Global Water Crisis

Global freshwater resources are threatened by rising demands from many quarters. Growing populations need ever more water for drinking, hygiene, sanitation, food production and industry. Climate change, meanwhile, is expected to contribute to droughts

1.2 billion people all over the world live without clean drinking water and 2.6 billion people without sanitary facilities
Major Region : Southeast Asia, South Asia, Africa South of Sahara, East Asia

Status of Water Shortage

Because of the increase of the world's population, especially countries like Middle East, Africa, Indonesia, Vietnam, India, and etc. under rapid economic growth, significant reduction of water use per capita is happening.

The deepening of uneven distribution of global water resources, is occurring significant water shortages in specified countries. (1/5 countries around the world, 3 billion people)

Large amounts of sewage and waste water generated by the rapid industrialization are contaminating the ground and the underground water. The reduced amount of drinkable clean water causes various water-born diseases. (each year, 5 million people killed)

Water Conversion Methods

Water Conversion Methods

Reverse Osmosis(RO) Filter System

• Need for clean sea water : Serious sea water contamination issue in the island regions in the west and south seas in Korea →Demand for tube well
• Must Operate Continuously : Intermittent operation, frequent filter replacements, unexpected increase of cost.
• Bacillus Not Eliminated : Dosing of chemicals (condenser, reducer: sulfuric acid, chlorine), increase of operating cost
• Pre and Post Treatment Systems / Professional Operator

Disadvantage : Accident and risk in the handling of dangerous chemicals by non-professionals, operating cost increase

Evaporation Distiller System(MED, MSF & MVR)

Evaporation distiller system, as the name implies, involve the heating of saline water and collecting the condensed vapor (distillate), to produce pure water. Evaporation distiller systems have been used for brackish water desalination and sea water desalination and can be sub-divided into three groups:
Multi-Effect Distillation(MED), Multi-Stage Flash Distillation(MSF), and Mechanical Vapor Recompression Distillation(MVR).

Multiple-effect distillation :
Multiple-effect distillation (MED) is a distillation process often used for sea water desalination. It consists of multiple stages or "effects". In each stage the feed water is heated by steam in tubes. Some of the water evaporates, and this steam flows into the tubes of the next stage, heating and evaporating more water. Each stage essentially reuses the energy from the previous stage.
The tubes can be submerged in the feed water, but more typically the feed water is sprayed on the top of a bank of horizontal tubes, and then drips from tube to tube until it is collected at the bottom of the stage.

Multi-stage flash distillation
Multi-stage flash distillation(MSF) is a water desalination process that distills sea water by flashing a portion of the water into steam in multiple stages of what are essentially countercurrent heat exchangers.

Mechanical Vapor Recompression(MVR) :
The main principle of Mechanical vapor recompression (MVR) is a direct compression of the evaporated steam to a higher pressure, thus temperature, so it can be re-used for the heating process in the Evaporator.

MVR is utilized to re-use waste steam to replace expensive steam generation by taking it to a higher pressure level. The MVR system is an energy efficient solution, since only 20 kW electrical MVR power per metric ton of steam is needed to rise the temperature per stage by 6-7°C.

Specific Comparisons of MVR & RO Distiller

Specific Comparisons of MVR & MED, MSF

MVR System

MVR Distiller
Distillation of sea water, brackish water, infected underground water, malignant waste water through a very effective heat pump system using mechanical vapor recompression (MVR) method for production of high purity water for drinking and industrial reuse.

Application

• Island region with drinking water insufficiency
• Inland region with underground water contamination, brackish water and sea water
• Facilities creating malignant waste water

Applications : MVR Drinking Water Conversion System

Features

• Simple design and constituents, only electric power source needed for operation
• 100% Naturally sterilization with high temperature : getting "ZERO" virus water
• Very Low specific energy consumption (coefficient of performance[COP] > 20)
• No chemicals dosing and No need of pre & post treatment
• Easy maintenance due to a compact MVR system with high speed turbo steam compressor
• Simple and reliable automation system without special crew training for operation
• Easy full access to heat transfer surfaces and steam compressor for after service
• Simple raw water pre-treatment, selectable heat exchanger materials
  (sea water : Titanium, muddy river & underground water : STS316L, STS304)

Research & Development Goal : Energy recovery & saving

Using the evaporation method to get clean water or salt is very common. Nowadays, reducing the energy needed to run the evaporation method based machines is a hot issue.

First, the simple SE(Single Effect) method takes about 620kcal to make 1L of distilled water. We boil the water and collect the steam. Finally, we cool it down to get pure water from the steam. But, this means that we are throwing away all the heat energy into air through cooling water. The water manufacturing cost increases as we waste more energy. To prevent the energy loss, people put the machines in serial lines, which is called MED or MSF method. But these were not quite satisfactory for us.

