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Cleanable API Processing Equipment and Systems 287
TABLE 3 Inside Diameter, Area, and Flow Rate for 5Feet/Sec in Condenser
Nominal diameter
(in.)
Internal diameter
(in.) Area (ft 2 ) gpm at Q (5 ft/sec)
1 13 = 16 0.0036 8
11= 2 15 = 16 0.0094 21
2 113= 16 0.0179 40
3 213= 16 0.0431 97
The designer has to make some important decisions on how differing use
points are combined to form aCIP circuit. Consider the system shown in Figure 2.
That system has a2-in. Teflon lined (TL) CIP header at the discharge of the process
transfer pump. Assume that this pump has anominal capacity of 50 gpm at 150 ft
head. It is the designer’s task to apportion adequate flow to various circuits and
ensure that the system hydraulics can be met to ensure the proper flow to each
branch of the circuit.
To do this, it is important to realize that there are three types of backpressure
patterns which may be present in acircuit.
& Aspray device:Generally,nonrotating sprays are designed for apressuredrop of
20 to 30 psi (46–69 ft of water).
& An open line: Pressure drop per 100 ft at 5ft/sec is generally in the range of 1to
3psig per 100 ft.
& Arestricted flow: Generally, ahigher pressure drop than an open line, but less
than aspray device.
It is important that aspray device is not included in acircuit in parallel with a
circuit with an open line. The flow through an unrestricted (open) line would
deprive the spray device of the appropriate flow of CIP fluid. Sometimes a
restriction flow orifice can be used to backpressure an open or restricted line so
that satisfactory hydraulic performance could be obtained with spray devices
included in the same circuit.
The glass-lined reactor portrayed in Figure 2utilizes the circuits summarized
in Table 4.
The process transfer pump needs to be evaluated to ensure that it is able to
provide adequate flows for both aqueous and organic fluids. It should be noted that
the pressure drop through pipe and fitting is affected by the fluid specific gravity.
In asimilar way, the discharge pressure ofacentrifugal pump varies with specific
gravity. Typical solvent specific gravities vary between 0.6 and 1.3 SG.
TABLE 4 Example of Flow Rate Through Sub-Circuits in Reactor CIP
Circuit Flow rate (gpm)
Reflux, distillate, or vent O 40 gpm
Overhead piping 5bubble sprays at 10Z 50 gpm
Condenser 2 spraysZ 60 total gpm
Dip tube O 40 gpm
Charge chute 2bubble sprays at 10Z 20 gpm
Instrument and baffle nozzles 20 gpm
Reactor vessel 2sprays at 30 gpmZ 60 gpm