large Axial flow centrifugal fan Common fault: the working medium of the fan in the cement industry often contains a certain amount of homogeneous particles with different sizes and shapes, such as the induced draft fan of the dust removal system and the blower for pneumatic conveying. Because these fans work in the dusty air flow, the dust particles in the air flow will not only wear the fan, but also attach ash on the fan blades, and the wear and ash deposition are uneven. As a result, the balance of the fan rotor is destroyed, which causes the fan vibration and shortens the life of the fan. In serious cases, the fan can not work normally. Especially, the fan blades are worn most seriously, Axial flow centrifugal fan manufactor It not only destroys the flow characteristics in the fan, but also easily leads to major accidents such as blade fracture and runaway. The wear of transmission parts is also a common problem of fans, including various shafts, rollers, reducers, motors, pumps and other bearing positions, bearing seats, keyways, threads and other parts. The traditional repair welding machine processing method is easy to cause material damage, resulting in deformation or fracture of parts, with greater limitations; Brush plating and spray re machining methods often require outsourcing, which not only requires long repair cycle and high cost, but also can not fundamentally solve the causes of wear (poor impact resistance and yield of metal) because the repair materials are metal materials; Many parts can only be scrapped and replaced, which greatly increases the production cost and inventory of spare parts, leaving the enterprise's good resource advantage idle and wasted
Correct maintenance is an important guarantee for the safe and reliable operation of the fan and the improvement of its service life. Therefore, Axial flow centrifugal fan manufactor 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, large Axial flow centrifugal 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
While meeting the new standard, the wet electrostatic precipitator can also control the haze fine particles, sulfur trioxide aerosol droplets, organic pollutants, heavy metal pollutants, etc., which has great social benefits. The air pollutant control mode of SCR+ESP/FF+WFGD+WESP is also a relatively effective way to control pollutants in Shangshan Coal fired Power Plant. Axial flow centrifugal fan manufactor Common dust control technologies, among which the dry electrostatic precipitator, the electrostatic fabric composite precipitator and the bag type precipitator are used as the front section dust control technology, cannot guarantee the ultra clean emission of flue gas dust after the desulfurization device, while the wet electrostatic precipitator arranged at the downstream of the wet desulfurization device will be used as a reliable terminal dust control technology. The working principle of wet electrostatic precipitator is similar to that of dry electrostatic precipitator. It is high-voltage corona discharge that charges dust or water mist, and charged particles reach the dust collecting plate under the action of electric field force, large Axial flow centrifugal fan However, in terms of the way of dust, the dry electrostatic precipitator uses mechanical vibration, while the wet electrostatic precipitator uses flushing fluid to flush electricity, so as to flush the dust captured on the dust collection plate into the ash hopper and then discharge the wet electrostatic precipitator. The advantages of the wet electrostatic precipitator are: because the mass and heat transfer processes occur simultaneously in the process of gas and liquid contact, this type of precipitator has the function of dust removal, It also has the function of flue gas cooling and absorption of harmful gases. Suitable for high temperature. High temperature, flammable, explosive and harmful gases; Normal operation and high purification efficiency; Dust and gas that can be used for gathering fog and dust; Exhaust volume balance; Simple structure. Low investment, convenient operation and maintenance.
Wet dust remover is a device that uses the action of water or other liquids and dusty gases to remove dust particles. When dust particles meet with sprayed water droplets, water films or wetted walls and devices The process of wetting, condensation, diffusion and sedimentation takes place, so it is separated from the gas to purify the gas. Anqing Axial flow centrifugal fan manufactor It is characterized by purifying dust at the same time It can also purify gas, large Axial flow centrifugal fan When the flue gas contains combustible components, the use of wet dust collectors can avoid equipment explosion, and the dust removal effect can generally meet the environmental protection requirements. The equipment is small and the investment is relatively low. Therefore, there are three wet dust collectors used in dust removal projects in mining, metallurgy, machinery, light industry, building materials and other industries. Sludge containing sewage must be treated, otherwise secondary pollution may occur, Therefore, it is not widely used as dry dust collector. There are many types of wet dust collectors. According to their structures, there are the following types: ① gravity spray wet dust collectors - spray scrubbing towers; ② Cyclone wet dust collector - cyclone water film dust collector, water film dust collector; ③ Self excited wet dust collector - impulse dust collector, water bath dust collector; ④ Packed wet dust collector - packed tower, turbulent ball tower; ⑤ Foam wet dust collector - foam dust collector Cyclone dust collector, leaky plate tower; ⑥ Venturi wet dust collector - Venturi tube dust collector; ⑦ Mechanical induction wet dust collector - water wheel dust collector.
Selection and application of fan performance (I) Description of fan performance: 1. № 10, 12, 16, 20 are converted according to dimensionless performance of № 10 model. 2. № 5, 6, 8 are converted according to dimensionless performance of № 5 model. 3. № 5 and below shall be determined according to the performance of the measured prototype. Note: According to the dimensionless performance curve conversion formula, total pressure H=ρ u2 H (Pa) flow Q=900 π D22 uQ (m3/h) shaft power N=N × D22u3 ρ/4000 (kw), where D2 - impeller outer diameter (m) u - impeller outer edge linear speed (m/s) ρ - gas density (Kg/m3), the required power rate shall be based on shaft power plus mechanical loss and motor reserve. 4. The solid line is № 5 model, and the dotted line is № 10 model. The performance of the fan is expressed by the flow, total pressure, main shaft speed, shaft power, efficiency and other parameters of the fan, and there are certain relationships between the parameters, which are listed in the following table. The relationship of fan performance parameters changes density ρ, speed n changes speed n, atmospheric pressure P, gas temperature t Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 ρ 1/ρ 2 N1/N2=(n1/n2) 3 ρ 1/ρ 2 η 1=η 2 Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 (P1/P2) (273+t2/273+t1) N1/N2=(n1/n2) 3 (P1/P2) (273+t2/273+t1) η 1=η 2 Note: 1. In the middle, Q represents flow (m3/h), H represents total pressure (Pa), N Represents shaft power (kw), η represents total pressure efficiency, ρ represents density (kg/m3), t represents temperature (℃), n represents speed (r/min), and P represents atmospheric pressure (Pa). 2. The footnote symbol 2 indicates the known performance and related parameters, and the footnote symbol 1 indicates the required performance and related parameters. (