Industrial Centrifugal-bladed Wiped Film Evaporator

Wiped film evaporators are widely used in industry. Wuxi Hongdinghua Chemical Equipment Co., Ltd. is often required to design such equipment that can achieve effects such as evaporation, Industrial Centrifugal-bladed Wiped Film Evaporator, concentration, degassing, decolorization, deodorization, drying, and reaction of the treated materials. At the same time, the materials have special physical or chemical properties, such as thermal sensitivity, viscosity, crystallization, coking, scaling, and other characteristics, combined with concentration requirements, The wiped film evaporator is a device that meets these constraint condition and has been widely used and achieved good treatment results.

Working principle of Industrial Centrifugal-bladed Wiped Film Evaporator

Centrifugal Wiped film evaporator is an efficient evaporator that forcibly forms a film through a rotating blades and flows at high speed. It has high heat transfer efficiency, short retention time, and can perform falling film evaporation under vacuum conditions.

The centrifugal wiped film evaporator consists of one or more cylinders with jacket heating and a rotating device inside the cylinder. The blades continuously wipe the material entering the centrifugal wiped film evaporator forming an even thickness film on the heating surface and moves downwards; During this process, the low boiling point components are evaporated, and the residue is discharged from the bottom of the centrifugal wiped film evaporator.

5. The inner wall of the evaporation section cylinder has undergone precision boring and polishing treatment, making the surface less prone to coking and scaling.

Characteristics and application of centrifugal wiped film evaporator

The structural characteristics of centrifugal wiped film evaporator are as follows:

1. Motor and reducer: Drive device for rotor rotation.

2. Vapor liquid separation chamber: materials enter the centrifugal wiped film evaporator tangentially through the inlet at the lower part of the vapor liquid separation chamber, and are continuously and evenly distributed on the wall of the evaporation chamber of the centrifugal wiped film evaporator through the liquid distributor at the lower part of the vapor liquid separation cylinder chamber. The secondary steam evaporated from the evaporation chamber rises to the separation chamber at the upper part of the centrifugal wiped film evaporator, and is separated from the liquid drops or foam that may be carried by the secondary steam through the gas-liquid separator installed in the vapor liquid separation chamber, The secondary steam is exhausted out of the centrifugal wiped film evaporator from the outlet at the upper end.

3. Liquid distributor: Installed on the rotor, the material enters the centrifugal wiped film evaporator from the tangential direction, and is continuously and evenly distributed in a film shape on the evaporation surface through the rotating liquid distributor.

4. Gas liquid separator: the gas liquid separator is installed upper part of the separation chamber, which traps the liquid drops or foam that may be carried by the rising secondary steam and makes it fall back to the evaporation surface.

5. Evaporation chamber: The inner wall of the evaporation chamber is the evaporation surface where it exchanges heat with the materials forced to form a film by the rotating blades and the heating medium inside the jacket.

6. Rotor: The rotor is composed of a rotating shaft and a rotating frame. The rotor is driven by an electric motor and a reducer, and drives the blades to move in a circular motion. Its strength, geometric dimensions, and stability must be guaranteed.

7.Blade: The blade moves in a circular motion, continuously wiping the liquid material onto the evaporation surface to form a thin film, in order to achieve the effect of thin film evaporation.

Sliding blade for centrifugal wiped film evaporator

Sliding blade is the most basic and common form of blade. The blade is installed in the four blade guide grooves of the rotor, and due to the centrifugal force of the rotor rotation, it is moving radially towards the inner wall of the evaporation cylinder, while also performing circular motion with the rotor. This wiping of the blade makes the material present a film turbulent state on the evaporation wall surface, greatly improving the heat transfer coefficient. At the same time, this continuous wiping can effectively inhibit the overheating, dry wall and scaling of the raw material. Usually, the sliding blade is made of polytetrafluoroethylene , which is suitable for working temperatures below 150 ℃; When the evaporation temperature is above 150 ℃, carbon fiber material needs to be used. The bottom surface of the blade is machined with a guide groove at a certain angle.

8. The bottom head is equipped with high-temperature resistant self-lubricating bearings, the bottom bearing should be convenient for material discharge and maintenance and repairing.

The operating performance characteristics of centrifugal wiped film evaporator are as follows:

1. Minimal pressure loss

In a centrifugal wiped film evaporator, the material "flow" and the secondary steam "flow" are in two independent "channels":

The material falls along the wall of the evaporation chamber and descends; The secondary steam leaves the evaporator almost unobstructed from the central of the cylinder, so the pressure loss is minimal.

2. Capable of operating under true vacuum conditions

Due to the extremely small resistance of the secondary steam from the evaporation surface to the condenser, it can maintain a high vacuum degree on the evaporation surface of the entire evaporation chamber wall. The Vacuum degree improvement effectively reduces the boiling point of the processed material.

