator is thin and long, and the efficiency is high; short and thick, the resistance is small, and the processing capacity is large. Increasing the cone length of the separator is beneficial to increasing the number of rotations of the gas stream in the separator, so that the material obtains more separation opportunities and improves the separation efficiency. However, in fact, due to the pulling action of the rising inner vortex on the downward vortex, the outer vortex of the lower vortex continuously enters the rising inner vortex during the downward rotation, so the cone of the separator is too long and There is no practical meaning, but it will reduce the processing power.
The diameter of the discharge opening is small, the radius of rotation of the air flow becomes smaller, the tangential speed increases, and the material falls hard under the action of centrifugal force, which is one of the main causes of blockage.
In view of the above, the improvement is as follows (Figure 2).
1. Increase the discharge opening. Since the taper angle is constant, the effective area of ​​the discharge opening is increased by about 1 time by shortening the length of the cone.
2. Set the guide rod to guide the inner vortex to eliminate the interference between the inner and outer vortex at the critical point.
3. Install the swinging baffle. The mixed airflow generates a large centrifugal force during the rotation process. Since the inertia of the material is many times larger than that of the air, most of the material is deflected toward the wall, and the spiral movement is performed under the driving of the airflow. The inertia force is quickly lost, falling along the wall and separating from the gas, and falling into the ash storage tank through the discharge opening. The baffle oscillates back and forth continuously, so that the fibers do not help to form a dough for favorable discharge.
4. Expand the ash storage box. The ash storage tank is an inseparable part of the cyclone separator, which is the final link to complete the separation of the gas-solid two medium. The improper treatment will seriously affect the separation efficiency, increase the discharge opening, and reduce the airflow undershoot resistance. In order to avoid more airflow entering the ash tank to form a fierce vortex, the trapped material is re-wound and entrained into the rising airflow to reduce the efficiency of the separator. In addition to expanding the volume of the ash tank, it is lengthened. The lower end of the cone extends into the transitional tube in the ash storage tank, so that the underflow resistance of the airflow increases, and the internal swirling flow cannot reach the ash storage tank, so that the negative pressure value in the tank is reduced, the pressure difference between the inside and the outside of the tank is reduced, and the air leakage rate is lowered. less.
C Introduce the fan exhaust vent into the measuring chamber to prevent fine fibers from flying out and purifying the external environment.
At present, due to the imperfect theoretical research on cyclone separators in China, the optimal structural dimensions cannot be effectively proposed. Moreover, the cyclone separator is affected by many production process parameters, and we can only continuously improve through observation and experiment to make it more perfect. The production practice proves that after the cyclone separator is improved, the clogging phenomenon is obviously eliminated, the single-machine production capacity is increased by more than 2 times, the separation efficiency is basically not reduced, not only meets the production requirements, but also shows good economic and social benefits.
The separator is mounted above the metering silo between the applicator and the paving machine and is the throat of the production line. For a long time, the separator has often been blocked and cannot be adapted to normal production. We have made several minor changes, but they have not improved their blockage. Later, through repeated observations and tests, the following major improvements were made and succeeded.
1 situation before improvement
The cyclone separator functions to separate the wood fibers from the mixed gas stream and feed them into a metering chamber. It works under negative pressure (Fig. 1). When the mixed airflow enters the separator to make the spiral downward movement, the material is deflected toward the inner wall of the cone under the action of centrifugal force. Due to the action of gravity and the movement of the airflow, the lower end of the cone The discharge opening is discharged. Because the wood fiber is light in weight and easy to agglomerate, when the output is increased, some wood fibers form an ash ring under the entrainment of the rising inner vortex, and circle at the intersection of the cone and the ash storage box, as the thickness of the ash ring increases. Large, the fiber drop is hindered, eventually leading to blockage, and the fiber flies out of the exhaust port.
2 debugging
The main factors affecting the performance of the cyclone separator are: inlet wind speed, mixed concentration, chip slack ratio, fiber shape, water content and initial viscosity of the glue. The fibers in the separator are mainly separated from the air by the action of centrifugal force, which is proportional to the square of the tangential velocity of the material.
