Neutralisation

The continual separation of filming agent and zinc-hydroxide provides for outmost economical waste-water-clearance.

This fully automatic system neutralises and clears one-step magnesium-zinc etching baths as well as nitric waste water in a fully automatic and continuous operation.

The flow volume amounts to approximatly 35 litres per hour. After the separation of oil and grease, the liquid flows into the neutralisation container, where it is neutralized by caustic soda lye. In the filter container the magnesium-zinc oxide is filtered out.

The neutralising system covers the following components:

Drain reservoir
A drain reservoir with integral float switch and automatic inflow control of the volume by a magnetic valve. The volume is also indicated by a level glass at the side. The container has a capacity of 500/1000/1500 litres.

Oil and grease separator
The flank protection oil is separated twice in this container, thus a safe and reliable oil  separation is ensured. This container also has a capacity of 500/1000/1500 litres.

Neutralising container
In this container the liquid is neutralised by caustic soda lye. The caustic soda lye is automatically pumped into the container by a hose pump.
The amount of caustic soda lye is determined by an electric measuring unit and automatically added. The lye is mixed with the liquid by a high-performance turbo mixer with the result, that the magnesium-hydroxide precipitates.

Filter container
In this filter container with overflow chambers the magnesium-hydroxide is filtered out by means of a one-piece filter bag.

Optionally a filter press can be installed instead of the filter container. Hierewith the filtering is improved considerably. After the closing of the chambers, the system operates automatically. A helical rotor pump conveys the liquid into the press.

Leveling facility
This fully automatically operating equipment is designed for the installation of the system on the same level as the etching machine or as a hoisting device for the purpose of pumping the neutralised and filtered liquid into the sewerage.

Final pH-check
The final pH-check is controlled by an additional measuring unit, which contains the following elements:

1 pH-regulator with amplifier, regulating elements
1 pH-measuring-electrode
1 immersion appliance

This final pH-check is installed at the drain of the filter container. It transmits the data to the pH-regulator. Since it is known, that after the precipitation of the magnesium, the pH-value drops by 1 pH, this regulator maintains the present pH-value of the liquid.

• Waste water sampling point
• Waste water quantity counter
• Control cabinet

The control cabinet contains the pH-measuring amplifier, a dotted-line recorder and a regulator with adjusting elements and electronic indication for the exact setting of the pH-measuring-value.
The dotted-line recorder is designed for the recording of the pH-values transmitted by the pH-measuring-electrode to a chart paper roll.