CVD-1500 Vacuum Freeze Dryer (15㎡ / approx. 150kg/batch)

CVD-1500 is a vacuum freeze dryer with an effective drying area of 15㎡ and a loading capacity of about 150kg per batch. It follows a three-stage process of “pre-freezing — sublimation — desorption”: shelf temperature -55~+120°C, cold trap (water catcher) temperature -45~-65°C, ultimate vacuum ≤10Pa. Its throughput falls between the 10㎡ model (about 100kg/batch) and the 20㎡ model (about 200kg/batch), making it suitable for production lines that want to move up to the low teens of square meters without jumping directly to 20㎡. The complete set belongs to the vacuum freeze dryer series and consists of six parts: drying chamber, water catcher, heating system, vacuum system, refrigeration system and electrical control system.

Technical Parameters

The number of shelf layers, tray size, installed power and overall dimensions are determined by tray specifications and configuration, and are confirmed per order.

Chamber and Insulation

• The drying chamber is a sealed vessel that combines vacuum pumping and heating drying. The material completes sublimation drying inside the chamber. The chamber body is made of 304 stainless steel.
• The material is placed in stainless steel trays on the shelves, loaded at a ratio of 8~12 kg per square meter of tray area.
• Each shelf layer is equipped with a material temperature probe to monitor the material temperature throughout the process and control the sublimation interface so it does not cross the eutectic point.
• Vertical door-opening structure enables in-situ freeze-drying of the material: loading, freezing and drying are completed in the same chamber without transferring between chambers.
• The water catcher (cold trap) is located at the rear of the drying chamber. Condenser coils are wound inside the cylinder and connected to the refrigeration unit, specifically to condense the water vapor sublimated from the material.

Vacuum and Refrigeration System

• The vacuum system consists of a backing vacuum pump and a Roots pump. The Roots pump is a booster pump and cannot be started on its own: first start the backing pump to pull the chamber vacuum below 1kPa, then the electric contact vacuum gauge automatically engages the Roots pump at the preset value.
• The ultimate vacuum is ≤10Pa, providing a sufficiently low vapor pressure for direct sublimation of ice in the material.
• The refrigerant is R404A. Pre-freezing refrigeration and water catcher refrigeration share one refrigeration system; pre-freezing and water catching proceed simultaneously.
• The working temperature of the water catcher adsorption surface is -45~-65℃, which directly condenses the sublimated water vapor into ice and prevents water vapor from entering the vacuum pump.
• The refrigeration unit can be selected as low-temperature screw type or two-stage piston type as required; under contact heating conditions, the shelf temperature can be lowered to -35℃.

Heating and Water Catching

• Contact circulating medium heating is used: the circulating liquid (commonly thermal oil) is heated in the liquid tank, then pumped through pipes into the shelves, and returns for the heating cycle.
• Shelf temperature range is -55~+120℃; when silicone oil is used as the circulating medium, the upper limit of shelf temperature is +120℃.
• The shelf temperature curve can be preset; during the sublimation stage, the temperature rises automatically according to the curve, reducing manual monitoring.
• The water catcher and heating work simultaneously: while heat is supplied to the material to sublimate the ice, the water vapor is condensed on the -45~-65℃ adsorption surface.
• The defrosting method is hot water spray. After a batch is finished, spray defrosting removes the ice on the adsorption surface before the next batch.
• 15㎡ effective area and about 150kg/batch loading capacity leave margin at the 8~12 kg/㎡ loading ratio.

Control System and Safety Design

• The control system is centered on a PLC with a touch screen as the human-machine interface, and can control the entire machine manually or automatically.
• Real-time recording of multiple temperature data points during the freeze-drying process, which can be viewed as curves.
• The main unit has a USB interface; freeze-drying data can be uploaded to a computer for storage, viewing and printing.
• The shelf temperature curve can be preset to automate the sublimation process.
• Roots pump start/stop, vacuum level and heating temperature are controlled by instruments in linkage at preset values, reducing human error.

Application Scenarios

Installation Conditions

• Site: The drying chamber and refrigeration unit are placed on level, hardened ground, with access reserved for maintenance and discharge; the specific footprint depends on the overall dimensions, confirmed per order.
• Power supply: 380V / 50Hz / three-phase.
• Cooling: The refrigeration unit is water-cooled or air-cooled per order; water-cooled models require connection to circulating cooling water.
• Drainage: Hot water spray is used for defrosting, so drainage and a floor drain should be provided nearby.
• Environment: Keep ventilated, away from dust and corrosive gases; do not stack materials around the drying chamber.

Warranty and After-Sales

One-year warranty for the complete machine; proposal within 2 hours, on-site arrival within 24 hours, fault resolution within 72 hours; one free on-site visit per year; lifetime technical support. If you need model selection calculations based on your material, leave a message on the Contact Us page, and we will match the model according to material moisture content and target output.

FAQ

How much material can CVD-1500 hold per batch?

At a loading ratio of 8~12 kg per square meter of tray area, 15㎡ effective area holds about 150kg per batch, adjusted slightly according to material form and tray specifications.

How long does one freeze-drying batch take?

Based on the three stages of “pre-freezing — sublimation — desorption”: pre-freezing about 2~3 hours, sublimation drying about 10~12 hours, desorption drying about 2~7 hours, totaling about 14~20 hours, varying with material moisture content and slice thickness.

What temperature should the cold trap reach? What vacuum level?

The working temperature of the water catcher (cold trap) adsorption surface is -45~-65℃, and the ultimate vacuum is ≤10Pa. The two parameters work together to keep ice sublimating continuously at low temperature and low pressure.

How are the vacuum pumps configured?

A rotary vane pump serves as the backing pump and a Roots pump as the booster. The Roots pump cannot be started on its own; it is automatically engaged after the backing pump pulls the vacuum below 1kPa.

How to choose between CVD-1500, CVD-1000 and CVD-2000?

CVD-1000 is 10㎡, about 100kg/batch; CVD-2000 is 20㎡, about 200kg/batch; CVD-1500 is 15㎡, about 150kg/batch, right in between. Choose the closest tier according to daily throughput. You can try calculations by material and output in the Selection Assistant.