Discover the Components of a Vacuum Distillation Fresh Water Generator

Table of Contents

1. Introduction
2. Components of a Vacuum Distillation Based Fresh Water Generator
   • 2.1 Heat Exchangers
   • 2.2 Deflector
   • 2.3 Demmeister
   • 2.4 Safety Valve
   • 2.5 Vacuum Breaker
   • 2.6 Sight Glass
   • 2.7 Adductor
   • 2.8 Distillate Pump
   • 2.9 Salinometer
   • 2.10 Three-Way Valve
   • 2.11 Flow Meter
   • 2.12 Hot Jacket Water Inlet
   • 2.13 Jacket Water Outlet
   • 2.14 Cooling Water Inlet
   • 2.15 Cooling Water Outlet
   • 2.16 Ejector Pump
   • 2.17 Strainer
   • 2.18 Overboard Valve
   • 2.19 Electrical Panel
   • 2.20 Indicating Instruments
   • 2.21 Compound Gauge
   • 2.22 Pressure Gauge
   • 2.23 Thermometers
   • 2.24 Vacuum Gauge
3. Step-by-Step Operation of a Fresh Water Generator

Components of a Vacuum Distillation Based Fresh Water Generator

A vacuum distillation based fresh water generator is a complex system that consists of various components working together to produce fresh water. Let's dive in and take a closer look at each of these components:

2.1 Heat Exchangers

At the heart of the fresh water generator, there are two essential heat exchangers - the bottom heat exchanger (evaporator) and the top heat exchanger (condenser). The bottom heat exchanger is responsible for the initial stage of the distillation process, while the top heat exchanger facilitates condensation by allowing water vapor to come into contact with the outside of the cold tubes.

2.2 Deflector

The deflector is a component that changes the directional flow of the vapor to remove any moisture carried along with it. It plays a crucial role in ensuring the quality of the distilled water produced.

2.3 Demmeister

As the vapor progresses, the demmeister comes into play. This critical component is strategically placed in the vapor flow path to remove any mist carried with the vapor. Its presence ensures the purity of the distilled water.

2.4 Safety Valve

Safety is of utmost importance in any system, and the fresh water generator is no exception. A safety valve is installed to safeguard against overpressure, preventing any potential damage or accidents.

2.5 Vacuum Breaker

The vacuum breaker comes into action when the fresh water generator is stopped. Its purpose is to break the vacuum, allowing for a smooth shutdown of the system.

2.6 Sight Glass

The sight glass provides a visual indication of the boiling of water inside the generator. It allows operators to monitor the process and ensure it is running smoothly.

2.7 Adductor

The adductor is a component that helps to maintain the required vacuum inside the shell of the fresh water generator. It aids in sustaining the optimal functioning of the system.

2.8 Distillate Pump

The distillate pump is responsible for extracting the fresh water from the condenser. It ensures the continuous flow of distilled water to the desired destination.

2.9 Salinometer

To test the salinity of the water produced, a salinometer is used. This instrument provides accurate readings and helps in ensuring the quality of the fresh water.

2.10 Three-Way Valve

The three-way valve enables versatile control over the water flow, allowing for efficient routing depending upon the salinity level required during operation. It ensures that the water is directed to the appropriate destination based on its salinity level.

2.11 Flow Meter

A flow meter is installed to accurately measure the quantity of fresh water generated. It provides valuable information about the system's performance and helps in monitoring the production.

2.12 Hot Jacket Water Inlet

The hot jacket water inlet is a crucial part of the distillation process. It allows for the entry of heated water into the evaporator, ensuring optimal heating conditions.

2.13 Jacket Water Outlet

The jacket water outlet is where the cooled water exits the evaporator after the heat exchange process. It plays a vital role in maintaining the temperature control of the system.

2.14 Cooling Water Inlet

The cooling water inlet is the entry point for the cooling water that circulates through the condenser. It helps in maintaining the optimal cooling conditions required for efficient condensation.

2.15 Cooling Water Outlet

The cooling water outlet is where the cooled water exits the condenser. It has absorbed heat from the vapor and facilitated its condensation, contributing to the fresh water generation process.

2.16 Ejector Pump

The ejector pump creates a vacuum in the generator and supplies seawater. It plays a crucial role in the distillation process, ensuring the continuous flow of water and efficient operation.

2.17 Strainer

To filter out any impurities or debris from the water before it enters the pump, a strainer is installed in the suction side of the ejector pump. It helps in maintaining the quality of the water and prevents any blockages in the system.

