Efficient spray drying system for desulfurization wastewater

Abstract

The invention provides an efficient spray drying system for desulfurization wastewater, which is characterized in that two ends of a slurry conveying pipeline are respectively connected with an external desulfurization wastewater concentrated solution and a liquid inlet of a slurry conveying pump, and a liquid outlet of the slurry conveying pump is communicated with a feeding hole of a spray drying tower through a high-pressure connecting pipeline; a material outlet of the spray drying tower is connected with a dust remover through a negative pressure dry powder conveying pipeline, and an air inlet of the spray drying tower is connected with external hot flue gas through a flue. According to the invention, the spray drying tower is improved in design, and the improved rectifying plate of the hot flue gas and hot air distributor is turbo-type; the flow guide plate is a groove disc type flow guide grid, after hot flue gas enters the drying tower and before the hot flue gas is in contact with atomized desulfurization wastewater, a flue gas flow field is uniformly designed without dead angles, the hot flue gas is uniformly diffused in the drying tower and is uniformly contacted with a concentrated solution, and the powder bin is improved to be a dead-angle-free conical ash hopper, so that ash discharge is facilitated, and ash particles are prevented from caking and adhering to the wall; the emptying section at the bottom of the powder bin is designed to be large in radius, and pipeline scaling and blocking can also be effectively avoided.

Description

technical field [0001] The invention belongs to the technical field of industrial wastewater treatment, and in particular relates to a high-efficiency spray drying system for desulfurization wastewater. Background technique [0002] Desulfurization wastewater is the most complicated type of wastewater in thermal power plants. The water quality is acidic (pH 4~6), and contains a large amount of suspended solids, ammonia nitrogen and heavy metal pollutants, as well as Ca2+, Mg2+, F-, SO42-, Cl-, etc. At present, the flue gas method is a popular process for treating power plant desulfurization wastewater in the market. The desulfurization wastewater is concentrated by multi-effect flash evaporation or MVR, and then the concentrated liquid is dried and solidified by high-temperature flue gas. The atomization method of the drying tower mainly adopts airflow spray gun or rotary spray. These two processing methods have the following defects: 1. The flue gas is biased and the res...

AI Technical Summary

Problems solved by technology

These two treatment methods have the following defects: 1. The flue gas is biased and the resistance is large

Flue gas deviation is a common phenomenon in most drying towers. The uneven gas flow field causes the concentrated liquid after atomization to evaporate, and the salt and dust cannot dry out, resulting in sticking to the wall and even water accumulation at the bottom of the tower; 2 1. The bottom of the drying tower is clogged with ash accumulation. The ash hopper at the bottom of the drying tower is a dead corner of hot flue gas. After normal operation, especially in winter, a lot of salt accumulates at the bottom of the ash hopper, which leads to agglomeration, and some even block the ash discharge port of the ash hopper at the bottom of the tower. , resulting in inability to discharge ash

3. Two-fluid atomizing spray guns and three-fluid atomizing spray guns consume a lot of air (the gas-liquid ratio is not less than 300:1), high energy consumption, and are easily affected by the pressure of the air source and water source, and are not easy to control. The ratio often deviates from the normal design range, resulting in large fluctuations in the atomization particle size, and the atomization cone shakes in a pulse-like manner in the tower, which is easy to cause dust on the wall, and the system has high resistance to operation, and even cannot operate normally.

4. The structure of the atomizer of rotary spray drying is complicated, and it needs transmission device and liquid distribution device, that is, atomization wheel.

In addition, another drying method is to spray the concentrated desulfurization wastewater directly into the high-temperature flue for drying, which greatly increases the risk of blockage and scaling of the flue

Images