Docstoc

RTA-2

Document Sample
RTA-2 Powered By Docstoc
					                                           Service Bulletin                                                            RTA–2
                                                                                                                         05.10.88
                                           Technical Information to all Owners of                                      (Reprinted 09.02.98)
                                           Sulzer RTA – Type Engines
                                           except RTA38 and RTA48




                                           Water Drain from Charge Air Receiver
                                           and Charge Air Temperature



                                                                                                  Contents:                                   Page



                                                                                                  1.    INTRODUCTION                           1
                                                                                                  2.    CHARGE AIR TEMPERATURE                 1
                                                                                                  3.    CHARGE AIR RECEIVER                    2
                                                                                                  4.    WATER DRAIN PIPING SYSTEM 2
                                                                                                  5.    STORAGE / HANDLING
                                                                                                        OF CONDENSATE                          2
28.08.07.40 – Printed in Switzerland
      07.40




                                       Wärtsilä NSD Switzerland Ltd   PO Box 414           Tel. +41 52 262 49 22
                                       Wärtsilä NSD Schweiz AG        CH-8401 Winterthur   Fax +41 52 212 49 17
                                       Wärtsilä NSD Suisse SA         Switzerland          Tlx 896 659 NSDL CH
1.    INTRODUCTION
The amount of condensate from the water separator after air cooler depends mainly on the
charge air pressure, the charge air temperature and the relative humidity and temperature of
the inlet air.
When operating in humid tropical areas the condense water quantities may be up to 0.05 -
0.08 kg/kWh (on a 7 RTA 84 up to 1000 kg/h has been measured).
Accumulation of condensate in the charge air receiver has to be avoided since water in liquid
or evaporated state, swept along by the air flow can have a negative influence on the piston
running behaviour and can increase corrosive wear to piston rings and cylinder liners.
Experience gained so far, particularly on vessels running under extreme tropical conditions,
has shown that the current condensate system does not always ensure sufficient drainage.

2.    CHARGE AIR TEMPERATURE
The often found practice to raise the charge air temperature after air cooler(s) in order to
avoid condensation is no longer advisable as condensation can not always be avoided with
todays highly supercharged engines.
We still recommend to operate the air coolers as follows:
- full specified cooling water flow (sea or fresh water), i.e. no throttling at part load
- sea water inlet temperature 25 - 32_C; resulting scavenge air temperature about
  5 - l5_C higher than cooling water inlet temperature depending on engine load
- cooling water inlet temperature for central cooling systems 25 - 36_C; resulting
  scavenge air temperature about 5 - 10_C higher than cooling water inlet temperature
  depending on engine load
(see also Service Instructions section 025 resp. 0250).
As already mentioned, water contained in the scavenge air does not only have a detrimental
effect in liquid condensed form but also the vaporized or gaseous state can increase corrosive
wear to piston rings and cylinder liners. Such conditions are mainly observed when operating
in humid tropical areas and can be explained by the effect of water content in the combustion
air on the dew point, as indicated in the following diagram.

     _C                                                    1   Typical liner wall temp.

                         4                                 2   Dew point in cylinder
                                                   3           during expansion stroke
                                                               with normal cooler
                                               2               operation and water
                                                               separation at ISO cond.
                   1                                       3   Same at tropical cond.
                                                           4   Same at tropical cond. but
                                                               with elevated scavenge
                                                               temp. and thus high water
                                                               content in combustion air
                                                   load%

From the diagram it can be seen that the operating range with liner wall temperatures above
dew point can be extended when the scavenge air temperature is lowered and the absolute
water content of the scavenge air is reduced to a minimum.

                                            1/2
3.     CHARGE AIR RECEIVER
The following improvements may be beneficial to engines in service suffering from corrosive
wear of piston rings and cylinder liners. It is recommended to consult the engine builder case
by case.

3.1.   RTA 58, 68, 76, 84 and 84 M (enclosures RTA 2/1 and 2/2)
In general, openings C and D (RTA 2/2) are provided. If this is not the case they have to be
carefully burnt out to enable the condensate, which may accumulate in the respective spaces,
to flow out. At the bottom fixation for the water separators, steel plates have to be welded in
on both sides (detail E RTA 2/2) to prevent water from by passing the separators with the air
flow (see as well encl. RTA 2/1). Proper welding all around is required.

