Parr Instrument Series 4560 - Manual (Page 10)

Mini Bench Top Reactors
P a r r I n s t r u m e n t C o m p a n y 10
Other Vessel Head Fittings
Safety Rupture Disc
There is a safety rupture disc attached to the head
which is intended to rupture and release the pres-
sure before it reaches a dangerous level. A metal
tag wired to the safety head identifi es the burst
pressure at room temperature for that particular
disc. A similar tag is furnished with each replace-
ment disc. This tag must remain with the apparatus
at all times so that both present and future opera-
tors will be aware of the disc rating. Users should
read the discussion of rupture discs given in the
Operating Instruction No. 231M for a complete
description of the characteristics of rupture discs
and the precautions to be observed when operating
pressure equipment protected by this type of safety
device.
A typical pre-bulged disc can be used to 90% of the
rating on the tag. For additional protection, the
user should install an adequate and safe venting
system for removing any toxic, fl ammable or vola-
tile materials which would be released if the rupture
disc should burst. A connector for attaching 3/8” OD
tubing to the discharge port of the rupture disc is
provided for this purpose.
Type J Thermocouple
A Type J Thermocouple in a 1/8” diameter stainless
steel sheath is installed in each reactor. In reac-
tors made of alloys other than stainless steel, the
stainless thermocouple is installed in a thermowell
made of the same alloy as the vessel. Connect the
thermocouple to the socket on the rear panel of the
temperature controller using the A470E2 extension
wire furnished with the reactor.
Pressure Gage
The pressure gage furnished with this reactor has
a T316 stainless steel Bourdon tube. Gages are
furnished in a variety of ranges to meet individual
needs. Typically, the gage and the rupture disc are
furnished as matched ranges. For applications
where a gage is selected with a range under 1000
psi, a relief valve is added and set to protect the
gage. A 1000 psi rupture disc is installed as the fail-
safe vessel protection.
For highly corrosive applications where the vapor
phase might corrode the stainless Bourdon tube,
Parr offers isolator assemblies in a variety of materi-
als. These isolators with their internal piston isolate
the vapors from the gage.
Heaters
The Mini Reactor Systems offer an array of heating
choices to suit the needs of the operator.
The 100 and 160 mL models are offered with a high
watt density band heater, which is to be clamped
directly onto the cylinder. After the vessel has been
placed in its holder, slide the heater onto the cylin-
der and tighten the clamping screw which projects
from the aluminum housing.
The 300, 450 and 600 mL Mini Reactors are standard
equipped with heating mantles housed in sturdy
aluminum shells. These mantles are made in three
sizes, designed to provide uniform heat distribution
to the walls and bottoms of these vessels. They are
attached to the support rod with a clamp, arranged
so that they can be raised or lowered on the rod as
desired.
Alternately the 300, 450 and 600 mL Reactor sys-
tems can be heated with an aluminum block heater
which features integrated cooling.
The high temperature Mini Reactor systems utilize a
higher wattage ceramic fi ber heater.
Parr heaters are offered with optional thermowell
port to accommodate the Parr A511E bayonet style
thermocouple, an open bottom to accommodate a
cylinder bottom drain valve, and/or the quick con-
nect mounting style for conveniently changing
heater size. Please consult the experienced cus-
tomer service staff at Parr Instrument Company for
assistance in determining the correct heater for your
reactor system.
Each heater must always be used with a vessel
of the size for which it was designed, and it must
always be fully attached to the vessel before heat is
turned on. Similarly, a short vessel must never be
heated in a deep heater. Without full contact with a
metal wall, a heater may overheat and burn out.