The selection of fans Product performance and fan performance listed in the selection table are based on the performance of delivering air under standard conditions. Therefore, when the use condition is non-standard, the H4-72-12 centrifugal fan must convert the use performance into the performance under standard conditions according to the relationship in the table above, and then select according to the performance and selection table. （3） Treatment of excessive or insufficient flow During use, excessive or insufficient flow often occurs. There are many reasons for this phenomenon. If the flow is high and low during use, it is mainly because the resistance in the pipe network is high and low, or the fan works in a non working area. If it is gradually reduced after a long time during use, it is mainly due to pipe network blockage. After the fan is newly installed, the flow is too large or insufficient during the formal operation. The main reasons for this phenomenon are as follows: 1. The actual value of pipe network resistance is too different from the calculated value. In the general pipe network characteristic equation, H=KQ2, if the actual value K of K-resistance coefficient is less than the calculated value K, the flow will increase; If the actual value K is greater than the calculated value K, the flow decreases. See (b) below.

2. The influence of the total pressure deviation Δ H of the fan itself was not considered during selection. When the actual total pressure of the fan was positive deviation, the flow increased; When the actual total pressure of the fan is negative deviation, the flow decreases. See (a) below. The relationship between the deviation of the pipe network characteristic curve and the total pressure and the flow can be eliminated by one of the following methods when the fan starts to officially operate after new installation, or when the flow is too large or too small during use. 1. Use the opening and closing of throttling device to adjust the flow. 2. Increase or decrease the flow by increasing or decreasing the fan speed. 3. Use a new fan with higher or lower pressure to increase or decrease the flow. 4. Change the pipe network to reduce the resistance coefficient of the pipe network to increase the flow. It must be pointed out that throttling devices are generally used to regulate the flow. However, when the actual flow is much larger than the required flow, this method wastes too much power and is very uneconomical. If conditions permit, the fan speed is usually reduced or the fan with lower pressure is replaced. When the throttling device is fully open, the flow is still too small. At this time, the throttling device has lost its function, so try to reduce the resistance coefficient of the pipe network to increase the flow, or increase the fan speed and replace the fan with higher pressure. However, the speed of the fans directly connected to the motor and the coupling cannot be changed generally. Only the fan driven by the pulley can increase or decrease the speed by changing the diameter of the pulley, but the speed of the fan cannot exceed the speed max in the performance and selection table.

Correct maintenance is an important guarantee for the safe and reliable operation of the fan and the improvement of its service life. Therefore, Sweeper fan company When using fans, full attention must be paid. Impeller maintenance: at the initial stage of impeller operation and during all regular inspections, whenever there is an opportunity, the impeller must be checked for cracks, wear, dust and other defects. The impeller must be kept clean whenever possible, major Sweeper fan The steel wire brush shall be used regularly to remove the dust and rust on the impeller. As the travel time increases, the dust can not be evenly attached to the impeller, which will cause damage to the balance of the impeller and even cause rotor vibration. As long as the impeller is repaired, it needs to be dynamically balanced again. If possible, the portable trial dynamic balancing instrument can be used for on-site balancing. Before dynamic balancing, check whether all fastening bolts are tightened. Since the impeller has been operating in an unbalanced state for a period of time, these bolts may have become loose. Bearing maintenance: frequently check the oil supply of bearing lubricating oil. If the box leaks oil, tighten the bolts of the end cover a little. If this is not enough, you may have to use new sealing packing. When the bearing lubricating oil is in normal use, it should be replaced at least once every six months. When it is used for the first time, it should be done after 200 hours of operation. The second oil change should be done in 1 to 2 months. After that, the lubricating oil should be checked once a week. If the lubricating oil does not deteriorate, the oil change can be extended to 2 to 4 months. The specified brand of lubricating oil (specified on the general drawing) must be used when replacing, The old oil in the oil tank shall be completely drained and cleaned before new oil can be filled. If the fan bearing needs to be replaced, pay attention to the following matters: before installing the new bearing, the bearing and bearing box must be very clean. Place the bearing in the oil with a temperature of about 70~80 ℃ and heat it before installing it on the shaft. Do not force assembly to avoid damaging the shaft. Maintenance of other supporting equipment: see the respective user manual for the maintenance of various supporting equipment, including motors, electric actuators, instruments, meters, etc. These operating instructions are provided by each supporting manufacturer. The manufacturer will pack these instructions together and provide them to the user

Main factors affecting the dust removal efficiency of wet electrostatic precipitator. The effect of electrostatic voltage, water volume and dust concentration on wet electrostatic precipitation efficiency is positive, that is, the dust removal efficiency increases with the increase of voltage, water volume and dust concentration. Among them, voltage has the most significant effect on dust removal efficiency, followed by water volume, and dust concentration has the least effect. The combination of static electricity and water mist can significantly improve the dust removal efficiency. The role of water in wet electrostatic precipitation. The water in wet electrostatic precipitator mainly exists as atomized water droplets. According to domestic research, water mist has a series of effects on the improvement of dust removal efficiency of wet electrostatic precipitator, major Sweeper fan Main mechanism: the water mist can keep the discharge electrode clean and keep the corona vigorous; The mist particles strike the dust collecting electrode to form a thin and uniform water film, Anqing Sweeper fan It can prevent the "secondary flying" of low specific resistance dust from tempering high specific resistance dust and prevent the occurrence of "reverse corona"; For the dust with strong viscosity, the electrode can be prevented from sticking; It is also suitable for collecting those flammable and explosive dust. The water mist is sprayed directly to the discharge electrode and corona area, and the discharge electrode also acts as an atomizer. The same power supply can realize corona discharge, water atomization, water mist and dust particle charging, realizing the organic combination of static electricity and water mist. The water mist is directly sprayed to the discharge electrode, which has a high charge. The collision interception, adsorption and coagulation of water mist with high charge mass ratio in the electric field can greatly improve the dust removal efficiency. The water mist strikes the dust collecting electrode to form water flow down, so that the dust collecting electrode is always kept clean, eliminating the vibrating device, and avoiding a series of problems caused by vibrating dust removal in dry dust removal. In the method of spraying water mist to the discharge electrode and corona area to further atomize the water mist, the static electricity does not directly contact the spray device, so there is almost no insulation problem. This method is completely different from the dedusting technology of "corona discharge atomizes water". The latter is almost impossible to insulate due to the direct contact between water and electricity, and it is actually difficult to achieve industrial application. The barbed electrode can produce a strong electrostatic field, and has a good corona discharge capacity. The electrostatic and water mist work together, and has a high dust removal efficiency

Before installation, first prepare the materials and tools for installation, and check the parts of the fan, especially the impeller, main shaft, bearing and other parts. If any damage is found, repair it, and then clean the inside of the bearing box with kerosene. In the process of installation, the following points must be paid attention to: 1. In order to prevent rust and reduce the difficulty of disassembly, some grease or machine oil should be coated on some joint surfaces. 2. When installing the bolts on the joint surface, if there are positioning pins, install the pins and tighten them before tightening the bolts. 3. Check that there should be no tools and sundries falling or left in the casing and other casings. Installed and used by CHANG factory bridge QIAO ISO9001 quality management system certification enterprise of Beijing No. 2 Blower Works 1. When installing the fan, the inlet and outlet must be provided with soft connection, and the weight of the gas transmission pipeline should not be added to the casing. Correct the gap size between the air inlet and the impeller according to the drawing, and keep the shaft in a horizontal position. 2. When installing the soft connection of the air inlet, the bolts of the air inlet itself can be directly used for connection. At this time, the air inlet is fixed by three countersunk screws.