Sliding rail type tube bundle rotational flow dust and mist removal device

Abstract

The invention discloses a sliding rail type tube bundle rotational flow dust and mist removal device, and belongs to the field of waste gas treatment. The device is located above a spraying layer inside an absorption tower. The device comprises n perpendicularly-arranged rotational flow dust and mist removal units, wherein n is larger than or equal to 1. The sliding rail type tube bundle rotational flow dust and mist removal device overcomes the defect that efficiency is low when load changes in the prior art, has the advantages of being capable of meeting the emission requirement within the boiler full-load range, and is flexible to adjust, convenient to operate, easy to implement and high in reliability.

Description

technical field [0001] The invention belongs to the field of waste gas treatment, and in particular relates to a slide rail type tube bundle swirling dust and mist removal device. Background technique [0002] At present, the existing coal-fired units in my country generally adopt the limestone-gypsum wet flue gas desulfurization process. Limestone, gypsum slurry, etc. in the state of fog droplets. With the increasing national environmental protection emission standards, it is necessary to perform deep dust removal on the clean flue gas after desulfurization. According to the newly promulgated "Emission Standards of Air Pollutants for Thermal Power Plants", the dust concentration emitted by the chimney is proposed to be 5mg / m 3 requirements. [0003] Dust and fog removal of flue gas is the most common process in the flue gas purification process. There are various types, but it is difficult to deal with the saturated wet flue gas containing a large number of mist droplets. ...

AI Technical Summary

Problems solved by technology

However, for this type of demister, the superficial flow velocity or the flow velocity in the pipe has a significant impact on the separation efficiency of the demister. Generally speaking, within a certain range, with the increase of the flow velocity in the pipe, the demister's The removal efficiency is improved, because the air flow rotates after passing through the gap of the swirl plate blades. With the increase of the superficial gas velocity, the tangential velocity of the air flow becomes larger, and the liquid droplets entrained in the air flow are affected The centrifugal force will also increase accordingly, which is beneficial to the separation of the droplets to the wall of the device; at the same time, with the increase in the tube, the turbulence of the airflow increases, and the secondary entrainment of the droplets becomes more and more serious. The secondary entrainment is mainly due to two effects: one is the atomization of the droplets when they collide, and the other is the shear force of the high-speed airflow acting on the free surface of the liquid film. When the secondary entrainment exceeds a certain value, the defogging The separation efficiency of the device also decreases

[0005] It can be seen that there is a contradiction between the flow velocity in the pipe and the dust removal efficiency. To maintain a high dust removal efficiency, the flow velocity in the pipe must be increased. If the flow velocity is too high, the proportion of secondary entrainment will be greatly increased, resulting in a decline in dust removal efficiency; on the other hand, The load of the boiler often fluctuates, usually between 30% and 110%, which also causes a huge change in the flow rate in the tube

In order to balance the above contradictions, the prior art usually adopts a compromise method, that is, a specific load point (such as 100% load or 70% load) is used as the design point for design, when the actual operating load is significantly higher than the design point , the secondary entrainment is serious, resulting in low removal efficiency, and when the actual load is significantly lower than the design point, the centrifugal force is insufficient and the separation effect is not high, and in severe cases, it cannot meet the requirements of the emission index

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