Filters

For thousands of years filtration has been used to reduce the level of dirt, rust, Suspended matter and other impurities from water. This is achieved by passing the dirty input water (influent) through a filter media. As the water passes through the media, the impurities are held in the filter media material. Depending on the impurity and the media, several different physical and chemical mechanisms are active in removing impurities from the water. Some of the equipment used to employ these mechanisms has changed dramatically over time. Other systems, such as depth filters, have undergone very little change.

The fundamental physical and chemical mechanisms that occur during filtration have become better understood over the years. These advances have allowed water treatment specialists to optimize the removal of impurities from the water. Filtration systems remove particulate matter and, because of the large surface area of filter media, they also can be used to drive chemical reactions that result in the removal of several contaminants. The following mechanisms for the removal of impurities by a given media are discussed in the next section.

• Occlusion - removal due to the impurity's particle size

• Adsorption - removal due to the impurity's adherence to the media

• Reduction - removal of free residual chlorine through conversion to chloride ions in the presence of activated carbon media

• Oxidation - removal of iron and manganese using oxidation, precipitation and filtration in the presence of greensand media

After a review of filtration theory, the operation and design of the following process units is discussed.

• Gravity filter - removal of suspended solids and turbidity

• Multi-media filter - removal of suspended solids and turbidity

• Activated Carbon filter - removal of free residual chlorine

• Greensand filter - removal of iron and manganese

• Cartridge filter - removal of suspended solids

Softener Unit

We offer a series of pre-engineered packaged softeners to meet the needs of small and medium industries. In addition, custom-built softeners are offered for larger requirements. Softeners are available as manual, semi-automatic and fully-automatic versions to suit our client's specifications and requirement.

The water softeners utilize a strong acid cation resin in the Sodium form to exchange the hardness salts in the raw water. Options are available in Mild steel and FRP vessels; Mono valves for the smaller units to multiple valves and piping for the larger units.

All Softeners are offered with a complete inbuilt regeneration system and brine tank. Both cocurrent and counter-current regeneration options are offered based on the inlet water quality.

Typical Application

• Low and medium pressure Boiler feed treatment

• Textile dyeing processing

• Cooling water treatment

• Air conditioning plants

• Food processing

• Hotels, Hospitals and Laundry

• Pharmaceutical

• RO pre-treatment

Ultra Filtration Plant

We provide the latest generation Hollow-Fiber ultra filtration systems. These ultra filtration membranes typically have pore sizes in the range of 0.01 - 0.10 µm and have a high efficiency in removing bacteria and most viruses, colloids and silt.

The advent of Ultrafiltration (UF) as a pre-treatment for Colloidal Silica removal, and tertiary treatment for Recycling plant has resulted in several advantages.

Typical benefits of an UF system include;

• Consistently low SDI in the UF filtrate

• Significantly reduced RO membrane fouling and cleaning frequency

• Extended RO membrane life

• Reliable production of high quality water regardless of raw water turbidity

• Higher RO membrane flux

• Smaller footprints lower land acquisition costs

• Lower consumption of operational and cleaning chemicals

• Modular design enables simple and efficient retrofits

The latest generation Hollow-Fiber configuration ultrafiltration membranes being used globally is backed by the technical expertise form the world's leading Membrane manufacturers like

• M/s Hydranautics, USA

• M/s Dow

• M/s GE

• M/s Team

• M/s Inge, Germany

• M/s Norit, Netherlands

The core of the ultrafiltration system is the membranes. All ultrafiltration systems are strictly designed as per the guidelines of the membrane manufacturers and are backed with the most advanced software projections.

Our vast in-house experience helps to build rugged UF systems which are:

• Less susceptible to fouling

• Use of proven and reliable components

• Easy access of online monitoring points

• High on energy saving

Reverse Osmosis (RO) System

Reverse Osmosis is a process that separates impurities from water by passing the water through a semi permeable membrane. The semi permeable membrane only allows very small atoms and groups of atoms such as water molecules, small organic molecules, and gases, to go through it. Hydrated ions, or ions that have been dissolved and are therefore surrounded by water molecules, cannot pass through the membrane.