3. High heat transfer coefficient, high evaporation intensity

The decrease in the boiling point of the material increases the temperature difference with the hot medium; The turbulent liquid film reduces thermal resistance; Similarly, the coking and scaling of materials on the wall are inhibited, and the partial heat transfer coefficient of the evaporation cylinder wall is also improved; Therefore, its evaporation intensity is very high.

4. Low-temperature evaporation

Due to the ability to maintain a high vacuum inside the evaporation cylinder, the boiling point of the treated material is greatly reduced, making it particularly suitable for low-temperature evaporation of heat sensitive materials.

5. Short flow time

The flow time of the material in the evaporator is very short, effectively preventing the decomposition, aggregation, or deterioration of the product during the evaporation process.

6. Low grade steam can be utilized

Steam is a commonly used thermal medium. By reducing the boiling point of materials and ensuring the same temperature difference, the temperature of the heating medium can be reduced. Utilizing low-grade steam is beneficial for the utilization of energy. Especially suitable as a final effect evaporator for multi effect evaporation.

7. Strong adaptability and easy operation

The structure of centrifugal wiped film evaporator is specialized. Centrifugal wiped film evaporator can be used to handle high viscosity, particle content, thermal sensitivity that are difficult to handle by conventional evaporators.

A material that is prone to crystallization. The centrifugal wiped film evaporator has high operating flexibility, stable operating conditions, low maintenance workload, and convenient maintenance.

The centrifugal wiped evaporator manufactured by HDH is widely recognized and accepted, and the centrifugal wiped evaporator designed and manufactured by HDH can be suitable for various needs:

1. Distillation 

2. Concentration 

3. Degassing 

4. Bleaching 

5. Deodorization 

6. Drying 

7. Reaction 

8. Crystallization (exerting the cooling function of the evaporator) 

9. Recycling (especially solvents or other useful substances used in the pharmaceutical industry) 

10. Purification (such as seawater desalination, separation of pure solution substances)

Details of centrifugal wiped film evaporator

Centrifugal wiped film evaporator is a type of wiped film evaporator. The reason why centrifugal wiped film evaporator is called "centrifugal" wiped film evaporator is because of the structural characteristics of the blade of centrifugal wiped film evaporator:

Each movable blade of the centrifugal wiped film evaporator is installed in four "U" shaped blade guide grooves with openings facing outward, and this type of blade can slide back and forth in the blade guide groove under the centrifugal force generated by rotation. Depending on the rotational speed and the movement resistance generated by the material, the sliding distance of the sliding blade varies. The sliding blade is a common form of blades, which is a rectangular column with a groove (liquid guide groove) at a certain angle on the end surface of the blade. Changing the angle of the liquid guide groove can adjust the liquid film retention time.

The blade of the centrifugal wiped film evaporator with groove faces outward, and the blade is thrown radially along the guide groove to the heating surface under the action of centrifugal force and moves circularly with the rotor. This continuous wiping makes the materials form turbulent liquid film on the evaporation surface, which improves the heat transfer coefficient. Moreover, because this continuous circumferential movement can effectively inhibit the phenomena of overheating, dry wall and scaling of raw materials, it ensures the uniform distribution of liquid film Thoroughly mix and perform good heat exchange.

Usually, the materials used for the blades are PTFE (polytetrafluoroethylene), synthetic graphite, or similar materials. It is suitable for working temperatures below 150 ℃; When the evaporation temperature is above 150 ℃, carbon fiber material needs to be used.

Wuxi Hongdinghua Chemical Equipment Co., Ltd. needs to comprehensively consider the following factors when assisting customers in selecting centrifugal scraper film evaporators:

1. Production capacity and operating parameters:

Including processing capacity:______

Feed concentration:______

Discharge concentration:______

Feed temperature:______

Discharge temperature:______

Operation duration:______

2. Material characteristics:

Material thermal sensitivity:_______

Material viscosity:_______

Material flowability at operating temperature:_______

Material foaming property:________

Solid content of material:_________

Material crystallization tendency:______

Material coking tendency:______

Is the material prone to aggregation______

3. Operating medium (heat source):

Water vapor: ______(pressure)

Cooling water temperature: ______℃

Cleaning solution (solvent):______

4. Material selection for manufacturing:

Surface polishing requirements:______

5. Site conditions:  

Space limitations:______

Climate conditions: indoor and outdoor 

The connection between energy and products: ________

Work platform, etc.

6. Regulations: 

Safety requirements: _______

Noise indicators: ______

Environmental protection indicators: _______

Blade type of Centrifugal wiped film evaporator

Wiped film evaporator ready for test running