Water Pressure in Underwater Dredges

In order to comprehend why this occurs remember to keep in mind that he energy of the water outside that pushes the water inside the tube is impending, or kept and it cannot be utilized until there is less pressure inside the tube. In other words, before all the energy can be utilized in order to give to the momentum of the column of water that is inside the tube, the water need to be forced out by the jet. For this reason the energy of the jet can leave the shorter column of water in the mixer a bit more times every minute than it would be able to in the ten foot column of the suction hose.

The last idea we just gave has many times been explained by saying that the suction is obtained by less amount of friction in the different pipes. However, this is not so. The forces of friction that are in the suction tube are equal no matter where you were to place the jet nozzle. Due to the fact that almost the same amount of water goes through in each circumstance these losses or gains must amount to nothing.

It is likely the high-pressure tube has a coefficient of friction that is the same or less than the coefficient of glass that is around 0.2. In other words if the pump were letting out 100 gpm from its outlet, the discharge through the plastic pipe of around 100 feet in length would be at 8 gpm. Due to the fact that the length of the moveable ejector high pressure tube is rarely over eighteen feet in length, and beside the fact that the water that is inside is moving down in order for gravity to speed it up, it is not likely that there is any loss of head whatsoever.

In most cases people should not concern themselves with the pressure losses that have been pointed out. Thankfully the modern dredges are made in a much better way and have a considerable amount of energy to spare for almost all types of situations and only when they are being used at their full capacity can the differences in effectiveness and efficiency be noticed.

So if the effectiveness of the moveable ejector is reduced why is that is has not disappeared completely? There is an easy way to explain this. There is not any other type of suction nozzle that works as effectively when working in places that have shallow water. There are even a lot of instances that are known of that this type of ejector works efficiently in less than six inches of water. All that is needed is sufficient depth in order to cover the mouth of the suction nozzle and enough water is obviously required to supply to the suction pump.