A-ENGINEERING NV

Waste Water Purification

As an engineering company, we use our technical know-how as well as our experience to provide solutions for problems caused by limescale.

Waste water sites in industrial plants are processing the used water of factories from their processes and soil water of contaminated land coming from other sites. The iron and salt levels of this water are very high. The waste water site is crucial in their drive for environmental protection and their motivation to evacuate only environmentally safe water. Most industrial factories have high standards for water quality and have especially chosen Calc-Tech because with this system the addition of chemicals is limited.

This process has increased the quality of the water and has decreased the usage of chemicals, making the Calc-Tech investment very cost efficient with a short payback time.

Application Example:  Neutralisation

Waste water plants use products (like NaOH, etc...) to increase the pH of waste water. These additions make the water more reactive for scaling in the tanks, pumps and pipes. These scaling problems should be avoided or limited in order to keep the maintenance cost down.

Our solution:

The image shows the coils, applied around the connection tube of 450mm between two tanks, before the NaOH is added. The water flow rate is constantly varying, in this example between 150 and 600 m³ per hour.

Eight coils are connected to the 19`` Calc-Tech system, containing four amplifiers.

In this way an inductive field is generated over more than three meters. Each set of coils is connected into a junction box. These boxes are connected to the 19`` Calc-Tech cabinet, approximately thirty meters away from the coils. The system consumes 1 KW.

Calc-Tech controls the frequency in function of the water flow which is measured by a flowmeter.

Error messages can be generated, informing the customers Scada system of any malfunction of the electronics and coils of the Calc-Tech.

Industrial Refrigeration Applications

Scaling is one of the big problems in cooling towers and heat exchangers. Calc-Tech protects these systems against scaling.

Application Example: Chicken Slaughterhouse

The factory consumes 800 000 Litres of fresh water on a daily basis, coming from the main town supply and from own wells. The main problem is a constant change in water hardness, impossible to solve with conventional softeners.

There are several heat exchangers and cooling towers that are congested very frequently due to the high water flow rates and the relatively hard water.

A Calc-Tech CT-19254 - rack is selected because the coils are installed at 5 different places and it helps in treating the complete factory against lime scale deposits in:

- Sanitary water circuit
- Process water
- The re-used water from the wastewater treatment plant

The two cooling condensers require inductive coils on the circulation circuit in order to achieve an adequate treatment. The towers had a 3mm thick layer of lime scale before Calc-Tech was applied. After three months nearly all of the scale was washed off and was collected in the bottom basin of the tower.

The purified water from the wastewater plant is not biological neutral and does not have a constant hardness, making it impossible to re-use in cleaning applications due to the formation of scale in the heat exchangers for the water. Calc-Tech was able to protect the heat exchangers so that this water could be used, saving a lot on fresh water consumption.

Even with a high water hardness (more the 50° fH) there is no more lime scale formation.

Infrastructure Applications

In hospitals and official buildings, people are very concerned about public safety and they try to avoid any possible contaminations of sanitary and potable water. Therefore many technical departments have decided to exclude ion-exchangers (softeners) as anti-scaling systems for the pipes and technical equipment. Scaling in equipment and pipes is the perfect environment for bacteria`s like Legionella.

Softeners add not only too much salt in the water, they are consuming salt and water which is very expensive and also they are a breeding place for bacteria`s.  Since Calc-Tech does not change the quality of the water, often Calc-Tech is selected as the only allowed anti-scaling system for the entire building.

Technical Description

The water for the building is supplied by one or several separate pipes. The first Calc-Tech will be installed; a second Calc-Tech system must be installed on the warm water circuit.

Application Example: Hospital

Main Supply Cold Water

The two separate pipes have a diameter of DN160. The pipe material is PE. A Calc-Tech system CT-250 was selected for the treatment of both pipes. Before applying the wires, the insulation has to be removed. After the wires are applied, the insulation can be installed again.

The Calc-Tech unit is adjusted for the average flow rates defined by the yearly water consumption.

Warm Water Circuit

The warm water circuit is divided into two lines, each containing three boilers. The pipes are copper, each with a different diameter (DN 80 and DN 120). A Calc-Tech system is installed just before the circulating pumps, protecting the boilers, pumps and copper pipes. Calc-Tech is adjusted based on the water speed through the pipes. This speed is defined by the circulating pumps.

Calc-Tech CT-250 is supplied with 230V, consuming only 65 W.