Marine Auxiliary Machinery 7e potx

[...]... controlled by thermo-pneumatic devices It is usual to make provision for warming the fresh circulating water before the main engines are started, either by steam or by circulating from the auxiliary jacket water cooling circuit The auxiliary sea-water cooling circuit for generator diesel prime movers may have its own sea inlet and pumps for circulation, with a cross connection from the main sea-water circulation...This page intentionally left blank 1 Main propulsion services and heat exchangers The heat produced by running machinery, must be removed to ensure the satisfactory functioning of the equipment Cooling is achieved primarily through circulation of water, oil and air but the abundant supply of sea water is normally... flow which is better than that of cupro-nickel It is also resistant to sulphide pollution in sea water While titanium has great corrosion resistance because it is more noble than other metals used in marine systems, it does tend to set up galvanic cells with them The less noble metals will suffer wastage unless the possibility is reduced by careful choice of compatible materials, coating of the titanium,... water The three sections are (1) the sea-water circuit; (2) the high temperature circuit; and (3) the low temperature circuit The duty sea-water pump takes water from the suctions on either side of the machinery space and after passing through the cooler it is discharged straight overboard The main and stand-by pumps would be of the double entry centrifugal type but, as an alternative, a scoop arrangement... salt-water system for the central cooling arrangement will be of the high quality needed to limit corrosion/erosion problems Water in the high temperature circuit, is circulated through the main engine and auxiliary diesels by the pumps to the left of the engine in the sketch At the outlet, the cooling water is taken to the fresh water distiller (evaporator) where the heat is used for the evaporation of... schematically in Figure 1.18 The unit comprises a stack of U-tubes contained in a fabricated mild steel condenser shell on which is mounted a single element two stage air ejector The condensate from the main or auxiliary condenser is used as the cooling medium, the condensate circulating through the tubes whilst the air and vapour passes through the shell The high velocity operating steam emerging from the first... the inter (or first stage) condenser Most of the steam and vapour is condensed when it comes into contact with the cool surface of the tubes, falls to the bottom of the shell and drains to the main or auxiliary condenser The remaining air and water vapour are drawn into the second stage ejector and discharged to the after (or second stage) condenser The condensate then passes to the steam drains tank .