Heat pump vacuum evaporators for energy-efficient evaporation

When you evaporate wastewater, rinse water or process solutions, energy is the main operating cost. Our vacuum evaporators with an integrated heat pump need 0.1 to 0.27 kWh of electricity per litre of distillate – a conventionally heated evaporator uses 1.3 to 1.4 kWh. The distillate can usually be reused directly, and the concentrate volume is reduced substantially.

How it works

The heat pump recovers the heat released when the vapour condenses and uses it again for evaporation.
No heating steam, no cooling tower: the plant runs on electricity only.
Under vacuum, the liquid boils at low temperature. This protects heat-sensitive substances and construction materials.

Energy demand compared

Vacuum evaporator with heat pump (S+P): 0.1–0.27 kWh of electricity per litre of distillate
Single-stage evaporation with steam: 1.3–1.4 kWh of energy per litre of distillate

Typical applications

Solvent recycling in the paint and coatings industry: cleaning agent is recovered and reused; plants at several sites of one customer.
Rinse water from pickling and electroplating: acids such as sulphuric and phosphoric acid are concentrated and returned to the process.
Chromic acid and precious-metal rinse water: valuable substances stay in the loop, wastewater volume drops sharply.
Rinse water from metalworking (deburring, vibratory finishing).
Ethanol and essential oils in explosion-proof (ATEX) design.
Degreasing baths, cutting fluids and oil emulsions as well as concentrates from membrane, ion exchange and electrolysis processes.

Product lines

EVA – natural circulation: for thin, solids-free solutions with low viscosity; approx. 30–190 l/h of distillate.
CONfix® – forced circulation: evaporation takes place in the flash vessel, not on the heating surface, so hardly any deposits form; for scaling, crystallising or more viscous media; approx. 50–620 l/h of distillate, larger units on request.
DRYfix® – dryer: with agitator and scrapers, dries down to low residual moisture, batch operation; approx. 10–50 l/h of distillate.

The plants operate under vacuum at approx. 70–80 mbar; the liquid boils at approx. 38–40 °C.

Refrigerant R513A

Our heat pumps use the refrigerant R513A. It replaces the formerly common R134a, is non-flammable and has a global warming potential about 56 % lower (GWP 631 instead of 1,430).

Service

Maintenance contracts specifically for heat pump plants
Express delivery of spare parts
In-house service for process, control and refrigeration technology

Materials and design

Stainless and duplex steels for standard media
Plastic-lined or solid plastic (e.g. E-CTFE, PVDF, PP) for acids
Special materials such as Hastelloy, titanium, zirconium, silicon carbide or graphite for highly corrosive media
ATEX and GMP design available
Batch or continuous operation, from small units up to approx. 1,000 l/h of distillate

From test to plant

We have built almost 100 plants of this type. Before you invest, we test your original medium in our pilot plant. You know in advance which distillate quality and energy demand to expect. Design, fabrication and commissioning come from one source.

Frequently asked questions

How much energy does a heat pump evaporator save?
Compared with steam-heated evaporation, energy demand typically falls by 80 to 90 % – from 1.3–1.4 kWh to 0.1–0.27 kWh per litre of distillate.

Which liquids are suitable?
Aqueous solutions such as wastewater, rinse water, dilute acids and alkalis, as well as solvent mixtures. Heavily scaling or very high-boiling media are clarified in a test.

Can the distillate be reused?
In most applications, yes – for example as rinse water or as recovered solvent.

Do I need steam or cooling water?
No. The plant only needs electricity.

How do I find out whether it works for my medium?
Send us the requirements questionnaire or a sample. We check feasibility in our pilot plant.

Can hydrochloric or hydrofluoric acid be concentrated?
Yes, with plastic heat exchangers. This requires an additional heat transfer circuit, which increases energy demand by about 10 %.

Enquiry

Fill in our requirements questionnaire or request a test with your medium: Contact