2.18 Overboard Valve

The overboard valve of the ejector pump allows for the discharge of water from the system after its usage. It ensures proper drainage and efficient operation of the fresh water generator.

2.19 Electrical Panel

The electrical panel is used to start the ejector and distillate pump. It provides control and monitoring capabilities for the operators.

2.20 Indicating Instruments

Various indicating instruments are fitted to monitor and assess the system's performance. These instruments include compound gauges, pressure gauges, thermometers, and a vacuum gauge.

• 2.21 Compound Gauge
• 2.22 Pressure Gauge
• 2.23 Thermometers
• 2.24 Vacuum Gauge

These indicating instruments collectively enable operators to monitor and regulate the fresh water generator, ensuring its efficient and reliable operation.

Step-by-Step Operation of a Fresh Water Generator

To understand how a fresh water generator operates, let's go through the step-by-step process:

1. Shut the vacuum breaker valve and note the flow meter reading.
2. Open the suction side valves of the ejector pump and purge the air from the system using the vent valve on the strainer.
3. Open the discharge side valves and the overboard valve.
4. Switch on the electric power and check the voltmeter reading.
5. Start the ejector pump and observe the ammeter reading. Note the ejector pump suction and discharge side pressures.
6. Open the seawater feed inlet valve to the evaporator. The ejector will suck the air and brine from the shell, creating a vacuum inside.
7. Monitor the vacuum gauge reading. Once it goes below 0.9 bar, open the jacket water outlet valve and then the jacket water inlet valve to the evaporator.
8. Partially close the jacket water bypass valve to achieve the required heating in the evaporator.
9. Note the temperature gauge readings of the jacket water at the inlet and outlet. Observe the boiling process taking place in the evaporator through the sight glass.
10. When the sight glass in the distillate line is filled with the distillate, open the valves in the distillate line and start the distillate pump. Monitor the ammeter reading.
11. Regulate the discharge valve of the ejector pump to maintain the water level at half of the gauge glass.
12. Observe the salinometer reading. When the salinity of the distillate exceeds 10 PPM, the three-way valve transfers the distillate either to the bilge well or back to the fresh water generator shell. When the salinity drops to less than 10 PPM, the three-way valve transfers the distillate to the fresh water storage tank.
13. This concludes the step-by-step operation of a fresh water generator.

Highlights

• Vacuum distillation based fresh water generators consist of various components that work together to produce fresh water.
• The heat exchangers (evaporator and condenser), deflector, demmeister, safety valve, vacuum breaker, sight glass, adductor, distillate pump, salinometer, three-way valve, flow meter, and other instruments are essential parts of the system.
• The operation of a fresh water generator involves starting the ejector and distillate pump, heating the water in the evaporator, and monitoring various parameters to ensure the production of high-quality fresh water.

FAQs

Q: How does a vacuum distillation based fresh water generator work? A: A vacuum distillation based fresh water generator works by creating a vacuum inside the shell. Sea water is then fed into the evaporator, where it is heated by the jacket water. As the seawater evaporates, the vapor is condensed using cooling water in the condenser, resulting in the production of fresh water.

Q: What is the purpose of the safety valve in a fresh water generator? A: The safety valve is installed to safeguard against overpressure. It ensures that the system remains within the safe operating limits and prevents any potential damage or accidents.

Q: How is the salinity of the distilled water monitored in a fresh water generator? A: The salinity of the distilled water is monitored using a salinometer. This instrument provides accurate readings and alerts operators when the salinity exceeds the desired level, allowing appropriate actions to be taken.

Q: What are the indicating instruments used in a fresh water generator? A: Indicating instruments such as compound gauges, pressure gauges, thermometers, and a vacuum gauge are used in a fresh water generator to monitor and assess the system's performance. These instruments provide valuable information about pressure, temperature, and vacuum levels, ensuring optimal operation.

Q: How is the flow of fresh water controlled in a fresh water generator? A: The flow of fresh water is controlled using a three-way valve. This valve enables the operator to route the water flow based on the salinity level. It can direct the distillate either to a fresh water storage tank or back to the fresh water generator shell, depending on the requirements.

Q: What is the role of the ejector pump in a fresh water generator? A: The ejector pump creates a vacuum inside the generator and supplies seawater. It plays a crucial role in maintaining the continuous flow of water and ensuring the efficient operation of the fresh water generator.