Provide pressure drop calculation estimates across both the inlet and outlet for a catalyzed packed bed reactor.
ESTIMATION OF GAS PRESSURE DROPS FOR REACTOR INLET DISTRIBUTOR and OUTLET BASKET
The client, an international engineering company, on behalf of the ultimate client, a fabricator of internal components for distillation columns and other process vessels based in Bahrain, contracted Process Engineering Associates, LLC (PROCESS) to provide an order of magnitude estimation of the pressure drops for both an inlet gas distributor, and an outlet basket, that were to be fabricated and installed in a vertical packed bed reactor.
This project involved utilizing the following process engineering techniques:
- Identification/development of a calculation procedure. The pressure drops were calculated by modeling each case as gas flow through a perforated plate; specifically, the “dry hole pressure drop” calculation for gas flow through a sieve tray. This correlation is a straightforward approach, but because each piece of equipment was geometrically very different from a sieve tray, the appropriate equivalent open area and total surface area had to be calculated for each case.
- Interpretation of design data. The relevant dimensions and geometry for each piece of equipment were determined from the client-supplied drawings which were lacking in detail and clarity.
- Use of simplifying assumptions. A number of simplifying assumptions were made to determine the appropriate open and total surface areas for each case. For the inlet distributor, the total open area was the sum of three different types of openings, and this was modeled as an equivalent number of 0.5″ diameter holes. For the outlet basket, the total pressure drop was the sum of the pressure drops through the basket (containing slotted openings), and an overlain wire mesh with square openings. The total open area was calculated using the hydraulic diameter (and not the geometric diameter) for these openings. The flow through each opening was also assumed to be unaffected by the flow through neighboring openings.
- Petroleum Refining
- Pressure drop estimation