Production system and production process for continuously preparing anhydrous sodium sulfate in acid bath

Abstract

The invention discloses a production system and a production process for continuously preparing anhydrous sodium sulfate in acid bath. The production system comprises a multistage flash evaporation device, an evaporator and a rotary airflow dryer; the multistage flash evaporation device is communicated with the evaporator through a preheater; the evaporator is communicated with a ripening tank; the ripening tank is communicated with a first-stage thickener; the first-stage thickener is communicated with a first-stage centrifugal machine; the first-stage centrifugal machine is communicated witha neutralizing tank; the neutralizing tank is communicated with a second-stage thickener; the second-stage thickener is communicated with the rotary airflow dryer; and by the production method of theproduction system, production of the anhydrous sodium sulfate is completed through multiple steps. The production system provided by the invention produces the anhydrous sodium sulfate by cooperatingthe multistage flash evaporation device and the evaporator with the rotary airflow dryer, so that the process flow route is shortened and the energy consumption is reduced; and meanwhile, sodium sulfate crystal particles obtained through production have large size, the crystal particles are uniform and full, and the apparent quality of the anhydrous sodium sulfate is high.

Description

technical field [0001] The invention relates to a production system and a production process, in particular to a production system and a production process for continuously producing sodium sulfate in an acid bath. Background technique [0002] The raw material of viscose fiber is cellulose fiber, which generally comes from wood pulp or cotton pulp; cellulose reacts with sulfuric acid in the spinning bath, so that it can be regenerated and restored to a fiber state; since the spinning bath uses sulfuric acid as the main medium, the industry It is generally called "acid bath" in China. [0003] When the fiber reacts with the acid bath, the sulfuric acid reacts with the sodium hydroxide to give water and sodium sulfate. To maintain a constant acid bath composition, it is necessary to remove water and remove sodium sulfate, the whole process is called acid bath regeneration. Sodium sulfate is also called sodium sulfate, and recovery of sodium sulfate from the acid bath can no...

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Problems solved by technology

[0005] The advantage of the above-mentioned first process route is that the obtained sodium sulfate particles are uniform, the process is mature, the degree of automation is high, and the process operation and process control are convenient; Sodium sulfate with 1 crystal water molecule, Glauber's salt is easy to deliquescence and inconvenient to store, and there are few fields of direct application. Generally, it needs to continue to process to remove the crystal water in Glauber's salt molecule to obtain Yuanming powder. This process requires a large number of equipment configurations. , large investment in equipment

[0006] The advantage of the above-mentioned second process route is that the process flow is short, and the disadvantage is that the process is unstable. The step-by-step cooling curve of multi-stage flash evaporation is just opposite to the solubility curve of sodium sulfate, resulting in uneven sodium sulfate particles and most of the crystals The size is small, the process can only run intermittently, the degree of automation is low, the labor intensity of the operators is high, the fine crystals are not easy to achieve solid-liquid separation, and it is easy to block the pipeline and separation equipment; the workload of operating and maintaining these equipment is large, and the The dismantling of the field resulted in severe acid leakage, poor working environment, and intermittent operation seriously affected the normal service life of dynamic and static equipment.

[0007] Both of the above two process routes are separated by centrifuge first, and then ordinary airflow dryer or fluidized bed dryer is used. Not only the process is long, the number of equipment is large, the height of the plant is high, the floor area is large, and the energy consumption is high. , the moisture content is not easy to control, resulting in frequent agglomeration or even blockage of Yuanming powder

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