Reasons for Location
Sometimes the location of a particular machinery or equipment is not merely due to aesthetic or design reasons but there might be some operational features associated with the specific location. Given below is a list of reasons why some equipment is found at the middle platform
Why generators are provided at the middle platform?
Generator are provided at the middle platform because in the extreme situation of flooding of bottom platform. immediate shutdown of the power supply or black out condition can be avoided.
Why Fresh Water Generator is located at the middle platform?
For normal steam generation the temperature is equal to the boiling point of water that is at 100o c at atmospheric pressure. In fresh water generator the temperature to which the sea water is heated is lower than that but because of it being at low pressure, the steam is generated. When the pressure is reduced, the boiling point of water also reduced; this is the basic principle behind the fresh water generator.
Normally the waste heat is used to heat water in the fresh water generator. Waste heat from the jacket cooling water or steam line can be connected for the purpose. If the fresh water is generated is located at the bottom platform, there would be a back pressure of sea water and sufficient vacuum will not be created. Hence the reason for it to be placed at the middle platform.
Why lube oil & heavy oil heaters are provided?
Heavy oil and lube oil is heated before entering the purifier for the effective purification of the oil, and since the purifiers are located at the middle tier, the heaters have to be there.