77
P a r r I n s t r u m e n t C o m p a n y
1 - 8 0 0 - 8 7 2 - 7 7 2 0
3
S p e c i a l t y & C u s t o m R e a c t o r s
When ordering mass flow controllers, you will
need to specify:
1. Type of gas to be metered (e.g. N2, H2, CH4)
2. Maximum operating pressure of the gas (100
or 300 bar)
3. Maximum flow rate range in standard cc’s per
minute (sccm)
4. Pressure for calibration of the instrument
Mass flow controllers are available for use to
1500 psi and to 4500 psi. Considerable savings
can be obtained if the mass flow controller is to
be used only to 1500 psi.
The schematic at right depicts
the installation of a mass flow
controller for the introduction of
gas to a continuous-flow reaction
system. Such installations are
enhanced with the addition of a
by-pass valve for rapid filling.
A purge line can also be
added. It is typically used for
feeding nitrogen or helium to
remove air before reaction or to
remove reactive gases before
opening the reactor at the end of
a run. The purge line includes a shut-off valve,
metering valve, and a reverse-flow check valve.
Shut-off valves can be automated when using
a 4871 Control system.
Liquid Metering Pumps
High pressure piston pumps are most often
used to inject liquids into a pressurized reactor
operating in a continuous-flow mode. For low
flow rates, HPLC pumps, many of which are
rated for 5000 psig, are excellent choices.
Series 5400 Tubular Reactor System Specifications
Shaded bar indicates specifications that change within series.
Model Number
5401 5402 5403 5404
Sizes
3/8 in.
1/2 in.
1.0 in.
1.5 in.
O.D. / I.D. (in.)
0.38 / 0.28 0.50 / 0.37 1.9 / 1.0
2.0 / 1.5
O.D. / I.D. (mm)
9.5 / 7.0
13 / 9.4
48 / 25
51 / 38
Heated Length (in.)
6, 12, 24
12, 24, 36
Max. Pressure (psi)
3000
5000
3000
Max. Temperature
550
550
350
Support Spools
No
Yes
Spiral Pre-Heat
No
Yes
No. Ports in Top Head
1
4
No. Ports in Bottom Head
1
4
Internal Thermocouple
Yes
temperature as the core of the reactor. The heater
length is normally divided into one, two, or three
separate heating zones, although it can be split
into as many zones as required.
We can furnish either a fixed internal ther-
mocouple in each zone or a single movable
thermocouple that can be used to measure the
temperature at points along the catalyst bed.
External thermocouples are typically provided for
control of each zone of the heater.
Gas Feed Systems
Various gas feeds can be set up and operated
from a
Gas Distribution Panel
. In order to
deliver a constant flow of gas to a reactor, it is
necessary to provide gas at a constant pressure
to an electronic
Mass Flow Controller
. This
instrument will compare the actual flow rate
delivered to the set point chosen by the user, and
automatically adjust an integral control valve to
assure a constant flow. Care must be taken to
size these controllers for the specific gas, the flow
rate, and the pressure of operation. A mass flow
controller needs a power supply and read-out
device, as well as a means of introducing the
desired set point.
FIC
Gas
F MFC
Gas
F
Open 3-Zone Split Tube Furnace with 1" I.D. Tubular Reactor.
