1、 Product overview and use:
DZLG series spiral vacuum dryer is a multi-functional fully closed vertical vacuum drying equipment integrating drying, crushing and powder mixing. Its drying efficiency is 3-5 times that of the "double cone rotary vacuum dryer" of the same specification. It is mainly used for powder drying in pharmaceutical, chemical, pesticide, food and other industries. It can realize closed continuous operation in the whole process and is the preferred drying equipment in the above industries.

2、 Equipment process characteristics:
The drying and mixing of powder is an important link in the production of API, so the selected drying and mixing equipment is the guarantee of the quality of its final product, and also the key to determine the production and operation costs. The "DZLG series single-cone spiral vacuum dryer" newly developed by our company leads the drying technology in the domestic chemical and pharmaceutical industry with its special structure and absolute advantages.

（1） The selection of dryer should meet the specific requirements and characteristics of various products and processes. The main contents are as follows:

1. Most of the raw materials processed in the production are heat sensitive, so the materials tend to agglomerate during the drying process, which requires shortening the drying time and improving the drying efficiency.
2. In the production of materials, the purity of the circulating gas used in the drying process will have a great impact on the quality of materials. The equipment adopts unique gas supply technology to reduce the impact of gas on the drying process. From the perspective of operation economy, it is hoped that all process pipelines can be fixed and installed, so as to save the rotary space required by similar double-cone dryers.
3. In order to keep the whole process continuous and reduce the leakage loss of materials at the same time, the solid discharge flow of the dryer is controllable. This can reduce the workload of manual handling in the cleaning area and prevent the material from being washed out.

（2） Structure and characteristics of DZLG series single-cone vacuum spiral belt dryer:

1. The working process of DZLG series single-cone vacuum spiral belt dryer is batch operation. After the wet material enters the silo, the heat supply area is 140% of the whole container area through the jacket on the cylinder wall and the internal heat supply of the propeller, and the material is heated and dried. Select the corresponding conical drying mixer model (working volume) to achieve the desired drying effect. The mixing dryer with the top-drive structure has the characteristics of drying and mixing capacity, as well as ample space, which is more convenient for users to carry out maintenance.

2. Stable operation and crystal protection:
The DZLG series spiral vacuum drying does not use any auxiliary tools in the drying and mixing process, but only uses the revolution and rotation of the conical mixing screw, which makes the material not only from the lifting of the mixing screw, but also continuously sheared and dispersed, ensuring that all materials in the silo can be fully moved, and can make the material not be squeezed by any external force except from the lifting of the screw, It avoids the ineffective friction between the powder and the equipment as well as between the powder grains, and the ineffective friction is often the main factor that causes the material crystal damage. This is also the fundamental reason why LZG series spiral vacuum drying can keep the crystal shape of materials intact during operation.

3. Top drive eliminates the possibility of product pollution caused by shaft seal:
The equipment can avoid the following disadvantages by using top drive and relative bottom drive:
The mixing paddle must be disassembled with special equipment for cleaning and maintenance
It is difficult to seal the agitator shaft seal without pollution and lack of quality assurance

4. Low operating energy consumption cost and high mixing efficiency:
DZLG series single-cone vacuum spiral belt drying is driven by a motor, with a unique design. The screw driven by the motor is used for lifting materials, and there is no energy consumption for blanking alone. It is particularly worth noting that in the process of mixing and drying, the traditional mixing and drying equipment provides a belt agitator. Its working principle is that when mixing, the moving material is like a whole, and a large amount of energy consumption is used for the circular movement of the whole material, so the drying efficiency provided by this mixing is low. The LZG series spiral vacuum drying provides a conical spiral stirring. The whole stirring paddle moves around the axis of the conical silo to ensure that the materials at different parts of the whole container can be stirred. With the spiral stirring, the materials at the bottom of the silo will be gradually lifted to the upper part of the container, and then fall naturally, and so on. This mixing mode makes the materials in the container fully and evenly mixed, eliminates the possibility of material agglomeration in the drying process, and greatly improves the mixing and drying efficiency of materials. Moreover, it has the advantages of wide range of treatment capacity and low energy consumption per unit mass.

5. Simple operation and convenient maintenance:
DZLG series single-cone vacuum spiral belt drying machine has simple and effective structure, which is easy for operators to understand. The simple button control makes the operation process very simple. Some maintenance work can be completed smoothly and quickly even without professional personnel. The set manhole can easily adjust and maintain the moving screw without complicated disassembly. The wearing parts of the equipment are very few. The drive unit such as bearing box is set on the top of the silo. It is easy for the user to remove the whole unit during maintenance, and the drive unit at the top has sufficient space.

