Equipment

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.

FREEAL is a unique technology

designed to improve the efficiency of

anodizing baths as well as of

different types of acid pickling

processes.

It 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 normal working conditions.

Once this enrichment exceeds the

“threshold” value, it becomes

dangerous and causes problems with

the management of the bath solution.

Sulphuric Acid Recovery System

FREEAL

The FREEAL unit

Equipment

• It 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 for 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 for disposal

neutralization, due to reduced acid

waste

• Improved 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

• Skid frame, made in stainless steel

AISI 304

• Flowing pump, made in anti-acid

material

• Columns, made of fibreglass for ion

exchange resins

• Flow-meter, in anti-acid material for

acid circuit

• Flow-meter, in anti-acid material for

tap water circuit

• Flow-meter, with reed contact for

signal transmission of water flow

rate to PLC

• Magnetic induction flow-meter, with

signal transmission of acid flow rate

to PLC

• Control membrane valves, made in anti

-acid material

• Pneumatic valves, made in PVC and

equipped with anti-acid membrane

• Manometer, made in anti-acid material

and equipped with membrane separator

• Drain valve, made in PVC, allows an

easy draining of water from the

columns

• Automatic breather column valve;

• Air pressure regulator, with gauge

to maintain the pressure within the

range

• Electro-pneumatic junction box, for

pneumatic valves control

• Electric Switchboard equipped with a

PLC to control the automatic phases

of the unit functioning

Some Advantages of the FREEAL System

Technical Description

FREEAL is an automatic system, pre-assembled

and tested at our factory.

It is self-contained in a stainless steel

frame, which makes easy the transportation

and prompt the installation.

List of Components

Automatic Functioning Software

FREEAL is now available in an enhanced version featuring a specific software for the

automatic functioning of the unit.

This means that the software will predict the aluminium content and automatically command

the functioning time and parameters in each individual tank.

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 related parameters.

Equipment

FREEAL Configurations

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

Italtecno complete with all the

following accessories:

Activated carbon filtration fibreglass

column and all related control

equipment

Acid feeding unit, including the tank

for storage of acid water and all

related control equipment

Water feeding unit, including the tank

for storage of tap water and all

related control 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 identical to the

previous one, with the only difference

that:

- the tank for storage of acid water

- the tank for storage of tap water

will be supplied by the Customer

(Italtecno 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 compensated by the

Customer with for example addition of

water

FREEAL Configurations

The FREEAL units can be supplied, as an

option, with an Automatic multi-tanks

control system, which allows one FREEAL

unit to operate in connection with

respectively two, three or four

anodizing tanks.

Equipment

Technical Description

The FREEAL units are available in five models and two operating modes: non-continuous and con-

tinuous.

Non-continuous FREEAL models have one single resin column; therefore, the phase with aluminium

absorption from the acid is alternate with the sulphuric acid discharge phase.

Continuous FREEAL models have got two resin columns; therefore when one column is absorbing

aluminium the second one is discharging sulphuric acid, and vice versa

FREEAL MODELS 200 400 650 800 1300

Resin capacity 200 litres 400 litres 650 litres 800 litres 1300 litres Columns diameter 500 mm 600 mm 800 mm 600 mm 800 mm Nr of columns 1 1 1 2 2 Type of process non- non- non-

continuous continuous continuous continuous continuous Al+++ removal capacity 0,8-1,1kg/h 1,7-2,2kg/h 2,7-3,3kg/h 3,3-4,0kg/h 5,4-6,4kg/h Sulphuric Acid discharge 2,0-4,2kg/h 4,0-8,3kg/h 7,0-14,0kg/h 6,5-13,0kg/h 11-22kg/h Overall dimensions 1220x1000 1300x1100 1500x1300 2000x1200 2300x1300 (h=2250 for all) Weight 160 kg 175 kg 210 kg 270 kg 290 kg Overall dimensions and weight are refer to the basic FREEAL unit. The performance data above reported makes reference to the following anodizing conditions:

• Sulphuric acid concentration 200 g/l

• Temperature 20°C

• Anodic coating thickness 20 mm

• Current density 1,5 A/dm2

Selection Criteria

An initial indication on the criteria to be employed for the appropriate selection of the

FREEAL units can make reference to the total output of the anodizing line:

FREEAL MODELS 200 400 650 800 1300

Production of 2200 m2/day 4400 m2/day 6900 m2/day 8400 m2/day 13500m2/day aluminium profiles

ITALTECNO Via Marinuzzi, 38 – 41100 Modena (Italy) Tel. +39 059 280362 Fax +39 059 280462 Internet: http://www.italtecno.com E-mail: info@italtecno.com