Mother liquor is a saturated solution that remains after the separation of precipitates or crystals during chemical precipitation or crystallization processes.

The traditional drying mother liquor mainly uses spray dryers. Under our repeated tests, there are many defects in this traditional process. Our company develops it with the concept of environmental protection

A complete set of new mother liquor drying system has been developed.

1、 Overview of mother liquor drying process

The mother liquor drying system consists of three parts: ① liquid evaporation ② separated liquid drying ③ cooling.

(1) Liquid evaporation

The evaporator is mainly composed of two parts: the heating chamber and the evaporation chamber. The heating chamber provides the heat required for evaporation to the liquid, promoting boiling and vaporization of the liquid; evaporateComplete separation of gas and liquid phases in the engine room.

(2) Separate liquid drying

The separated liquid (with a tax rate of 70%) is subjected to secondary drying using a single axis disc. Disc dryer as a new type of drying equipment for drying mother liquorCompared with spray dryer, the drying material is relatively good. Now it has become a mature drying process, and its market share is notAlways high. The main body of the disc dryer consists of a cylindrical outer shell and a set of centrally penetrating discs. The disk group is hollow, and the heat medium comes from hereIt flows through and indirectly transfers heat to the material through a disc. The material passes between the disc and the shell, receiving heat transferred by the disc and evaporating water,The water vapor formed by the evaporation of material moisture accumulates in the dome above the disc, is carried out of the dryer by a small amount of ventilation, and enters the condenser to remove the gasOr steam can be converted into liquid, quickly transferring the heat in the tube to the air near the tube. The working process of the condenser is a heat release processThe process, so the condenser temperature is relatively high. The wastewater flowing down from the condenser flows into the buffer tank for centralized collection and is handed over to the sewage treatment plantReason. The disc of the disc dryer has two functions: firstly, it provides sufficient heat exchange area for the material, and secondly, it rotates slowly to dry the discThe small thruster on the dryer pushes the material to flow in the designated direction and plays a stirring role. The disc dryer utilizes the double-sided heat transfer of each disc, which canTo provide a large heat exchange area in a small space, which makes the disc dryer compact in size. The rotation frequency of the disc is adjustable, with a speed of about 5r/minTherefore, the wear and tear is minimal. The disc surface is perpendicular to the shaft, so its rotation does not affect the flow of materials. The disc edge of the disc dryerThere are some small blades with a certain inclination angle, which not only help the material flow in a directional manner, but also play a role in stirring. The shell is stationary, itContaining materials and water vapor generated by material evaporation. There is a fixed scraper on the inner wall of the shell. The scraper is very long and extends into the gap between the discs to prevent large gapsThe block material is solidified on the disc. Similar to the blades on a disc, a fixed scraper also serves as a stirrer. Disc dryer and other indirect dryersCompared with other devices, the equipment has the advantages of large heat transfer area, good stirring effect, and better promotion of water evaporation and removal. It is a newly developed improved modelConnect the heating dryer. The disc dryer is mainly composed of a stator (shell), a rotor (turntable), and a driving device. The disc dryer is operated through a turntableThe function of the edge pushing/agitator is to evenly and slowly transport the material through the entire dryer, and it is dried by thermal contact with the turntable.

(3) Cooling

The moisture content of the discharged material after drying by the disc dryer is 35%~40%, and it is then sent to the cooling machine. Our company is equipped with the following two types of cooling machines (one or the other):

（1） Cooling blade dryer

Wedge shaped hollow blades are densely arranged on the hollow shaft, and the refrigerant flows through the blades through the hollow shaft, while the refrigerant flows into the shell jacket. The refrigerant passes through the rotary joint,Flowing through the hollow mixing shaft to ensure cooling effect. While cooling the blades and jacket with refrigerant, the upper part of the discharge port can be simultaneously dehumidifiedGreatly increase the drying strength of the equipment. The evaporated water is carried out of the dryer by the dehumidification fan, and the dust is recovered by the cyclone separator.

（2） Cooling Spiral

The cooling screw conveyor utilizes a double-layer U-shaped groove and the action of circulating water to force the material to undergo physical cooling during operation, resulting in a faster material running speedThe temperature should not be too fast, and it should be discharged quickly when the temperature is reached! The cooling screw conveyor includes a cylinder, a rotating shaft with a rotating plate, bearings, and a driving deviceThere is an external cooling water jacket outside the body, and the two ends of the shaft are empty tubes. The cavity of the spiral plate is connected to the empty tubes at both ends of the shaft, and the cooling water flows through the inlet empty tubesAfter the spiral plate cavity, it flows out through the outlet air pipe, forming an internal cooling water channel. The material is cooled evenly during transportation, and the cooling effect is good.