TIF RG5410A Refrigerant Recovery Machine - Manual (Page 10)

HELPFUL HINTS FOR
REFRIGERANT RECOVERY - cont.
This is probably never noticed in charging, because the
pressure opens the grommet, but during recovery (or with
suction) the deformed grommet severely restricts the flow
of refrigerant.
REFRIGERANT RECYCLING
Current regulations state that used refrigerant shall not be
sold, or used in a different owner's equipment, unless the
refrigerant has been laboratory analyzed and found to meet
the requirements of ARI 700 (latest edition). As a result,
recycling and verifying ARI 700 conformance isn't econom-
ically justified in most cases. It's still a great idea to do as
much cleaning of refrigerant going back into the same sys-
tem (or owners system) as possible. We recommend using
the largest, high-acid capacity filter, that are economically
feasible. Put these filters on the suction or inlet side of the
recovery unit. Change filters often.
The recovery of large amounts of liquid refrigerant can
sometimes carry with it large quantities of oil, if the system
being serviced doesn't have an adequate oil separator
installed. If this recovered refrigerant isn't going to be liquid
charged back into the same system, you might want to sep-
arate the refrigerant from the oil in order to measure the oil
(to know how much oil to charge back into the system).
Refrigerant sent back for reclaim does not need to have the
oil removed. One of the simplest and most cost effective
ways to achieve this is to use a (30 or 50 lb.) tank in line
with your recovery machine. Connect the system to the liq-
uid port of the tank, then from the vapor port of the tank
connect to the input of your recovery machine. A second
tank, for storing refrigerant, should then be connected to
the output of the recovery machine. If you encounter large
amounts of liquid you will need to put a band heater around
the first tank. When the recovery job is complete the oil can
be removed, from the first tank, by applying a small amount
of pressure, using nitrogen, to one of the ports and extract-
ing the oil from the other. If you are going to remove the oil
from the vapor port you will need to turn the tank upside
down. Always wear safety glasses when performing this
operation as the oil may be acidic and could cause severe
burning.
KEEPING THE DIRT OUT
During the recovery process your recovery machine can be
exposed to debris that can, potentially, damage it. This
includes brazing spatter and copper/ brass slithers. Further
contamination can be introduced from the refrigerant stor-
age tanks. To prolong the life of your recovery machine,
always use an inline filter at the inlet Port.
Whenever you are charging a system from a recovery cylin-
der it is a good idea to use an in-line filter to protect the sys-
tem from contamination. Again, change your in-line filters
often.
GETTING THE LIQUID OUT
See diagram on page 13 of this manual
Push/pull is a method of removing bulk liquid from a sys-
tem using the pressure differential created by the recovery
machine. Push-pull will generally not work on smaller sys-
tems because there is no bulk liquid reservoir to create a
siphon from.
Push-pull is mostly used on systems with a receiver tank or
those with greater than 20 lbs. of refrigerant, or when trans-
ferring from one tank to another. The rate of liquid transfer
is very much dependent on hose size, with larger hoses pro-
viding much better throughput.
Another trick is to cool the tank, if it's partially filled, prior
to or during recovery. This operation will lower the pressure
in the storage tank and therefore speed up recovery. There
must be a minimum of 5 lbs of liquid refrigerant in the tank
you wish to chill. This operation can be performed prior to
or during the recovery. See the two set updiagramsand pro-
cedures on page 13-14 of this manual.
There is nothing magic here, you are simply using your
recovery machine to make a refrigerator where the tank is
the evaporator. By throttling the output valve, you're effec-
tively creating a capillary tube or an expansion device, but
you need to adjust the back pressure to suit the conditions
and the refrigerant. Five to ten minutes of chilling can pro-
duce some very dramatic tank cooling, depending on the
conditions. If there are any non condensables in the tank
this process will not work. The greater the quantity of refrig-
erant in the tank the longer the process will take.
10