“Water, water, everywhere, nor any drop to drink.”
See how precisely my buddy from the 18th century, Samuel Taylor Coleridge, penned down the significance of a Fresh Water Hydrophore System in a ship… Water, one of the most fundamental necessities of humankind since day one is highly valued on board a ship.
Freshwater is essential for drinking, cooking, toilets, kitchen, laundry, etc. and an uninterrupted chain of supply is inevitable across all these domains inside a ship at all times.
May I present to you the most viable solution, Hydrophore.
Table of Contents
What is a Hydrophore ?
A hydrophore is a scientific instrument used to draw up water samples from any source at any depth. A hydrophore system is a pressurized reservoir, which in addition to obtaining the sample, stores it and transports it to any region with minimum to a maximum degree of requirement continuously all around its pathways across various distances.
The hydrophore tank is filled with 70% water and the rest with air. The air is supplied and kept at a required pressure value and the force imparted upon the water acts as its driving force like a spring. It might be stored on the port side and/or the starboard side on the bottom of the ship, preferably.
This system can be seen widely implemented in the sector of fire force, sprinkler systems, and of course in marine vessels.
Why a Hydrophore System?
You might be wondering that if transportation is the objective, why not use a pump??
A hydrophore system is preferred over a centrifugal pump because of 2 key reasons;
- Electrical energy consumption: A centrifugal pump requires electrical energy as input to work, while a hydrophore does not. So electricity can be conserved.
- Irregular pressure drops: In centrifugal pumps, frequent cut-in and cut-off (starting and stopping) of a motor causes irregularities in sustaining stable pressure values. So we use a hydrophore system that utilizes pressure energy for its mechanical work instead of electrical energy and would maintain stability in the pressure developed.
Parts of The System
The working mechanism will follow, but first, let’s take a look over the various moundings involved:
- Filling Valve: Fills the fresh water tank with water from the Fresh Water Generator and salinometer.
- Side Glass: Present in both freshwater tanks and hydrophore tanks and is used to check the quantity of water held.
- Inlet Valve – Filter – Null Return Valve: An arrangement of these 3 pieces of machinery is present in between the tank and hydrophore and each ensures the following work respectively.
- The inflow of water from the storage tank
- Extra filtering before admission
- Ensuring zero backflow
Connectivity of Hydrophore System
- Manhole doors: Located occasionally at the bottom of the tank to allow skilled personnel to enter and leave for maintenance.
- Drains: Located at the bottom to drain the water out.
- Service air valve: This is an auxiliary compressor that provides a low-pressure air supply into the tank, generally at 6 bar, after being filled with water.
- Pressure gauge: Measures the pressure of the contained air.
- Relief valve: Removes air if by chance the pressure value exceeds the expected.
- Vent pipe: Used in venting process while in maintenance or charging of the tank.
- Inlet valve and outlet valve: Works as the name suggests for the hydrophore tank.
The outlet further extends to various zones.
- Pressure switch: This is an important tool that has a prominent role in the working of the system and could be well explained in the next section hopefully.
TELL ME HOW IT WORKS ALREADY!
Okay then, let’s get into it.
The hydrophore tank, after being filled with 70% water, has incoming air which is maintained inside with pressure values;
Cut-in Pressure = 2.5 to 3.5 bar
Cut-off Pressure = 4.5 to 6.5 bar
If the pressure reaches:
- cut-in value: Water flows into the tank from the storage.
- cut-off value: The inflow is halted.
This is controlled by a start/stop switch and the pressure value differs according to different manufacturers.
- The water level continuously decreases due to repeated consumption.
- Thus the volume of air expands reducing the pressure.
- As the pressure lowers to the cut-in value the pressure switch gets activated, which is further connected to the start/stop switch and initiates the inflow of water.
- The flow progresses and the water level rises until it gets to a certain level where the pressure value equals the cut-off value.
- And then the pumping is stopped.
Thus the tank is filled and ready for the next round, repeat.
What is the Process of Charging Here?
Charging in a hydrophore system is simply the supply of compressed air into the hydrophore tank.
- Before commencement, the output valve in the tank is closed and the input valve is opened to ensure zero wastage.
- Now the pump is operated manually and water from the storage starts to fill the tank. The change in water level can be noted through a side-view glass that is calibrated.
- As soon as the level reaches 70%, the auxiliary service air valve is opened and air of 6 bar pressure flows into it.
- Now the pump is transformed back to the auto mode which ensures to terminate the inflow as soon as the pressure value reaches the cut-off value.
And the system is charged for action. Further, 2 cases of undercharging and overcharging can be expected;
- Undercharging: The pressure values set within the system are insufficient to act as the driving force and the water may not reach specific areas.
- Overcharging: The system gets highly pressurized and
- Leakage may occur
- May cause sputtering of water at outlets.
So the work is done?
Yepp, after all these ventures and a little bit of Ag+ ions to mineralize it for consumption, the water droplets can smother the thirst and needs of the mariners, seafarers, and other sea personnel anywhere in the ship. Giving no more need for my buddies to sing “nor any drop to drink.”