Skip to main content

Double evaporation boilers

  • A double evaporation boiler uses two independent systems for steam generation and therefore avoids any contamination between the primary and secondary feedwater.
  • The primary circuit is in effect a conventional watertube boiler which provides steam to the heating coils of a steam-to-steam generator, which is the secondary system.
  • The main reason for the adoption of this design of boilers is to allow use of modern high efficiency watertube boilers witghout fear of damage through contamination by cargo or fuel oils.The basic design consists of a D-Type boiler design upon which is mounted a Steam/Steam generator drum.
  • The steam generated by the main boiler heats water in the Steam/Steam generator which produces steam requirements.
  • The primary drum is initially filled with high quality feed water and suitably dosed.
  • The  main  reasonfor  the  adoption  of  double  evaporation  boilers  in  tankers are  concerned  of  damage  caused  by  oil  and  sulphur  which  enters  the  feed  systems  through  leaky  steam  heating  coils  used  for  heating  the  oil  in  cargo  tanks.

Comments

  1. It is really a helpful blog to find some different source to add my knowledge.
    Boiler Repair Watford

    ReplyDelete
  2. Mesmerized article written on this blog with other relevant information. It is straight to the point that how we can improve our skills as well as how we can be represented to a new stream of professionalism.boiler repair

    ReplyDelete
  3. sir please upload marine boilers notes

    ReplyDelete
  4. Boiler Repairs

    Assert Heating Services is one of the best Heating Engineers in London offering a full range of heating system Installations as well as gas and modern plumbing services.

    ReplyDelete
  5. Boiler Servicing

    Assert Heating Services is one of the best Heating Engineers in London offering a full range of heating system Installations as well as gas and modern plumbing services.

    ReplyDelete
  6. Such a amazing and informative blog.
    Thanks for sharing this blog on double evaporation boilers.
    I have a confusion regarding new boiler installation Glasgow, that how much landlords or property owner have the permission to use the boiler in a single apartment.

    ReplyDelete

Post a Comment

If you have any doubts.Please let me know

Popular posts from this blog

Differences between MC/MC-C and ME/ME-C engines

The electrohydraulic control mechanisms of the ME engine replace the following components of the conventional MC engine: Chain drive for camshaft Camshaft with fuel cams, exhaust cams and indicator cams Fuel pump actuating gear, including roller guides and reversing mechanism Conventional fuel pressure booster and VIT system Exhaust valve actuating gear and roller guides Engine driven starting air distributor Electronic governor with actuator Regulating shaft Engine side control console Mechanical cylinder lubricators. The Engine Control System of the ME engine comprises: Control units Hydraulic power supply unit Hydraulic cylinder units, including: Electronically controlled fuel injection, and Electronically controlled exhaust valve activation Electronically controlled starting air valves Electronically controlled auxiliary blowers Integrated electronic governor functions Tacho system Electronically controlled Alpha lubricators

Why is a man hole door elliptical in shape?

Any opening in a pressure vessel is kept to a minimum and for a man entry an elliptical hole  is lesser in size than the corresponding circular hole. More over it is prime concern to have a  smoothed generous radius at the corners to eliminate stress concentration. Hence other  geometrical shapes like rectangle and square are ruled out.  To compensate for the loss of material in the shell due to opening, a doubler ring has to be  provided around the opening. The thickness of the ring depends on the axis length along the  dirrection in which the stresses are maximum and the thickness of the shell. It is important to  align the minor axis along the length of the vessel, as the stress in this direction is  maximum. Longitudinal stress: Pd/2t where P= pressure inside the vessel, d= diameter of the arc, t=  thickness of the shell plating  Circumferential stress: Pd/4t  More over a considerable material and weight saving is achieved as minor is along the  direction of maximum stress.

Shell Expansion Plan

It is a two dimensional drawing of a three dimensional surface of the ship’s hull form. This plan is very useful for the following information:It is used for marking the location of a hull Damage on this plan by identifying the strake number , letter and frame number so that the exact location of the damage and also suggested repairs are marked in a localised copy. The shell expansion can be used for finding areas of painting surfaces such as topside, boot topping and bottom areas by applying Simpsons rules directly.  In the shell expansion the vertical scale used is different from the horizontal scale and a suitable adjustment has to be made when calculating areas. This becomes useful in solving disputes concerning areas of preparation and painting. It gives information on the thickness of the original strake which is indicated by the number in the circle shown in the strake.  The quality of steel used is also shown by letters A,B,D E and AH, BH,DH, EH.