3、 Equipment structure features and functions:
1. The equipment is internally heated by jacket and screw belt, which increases the overall heating area of the equipment by about 40%.
2. The single-screw belt agitator used in the equipment is a patented product of our company, which can achieve the effect of bottom-up circulation mixing and obtain forced heat transfer performance. When the material filling rate is between 40% and 100%, 100% heating utilization can be obtained. Suitable for mixing and drying of fine materials.
3. Fully sealed system, no foreign matter pollution, high cleanliness, especially suitable for mixing and drying of pharmaceutical intermediates and APIs, and also suitable for mixing and drying of sterile APIs.
4. The gap between the single-screw stirrer and the vessel wall is small, which can effectively prevent the material from sticking to the surface of the vessel wall.
5. The conical cylinder structure with small angle is adopted to make the unloading speed fast, clean and free of material accumulation.

6. Equipped with recoil device:
During material drying, dust raised due to material drying is adsorbed on the vacuum collector, blocking the vacuum channel, and the blockage of the gas channel directly leads to the extension of drying time. The lower the temperature and the shorter the drying time of the material in the drying process, the smaller the impact on the material quality. For the above reasons, the single-cone dryer developed by our company is equipped with a blowback device on the vacuum collector, which can keep the vacuum channel unblocked during the drying process of materials, thus ensuring the drying time and drying quality.
7. The bottom discharge valve is a plate valve with reliable sealing, which is conducive to vacuum drying.
8. The equipment has compact structure, smooth operation, good sealing, no lubrication leakage, simple operation and long service life.

4、 Working principle:
This machine is equipped with a heating jacket from the heating cone. The heat source is hot water, heat transfer oil or low pressure steam, so as to maintain a certain temperature on the inner wall of the cone. The variable-frequency speed-regulating motor drives the single spiral belt agitator to rotate through the parallel helical gear reducer. The material with animals rotates along the conical drum and is lifted from bottom to top. After reaching the high point, the material automatically flows to the center of the vortex and returns to the bottom of the conical drum under the action of gravity and inertia. The whole process causes the material to be forced heated in the conical drum, with relative convection and mixing. The heat diffuses in the material, making the material move in an all-round irregular reciprocating motion, Complete high-frequency heat transfer and exchange of materials with single spiral belt and cylinder wall surface, and achieve the effect of heating and drying in a short time. Thus, the water inside the material is continuously evaporated. Under the action of the vacuum pump, the water vapor is led out by the vacuum pump. If it is necessary to recover the liquid, it can be recovered by adding a condenser and a recovery liquid storage tank. After drying, open the lower discharge valve to discharge.

5、 Main structure:
This machine is composed of motor, reducer, frame, mechanical seal, metal sintering mesh filter, hollow double-screw belt mixer, conical cylinder with jacket heating, discharge valve and other components.
1. Transmission and sealing part:
It is composed of motor, reducer, frame and mechanical seal.
1.1 Motor: variable frequency speed regulation motor is adopted, and the speed can be adjusted as required during operation.
1.2 Reducer: SLFA series helical gear reducer has stable and reliable operation, low noise and long service life.
1.3 Rack: self-designed, with high manufacturing accuracy. There are two pairs of roller bearings inside, which can adjust the height and radial swing of the mixer.
1.4 Mechanical seal: single-end sanitary type with material receiving and flushing chamber, with good sealing.


2. Mixer:
The hollow mixing shaft is connected with the hollow spiral belt with support rods, and the upper and lower ends connected with the hollow spiral belt are connected with hollow support rods to form a circuit that can pass through the heat medium. In order to ensure that the material does not adhere to the cylinder wall, the gap between the spiral belt and the cylinder wall is very small.

3. Tank body:
This part is composed of upper head, conical cylinder, vacuum filter, discharge valve, etc.
3.1 Upper head: bearing transmission part and agitator; The nozzle on the inner surface is in arc transition. All materials in contact with materials are 316L. The process pipe orifice is as follows: DN400 sanitary manhole, pressure gauge, explosion-proof lamp, mirror port, feed port, cleaning port, vacuum port, etc.
3.2 Lower cone with heating jacket: the inner surface is smooth and free of dead angle, which can fully dry the material. When discharging, use the rotation of the mixer to make the discharging fast and clean.
3.3 Filter: metal sintered screen is adopted, with high filtering accuracy and large filtering area. In addition, an exhaust port is set at the vacuum outlet to carry out compressed air blowback regeneration on the filter during exhaust.
3.4 Discharging valve: it adopts a plate valve, which has fast discharging speed, convenient operation, and no residue or dead angle.