Increasing the inlet wind speed can speed up the rotary motion of the airflow in the separator, and the centrifugal force of the material is increased, thereby improving the separation efficiency and the processing capability. In reality, however, the damper of the separator fan can be adjusted to a small amount. Increasing the wind speed, the airflow creates a strong eddy current in the separator, preventing the material from reaching the inner wall of the separator housing. At the same time, due to excessive centrifugal force, the material rebounds, causing the fibers to float at the bottom of the cone, eventually causing blockage. When the wind speed is reduced, the air flow in the system is insufficient, which may cause the air supply pipe to be blocked. The commissioning proved that adjusting the air delivery system could not improve the clogging of the separator.
3 analysis and improvement of the program
According to the data, the cyclone separator is basically designed according to the American long cone cyclone separator, and the taper is small and the cone is long. Compared with the domestic cone type cyclone separator, the structure type is the same, but in the structural size, it has the characteristics of long cone length and small discharge opening.
In general, the shape of the cyclone separator is thin and long, and the efficiency is high; short and thick, the resistance is small, and the processing capacity is large. Increasing the cone length of the separator is beneficial to increasing the number of rotations of the gas stream in the separator, so that the material obtains more separation opportunities and improves the separation efficiency. However, in fact, due to the pulling action of the rising inner vortex on the downward vortex, the outer vortex of the lower vortex continuously enters the rising inner vortex during the downward rotation, so the cone of the separator is too long and There is no practical meaning, but it will reduce the processing power.
The diameter of the discharge opening is small, the radius of rotation of the air flow becomes smaller, the tangential speed increases, and the material falls hard under the action of centrifugal force, which is one of the main causes of blockage.
In view of the above, the improvement is as follows (Figure 2).
1. Increase the discharge opening. Since the taper angle is constant, the effective area of ​​the discharge opening is increased by about 1 time by shortening the length of the cone.
2. Set the guide rod to guide the inner vortex to eliminate the interference between the inner and outer vortex at the critical point.
3. Install the swinging baffle. The mixed airflow generates a large centrifugal force during the rotation process. Since the inertia of the material is many times larger than that of the air, most of the material is deflected toward the wall, and the spiral movement is performed under the driving of the airflow. The inertia force is quickly lost, falling along the wall and separating from the gas, and falling into the ash storage tank through the discharge opening. The baffle oscillates back and forth continuously, so that the fibers do not help to form a dough for favorable discharge.
4. Expand the ash storage box. The ash storage tank is an inseparable part of the cyclone separator, which is the final link to complete the separation of the gas-solid two medium. The improper treatment will seriously affect the separation efficiency, increase the discharge opening, and reduce the airflow undershoot resistance. In order to avoid more airflow entering the ash tank to form a fierce vortex, the trapped material is re-wound and entrained into the rising airflow to reduce the efficiency of the separator. In addition to expanding the volume of the ash tank, it is lengthened. The lower end of the cone extends into the transitional tube in the ash storage tank, so that the underflow resistance of the airflow increases, and the internal swirling flow cannot reach the ash storage tank, so that the negative pressure value in the tank is reduced, the pressure difference between the inside and the outside of the tank is reduced, and the air leakage rate is lowered. less.
C Introduce the fan exhaust vent into the measuring chamber to prevent fine fibers from flying out and purifying the external environment.
At present, due to the imperfect theoretical research on cyclone separators in China, the optimal structural dimensions cannot be effectively proposed. Moreover, the cyclone separator is affected by many production process parameters, and we can only continuously improve through observation and experiment to make it more perfect. The production practice proves that after the cyclone separator is improved, the clogging phenomenon is obviously eliminated, the single-machine production capacity is increased by more than 2 times, the separation efficiency is basically not reduced, not only meets the production requirements, but also shows good economic and social benefits.
Noise barriers are mainly used for sound insulation and noise reduction of highways, expressways, elevated composite roads and other noise sources. Inserting a facility between the sound source and the receiver makes the sound wave propagation have a significant additional attenuation, thus weakening the noise influence in a certain area where the receiver is located. Such a facility is called a sound barrier. It is divided into traffic noise barriers, equipment noise attenuation noise barriers, industrial boundary noise barriers, and highways and expressways, where various types of noise barriers are most used.
Sound Barrier,Noise Barrier,The Sound Barrier,Acoustic Barrier
Anping County Xinhai Traffic Wire Mesh Manufacture Co., Ltd , https://www.xhmetalfence.com