3.2.   RTA 52 and 72 (enclosure RTA 2/3)
Two different executions exist depending on the type of turbocharger. Both designs of charge
air receiver have been adapted to the new standard right from the beginning. Just the cutouts
(E) in the outer two side plates, bounding the water separator area, may have to be sealed.

3.3.   RTA 62 (enclosure RTA 2/3)
Engines in service may be adapted by fitting deflecting plates (G) and closing the cutouts (E)
in the outer two side plates, bounding the water separator area.
The triangular openings (K) at the bottom fixation of the water separator can be sealed.The
air deflecting plates (G) ensure that the separated condensate can drain to the piping system
without being picked up again by the air flow.
Closing the cutouts (E+K) prevents the condensate flowing into the other charge air receiver
spaces. Welding is to be carried out carefully.

4.     WATER DRAIN PIPING SYSTEM (enclosure RTA 2/4 and 2/5)
On the mentioned enclosures the two different piping system designs for
RTA  8 and 2 series" engines are compared. We recommend to install the automatic
condense water drainage system which will ensure sufficient cross sectional area for proper
drainage under all operating conditions (encl. RTA 2/6).
Some automatic drain valves may have been supplied with a rather fine meshed filter.
This filter must be removed.
A small by pass line permits a continuous limited flow of charge air and condense water.

5.     STORAGE / HANDLING OF CONDENSATE
As mentioned in the introduction considerable condense water quantities may have to be
dealt with.In case of drainage to the bilge such quantities may exceed the capacity of the (dry)
bilge concept and frequently cause high level alarms. However, on no account should the
drain cocks be closed to prevent alarms.
Drainage to a tank for pumping over board via the oily water separator should be considered.

ENCLOSURES: as mentioned




                                             2/2
                     WATER SEPARATOR DRAIN



                       RTA 84 M                                  RTA 58
                                                                 RTA 68
                                                                 RTA 76
                                                                 RTA 84




                           Ç
                          ÇÉÉÉÉÉÉÉÉÉÉ
                          ÇÇ
                          ÇÇ
                          ÇÇ
                           Ç
                          ÇÇÇÇ
                  ÉÇÇÇÇÇÇ ÇÇ
                          ÉÇ
                  ÇÇÇÇÇÇÇÉÇÇÇÇ
                  ÇÇÇÇÇÇÇ           B                        B
                  ÇÇÇÇÇÇÇ
                  ÇÇÇÇÇÇÇ                              AIR

                  ÇÇÇÇÇÇÇ
                  Ç  C
                  ÇÇÇÇÇÇÇ ÇÇÇÇ
                           ÇÇÇ
                  ÇÇÇÇÇÇÇ ÇÉÉÉÉÉÉÉÉÉÉ
                  ÇÇÇÇÇÇÇ ÇÇÇÇ
                     C                   Water drain




B-B
      Ç                     C-C
                                ÉÉ
      Ç                         ÉÉ
   ÉÇÇÇÇ
                                ÉÉ
    É Ç
      É                           É
                                ÉÇÇÇÇÇÇÇÇ
      É
   ÉÉ Ç                         É
                                ÇÉ
   ÉÉ
The condensate collecting space must be isolated
within the charge air receiver. The lateral openings
are to be sealed by welding-in small plates.