So, we thought to compress the low pressure steam with a compressor(which works with 20kcal of electric energy). We then used this compressed steam to boil the original water where the steam came from via heat exchangers. This became an ideal machine, MVR, which can recycle up to 90% of the original input energy shown in the SE method.

Energy Balance Scheme of MVR Distiller

When 1 liter of 20°C raw water receives 620 kcal of energy, saturated steam is made through 100°C saturated liquid.
As this low pressure steam is compressed with a turbo compressor, using approximately 20 kcal of electric energy, the temperature rises up to 107°C.
Thermal energy of this high pressure 107°C steam is transferred to 100°C raw water through a large latent heat exchanger and the energy of the 107°C condensed water is transferred to 20 ℃ raw water through small sensible heat exchangers, finally condensed water of 25°C is made.
For an efficiently energy utilization, the variety of operational temperature difference is achieved by variable speed operation of steam compressor (3~10°C).
By inputting 20 kcal of electric energy, 620 kcal of thermal energy is recovered and recycled.

Water Recovery Rate and Power consumption

The input raw water can be concentrated until max. 100,000ppm(=10% density) by MVR Distiller
→ Water recovery rate = {1-TDS/(100,000ppm)} x 100
* Example : in case of TDS 15,000 of input raw water
Water recovery rate ={1-15,000/100,000}*100=85% , Rejected water rate : 15%
It means we are able to extract pure drinking water of 85% from input raw water.

Power consumption calculation formula, based on our experiences :
→ Power consumption(kWh/ton) = 145/100 * (concentration)^2 + 27
* Example : in case of TDS 15,000 of input raw water, concentration may be 1.5, expressed by percentage of density of impurity dissolved in water.
Power consumption = 145/100 * 1.5^2 + 27 = 30.3(kWh/ton)

Original technologies required for developing MVR

• High speed blower, steam compressor, plate & pipe type heat exchanger
  : designing/manufacturing/operating technologies
• Automation/control and system integration technologies
• 100% self-developed technologies

Main Component

• evaporation tank
• condensation tank
• (pipe type) latent heat exchanger
• turbo steam compressor
• circulation pump
• sensible heat exchangers
• electric heater condensed/concentrated/raw water pump
• equipment controller & automatic operation panel

Automatic Controller

HMI Hardware Features :

• Embedded high speed CPU
• Visualizes up to 16.7 mega colors
• Supports serial(RS232C, RS422, RS485) and Ethernet communication
• Resistive type soft touch
• Supports Window 7 (32 bit)
• Including USB and SD memory card slot for data storing

HMI Software Features : (provides the same environment as SCADA)

• Edit project data
• Defines TAGs in Real-time DB
• Configures network
• Sets up advanced functions (Log, Alarm, Trend, Recipe...)

High Performance Control System

The system is composed of the basic unit made of the high performance programmable logic controller (LS_GM6_PLC), with the special modules(sending & receiving 4-20 mA signal from/to sensors, temperature, pressure, level meter, flow meter, inverters, etc), and the 16,700,000 true color HMI touch screen used for taking and confirming a user's operational commands, displaying status and trends, and storing of data.
It is equipped with RS232, RS485, and Ethernet communication ports to communicate with other equipment, and it is programmed to enable remote operation with an existing other system, and also to control a number of MVR distillers efficiently and individually.

Visible & Easy Operation on Human-Man-Interface System with Full Colored Touch Screen helps your reliable and easy operation:

The visually and easy-to-use HMI touch screen panel takes the user input parameters required for operation, shows the status map, the trends of the major parameters, alarms, and the causes of any errors, as well as the storage capacity of the operational data.
Following the directions on the touch screen, you first push the start button, and simply watch the operational status.
If there are any problems with the equipment, it shows where, why, and when the problems began at a glance, automatically saving the data and stopping the equipment safely.
In other words, you can become a professional operator without any special training.

MVR Distiller Model & Specification

**Fixed Model

**Moving Type

- All models can be supplied by either fixed type or moving type according to user’s requirement.
- All models except ADR 200 can be supplied by moving type.

** Tiling-Up Model

- According to user’s requirement, we can meet the requested capacity by tiling-up model thru combining our MVR distiller ADR 200.
- In case of increasing water consumption after installing MVR distiller, it is possible to add additional MVR distiller easily.

Water Production Cost Analysis

Drinking Water Quality Check By Governmental Institute

Installation Case

• Maritime Affairs and Fisheries Office Control Center at Busan New Port
• Water Consumption : 20 ~ 50 (ton/day)