Rotary Vacuum Paddle Dryer

Working Principle and Applications: 

Working principle: PZG Rotary Vacuum Paddle Dryer is horizontal, mechanically agitated vacuum dryer, which gives low temperature drying, mixing and breaking effects simultaneously. The apply of vacuum is to lower the boiling point of water or solvents contained in wet material to be dried. 

RVPD consists of a jacketed cylindrical vessel and a hollow rotor fitted with straight paddles or double-walled discs to considerablly increase heating surface. Heating medium, such as steam, hot water or hot thermal oil, is forced to circulate both inside the jacket and hollow rotor to form heating surface. 

Wet material is gravity fed into the drying chamber via the infeed port with screw feeder, then vacuum and heat are applied to reach the evaporation point of water or solvents contained in wet material. Meanwhile, the hollow rotor rotates in different directions to completely mix, move and break the wet material for fast and uniform heat transfer. Moisture evaporates rapidly and is extracted as vapor by the vacuum pump. Tubular condenser is installed to recover the evaporated moisture. The drying process can be batch or continuous operation. 

Applications:  PZG Rotary Vacuum Paddle Dryer is ideally suited for low temperature drying of wet powders, filter cakes, sticky pastes or slurry materials in various industries with the following special features: 

1) Heat sensitive and/or oxygen sensitive 

2) Contained solvents and need to be recovered 

3) Hazardous and/or smelly wet materials (has to contain the release of pollutive substances) 

Technical Features: 

• Low-temperature drying: The vacuum of the drying system can reach as high as 4000 Pa, under which the water boiling point is only about 45-50 ℃. High vacuum makes low-temperature drying feasible and high efficent. Vacuum drying is ideally suited for heat sensitive and/or oxygen sensitive wet materials. 
• Low-energy consumption: Due to lower evaporation point under vacuum, the required sensible heat is reduced and the wet material to be dried does not have to be heated as much as in conventional thermal drying. And the heat loss caused by heat radiation and offgas is very little. 
• Almost zero-emission: The drying process is carried out in a completely air-tight system and the evaporated moisture is trapped/recovered by the tubular condenser. The whole drying process is almost zero-emission. 
• Fast and uniform drying: The specially designed agitator paddles welded on the disc periphery and the scraper bars installed between the discs can completely mix, move and crush the wet material  for uniform heating. 
• Batch or continuous operation: The drying process can be batch or continuous to cater to different working conditions. 

Typical Models

Note: Our PZG Rotary Vacuum Paddle Dryer is available in many sizes and configurations. The above models with typical design are indicative only. 

FAQ: 

Q: What information is needed in order to get a quote? 

A: Our Rotary Vacuum Paddle Dryer is customized according to specific wet material and drying capacity ( normally 100 kg to 3 tons/h). The following information is needed to work out a detailed quote:

1) Detailed information of wet material to be dried: 

• Wet material name, main components, bulk density etc;
• Wet material status (wet powder, filter cake, paste or slurry etc.)
• Specifc properties (corrosive, toxic, flammable, smelly etc.) 
• Moisture type (water or solvents) 

2) Initial moisture content; target moisture content in dried product; 

3) Required drying capacity in kg/h; 

4) Heating medium (Steam, hot water or hot thermal oil) 

5) Power supply type: 220V/380V/415V/440V, 50/60Hz, three phase 

Q: What is your normal lead time? 

A: All our dryers are customized. The normal lead time is 50-60 days after receiving the advance payment.

Q: How the dryer is delivered? 

A: Rotary Vacuum Paddle Dryer is big indutrial machine and the gross weight ranges from 3 tons to 50 tons. When the heating surface is less than 60 M2, the dryer body can be shipped by 40 feet HQ container; 60-100 M2 should be shipped by 40 feet OT container; more than 100 M2, the dryer body has to be dismantled for shipping. 

Q: What kind of after-sale service can you provide? 

A: 1)  All our machines are fully tested before shipping. Detailed operation manual, which includes photos, installation & operation videos, layout drawings, electric drawings etc. is delivered with the machine. So the end-user can easily install and operate the machine. 

2) In response to cutomer's invitation, technicians can be sent to the end-user's workshop for installation, commissioning and training. 

3) Provide life-long technical consultation and favorable spare parts.