OPERATION OF REVERSE OSMOSIS SYSTEM

ABHA

OPERATION OF REVERSE OSMOSIS SYSTEM

To provide the operating procedure for the Reverse Osmosis system.
This procedure covers the operating procedure for the Reverse Osmosis system.
PROCEDURE
The Reverse Osmosis system is fed with softened water stored in a tank with a capacity of 5000 Liter.

The feed pump pumps water from the tank to the microfilter (5 microns). Before water enters the 5-micron filter, the dosing systems add sodium metabisulphite and anti-scale solutions to the water.

After the microfilter, the water is pumped by the high-pressure pump to membrane filters of 1st order- Reverse Osmosis-1. After dosing with 1% NaOH solution the filtered water is fed to a Multi-Purpose Tank, from which it is supplied to membrane filters of 2nd order- Reverse Osmosis -2 by the high-pressure pump.

Water, purified from mechanical impurities, is fed to an electro-deionizator. The electrodeionizator purifies water at the ionic level.

The purified water further passes through a UV water purification system and is collected in a storage tank with a volume of 1500 L.

Purified water from the tank is fed by the high-pressure pump to the circulation loop, from which the water can be withdrawn by rooms in Production.

DESCRIPTION AND FUNCTION OF REVERSE OSMOSIS SYSTEM ASSEMBLIES SOFTENED WATER STORAGE TANK

After the 1st stage of purification and softening, the water reaches the storage tank.

The tank has a capacity of 5000 liters and is equipped with a level sensor.

The sensor transmits data about the presence of water in the tank to the monitor screen.

If the water level drops to the critical mark, the feed pump switches off automatically.

MICROFILTER FEED PUMP

A horizontal, linear centrifugal pump is intended for softened water pumping from the tank №1 with the capacity of 5 м3 to the microfilter inlet port. Working pressure created by the pump – 4 kg/cm². Pump efficiency should not be less than 1600 l/h.

DOSING WITH SODIUM METABISULPHITE

The filtered water is dosed with sodium metabisulphite solution. Sodium metabisulphite favors free chlorine neutralization in water.

Dosing with 1% metabisulphite solution is carried out by means of the chemical substances dosing system, which consists of the tank, dosing pump with the electromagnetic control, the built-in relay, and the device for chemical substance injection.

The dosing velocity is 1,2 – 2,4 l/h depending on the amount of free Cl in the water.

The oxidation-reduction potential (ORP) meter is designed for free chlorine detection and is located lower in the chemical substances dosing system before the shutoff valve. As soon as the device detects free chlorine, the shutoff valve opens automatically and water is directed to the drain.

DOSING WITH ANTI-SCALING AGENT
The scale formation is a tendency of the reverse osmosis membranes, which influences the reverse osmosis membranes operation. Therefore the softened water is dosed with 1 % anti-scaling agent solution, which prevents scale formation. Dosing with anti-scaling agent is carried out by means of the chemical substances dosing system, which consists of the tank, dosing pump with the electromagnetic control, the built-in relay and chemical substance injection device. Dosing velocity is 0,6 – 1, 2 l/h.
PARTICLES FILTRATION (5 micron filter)
Before entering the reverse osmosis system membranes, the water passes through 5 micron filter, due to which the solids quantity, which can lead to reverse osmosis membranes chocking, is reduced. The 5 micron filter cartridges are replaceable. Periodicity of replacement is once in six months. After filtration the water is fed to the high pressure pump.
HIGH PRESSURE PUMP-1
The pressure is increased by the high pressure pump to 10-13 kg/cm², so that the feed water could pass through the spiral coil of the reverse osmosis membrane. Thus the water is purified to achieve the necessary quality for further use. The pressure can be adjusted by the pressure-relief valve
REVERSE OSMOSIS SYSTEM-1
The filtration process in the reverse osmosis membranes is of cross-sectional character. When water hits the membrane, the majority of minerals which are present in water, are removed and only small part of them can pass through it in water. Therefore the reverse osmosis system has three flows. The first flow is feeding, the second – rejected (concentrate), the third – filtered (permeate). The part of the concentrate (1000 L) is directed through the reverse valve to the feeding flow for re-purification, and a part is drained through the valve with the velocity of 400 l/h. The filtered water, having passed the sodium hydroxide dosing system is fed to multi-purpose tank.
DOSING WITH SODIUM HYDROXIDE (Na OH)
At the reverse osmosis system -1 (RO-1) outlet the sodium hydroxide (NaOH) dosing system id located, intended for рН level regulation. Dosing with the 1 % sodium hydroxide solution is carried out by means of the dosing system consisting of the tank, dosing pump with the electromagnetic control, the built-in relay and the chemical substances injection device. Dosing velocity is 0,6 – 1, 2 l/h.
MULTI-PURPOSE TANK
Water with the required рН level (8-8,5) is gathered in the multi-purpose tank and is fed by the high pressure pump to reverse osmosis membranes. The above mentioned tank can be used for sanitation treatment of the reverse osmosis-2 membranes and electrodeionizator. The tank is isolated and has an electric heater for carrying out of sanitary treatment with hot water.
HIGH PRESSURE PUMP-2
The pressure is increased by the high pressure pump to 10-12 kg/cm², so that the feed water could pass the spiral coil of the reverse osmosis membrane with a certain speed to provide the necessary quantity of filtered water. The high pressure pump is equipped with the pressure gauge and frequency converter to secure the pump proper functioning. The feed water velocity can be adjusted by the pressure-relief gauge and should be 800 – 1000 l/h.

