get inspired with InVerTec

Microwave & plasma technology

Microwave technologies and plasma processing are further core competencies of InVerTec.

Heating and drying procedures are classical applications for microwaves1. At InVerTec, these technologies are combined with our know-how from other areas, such as fluidized-bed and CVD processes, with the intention of establishing new products and procedures.

For a variety of applications, the use of microwave technology can lead to improved energy efficiency in comparison to conventional heating processes. Microwave heating is based on the dielectric heating effect2 and can thus take advantage of specific material properties. Often, more direct heating of reactant agents or drying goods is possible, without undesired side effects such as heating of the reactor wall itself. In most cases, this leads to a significant increase in energy efficiency.

Generally, whenever the heat input or temperature control of a process is problematic, the use of microwaves provides major advantages, particularly when one material needs to be selectively heated while another is required to stay cold.

Furthermore, microwave processing makes it possible to attain process parameters which could not be achieved by conventional methods. Microwave-assisted plasma3 treatments cover a broad range of applications. The main applications are surface coating, such as plasma coating, plasma etching, and plasma sterilization processes.

Applications for microwaves in process engineering:

  • Atmospheric plasma torch
  • Plasma fluidized-bed reactor
  • Microwave freeze-drying
  • Microwave drying
  • Pressurized reactor for fluid flow heating at 30 bar
  • Microwave tunnel kiln for homogeneous surface heating and activation

1 Microwaves:

Microwaves are high-frequency electromagnetic waves that are usually used for thermal processing. For these applications, a frequency of 2.45 GHz is common.

2 Dielectric heating effect:

Heat generation in poorly conductive or non-conductive materials, caused by a high-frequency alternating field, is called dielectric heating. Materials with a non-symmetric molecular structure form an electric dipole and begin to oscillate in the alternating field. As a result, electric engergy is converted into heat. Materials with a symmetrical structure cannot be heated because of the missing electric dipole.

3 Plasma:

The state of plasma describes a condition of a gas whose components are partially or completely ionized.

Mikrowellen Gefriertrockner
Mikrowellen Gefriertrockner

Microwave Freeze Dryer

Turnkey installation:

  • Customer designed microwave applicator
  • High quality microwave power supply
  • Safety equipment meets highest standards
  • Remote condenser
  • Vacuum pump

Applications of microwave-assisted freeze drying:

  • Food
  • Pharmaceuticals
  • Ceramic green bodies
  • Nano materials

Microwave power supply :
Switch mode power supply and separate head

Frequency:
2.45 GHz

Microwave head:
Water-cooled magnetron with isolator, N-BNC detector

Output power:
2kW, 3kW; Adjustable from 0 -100% in CW and pulsating modes

Applicator:
Vacuum vessel 640mm x 700 mm

Control panel:
Lab-View© based measurement of all process parameters; MW-power control by pressure measurement

Options:
Temperature measurement by fiber optics; Plasma control sensor; Auto-tuning system; Rotating sample holder

Microwave Plasma Torch

Mini-plant installation:

  • Plasma applicator
  • High-quality microwave power supply
  • Safety equipment meets highest standards
  • Particle collection system
  • Precursor-/Particle dosing system

Applications of microwave plasma torch processes:

  • Synthesis of nano powders
  • Coating of particles
  • Particle surface treatment / etching / cleaning
  • Suspension plasma spraying

Microwave power supply:
Switch mode power supply and separate head

Frequency:
2.45 GHz

Microwave head:
Water cooled magnetron, with isolator, N-BNC-Detector

Output Power:
3kW, 6kW; Adjustable from 10-100% in CW mode and from 0-100% in pulsed mode

Applicator:
Mono-mode Cavity

Control panel:
Lab-View© based measurement of all process parameters

Options:
Pyrometer; Plasma control sensor; Auto-tuning system; Mass flow controller; Vaporizer

Conveyor Belt Applicator
Thermal Image - Microwave Applicator

Conveyor Belt Applicator

In-line installation:

  • Customer-designed microwave applicator
  • High-quality microwave power supply
  • Safety equipment meets highest standards
  • Roll-to-roll treatment for textiles, foils, and membranes
  • Conveyor belt for bulk goods

Applications for foils and membranes:

  • Heat treatment, preheating
  • Drying
  • Coating
  • Debinding
  • Gluing-/Bonding

Microwave power supply:
Switch mode power supply and separate head

Frequency:
2.45 GHz, 915 MHz

Microwave head:
Water cooled magnetron, with isolator, N-BNC detector

Output power:
2kW, 3kW, 6kW; Adjustable from 10-100% in CW mode and from 0-100% pulsating mode

Applicator:
Mono-mode cavity

Control panel:
Lab-View© based measurement of all process parameters

Options:
Pyrometer; Plasma control sensor; Auto-tuning system; Lock system for working under controlled atmosphere

Fluidized Bed Reactor

Fluidized Bed Reactor

Turnkey installation:

  • Customer-designed microwave applicator
  • High-quality microwave power supply
  • Safety equipment meets highest standards
  • Jet-feeding system
  • Solid output
  • Cyclone-/Filter system

Applications:

  • Particle coating, drying, pyrolysis
  • Chemistry (heterogeneous reactions)
  • Minerals processing

Microwave power supply:
Switch mode power supply and separate head

Frequency:
2.45 GHz, 915 MHz

Microwave head:
Water cooled magnetron, with isolator, N-BNC detector

Output power:
2kW, 3kW, 6kW; Adjustable from 10-100% in CW mode and from 0-100% in pulsating mode

Applicator:
Mono-mode cavity

Control panel:
Lab-View© based measurement of all process parameters

Options:
Pyrometer; Plasma control sensor; Auto-tuning system; Batch or continuous operation; Mass flow controller