                                                                   RTA-2/1
RTA-2/2
                                                                                    0 = Water drain
                                                            R = 60 mm for RTA76, 84 and 84M
                                                                     R = 50 mm for RTA58 and 68
   ÉÉÉÉÉÉ      ÉÉ        ÇÇ
                É
               ÉÇÇÇÇ      É
                          ÇÇÇ
                            welded in
                            carefully
                É
               ÉÇÇÇÇ
                         ÇÉÇÇ
                                                        R                                  R
   ÇÇÇ
    ÉÉ         ÉÉ         É bar to be
                            Flat steel
    ÉÉ         ÉÉ         É
    ÉÉ
    ÉÉ                                                       D                             C
                                                                     already provided
    ÉÉ              E
                                                                    To be cut out if not
       D    D       D
  É0
  Ç É ÉÉ Ç ÉÇ               0
  É É ÉÉ É É
  ÉÇÇÇÇÇÇÉÇÉÉÉ                                          0            D    0
  ÉÉÉÉÉÉÉÉÉÉ
       E
  É É ÉÉ É ÉE          ÉE   E
                            É
                            Ç       E                                    E           C
                0
  É É ÉÉ É É ÇÇÇÇÇÇÇÇÇÇÇÇÉ
                  ÇÇ É
       C                C   C       C
  É É ÉÉ É É
  É É ÉÉ É
  Ç É ÉÉ É É ÇÇÇÇÇ É        É
       ÉÉ É É Ç Ç
  ÉÇÇÇÇÇÇÇÇÇÇÇ ÇÇÇÇ
  É É ÉÉ É É ÉÇÇÉÇ É   É    É
                  Ç
                  Ç
  É É ÉÉ É É ÉÇÇÇÇÇ É
                            É
                            É                               A                                    A
  É É ÉÉ É É
  ÇÇÇÇÇÇÇÇÇÇÇÇ    Ç    É
                  ÇÇÇÇÇÇÇÇÇÉÇ
       Turbocharger on free end                                 B-B turned by 90°
                                                                 B
                                        0       D       D            D       0
                 ÉÉ Ç Ç
                 ÉÉ É É É ÉÉ
            ÉÉÉÉÉÇÇÇÇÇÉÇÉÇÉÉÉÉÉÉÉÉ
                 ÉÉ É É É ÇÇ
                    É É É ÉÉ
                 ÉÉÉÉÉÉÉÉÉÉÉ    E           E       E           E        E
             É ÉÉ É É É ÉÉ
           ÇÇÇ          C
                               É    C           C       C            C       C             C
             É ÉÉ É É É ÉÉ     É
             É É ÉÉ É É É ÉÉ É É
           ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ
               É ÉÉ É É É ÉÉ É É
             ÉÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ
             É É ÉÉ É É É ÉÉ É É
             É É ÉÉ É É É ÉÉ É É
           ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ
                                                                 B
                            A - A turned by 90°
                                 CHARGE AIR RECEIVER
                         WATER SEPARATOR DRAIN

                                      E =Cutouts in the outer two side
                                         plates, bounding the water separator
                                         area, to be sealed.
                                      F   =Deflecting plates have been introduced
                                      G =Deflecting plates to be fitted
                                      H =Drain from charge air cooler housing
                                      I   =Condensate drain from separator
                                      K =Openings to be sealed, RTA 62 only
                                      0   =To drain piping system


    RTA62                            RTA52; VTR 454/564            RTA52; VTR 354
    RTA72; VTR 714                                                 RTA72; VTR 454/564
        É                        É                             É
        ÉÇÇÇ                     É                             É
        É
        ÇÇÇÇ                     ÉÇÇÇ
                                 ÇÇÇÇ                          ÇÇÇÇ
                                                               ÉÇÇÇ
        É
        ÇÇÇÉÉÉ                   É É
                                 ÇÇÇÇÉÉ                        É
                                                               ÇÇÇÉÉÉÉ
        É Ç
        ÇÇÇÉÉÉ
        É Ç
        ÇÇÇÉÉÉ
                                 É É
                                 ÇÇÇÇÉÉ
                                 ÇÇÇÇÉÉ
                                 É É
                                                               É Ç
                                                               ÇÇÇÉÉÉÉ
                                                               É Ç
                                                               ÇÇÇÉÉÉÉ
        É
        Ç Ç                      Ç
                                 É                             É
                                                               Ç Ç
        É
        É            AIR
                                 É
                                 É                       AIR
                                                               É
                                                               É                  AIR
    A   É                    A   É                             É
        É                        É                   E
                                                               É
        É                        É                             É
        ÉÉÇÇ Ç E
                                 ÉÇÇÇÇÇÉÉ                      É Ç Ç          E
B       É Ç
        ÉÉÉÇ Ç               G
                                 ÉÉÉÉ
                                 ÉÇÇÇ Ç
                                 ÇÉÉÉÇÉ                    F
                                                               É Ç Ç
        ÉÇÇÇÇÇ
        ÉÉÉÇ Ç                   ÉÉÉÉ
                                 É
                                 ÇÇÇÇÇÇ                        É ÇÉÉÇ
B
        É É
        É Ç
        ÉÉÇÇ
        ÇÇÇÇ É I         H
                                 ÇÇÇÇÇÇÉ
                                 ÉÉÉÉ
                                 É                             É ÉÉÉ
                                                               ÇÇÇÇÇÇÇÇ
        É Ç
        É
        É
        É
        ÇÇÉÇ
        0
        É
        Ç                        É
                                 ÇÇÇÇÇÇÉ
                                 É
                                 É
                                 0
                                 É
                                 Ç      É        H
                                                                  ÉÉÉ
                                                                          0
        É
        ÇÇÇÇ                     É
                                 ÇÇÇÇÇÇ
               A-A                                         B-B
                                                  É
                                                  É
                     E
                                                  É
                                                  É            K

