7
Description
Where necessary, refer to the drawings in the
Equipment Diagrams
section.
Overview
The reactor vessel is set on a baseplate which is designed to be located on the four
studs of the CEXC service unit and then secured by thumbnuts. The reactor is
supported by three pillars; position the reactor on the CEXC service unit such that a
single pillar is to the front.
A stainless steel coil inside the reactor provides the heat transfer surface for either
heating or cooling the chemical reactants. The coil is connected either to the hot
water circulator (for exercises above ambient temperature) or the optional CW-17
chiller. The coil inlet is at the front of the reactor and the coil return is at the rear of
the reactor (for exercises below ambient temperature).
A stirrer (turbine agitator) works in conjunction with a baffle arrangement to provide
efficient mixing and heat transfer. The stirrer is driven by an electric motor mounted
in the lid of the reactor. The motor is controlled by the software supplied with the
Service Unit. The electrical socket for the motor is located at the rear of the service
unit.
Glands in the reactor lid house the conductivity and temperature sensors provided
with the service unit. The larger of the two glands is for the conductivity probe. The
glands are unscrewed by hand, the probes inserted completely into the reactor until
they rest on the reactor base and then the glands re-tightened by hand. Electrical
sockets at the rear of the service unit are provided to connect each probe. These are
of different size so that the probes cannot be wrongly connected. The conductivity
probe can be connected to low or high conductivity channels to suit the range of
measurements expected. For normal use the probe should be connected to the high
conductivity channel.
Flow of materials
The two feed pumps on the service unit pump the chemical reagents from the two
feed bottles into the reactor separately through connectors in the base of the reactor.
As reagents are pumped into the reactor, the level increases until it finally overflows
the stand pipe and flows to drain. The stand pipe may be adjusted in height by
loosening the hexagonal gland nut. A mark is etched onto the stand pipe. For
maximum operating volume of the reactor, this mark should be aligned with the gland
nut. A stop prevents the stand pipe from being completely removed, and this also
defines the minimum working volume which is half of the maximum volume.
When the reactor is not being used, it can be drained using the valve sited on the
underside of the reactor.