REVERSE OSMOSIS SYSTEM-2
The return osmosis unit consists of a membrane with the spiral coil, placed in a pressure pipe which can be treated with hot water.
ELECTRODEIONIZATOR
After the membranes of the reverse osmosis-2 water reaches the electrodeionizator through the automatically operated valve and T-valve. In case of unsatisfactory conductivity (more than 4,3 µS/cm) the water is directed to drain through the shutoff valve. The electodeionizator further reduces the total particulate matter and provides electro conductivity of the purified water according to SPhU standards (less than 4,3 µS/cm). The ion-exchange resin constantly regenerates.
UV PURIFICATION SYSTEM-1
The UV purification system-1 is an effective way for microbes quantity reduction in water. The UV purification system-1 has the following working parameters: flow velocity of 1 m3/h, water temperature according to an ambient temperature, transmission factor > 90 %. Radiation intensity and general operating time of UV lamps is controlled by the meter. UV lamp operating time should constitute not more than the time indicated by the UV lamps manufacturer (7500 – 8000 hours).
PURIFIED WATER SOTRAGE AND DISTRIBUTION TANK
The purified water storage tank is made of stainless steal and has a capacity of 1500 L, equipped with casing for sanitation treatment. The tank is supplied with the water level sensor which transmits data about presence of water in the tank to the monitor screen. When the water level in the tank exceeds the maximum allowed level, the valve closes. The purified water flow is redirected to the multi-purpose tank. In case the water level in the tank decreases to minimum allowed level, the pump supplying purified water to the circulation loop is switched off automatically. The conductivity probe is situated in the line of water supply to the distribution loop. It shows the purified water conductivity in the real-time mode. If the conductivity permissible limit is exceeded – 1.3 µ/sm at 20°C, the shutoff valve automatically opens and water is directed to the drain.
PURUFIED WATER CIRCULATION PUMP
Circulation pump transfers the purified water from the tank to the distribution loop. The pump efficiency constitutes 2,7 m³/h. The pressure supported in the distribution loop is 2-4 kg/cm2. The turbulent flow velocity in the circulation loop should be not less than 1,0 m/s.
UV PURIFICATION SYSTEM-2
The UV purification system-2 is an effective way for microbes quantity reduction in water. The UV purification system-2 has the following working parameters: flow velocity of 1 – 2,5 m3/h, water temperature according to an ambient temperature, transmission factor > 90 %. Radiation intensity and general operating time of UV lamps is controlled by the meter. UV lamp operating time should constitute not more than the time indicated by the UV lamps manufacturer (7500 – 8000 hours).
START OF THE REVERSE OSMOSIS SYSTEM IN AUTOMATIC MODE
Turn on the power supply on the side of the control panel.
Compressed air should be supplied with the working pressure of no less than 6 kg/cm².
The whole system can be started in the automatic mode with the help of mode selection switches on the front door of the control panel.
Set the working mode selection switch of the purified water distribution system to AUTO.
Set the working pump selection switch DP-01/DP-02 to the position corresponding to the working pump.
Set the reverse osmosis system-2 mode selection switch to AUTO.
Set the reverse osmosis system-1 working mode selection switch to AUTO.
Switch on the UV system.

SOPs