Dust Treatment Solution for High Pressure Suction Fan in the Splicing Unit
The splicing unit is the main model of the current splicing equipment.The cigarette stick conveying system of this unit uses a spider hand mechanism to transfer the cigarette smoothly, without damage to the appearance, without collision, and other advantages. The spider hand mechanism suction claw is provided by the use of negative pressure air to absorb the cigarettes on the smoke transfer guide and convey them to the flue receiving trough of the smoke inlet drum of the YJ27 adapter machine. Negative pressure to help complete the task of cigarette delivery.
During the operation of the equipment, spider hand suction claws often appear in the process of conveying cigarettes into the flue receiving trough of the smoke drum, such as flying smoke, falling cigarettes not in place, and running bars. After inspection, it was found that this kind of failure phenomenon is due to the low wind force of the spider's suction claw, and the suction claw cannot smoothly absorb and transfer the tobacco sticks on the smoke transfer guide to the smoke trough of the drum wheel. Clean up the accumulated dust on the negative pressure vortex fan impeller, which directly affects the online product quality and equipment operation efficiency
I. Failure analysis According to the working principle of the spider hand, the suction claw of the spider hand mechanism uses negative pressure air to suck the tobacco sticks on the smoke transfer guide and transport it to the smoke receiving groove of the inlet drum wheel of the Y27 type mounting machine (Figure 1). While the suction claw sucks and transfers the cigarettes, a part of the dust and smoke will enter the negative pressure channel with the suction claw. 2) Analysis of low pressure and low flow direction of the spider hand mechanism. Because the negative pressure of the vortex suction fan is provided to the spider hand suction claw by the spider hand rotating arm, gear sleeve, and other parts. When the spider hand parts are transported at high speed, while the oil and grease lubricate the parts of the mechanical transmission, a small amount of lubricant and grease will inevitably enter the negative pressure channel with the negative pressure.
2. Analysis of the working principle of the vortex fan based on the working principle of the vortex fan. The impeller of Beijing Meiqile Electromechanical Equipment consists of several 40-piece impellers. It is similar to the large impeller of the turbine. As shown in Figure 2, the air in the middle of the impeller blade is affected by Under the action of centrifugal force, it moves to the edge of the impeller, where the air enters the circular cavity of the pump body, and recirculates from the starting point of the blade in the same way. The circulating air fan flow generated by the impeller rotation is used for negative pressure for the spider hand mechanism. Fan speed is 2800mmin, negative pressure value is 0027MPa, power is 1.1kW, maximum flow is 125mh.
The outlet of the fan is connected with the dust removal pipe of the centralized workshop to remove the smoke and dust sucked out by the vortex suction fan. During the work process, a large amount of smoke, dust and a small amount of oil and grease leaking during the operation of the spider hand mechanism are entered into the negative pressure channel with the negative pressure, and enter the fan casing with the negative pressure airflow (Figure 3). The high-speed rotating impeller causes the air volume to decrease on both sides, causing equipment failures such as spiders throwing smoke, dropping cigarettes, and inadequate cigarette support. The impeller rotates out of balance, accelerates the damage of the fan bearing and the motor. The working position of the vortex fan is horizontal installation, cleaning, installation and maintenance are inconvenient.
According to the structural analysis of the vortex fan, in order to quickly dissipate the fan in high-speed operation, the fan casing and impeller are made of cast aluminum material, and the assembly process is required to be strict. Frequent disassembly makes the screws that fasten the casing easy to thread, the casing is not tightly closed, and the accuracy of the impeller assembly is reduced, which directly affects the performance of the fan.Because the fan is installed horizontally on the device, the location space is narrow, and the overall disassembly and inconvenience are required. People can cooperate to complete the entire disassembly, cleaning, and installation process, and the entire work process takes about 2h.
Third, improvement measures According to the working principle of the vortex fan, the inside and outside of the fan casing are surveyed, measured, and the impeller rotation direction is analyzed. Based on the working conditions, the final improvement plan is determined through multiple tests and verifications. It is decided to drill a 4mm diameter through hole on each of the inclined sides of the fan end cover above the fan outlet, and connect (fix) with the 6mm air joint, as shown in Figure 4. Align the high-pressure airflow to the two sides of the high-speed rotating impeller for cleaning, so that the dust and smoke adhering to the two sides of the impeller are affected by the high-pressure airflow and the air in the middle of the impeller blades is subjected to centrifugal force. Dust and smoke on both sides of the impeller are discharged in time.
6mm gas connector connection and high-pressure gas pipe with outer diameter of 6mm are connected to the single solenoid valve p6m gas connector. Figure 2Y17sE Spider hand negative pressure gas single solenoid valve is opened and closed by PC control. When the device is stopped, the one-way channel solenoid valve conducts high pressure. The air cleans both sides of the rotating impeller. When the equipment is running, the one-way solenoid valve is closed, and the high-pressure air is stopped.
When the equipment is shut down, the one-way solenoid valve is closed after the fan is closed, and the high-pressure air is stopped. This improved design can not only achieve the effect of cleaning the air inlet, but also save energy. This system works only during the rest time of the equipment operation, and does not affect the normal operation of the equipment. The system pressure effectively avoids the phenomenon that affects online product quality and equipment operation efficiency, reduces maintenance frequency, and saves maintenance costs.
In order to avoid the phenomenon that the equipment is shut down and smoke is poured back from the centralized dust removal pipe, it is recommended that the workshop start the centralized dust removal equipment 10n before each cold car is turned on. At this time, the equipment uses a one-way solenoid valve to conduct high-pressure air to the rotating impeller during the time to prepare for startup The cleaning on both sides effectively melted the smoke and dust and caused the fan to jam, reducing the maintenance workload.
4. Improving the thoughts By improving the dust accumulation system of the vortex fan, improving the adaptability and stability of the equipment, and ensuring product quality. After the effective operation rate of the hoisting equipment was tested and operated for 3 months in the 4th unit of the workshop, no failure phenomenon such as flying smoke falling out due to the blockage of the vortex fan was found, and this phenomenon was gradually promoted on other 8 equipment in the workshop. Improved to the ring control, vortex negative pressure fan, thousands of operations, no maintenance required, high reliability, energy saving and high efficiency
V. Analysis of results After recent years of application and operation observations, Unit 7 equipment has a strong adaptability to the system of swirling negative pressure fan dust accumulation, reducing the phenomenon of flying smoke, falling smoke, and inadequate smoke during the operation of the equipment. The effective operating rate of the equipment has been greatly improved. In the second half of 2016, the dust accumulation of the vortex negative pressure fan of the 4th unit of the 207 vehicle was significantly higher.