INSTALLATION AT PPC PTOLEMAIDA

Created in: 21-07-2011

On 01/09/2010, a new water treatment system was commissioned, with a capacity of 1200 m³/day, for the Public Power Corporation of Greece in Ptolemaida.  The system produces 50 m³/h (1200 m3/day) ultrapure water, based on the specifications applicable to thermoelectric stations (0.06 microsemens/cm, Na < 3 ppb, SiO2 < 10 ppb) the inlet feed water coming from a brackish well.

The system is installed in 2 x 40 ft high cube containers, thermally insulated (with ventilation, air-conditioning/heating), placed on mobile platforms, as, besides being used in Power Station of Ptolemaida, it is also possible to be moved to the other units in the wider region of Kozani - Florina (Power Stations of Kardia, Ag. Dimitrio, Amidaio, Meliti) in order to cover the emergency needs, in the case of malfunction of the current resin de-ionizers.  In these cases, the inlet water is softened water from the station.  Each of the station has stand-by pipework and electrical supply, such that the plant can be installed when needed.

The specific water treatment system is an innovative and pioneering product for TEMAK.  The large capacity and high quality of water, is rovided due to a series of innovative, cutting-edge technologies (some of which have been applied in Greece for the first time), replacing the conventional methods but also pointing to future water treatment methods.  These innovative processes are summarized as follows:

• Ultra Filtration. The inlet water is collected in a tank and the continues to 4 racks of UF membranes, total capacity of 75 m³/h.  The filtered water is stored in a filtered water tank, and then pumped into the reverse osmosis membranes.  All the above mentioned equipment is placed in a "pretreatment" container.  This system replaces the conventional method of turbidity removal by sand filters and a series of cartridge filters.  The efficiency of the system is absolute, as it successfully removes 99% of the turbidity.

• Reverse osmosis membrane modules. The pre-treated water passes twice via reverse osmosis membranes, producing water with a conductivity of approximately 3 μS/cm.

• CO₂ degasser membrane modules. Replacing the up-to-date methods (Dosing NaOH, Air Stripper, etc), the process for removal of CO₂, takes place with the use of special membranes, from which the current of air is provided either by blower, or vacuum pump, or pressurized air from the Power Station.
• CEDI - Continuous Electro-Deionization. Replacing the conventional method of de-ionization with mix bed resin tanks and chemicals for regeneration, the final treatment of water (purification), takes place via a CEDI.  The CEDI provides a constant current of high voltage inside modules which have semi permeable membranes and mixed bed resin.  The water enters the modules and comes out with the absolute conductivity of 0.055 μS/cm.  The resin removes the remaining ions in the water and is regenerated continuously with H+ and OH ions produced by a constant electrical current.  As such, there is no need for chemicals or stopping of the palnt, for the time consuming regeneration with NaOH and H₂SO₄.
• Automation Instruments. The automation system controls a range of parameters and regulates accordingly the function of the plant.  The control of all pumps in the system being via inverters allows the plant to adjust to different conditions which may occur to every Power Station (conductivity, temperature, hardness, etc).  The network of the measuring instruments and control system relies on the Profibus communication protocol.  It removes the need for a big portion of the internal cabling in the containers, as well as the maze of connections inside the PLC panel.  The central PLC is not the point anymore where all the signals and cables are ending.  We have placed local control docks, which are independently supplied with a current of 24VDC.  They are connected in series with one cable only (Profibus type), which ends in the corresponding Profibus gate in the PLC.  Every signal, either analog or digital from and to the PLC, does not have a separate cable but instead is given one digital protocol address.  Via the Profibus cable, the different messages are distributed from / and to each address.

• Mobile Units. All the above mentioned equipment is placed in containers which are placed on mobile platforms.  In special cases, the unit can be transferred by 2 tractors to any station and within a few hours get connected with the power supply and piping (with detachable ducts) and produce immediately the necessary quantity and quality of water.

TEMAK, with 35 years of very strong presence, 70 people as a constant workforce and self-owned premises of 7500 m2 in Athens and Thessaloniki, remains steadily the biggest Greek company in the field of water treatment (total water treatment solutions, chemicals, and flow control equipment).  In its production line, high quality products are manufactured for a wide range of needs of the local and international market, from simple home systems, to highly specialized industrial systems.

The highly trained scientific and technical personnel of TEMAK are always available to choose flexible and reliable solutions, covering the specific needs, or to design from the beginning a new product, totally customized based on the specifications of the client and the latest technologies in water treatment.