Overview of Single Cone Vacuum Drying Machine Equipment
The vacuum single cone dryer developed by Baide Drying is an efficient and multifunctional fully enclosed vertical vacuum drying equipment that integrates vacuum distillation, crushing, powder mixing, and drying. The drying efficiency of the fully enclosed vertical vacuum ribbon dryer is 3-5 times that of the same specification double cone rotary vacuum dryer and vacuum box dryer. The vacuum single cone dryer combined with special drying technology can adapt to the drying of materials with high viscosity, poor thermal penetration, easy rolling and clumping.

The single cone vacuum dryer is equipped with a heating jacket on the heating cone, and the heat source is hot water, thermal 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 screw belt agitator to rotate through a parallel helical gear reducer, and the animal material is rotated along the conical cylinder and lifted from bottom to top. After the material reaches the high point, it automatically flows towards the center of the vortex and returns to the bottom of the conical cylinder by gravity and inertia. The entire process forces the material to be heated inside the conical cylinder, with relative convection and mixing. The heat diffuses among the materials, causing them to undergo irregular reciprocating motion in all directions, completing high-frequency heat transfer exchange between the material and the single screw belt and cylinder wall surface, and achieving heating and drying effect in a short time. Thus, the internal moisture of the material continuously evaporates. Under the action of the vacuum pump, the water vapor is drawn out by the vacuum pump. If it is necessary to recover the liquid, a condenser or a recovery liquid storage tank can be used for recovery. After drying, open the discharge valve at the bottom to discharge the material.

Process flow diagram of single cone vacuum dryer

Main structure of single cone vacuum dryer
This machine consists of a motor, reducer, frame, mechanical seal, metal sintered mesh filter, hollow double screw belt agitator, conical cylinder with jacket heating, and discharge valve.
1. Transmission and sealing parts: composed of electric motor, reducer, frame, and mechanical seal.
① Electric motor: adopts variable frequency speed regulation motor, and the speed can be adjusted as needed during operation.
② Reducer: SLFA series helical gear reducer, runs smoothly and reliably, has low noise, and has a long service life.
③ Rack: self-designed and manufactured with high precision. Equipped with two sets of roller bearings, the mixer height and radial swing can be adjusted.
④ Mechanical seal: single end sanitary type with material receiving and flushing chamber, good sealing performance.
2. Blender: The hollow mixing shaft is connected to the hollow screw belt with support rods, and the upper and lower ends connected to the hollow screw belt are formed 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 screw belt and the cylinder wall is very small.
3. Tank body: This part consists of an upper head, a conical cylinder, a vacuum filter, a discharge valve, etc.
① Upper head: carries the transmission part and agitator; The inner surface connecting ports have rounded transitions. All materials in contact with the material are 316L. The process pipe openings are as follows: DN400 sanitary manhole, pressure gauge, explosion-proof sight light, sight glass port, feeding port, cleaning port, vacuum port, etc.
② Lower cone with heating jacket: The inner surface is smooth and free of dead corners, which can fully dry the material. When discharging, use the rotation of the mixer to quickly and cleanly discharge the material.
③ Filter: Made of metal sintered mesh, with high filtration accuracy and large filtration area. And an exhaust port is set up at the vacuum outlet to perform compressed air blowback regeneration on the filter during exhaust.

Structural diagram of internal heating spiral belt single cone vacuum dryer equipment

