Fans can be classified into several types according to the materials used, such as iron shell fans (ordinary fans), glass fiber reinforced plastic fans, plastic fans, aluminum fans, stainless steel fans, etc. Wet electrostatic precipitator Price In the direction of gas flow. Fans can be classified into centrifugal, axial, diagonal (mixed flow) and cross flow fans according to the direction of gas flow. (1) Centrifugal fan. The airflow enters the impeller of the fan axially and flows mainly along the radial direction. This type of fan is made according to the principle of centrifugal action, and its products include centrifugal fan, centrifugal blower and centrifugal compressor. (2) Axial flow fan. The airflow enters the impeller of the fan axially and flows approximately along the axis on the cylindrical surface. Such fans include axial fans, axial blowers and axial compressors. (3) Rotary fan. Nanning large Wet electrostatic precipitator Use the rotor rotation to change the air chamber volume to work. Common varieties include Roots blower and rotary compressor.
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.
Forecast from domestic market capacity. Nanning Wet electrostatic precipitator Price Fans vary greatly according to different pressure and flow requirements. Therefore, the fan demand should be differentiated according to its type and size, and predicted according to the demand of different industries. According to incomplete statistics, the annual average growth rate of national fan output was 13.8% from 1980 to 1996. large Wet electrostatic precipitator It is estimated that the total output of wind turbines in China will be 2.6 million to 2.9 million in 2005 and 3.1 million to 3.25 million in 2010. According to the statistics of fan industry over the years, it is predicted that the output of centrifugal compressors will be 1.6 million to 1.8 million in 2005 and 2 million to 2.1 million in 2010; The output of axial compressor is 260000 in 2005, and is expected to reach 360000 in 2010; The market share of turbine compressor and blower will reach about 70% in 2005
Main working principles of wet electrostatic precipitator: large Wet electrostatic precipitator Spray the water mist to the discharge electrode and corona area. The water mist will split and further atomize after being charged in the powerful corona field formed by the barbed electrode. The collision interception, adsorption and coagulation of electric field force and charged water mist will jointly trap the dust particles. Finally, the dust particles will reach the dust collecting electrode and be trapped under the drive of electric field force. The water forms a continuous water film on the dust collecting electrode, and the captured dust is washed into the ash hopper and discharged with water. Operating principle of wet electrostatic precipitator. The dedusting process of electrostatic precipitator can be divided into four stages: gas ionization; The dust is charged with ions; Charged dust moves towards the electrode; Remove the dust on the electrode. Only the objects removed by wet electrostatic precipitation are dust and droplets, but their working principles are different due to the differences in physical characteristics between droplets and dust. In principle, Nanning Wet electrostatic precipitator First of all, the existence of water droplets has an impact on the electrode discharge. To form emitting ions, free electrons in the metal electrode must obtain enough energy to overcome the ionization energy and cross the surface barrier to become emitting electrons. It is an effective measure to reduce the surface barrier by bringing water on the electrode surface. After the metal surface is covered with water, the original "metal air" interface is divided into "metal water" interface and "water air" interface. The potential barrier of the latter two interfaces is much lower than that of the former interface. In this way, after the metal surface is filled with water, the original high barrier will be divided into two low barriers, which will greatly weaken the blocking effect of the surface barrier on free electrons and make electrons easy to launch. In addition, Wet electrostatic precipitator Price Under the action of electric field, various impurity ions in water can easily cross the surface barrier and become emission ions. All of these have changed the electrode discharge effect, enabling corona discharge under low voltage. Secondly, due to the existence of water droplets, the resistance of water is relatively small. When water droplets combine with dust, the specific resistance of dust with high specific electricity decreases, so the working state of wet electrostatic precipitator will be more stable; In addition, since the wet electrostatic precipitator is washed by water flow and has no rapping device, it will not produce secondary dust.
large Wet electrostatic precipitator 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, Wet electrostatic precipitator Price 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