Carbon black fan

Carbon black fan (specialized centrifugal fan for carbon black production line) is a high-pressure centrifugal fan used for furnace carbon black production process. It is the power core of the entire production line and is used to complete combustion and combustion assistance gas supply, exhaust gas suction and pressurization, bag filter backwashing, and pneumatic conveying of carbon black powder. Characteristics of the medium: ultrafine carbon black dust, high temperature, combustible components containing CO in the exhaust gas, highly prone to dust accumulation and wear, with explosion risk, and extremely high requirements for sealing, wear resistance, and explosion prevention.

1、 Classified by process use

1. The combustion furnace combustion fan (9-12, 9-26) supplies process combustion air to the reaction furnace, with stable air pressure and no pulsation in the airflow, ensuring a stable air-fuel ratio and directly affecting the quality of carbon black products. The medium is clean air at room temperature.

2. Exhaust gas suction/pressurization fan (THWF/FWG series) extracts high-temperature exhaust gas (180-350 ℃) from carbon black, which contains ultrafine carbon black dust and CO combustible gas and must be explosion-proof; Send the exhaust gas into the waste heat boiler and exhaust gas combustion system. It is the most demanding fan in the entire production line.

3. Bag filter backwash blower high-pressure pulse backwash air source, cleaning carbon black bag filter material, high-pressure small flow.

4. The carbon black powder collected by the conveying/reflux fan is extremely fine and has strong adhesion, and the blades are prone to scaling and dust accumulation.

5. The packaging vacuum fan collects dust from the packaging section.

2、 Structural characteristics of the whole machine

Shell (thickened steel plate)+dedicated anti dust impeller+air inlet+bearing box+common base

1. Impeller: Adopting a special blade shape that is not easily prone to dust accumulation; Welding tungsten carbide wear-resistant layer on the working face under dust conditions; Some parts are made of stainless steel. Ultra fine carbon black easily adheres to the blades, and uneven dust accumulation directly causes vibration spikes.

2. Sealing (of utmost importance): Multi stage labyrinth+carbon ring composite seal, prevents carbon black dust from entering the bearing box, and also prevents leakage of CO containing exhaust gas, avoiding explosion hazards. Ordinary packing seals are not suitable for carbon black working conditions.

3. Bearing box: heavy-duty bearings; The high-temperature exhaust model is equipped with an extended heat dissipation shaft to isolate high-temperature conduction; High temperature conditions can choose water-cooled bearing seats.

4. Thickening of the shell snail shell and installation of wear-resistant lining plates in areas prone to erosion. Accessories: Explosion proof motor, high temperature and anti-corrosion soft connection, spring shock absorber, imported air damper, muffler, coupling guard, explosion-proof variable frequency control cabinet

3、 Core Features

1. Anti dust design: optimized blade shape to reduce the adhesion of ultrafine carbon black; Even if there is dust accumulation, it is easy to clean

2. Wear resistant and high temperature resistant, the exhaust fan can withstand 200 ℃ and dusty flue gas for a long time

3. Strict explosion-proof: The medium contains CO combustible exhaust gas, and the whole machine is designed to be explosion-proof, anti-static, and spark free

4. Multi level composite seal, preventing dust intrusion and combustible gas leakage

5. 24-hour continuous operation, stable wind pressure, equipped with frequency conversion, adaptable to production load fluctuations

6. High standard dynamic balancing of impeller at factory to suppress vibration caused by dust accumulation

4、 Material selection

Combustion fan: Q235 carbon steel

Exhaust/dust containing fan: shell Q235, impeller Q345 welded with tungsten carbide; 304 stainless steel is selected for corrosion conditions

Ultra high temperature, sulfur-containing exhaust gas: 310S heat-resistant stainless steel

5、 Key parameters for selection

1. Usage: Combustion assistance/Exhaust gas pressurization/Backblowing/Powder conveying

2. Airflow, total pressure

3. Medium temperature, carbon black dust concentration, exhaust gas composition (with or without CO and sulfides)

4. Is it explosion-proof

5. Transport medium: clean air/exhaust gas containing carbon black/carbon black powder

6. Wear resistant solution and sealing form

7. Is it variable frequency speed regulation

6、 Installation points

1. High temperature resistant fluorine adhesive tape is used for soft connections in import and export to isolate vibration and absorb thermal expansion

2. Pipeline independent support, pipeline weight cannot press fan flange

3. Negative pressure exhaust system, flange sealing must be tight to prevent air infiltration (mixing with air can easily cause exhaust explosion)

4. Pre installed coarse separation device at the air inlet reduces the entry of large particles into the fan and mitigates wear and tear

5. The base is equipped with spring shock absorbers to reduce the overall vibration of the machine

6. Grounding and anti-static measures must be provided

7、 Common faults

1. Dust and scaling on the impeller: The ultra-fine powder of carbon black adheres to the blades, causing dynamic balance failure and excessive vibration, which are the most common faults of carbon black fans

2. Sealing failure: Carbon black dust enters the bearing, causing rapid damage to the bearing; Flammable exhaust emissions overflow, posing a safety hazard

3. Blade wear and perforation, shell erosion and leakage

4. Excessive temperature rise of bearings under high temperature conditions

5. The exhaust system leaks air and mixes with air, posing a risk of combustion and explosion