What do you mean by risers and downcomers, Mechanical Engineering

Q. What do you mean by Risers and Downcomers?

Risers and downcomers shall be staggered along the shell of the WHB and steam drum for uniform water/steam circulation in the system, taking into account the varying heat fluxes along the length of tubes. Film boiling (or dry-out) must be avoided in order to prevent tubes from destroying by deformity. The first pair of downcomers and the riser shall not be located further than 150 mm (6") form the inlet tubesheet. This distance of 150 mm is from the edge of the tubesheet to the nearest edge of the downcomer pipes.

The downcomer flow velocity shall be restricted to 1.52 m/s (5 ft/s). impingement plates, if provided shall not be welded to nozzle necks and tubes. Perforated plates are not acceptable.

The circulation of WHB system shall be computed for each circuit of downcomer and risers. A detail FEA shall be performed to predict water/steam circulation ratios. The FEA shall be based on an internationally recognized program, such as ANSIS or ALGOR and shall be submitted to WorleyParsons Canada for approval. Unsuitable programs, unacceptable to WorleyParsons Canada, shall be avoided.

Posted Date: 7/10/2013 1:20:31 AM | Location : United States

Related Discussions:- What do you mean by risers and downcomers, Assignment Help, Ask Question on What do you mean by risers and downcomers, Get Answer, Expert's Help, What do you mean by risers and downcomers Discussions

Write discussion on What do you mean by risers and downcomers
Your posts are moderated
Related Questions
Evaluate Young modulus of elasticity - Ultimate stress: Q:   The following observations were made during tensile test on mild steel specimen 40 mm in diameter and 200 mm long

METAL TRANSFER IN CO2 WELDING In CO 2 welding, two distinct types of metal transfers are identified viz. short circuiting transfer and free flight globular transfer. Short Cir

how to find acceleration by Klein construction

Plate clutch movement on center clutch : Place plate clutch on centre clutch as shown in the picture and move the plate clutch up and down, while moving the plate clutch in the ce

Maintenance of Railway Line Importance of Maintenance The need for maintenance of railway lines arises out of the following considerations : (a) The track rests on

Determine the RF on the scale: A length of 3 km on the ground is presented via 6 cm length on a map. Determine the RF on the scale on that it has been drawn.  RF = Length o

In a steam jet refrigeration system, the ejector extracts 3.3 m3/s of saturated water vapor at a temperature of 7.2 °C from the flash chamber. The return water from the cooling coi

Interpoles or commutating poles Interpoles are ?xed to the frame in among main poles. They are used for sparkless commutation, i.e, to improve commutation.