Water film cooling method and device for recovering trace yellow phosphorus in yellow phosphorus tail gas

Abstract

The invention discloses a water film cooling method and device for recovering trace yellow phosphorus in yellow phosphorus tail gas. The device comprises a process water pipe, a steam pipeline, a yellow phosphorus tail gas inlet pipe, a water film cooler, a yellow phosphorus storage tank, a cooling water pump and a water cooling tower. According to the device and the method, the yellow phosphorustail gas with higher temperature of 55-58 DEG C is cooled to 40-42 DEG C by the water film cooling device, most yellow phosphorus steam generates liquid yellow phosphorus due to the reduction of the steam pressure of the yellow phosphorus in the cooling process, and the liquid yellow phosphorus is isolated from the cooling pipe by the water film to prevent pipe wall deposition, thereby recoveringthe yellow phosphorus; and more yellow phosphorus is collected, so that the energy consumption is relatively reduced, the content of elemental phosphorus in yellow phosphorus tail gas is reduced, andthe harm of the elemental phosphorus escaping everywhere is reduced.

Description

technical field [0001] The invention relates to the technical field of energy saving and environmental protection, in particular to a water film cooling method and device for recovering trace amounts of yellow phosphorus in yellow phosphorus tail gas. Background technique [0002] At present, domestic small and medium-sized phosphorus production enterprises all use the condensation method to recover yellow phosphorus. The condensation process of phosphorus vapor is to cool the furnace gas to a temperature lower than the dew point temperature of phosphorus. The furnace gas is cooled in the condensation tower, and the tail gas temperature drops from 150 to 160 °C. At 35-40°C, the phosphorus vapor changes from the gas phase to the liquid phase. The particle size of the phosphorus droplets just condensed is very small, and they need to grow to a certain particle size before they can be collected. The phosphorus droplets in the tail gas account for a small amount of the total gas ...

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Problems solved by technology

Yellow phosphorus spontaneously ignites when it sees air, and once it leaks, it will cause a combustion explosion accident, which is quite unsafe. Not to mention the huge loss of yellow phosphorus, it will also bring harm to the desulfurization process and cause the desulfurization process to be abnormal. Therefore, reducing the temperature of yellow phosphorus tail gas has become a top priority.

[0007] The cooling of yellow phosphorus tail gas can be directly cooled by process water: the yellow phosphorus tail gas is sprayed and washed with process water in a washing tower, which can reduce the temperature of yellow phosphorus tail gas to the required temperature. After washing and cooling, the washing water has been washed by yellow phosphorus and Dust pollution also requires sewage treatment, but it requires a large amount of process cooling water. The washed sewage is mixed into the system sewage for sewage treatment, resulting in excessive circulating water and cannot be discharged. This method is not advisable, so yellow phosphorus enterprises generally There is no low temperature circulating water available

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