Reverse Osmosis (RO) uses a specialized membrane material that is selective about what it allows to pass through, and what it prevents from passing. The RO membranes pass water very easily because water has a small molecular size, but membranes stop many other contaminants from passing through. Only water and small non-ionized (or non-charged) molecules are allowed to pass through. RO has become very popular for water purification applications due to its ability to remove both suspended and dissolved impurities without the need for regenerate chemicals. Reverse Osmosis systems can be found today in a wide range of facilities: kitchens, hospitals, refineries, power plants, semiconductor manufacturing facilities, manned spacecraft, sailboats, etc.

The heart of the reverse osmosis system is the "membranes". We realize the importance of this and strictly design all our systems as per the guidelines of the membrane manufacturers. All Reverse Osmosis systems are designed utilizing the latest generation spiral wound thin film composite polyamide membranes. These membranes have extremely high resistance to fouling and offer the best energy savings achievable globally. The Reverse Osmosis units are designed in a compact skid with easy access to monitor check points and sample valves. These features come from the extensive field experience that we have in operating and maintaining the plants in over 6 countries. The standard systems are offered with the manual option and field instruments to monitor the performance and necessary safety interlocks to protect the membranes.

Typical packaged system comprises of

• 10 micron cartridge pre filter

• Flow switch

• Pressure booster pump

• Membrane modules

• Reject control valves

• Tubing and fittings

• Permeate flow indicator

• Pressure gauges

• Automatic ORP dump valve control

Optional Upgrade packages include

• Feed pump

• Pre-treatment filter

• Chemical dosing systems

• Auto flushing

• Micro PLC based controller

• CIP system with cartridge pre filter

Industrial RO Units

We offer industrial models to meet the brackish water treatment requirement of the industries. The industrial units are constructed based on a process expertise and field experience that we possess backed by leading membrane manufacturers like Hydranautics and Toray.

Industrial units are custom-made to meet a variety of applications to suit individual customers. Precise engineering helps to produce RO systems that are efficient and dependable for years. All industrial units utilize the state-of-the-art latest generation thin film composite polyamide membranes.

The Reverse Osmosis block is built as a compact and rugged skid with aesthetic piping. As an option we supply stainless steel / FRP housing for the membranes. The piping for the RO systems is available in normal SS 304 / SS 316 to higher versions like electro-polished stainless steel for specific applications. The basic versions are offered with manual option with online monitoring instrumentation with all safety interlocks, and a completely pre-wired control panel and an electrical switch gear panel.

The basic versions can be easily upgraded to a high level of automation with either a PLC based control system

De-Mineralisers

We offer an array of pre-engineered packaged de-mineraliser units and custom-built de-mineraliser to meet individual customer requirements.

Packaged De-mineralizes comprise of two pressure vessels in MS / FRP filled with Strong Acid Cation and Strong Base Anion resin respectively. All packaged plants are skid mounted, completely assembled including necessary piping valves and chemical tanks for regeneration.

De-gasifiers In this we offer a full range of degassers to suit the packaged and custom-made de-mineraliser. Degassers when installed downstream of the cation unit removes the carbondioxide, thereby reducing the load on the downstream unit. This results in cost savings by way of reduced chemical consumption. Standard units comprise of a tower in mild steel rubber lined / FRP construction along with a blower and transfer pump in stainless steel construction. Additional pump and blowers are offered as options.

Custom Designed DM Plants To meet specific customer requirements, we have built de-mineralisers incorporating Weak Acid Cation and Weak Base Anion to handle water containing high amounts of alkalinity, chlorides and sulphates.

All DM units are available as manual, semi-auto or full-auto options with PLC based control systems. Automatic systems can be easily upgraded to be linked to client DCS if required.

Mixed Bed De-mineralisers Mixed bed de-mineralisers are used on the downstream of the DM unit to achieve high purity levels in the treated water. We confer packaged and custom-built mixed bed de-mineralisers. These mixed bed units comprise of a single vessel with a mixture of cation and anion resins and are offered with complete service and regeneration piping, self supportive skid foundation and chemical tanks for regeneration