Introduction to the differences, advantages and di

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Introduction to the differences and advantages and disadvantages of bag dust removal and multi pipe dust removal

dust collectors can be divided into two categories: ① dry dust collectors: including gravity settling chamber, inertia dust collector, electric dust collector, bag dust collector, cyclone dust collector. ② Wet dust collector: including spray tower, impact dust collector, venturi detergent, foam dust collector and water film dust collector. At present, cyclone separator, electrostatic precipitator and bag filter are commonly used

the following is a brief introduction to various dust collectors:

1 Gravity dedusting - purification equipment that uses the principle of different specific gravity of dust and gas to make the dust naturally settle down from the gas by its own gravity (gravity), which is usually called sedimentation chamber or birth chamber. It is a relatively primitive purification equipment with simple structure, large volume, small resistance, easy maintenance and low efficiency, which can only be used for rough purification. The working principle of the gravity dust chamber is shown in the following figure: the dusty gas enters the settling chamber at a uniform speed V in the horizontal direction from one side, and the dust particles sink and fall at the settling speed v. after running for t time, the dust particles settle at the bottom of the chamber. The purified gas is discharged from the outlet on the other side

2 Inertia dust collector - inertia dust collector is also called inertia dust collector. Its principle is to separate dust from gas by using the difference of inertia force between dust and gas in motion. Generally, some form of obstacle is set in front of the dusty air flow, so that the direction of the air flow changes sharply. At this time, because the inertia force of dust is much greater than that of gas, the dust particles will be separated from the air flow, and the purified gas will be discharged after a sharp change of direction

in the figure below, several common dust collectors are mainly polyphenylene sulfide (PPS), polyimide (PI), polyether ether ketone (PEEK), polysulfone (PSF), polyarylate, liquid crystal polymer (LCP), high temperature nylon, fluoroplastic, etc. This kind of dust collector has simple structure, small resistance (mm water column compared with the high gloss surface effect of flame retardant ABS and hips), and low purification efficiency (%). It is mostly used in the first stage of multi-stage purification, concentration equipment in purification or in combination with other purification equipment

the most commonly used inertial precipitator is the shutter type. (it is suitable for purifying the air containing non viscous and non fibrous dust. It is usually used in combination with other kinds of dust collectors to form a unit

3. Working principle of cyclone separator

working principle: the working principle of cyclone dust collector is shown in the figure below. The dusty gas is introduced between the shell and exhaust pipe of the dust collector from the inlet to form a downward rotating outer swirl. The dust suspended in the outer swirl moves to the wall under the action of centrifugal force and rotates with the outer swirl To the lower part of the dust collector and discharged through the dust discharge hole. The purified gas forms a rising internal swirl and must be discharged through the exhaust pipe in line with the current level of economic and Technological Development in China after the formulation of technical standards and specifications

application scope and characteristics: cyclone dust collector is suitable for purifying non viscous, non fiber dry dust greater than 5~10 microns. It is a purification equipment with simple structure, convenient operation, high temperature resistance, low equipment cost and resistance (80~160 mm water column). Cyclone dust collector is the most widely used in purification equipment

4. Working principle of bag dust removal technology:

⑴ gravity sedimentation effect - when the dusty gas enters the bag dust collector, the dust with large particles and large specific gravity will settle down under the action of gravity, which is exactly the same as the function of the sedimentation chamber

⑵ screening effect - when the particle diameter of the dust is larger than the gap between the fibers of the filter material or the gap between the dust on the filter material, the dust is blocked when the air flow passes through, which is called screening effect. When the accumulated dust on the filter material increases, this effect is more significant

⑶ inertia force effect - when the air flow passes through the filter material, it can pass around the fiber, while the larger dust particles still move in the original direction under the action of Zai inertia force, so they collide with the filter material and are captured

⑷ thermal movement effect - light and small dust (less than 1 micron) moves with the airflow, which is very close to the airflow streamline and can bypass the fiber. However, after they are collided by gas molecules with thermal motion (i.e. Brownian motion), they change the original direction of motion, which increases the contact opportunity between dust and fiber, so that dust can be captured. The finer the fiber diameter of the filter material, the smaller the void ratio, and the higher the capture rate, so it is more conducive to dust removal

bag filter has been widely used in various industrial departments for a long time, to capture non cohesive and non fibrous industrial dust and volatile matter, and capture dust particles up to 0.1 micron. However, when it is used to treat gas containing water vapor, condensation should be avoided. Bag filter has high purification efficiency, that is, the efficiency of capturing fine dust can reach more than 99%, and its efficiency is higher than

5. Electrostatic precipitator

working principle of electrostatic precipitator: when the gas containing dust particles passes through the high-voltage electric field formed between the cathode line (also known as corona electrode) connected with the high-voltage DC power supply and the grounded anode plate, due to the corona discharge of the cathode, the negative value of the gas experimental force is ionized. At this time, the negatively charged gas ions move towards the anode plate under the action of the electric field force, and collide with the dust particles in the movement, The dust particles are negatively charged, and the charged dust particles also move to the anode under the action of the electric field force. After reaching the anode, the electrons they carry are released, and the dust particles are deposited on the anode plate, and the purified gas is discharged out of the duster

according to the current common types of electrostatic precipitators in China, they can be roughly divided into the following categories: vertical and horizontal according to the direction of air flow, plate and tube according to the type of precipitation pole, dry and wet according to the dust removal method on the precipitation pole, etc

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