Page 161 - Introduction to Marine Engineering
P. 161

Auxiliaries



























                                           J
                              Extent of  packaged plant
                Gate valve
                                         1  WCs and urinals
                Butterfly  valve
                                         2  Separation section
                Non return valve        3  Separated liquids tank
              £s  Screw down non return valve  4  Separated solids tank
                                         5  Tablet tray
               Ad Pressure relief  valve  6  Treatment  tank
                                        7  Self cleaning filter
                                        8  Grinder  pump
                                        9  Sullage pump
                                        10  Sanitary  pump
                                        11  Sanitary pump
                                        12  Accumulator
                                        13  Control panel
                                        14  Sullage tank
                                        15  Overflow
                                        16  Overboard discharge
                                        17  Deck discharge to shore facility
                                        18  External flushing water supply
                                        19  Pressure gauge
                                        20  Treatment  tank  vent
                                        21  Sullage tank vent
         Figure  7.9 Chemical sewage  treatment plant



          aeration  compartment  where  it  is  digested  by  aerobic  bacteria  and
          micro-organisms,  whose existence  is aided by atmospheric  oxygen which
          is  pumped  in.  The  sewage  then  flows  into  the  settling  compartment
          where  the  activated  sludge  is settled  out.  The  clear  liquid  flows  to  the
          chlorinator  and  after  treatment  to  kill  any  remaining  bacteria  it  is
          discharged.  Tablets  are  placed  in  the  chlorinator  and  require
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