Liebe Leser,
Ich studiere Biotechnologie und in einer Vorlesung bekam ich die Aufgabe eine Ordering Specification für ein Check valve zu verfassen.
Leider weiß ich nicht genau wie ich das angehen soll. Könnt mir jemand helfen?
Fermentation System
A) Design Parameters:
Bioreactor: Working volume: 15.000 L
Gross volume: 20.000 L
Height / Diameter ~ 2,5 : 1
Volume of the Jacket: 750 L
Design pressure of the jacket: Equal to the bioreactor vessel
Cleaning of the bioreactor by CIP:
CIP nozzle should be efficient to clean the inner surface of the tank
Bottom valve should be large enough, to enable free drainage of the CIP solution (CIP return line)
Assumptions: Static head: ~ 3m; Density of the CIP solution: ~ 1 kg / dm³
Medium addition: a) For start up operation (before inoculation of the bioreactor) a fast medium transfer is required:
Maximum period of medium transfer (via head pressure on the medium holding tank): 90 min
Length of the pipe (from bottom valve of the medium holding tank up to the inlet valve): 10 m
Static head: 5 m; Head pressure on the medium holding tank: 0,5 bar
b) For Fed-batch or Chemostat operation reduced (and controlled) medium addition is required:
Medium is added to the bioreactor via a peristaltic pump. Flow rate range of the pump: 100 – 1000 L / h
pH control: pH can be controlled using a head flush of the bioreactor with a mixture of air and CO2. For an efficient
control of the pH the turnover rate of the surface gas head volume should be at least 1 times per hour.
(Assume that the bioreactor is operated with no overpressure)
Exit air line: The exit air line is designed to enable an exchange of the air filter cartridge (when it is clogged) during
fermentation. Thus steaming of the exit air line is required. A maximum steam flow of 5 kg/hr is sufficient.
To suppress vapour condensation on the surface of the membrane, the filter housing should be
continuously heated (by steam). The exit air filter is also used for breaking the vacuum in the bioreactor
formed during the cooling cycle of the SIP procedure. Assume that inlet air flow rate of 300 Nm³/hr are
required to suppress vacuum formation (P ~ 0,1 bar; inlet pressure ~ 2 bar)
Aseptic operation
Temperature control of the bioreactor: Volume of the pipe loop: 50 L
Total volume of the heating / cooling loop should be recycled 20 times per hour in order to allow a precise
temperature control.
The piping (length: 12 m) should not cause a larger P than 0,2 bar for the required recycling rate
P of the heat exchanger is assumed to be 0,25 bar at the defined flow rate
P for the jacket can be neglected