Low temperature heat pump vacuum evaporators

At Condorchem Envitech we supply a complete range of heat pump evaporators that are highly versatile, easy to use and install. Every heat pump evaporator that we manufacture is customized to meet our customers needs.

Heat pump evaporators use electricity as a source of energy and they are a very efficient technology to concentrate, minimize and treat a wide variety of effluents and liquid waste.

Condorchem Envitech’s heat pump evaporators range focuses on three different product types:

• Standard Heat pump vacuum evaporators
• Heat pump vacuum evaporators with internal scraper
• Vacuum evaporators with heat pump dryer

The models on offer are the following:

• Envidest LT DPE and Envidest LT VS: standard equipment (we have on offer the titanium CR model, for highly corrosive waste water).
• Desalt LT VR: equipment with internal scrapers for fouling or very dense liquids treatment, capable of achieving elevated concentrations.
• Desalt LT DRY: concentrated waste drying equipment.

Condorchem Envitech’s offer on heat pump vacuum evaporators focuses in three types of different products:

Standard

There are two different standard heat pump vacuum evaporator models available: Envidest LT DPE for flow rates of 250-2,500 L/day and Envidest LT VS for flow rates of 3,000-15,000 L/day. Their main features are:

• Operating flow range: 250-15,000 L/day
• Power consumption: 150 kWh/m3 distillate
• Heat exchanger submerged to form a toroid
• Operation completely automatic
• Constructed with AISI 316. Also available in special anti-corrosion alloys if necessary.

With internal scraper

The Desalt LT VR model is a heat pump vacuum evaporator with an internal scraper especially recommended for treating fouling wastewater and high density aqueous solutions. Their most relevant features are:

• Flows of 250-3,000 L/day (for higher flows, see VR-WW equipment)
• Electrical energy consumption: 250 kWh/m3 distillate
• Internal scraper to prevent incrustations and achieve maximum residue concentration
• Heat exchanger with outer jacket
• Operation completely automatic
• Constructed with AISI 316. Also available in special anti-corrosion alloys if necessary

With dryer

The Desalt LT DRY evaporator is designed to obtain semi-solid concentrates, as well as to recover raw materials present in the treated water. Their main features are:

• Flow rates from 250 to 1,000 L/day
• Electrical energy consumption: 250 kWh/m3 distillate
• Horizontal configuration of the evaporation boiler for easy extraction of solid or paste residue
• Heat exchanger with outer jacket
• Operation completely automatic
• Constructed with AISI 316. Also available in special anti-corrosion alloys if necessary

• Minimization of the waste volume to be managed
• Significant reduction in waste management costs
• Production of an excellent quality distillate
• Possibility of implementation of a zero discharge system
• Fulfillment of the current regulations on discharge of effluents
• Reduction in greenhouse gas emissions when transporting the waste
• Low maintenance and little need for supervision

• Oily emulsions, coolant fluids, mould release agents
• Purging of compressors, water from washing floors
• Water from washing tanks and reactors (in the chemical, pharmaceutical, cosmetic and perfumery industries)
• Working and wash baths in galvanic processes and surface treatments
• Penetrating liquids
• Graphic arts waste (e.g. cleaning water and paint)
• Water treatment plant reject (e.g. reverse osmosis and demineralizers)
• Leachate from municipal solid waste dumps
• Digestate from biogas generation plants
• Food and beverage industry
• Pickling industry
• Energy generation
• Paper, minerals and extraction industries

These are electric vacuum evaporators that operate at a temperature of 40°C and provide a significant reduction in the COD of the distillate and a low amount of discharge concentrate. The technology has a low maintenance cost, is fully automated and ensures consistent distillate quality by providing complete separation of metals and surfactants. These evaporators also have a foam control system.

Vacuum evaporators can treat an aqueous waste stream efficiently and simply without using reagents. They are highly effective even when conventional technologies are not viable. Using a vacuum evaporator, waste effluent is transformed into two streams: one, highly concentrated (perhaps even dry) and the other high quality water. Evaporators work under vacuum conditions to reduce the boiling temperature of the liquid effluent and lower energy consumption.

The operation of a heat pump vacuum evaporator is based on bringing the effluent to its boiling point, which is around 40°C when working under vacuum conditions. When the effluent begins to boil in the evaporator boiler tank, the steam condenses and is withdrawn from the system as more effluent is fed into the boiler tank.

The effluent being fed is preheated by a heat pump so the evaporation process continues.

The operation of the heating system to evaporate the effluent is based on the refrigeration cycle of a gas in a closed circuit. The refrigeration gas is compressed by a compressor, as a result of which its temperature and pressure increase. It then circulates through the heat exchanger of the evaporator itself, heating the feed. In the heat pump evaporator as the system operates under vacuum, the boiling temperature is around 40 ºC. The refrigeration liquid leaves the evaporator’s exchanger and is decompressed and cooled using an expansion valve.

Passage through a second heat exchanger (the condenser) causes the vapor formed in the evaporator to condense and its temperature to increase immediately prior to passing through the compressor again, thus repeating the cycle. The same refrigeration fluid allows the feed to be evaporated and the vapor generated to be condensed, therefore the system does not require any other heating or refrigeration source. This means that the process is highly advantageous from an economic and management viewpoint.