Reverse Osmosis Systems
An industrial water purifier, or an industrial RO water purification system also known as Reverse Osmosis, is one of the water purification methods whose process is inspired by nature. The design and construction of the industrial RO water purifier utilize the general principle of freshwater's tendency to migrate toward saltwater. Given the problem of water scarcity in modern life and the need for water desalination for various industrial and household applications, the production of industrial RO desalination systems is of the utmost importance
In reverse osmosis water desalination, raw (untreated) water is pumped under pressure into a chamber containing a semipermeable membrane. Since almost only pure water can pass through the membrane, nearly pure water is produced on one side, while the concentrated water containing impurities is produced on the other. This external pressure is greater than the natural osmotic pressure, so smaller molecules pass through the membrane's pores, while larger molecules are unable to pass through.
It should be noted that the pore size of a membrane is even smaller than that of a virus or bacterium. Larger molecules are carried away in a side stream and are discarded. In general, the reverse osmosis process works as follows:
Brine with high salt content enters the system
A pressure pump is used to transfer the brine to the fresh water side.
In the path of the brine flow to the fresh water side, a semi-permeable membrane with very small pores is placed to prevent salts from passing into the fresh water section.
After several uses, the reverse osmosis system requires the filter and semi-permeable membrane to be cleaned using various methods, such as backwashing and chemical agents.
It is very important to note that depending on the water type and its mineral content, pre-treatment may be necessary. For this purpose, various devices such as ultrafiltration, carbon filters, and sand filters, etc., are used. Using these equipment reduces a large amount of water contaminants, which prevents damage to the reverse osmosis membrane and increases its lifespan
Industrial Reverse Osmosis (RO) Water Purification System EquipmentTo implement the RO water purification process, the following equipment is required
Pre-treatment system including sand filters, carbon filters, and cartridge filters
Semipermeable membrane
High-pressure pump
Antiscalant injection package, including an injection pump and tank
Caustic and acid injection package, including an injection pump and tank
Mounting chassis
Power distribution board and control circuit
CIP system
High-pressure multistage pump: Provides the pressure required for water to pass through the membrane in the reverse osmosis process.
Feed pump or sand filter pump: Injects raw water into the sand filter at an appropriate pressure for initial treatment.
Make-up pump: Responsible for transferring water from the source into the unit.
Jumbo filter housing: A housing for holding and protecting larger filters, such as fiber or carbon filters.
Membrane filter or membrane: The main part of the reverse osmosis system that desalinates water by removing small contaminants.
Fiber/fabric filter: Removes sediment, sand, and suspended particles larger than 5 microns from the water.
Pressure Vessel: A cylindrical chamber that houses the membranes and withstands the pressure required for the purification process.
Activated Carbon: Absorbs chlorine, chemicals, color, and unpleasant odors from the water.
Fiberglass Sand and Carbon Filter Tank: Tanks for holding sand and carbon filters that perform the pre-filtration process.
Steel Cartridge Filter Housing: A housing for steel cartridge filters used in specific industries
UPVC Pipes and Fittings: Used for transporting water in various parts of the system and are resistant to corrosion.
Pressure and Low-Pressure Switches: These switches control the incoming water pressure and shut down the system if the pressure goes above or below the permissible limit to prevent damage to the pump.
Stainless Steel Fittings: Used to connect various components and are highly resistant to pressure and corrosion.
Pressure Gauge: Displays the water pressure at different points in the system, such as the inlet and outlet of the membranes.
Flow Meter: Measures the flow rate of water in the feed and effluent lines.
REVERSE OSMOSIS CONTROLLER: The device's control board that manages the flushing, pressure, and pump operation processes.
Sand Filter Valve: Used to control the water flow and perform backwashing operations in the sand filter.
Automatic Sand Filter Valve: This valve automatically performs the backwash and rinse operations of the sand filter.
Dosing Pump: Adds chemical solutions, such as scale inhibitors and anti-scalants, to the incoming water to prevent membrane damage.
Industrial Water Purification System Control Equipment and Instruments
The process of transferring water through a semi-permeable membrane to remove ions, salts, and contaminants requires applying pressure, with the amount of pressure applied to the water depending on the level of contaminants and other factors. For this reason, control equipment is used in various parts of the device to ensure the final water output achieves over 98% removal of salts and 100% removal of bacteria and viruses. The most important control equipment used in the industrial water purifier produced by the Haft Industrial Group includes:
Flowmeters
Steel or SuperPipe and V.C. fittings for high and low pressure lines
Flow control valves, sampling valves, and pressure relief valves
Electrical conductivity meter Electrical Conductivity Meter (conductivity meter)
pH Meter
Pressure Gauge
Low Pressure Switch & High Pressure Switch
Ways to Improve Quality in the Water Desalination Process
One of the most important and primary factors that determines the quality of the reverse osmosis output is the TDS level, which should be reduced as much as possible. To improve the efficiency and performance of the equipment and the reverse osmosis process, there are several strategies, which include:
Choosing a Standard Membrane for the Reverse Osmosis System
In addition to the pump, chassis, and other components used in the design of these systems, the membrane is of the utmost importance and has a direct impact on the efficiency of the industrial water purification system. Therefore, a suitable membrane must be used that is appropriate for the type of water and its dissolved salts. The pore size of the membranes is very important, and the appropriate membrane must be selected based on the type of water and the salts and particles present in it. It should also be noted that membranes must be periodically regenerated or replaced using backwashing or other methods.
Reverse Osmosis Pretreatment
One of the most important steps to improve the efficiency and performance of reverse osmosis is to perform pretreatment. Based on the analyses conducted on the water, the type of process implemented for pretreatment is determined. Accordingly, the pretreatment may involve either hardening or filtration! The water produced in this stage will have a lower level of contaminants and salts. As a result, the membranes will accumulate deposits more slowly, and their regeneration will be required at longer intervals
RO Water Purifier Design
In the design of an industrial RO water purifier, there are several factors that, if not observed, can negatively impact the device's efficiency and performance. One of the most important of these is designing based on the type of salts present in the water. The appropriate filter and membrane for their removal should be used, taking into account the type and amount of salts present in the water. Additionally, the capacity of the industrial water purifier must be measured and calculated based on environmental conditions. The selection of the housing material and the corrosion resistance of all internal components must also be made in accordance with standards.
In this article, an overview of the reverse osmosis system was provided. At the end, based on the water type and operating conditions, the appropriate reverse osmosis system and its capacity will be estimated.