        ÇÇÇÇÇÇÇ
        É                                         É
        É                                         É
                                                ÇÇÇÇÇÇÇÇÇ
        É                                         É
                                                                              RTA-2/3
             RTA58, RTA68, RTA76, RTA84, RTA84M ENGINES
              WATER DRAIN FROM CHARGE AIR RECEIVER

PREVIOUS DESIGN




                                         Cock
                                         Level switch for receiver
                                         drainage (high level alarm)
                                         on special request
                                         Sight glass
                                         Water drain from charge
                                         air receiver
                                         To bilge or oily-water
                                         drain tank
                                         To portable cleaning unit,
                                         cleaning tank or bilge
                                         Wash water from charge air
                                         cooler
                                         Throttling plate

NEW DESIGN



                                         Level switch for receiver
                                         drainage (high level alarm)
                                         on special request
                                         Automatic drain valve

                                         By-pass(permanently open)


                        1
                                         Water drain from charge
                                         air receiver
                                         To bilge or oily-water
                                         drain tank
                                         To portable cleaning unit,
                                         cleaning tank or bilge
                                         Wash water from charge air
                                         cooler
                                         Cocks; only shut cock 1
                                         when washing
                                         cooler in port

                                                                 RTA-2/4
                  RTA52, RTA62, RTA72 ENGINES
             WATER DRAIN FROM CHARGE AIR RECEIVER
PREVIOUS DESIGN




                                    Cock
                                    Level switch for receiver
                                    drainage (high level alarm)
                                    on special request
                                    Sight glass
                                    Water drain from charge
                                    air receiver
                                    To bilge or oily-water
                                    drain tank
                                    To portable cleaning unit,
                                    cleaning tank or bilge
                                    Wash water from charge air
                                    cooler
                                    Throttling plate


NEW DESIGN



                                    Level switch for receiver
                                    drainage (high level alarm)
                                    on special request
                                    Automatic drain valve

                                    By-pass (permanently open)

                                    Water drain from charge
                                    air receiver
                     1


                                    To bilge or oily-water
                                    drain tank
                                    To portable cleaning unit
                                    or cleaning tank or bilge
                                    Wash water from charge air
                                    cooler
                                    Cocks; only shut cock 1
                                    when washing
                                    cooler in port

                                                             RTA-2/5
                           AUTOMATIC DRAIN VALVE




                                                                          4
    1

    9
                                           ÇÇÇ
                                           ÇÇÇ
                                           ÇÇÇ
                                           ÇÇÇ
                                           ÇÇÇ
                                                                          2
                        ÉÉÉ
                        ÉÉÉ
                        ÉÉÉ
                         É
                        ÉÉÉ
                         É
                        ÉÉÉ
                         É
                        ÉÉÉ
                        ÉÉ
    7
    6
                                                                          8
    3

    5

                              Mesh filter to be removed if fitted



1       Housing upper part                 6    Float control
2       Joint ring (copper or soft iron)   7    Float control body with rotary valve
3       Housing lower part                 8    Float with lever
4       Control valve                      9    Fixation screw
5       By-pass (connection)




                                                                              RTA-2/6

				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:102
posted:7/7/2010
language:Uzbek
pages:9