Structural diagram of single cone spiral high-efficiency mixing dryer equipment

Process characteristics of vacuum single cone dryer
The drying and mixing of powders are important steps in the production of active pharmaceutical ingredients, so the selection of drying and mixing equipment is the guarantee of the final product quality and also the key to determining the production and operating costs. The vacuum single cone dryer newly developed by Baide Drying improves the drying technology of the domestic chemical and pharmaceutical industry with its unique structure and advantages.
1. The selection of dryers needs to meet the specific requirements and characteristics of various products and processes. The content mainly includes the following aspects:
① Most of the raw materials processed in production are thermally sensitive, so material clumping often occurs during the drying process. This requires shortening the drying time as much as possible to improve drying efficiency.
② In material production, the purity of the circulating gas used in the drying process can have a significant impact on the quality of the material. This device adopts a unique gas supply technology to minimize the impact of gas on the drying process. From the perspective of operational economy, it is hoped that all process pipelines can be fixedly installed to save the required rotary space for double cone dryers.
③ In order to ensure the continuity of the entire process and reduce material leakage losses, the solid discharge flow rate of the dryer is controllable. This can reduce the workload of manual loading and unloading in the cleaning area and prevent material from being washed out.
2. Structure and characteristics of vacuum single cone dryer
① The working process of the vacuum single cone dryer is an intermittent batch operation. After the wet material enters the silo, it is heated by the jacket on the cylinder wall and the inside of the propeller, so that the heating area reaches 140% of the entire container area, and the material is heated and dried. And select the corresponding cone type drying mixer model (working volume) to achieve the desired drying effect. The hybrid dryer with an upward drive structure has the characteristics of efficient drying and mixing capacity, ample space, and easier maintenance for users.
② Smooth operation, protecting crystal form
The vacuum single cone dryer does not use any auxiliary tools during the drying and mixing process, but only utilizes the stirring of the heating screw inside the cone. This ensures that the material is continuously sheared and dispersed by the lifting of the stirring screw, ensuring that all materials in the silo can move fully and that the material is not subjected to any external force except for the lifting of the screw slurry. This avoids ineffective friction between the powder and the equipment, as well as between the powder grains, which is often the main factor leading to the destruction of the material crystal form. This is also the fundamental reason why the vacuum single cone dryer can maintain the integrity of the material crystal shape during the operation process.
③ Top drive eliminates the possibility of contamination caused by shaft seals to the product
By using top drive instead of bottom drive, this device can avoid the following drawbacks: the mixing blade must be disassembled using specialized equipment for cleaning and maintenance, and the sealing of the mixing blade shaft is difficult to achieve true sealing, lacking quality assurance.
④ Low operating energy consumption cost and high mixing efficiency
Driven by a motor, the design is unique. The spiral driven by the motor is used to lift materials, without the energy consumption for unloading alone. It is worth noting that in the process of mixing and drying, traditional mixing and drying equipment provides a belt type stirring blade. Its working principle is that during the stirring motion, the moving material acts as a whole, and a large amount of energy is used for the circular motion of the entire material. Therefore, the drying efficiency provided by this stirring is low. The vacuum single cone dryer provides a conical internal heating spiral belt stirring, and the entire stirring blade moves in a circular motion around the axis of the conical silo, ensuring that materials in different parts of the container can be stirred. As the spiral belt stirring progresses, the materials at the bottom of the silo are gradually lifted to the top of the container, and then naturally fall down, and so on. This mixing mode ensures that the materials inside the container are thoroughly and uniformly mixed, eliminating the possibility of material clumping during the drying process and greatly improving the mixing and drying efficiency of the materials. And it has the advantages of a wide range of processing capacity and low energy consumption per unit mass.
⑤ Easy to operate and maintain
The mechanical structure of the vacuum single cone dryer is simple and effective, easy for operators to understand, and the simple button control makes the operation process very simple. Some maintenance work can be completed smoothly and quickly even without professional personnel, and the set manhole can easily adjust and maintain the moving screw without complex disassembly. The device has very few vulnerable parts, and the drive unit such as the bearing box is located at the top of the silo. Users can easily remove the entire unit during maintenance, and the space for the top drive unit is also relatively spacious.
3. Comparison with the advantages of conventional vacuum dryers - taking a dryer with an equivalent volume of 2000L as an example

Choosing the correct rotor for a vacuum single cone dryer
One of the most important components in the design of a vacuum dryer is its agitator. To choose the right mixer with the correct characteristics, it is necessary to understand the properties of the feed and the desired results of the vacuum drying process.
1. Screw mixer
The screw mixer is a well validated design suitable for drying powders, filter cakes, pastes, and slurries under atmospheric or vacuum conditions. It is suitable for almost all products, even sticky products. Due to its excellent performance in conveying products along the container wall, it ensures efficient drying cycles and can be applied to dryers with a drying capacity of over 20000 liters.
2. Paddle mixer
When the viscosity of the product is low, a paddle stirrer can be used to achieve optimal temperature control and product transportation between the rotor tip and the container wall. When needed, it can be used to thoroughly mix the product after the drying cycle.
3. Belt mixer
For products with low initial moisture content and good flowability, a belt mixer is a better alternative than a screw mixer. It can mix larger quantities of products at once, achieving better heat transfer and reducing drying time.

Technical parameters of vacuum single cone dryer