Crystallizers for wastewater treatment and zld

Introduction to vacuum crystallizers

Crystallization is a separation method in which the formation of a solid (crystal or precipitate) is produced from a homogeneous, liquid or gaseous phase. The solid formed can be very pure, so crystallization is also used industrially as a purification process.

The solution must be supersaturated before crystallization can occur. The Crystallization processes differ from one another in the method by which supersaturation is achieved. In general, it can be achieved in three different ways:

  1. Supersaturation produced by cooling the solution with negligible evaporation.
  2. Supersaturation produced by evaporation of the solvent with little cooling.
  3. Evaporation by a combination of cooling and evaporation in adiabatic evaporators (vacuum crystallizers).

The Crystallization process is not simple and the most important step is the formation of solid crystals in the liquid solution. The solution is concentrated and cooled until the concentration of the solute is higher than its solubility at that temperature, and the solute forms almost pure crystals.

Condorchem Envitech Offer

Condorchem Envitech has extensive experience in the design, manufacture and installation of wastewater crystallizers for different types of industry, each with its own peculiarities.

At Condorchem Envitech we are specialists in vacuum crystallizers for the treatment of high pollutant effluent and the concentration of raw materials.

Our DESALT® equipment provides a very high percentage of clean water to be discharged or reused, and a minimum solid concentrate to be sent for disposal or used as raw material to be recovered or as a by-product.

Crystallization is a good option if you are committed to zero discharge. This technology is particularly suitable for high salinity effluents (brines).

Condorchem Envitech’s range of crystallizers for wastewater treatment includes the following equipment:

Desalt LT DRY

For applications in which simultaneous concentration and drying in the same equipment is required: Crystallization of brines, concentration of spent working baths and concentration of extracts and fragrances.

The product can be extracted manually or with the help of a spindle (optional).

It is a vacuum evaporator-crystallizer: electric, low temperature and of horizontal construction. It is operated by an electric heat pump, has a very compact structure and does not produce emissions or odors. It can be built in highly corrosion resistant materials if required.

It is designed to obtain solid, crystalline, paste or gelatine concentrates, as well as to recover raw materials present in wastewater.

Its capacity range is 250-1,000 L/day.

Desalt LT VR

For applications to treat fouling liquids, brines, glues, inks and paints, for example.

It is a vacuum evaporator-crystallizer, of vertical construction with an internal scraper with blades. The heating is via steam or hot water. It can be manufactured in highly corrosion resistant materials if required.

It is designed for the concentration or Crystallization of brines and concentrated fluids from an evaporator. Organic fluids can be concentrated into paste form. The equipment is especially recommended for treating fouling wastewater and high density aqueous solutions.

Its capacity range is 500-3,000 L/day.

Our wastewater crystallizers

Advantages and applications


  • Minimization of the waste volume to be managed
  • Significant reduction in waste management costs
  • Possibility of implementation of a zero discharge system
  • Fulfillment of the current regulations on discharge of effluents
  • Reduction of the need to store large volumes of waste
  • Reduction in greenhouse gas emissions when transporting the waste
  • Absence of reagents (except for antifoam in some cases)


  • Treatment of effluents with a high contaminant load
  • Useful when treated effluents cannot be discharged (implementation of a zero discharge system)
  • Treatment of effluents when conventional techniques are not effective (as in the case of brines)
  • Concentration of raw materials
  • Maximum concentration of waste when external management costs are very high

Functioning/operation of wastewater crystallizers

The operation of a crystallizer is very similar to that of a vacuum evaporator, except that it is designed to evaporate all the solvent and leave a very concentrated, pasty, gelatinous or crystalline product. There is usually a side opening so that it is easy to open and accessible for the manual extraction of the crystallized salts. At the end of the working cycle, the vacuum is released and the boiler contents are manually discharged with a scraper blade via one of the front doors.

Crystallizers can work well with a heat pump, steam or hot water.

Desalt DRY

Desalt VR