Which is a good washing tower

Application of wet scrubbing tower

Process Characteristics

(1) Characteristics of water washing and dust removal process

① Compared with the steam capture process, the dust removal efficiency of the water washing dust removal process is more than 5% higher, and the production cost per ton of product is 6.71 yuan lower.

② The process flow is long, requiring more auxiliary equipment, and the basic investment is larger than that of steam capture technology.

③ The aqueous solution needs to be dehydrated, and the solid material containing water needs further treatment and cannot be directly returned to the production system.

④ When the external environmental temperature decreases, salts in the aqueous solution will supersaturate and precipitate, which can easily cause pipeline crystallization and blockage.

(2) Characteristics of steam capture technology

① The process flow is short and the basic construction investment is low.

② For most fertilizer varieties, the captured dust with a moisture content of less than 10% can be directly returned to the production system. <>

③ It is easy to form an adhesive layer on the wall of the washing tower, and when the gas velocity is not controlled properly or there is a large amount of dust accumulation at the bottom of the tower, it is easy to form entrainment and floating dust.

④ When the gas velocity does not match the steam volume, the moisture content of the dust is higher.

⑤ Compared with the water washing dust removal process, the dust removal efficiency is relatively low and the production cost is relatively high.

Application of wet scrubbing tower

Principle of action

The function of this new type of scrubber is based on the principle of counter current contact between the medium speed dusty airflow and the relatively high-speed compressed air atomized liquid flow, which creates a highly effective turbulent flow zone for collecting small dust particles, known as the high-speed impact zone. Figure 1 shows a schematic diagram of the flow pattern of a washer used to illustrate its operation. The dusty gas flows into the top of the contact cylinder from top to bottom, and the atomized liquid sprays into the contact cylinder from bottom to top. The turbulent flow causes the dust particles to be trapped. Wet dust particles are captured through collision with the liquid surface and additional contact when passing through a water curtain that descends along the contact cylinder by airflow. Before the airflow is sucked into the suction system and directly discharged to the atmosphere in the compression system, it needs to be dehydrated through a impeller type dehydrator.

By applying this counter current contact effect, the nominal gas flow rate is 6000 feet per minute, and only a pressure drop of 3-5 inches of water column is required. This allows for the use of low-speed fans to reduce maintenance costs. The air used for water atomization can be supplied by a positive displacement blower at a pressure of 5-10 pounds per square foot. The collection efficiency can be changed by adjusting the ratio of atomized liquid to processing gas (L/G) and the ratio of air to water inside the nozzle (A/W). The total gas flow rate processed by the device can be reduced to 50% of the rated value without the need for a gate or regulating device in the contact area, without affecting the collection efficiency. The nozzle used to atomize and pressure the washing solution into the contact area has a larger cross-sectional orifice, allowing for the recirculation of slurry with high solid content (5% by weight) without the risk of blockage. The high concentration limit for solid content in liquids is equivalent to the concentration at which viscosity is too high for atomization. This concentration varies with the nature of the collected dust particles. For example, it is successful for mud containing 30% fly ash, but for mud containing iron oxide chips, 10% is the high concentration limit for good operation. Due to the need to treat the mud discharged from the scrubber, the use of high concentration mud brings economic benefits to the waste treatment system.