Waste water treatment plants division

Freeal Plus

Sulphuric Acid Recovery System
Great saving | improved quality of Anod|C Coat|NG.
Fully automatic control of aluminium concentration

FREEAL is a unique technology designed to improve the efficiency of anodizing baths as well as of different types of acid pickling processes.

lt is in fact well known that these kind of solutions become enriched with aluminium ions and/or other metals they come in contact with, during normai working conditions.

Once this enrichment exceeds the “threshold” value, it becomes dangerous and causes problems with the management of the bath solution.

In case of aluminium anodizing, the optimal concentration of aluminium in solution is considered to be 10 grams per litre, whereas concentration levels in excess of 15 grams per litre effect the correct function of the solution and impede the

work process, resulting in the complete or at least partial disposal of the acid solution.

FREEAL is designed with the aim to maintain the aluminium content in the solution at a constant desired level. This is achieved by drawing quantities of the acid solution from the process bath into the FREEAL system, purifying and delivering it back to the bath.

Automatic Funtioning Software

FREEAL is now available in an enhanced versi on featuring a specific software for the automatic functioning of the unit. This means that the software will automatically command the functioning time and parameters in each individuai tank, with the automatic calculation of the right parameter necessary to keep aluminium concentration constant in all tanks.

In this way it is not any longer required the intervention from the operator in order to determine the working time of the unit and the relateci parameters.

Some advantages of the freeal system

  • lt is possible to achieve up to 90 till 95%efficiency (depending on individual operational conditions) thus realizing significant savings in acid consumption. Acid consumption due to the drag out remains of course unchanged.
  • The electrical energy required tor the anodizing bath operation is reduced. (When the aluminium concentration in the solution increases, the voltage required to get and keep the same current density increases as well).
  • Reduction in the consumption of the chemical reagents required for the neutralization of the exhausted waste
  • Reduced cost tor disposal neutralization, due to reduced acid waste
  • lmproved anodizing quality is achieved with enhancement in the conditions of the downstream processes (i.e. electrocolouring)
  • Minimized downtime of the line by elimination of dumping and reduced tank maintenance

TECHNICAL DESCRIPTION 

FREEAL is an automatic system, pre-assem­bled and tested at our factory. 

lt is self-contained in a stainless steel frame, which makes easy the transportation and prompt the installation. 

FREEAL configuration

  1. The FREEAL units can be supplied, as an option, with an Automatic multi-tanks contro! system, which allows one FREEAL unit to operate in connection with respectively two, three or tour anodizing tanks. 

Each of the five FREEAL models (model 200, 400, 650, 800 and 1300) can be supplied in three different configurations 

Full buffer tanks configuration: in this case the FREEAL unit will be supplied by ltaltecno complete with all the following accessories:

  • Activated carbon filtration fibre­glass column and all relateci control equipment
  • Acid feeding unit, including the tank for storage of acid water and all relateci control equipment
  • Water feeding unit, including the tank tor storage of tap water and all relateci contro! equipment

This configuration allows the maximum in terms of flexibility, since the presence of intermediate storage tanks will make independent the anodizing tanks operation from the functioning of the FREEAL unit.

Partial buffer tanks configuration: this configuration is identica! to the previous one, with the only difference that: o the tank tor storage of acid water o the tank for storage of tap water will be supplied by the Customer (ltaltecno will anyway supply the support frames and the control equipment for these two tanks); this configuration will allow to the Customer some price saving on the cost of the two tanks and their transportation.

Basic configuration: with this configuration the carbon filtration, the acid feeding unit and the water feeding unit are NOT supplied. This is of course the less expensive of the three configurations. The FREEAL unit will be directly connected to the anodizing tank(s), e.g. via the pump of the cooling circuit; this may cause some variations on the level of the solution inside the anodizing tank; if necessary these variation may be compensateci by the Customer with tor example addition of water.

Technical description

The FREEAL units are available in 5 models and in two operating modes: non-continuous and continuous Non-continuos models have one single resin column: therefore, the phase with aluminum absorption from the acid is alternate with the sulphuric discharge phase.

 

Overall dimensioni and weight are refer to the basi FREEAL unit.

The performance data above reported make reference to the following anodizing conditions:

  • sulphuric acid concentration 200 g/l
  • temperature 20 gradi C
  • anodic coating thickness 20 mm
  • current density 1,5 A/dm2

Selection criteria

An initial indication on the criteria to be employed for appropriate selection of the FREEAL units can make reference to the total output of the anodizing line:

Cost saving

In addition to the operation advantages, FREEAL also provides a significant contribution in reducing the consumption of sulphuric acid. The following spreadsheet provides a reference to a typical application. (total installed capacity 40.000 Amps).

Feel free to ask to our commercial department
service@italtecno.com