Sampling apparatus for cryogenic food freezers

Sampling device removably mounted proximate the discharge opening in an immersion freezer to collect samples of frozen product as they exit the immersion freezer conveyor and are deposited into a second freezing or equilibrating device.

FIELD OF THE INVENTION 
The present invention pertains to safe removal of product samples from an 
immersion-type freezer at the discharge roller. 
BACKGROUND OF THE INVENTION 
Immersion-type cryogenic freezers are used for processing food products to 
individually freeze things such as shrimp and the like. Immersion-type 
freezers are sometimes mated to a tunnel freezer so that initial freezing 
takes place by dipping the product, e.g. shrimp, into a bath of liquid 
cryogen, removing the product from the bath and conveying to a freezing or 
equilibrating apparatus, e.g. a tunnel freezer where the vaporized cryogen 
is used to final freeze the product after initial crust freezing. Air 
Products and Chemicals, Inc. of Allentown, Pa. sells such freezers with 
the immersion part being identified as a CRYODIP freezer and the tunnel 
portion being identified as a CRYOQUICK freezer. 
One of the problems with using the combination of the immersion and an 
after treatment apparatus is the sampling of product as it exits the 
immersion freezer to determine the degree of freezing so that the speed of 
passage through the apparatus and other parameters of the said apparatus 
can be adjusted. Normally to take a sample the immersion freezer must be 
opened exposing the sample taker to the liquid cryogen, and cryogen vapors 
which in the case of the cryogen being liquid nitrogen can be potentially 
harmful to the worker and also result in upsetting the entire freezing 
process. 
BRIEF SUMMARY OF THE INVENTION 
The present invention includes a sample access port and sample device 
placed in the immersion freezer proximate the discharge roller, e.g. where 
the conveyor reverses direction and where the product falls from the 
immersion freezer conveyor onto the tunnel freezer conveyor so that the 
samples can be withdrawn without opening the immersion portion of the 
freezing system.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, 10 designates an immersion-type cryogenic freezer. 
Freezer 10 includes housing 12 adapted to contain a bath of liquid 
cryogen, e.g. liquid nitrogen shown as 14. Housing 12 of freezer 10 that 
is made in the form of an insulated container. Housing 12 can be made into 
a single bottom section and a multiple opening top section or can be made 
in two parts, top and bottom, that can be opened for cleaning as is well 
known in the art. Product to be frozen is introduced through a product 
entry port 16 as shown by arrows 17. The product drops into the freezer 
into the liquid bath and is conducted by a conveyor 18 through the bath 
and then outwardly through a discharge opening 22 in the housing 14. 
Normally the conveyor 18 is inclined so that the product 17 emerges from 
the bath so that residual liquid can drain back into the bath and is not 
conveyed out of the freezer 10. The product is discharged from conveyor 18 
onto a second conveyor 24 which is shown as part of any other type of 
freezer or temperature equilibrating apparatus 25 to which the immersion 
freezer can be mated as is well known in the art. 
In view of the fact that the operator of such a combined immersion and 
equilibrating freezing device needs to adjust the freezing parameters 
based upon the depth of freezing of the product in the immersion section 
of the process in freezer 10, it is necessary for samples to be taken as 
they exit the conveyor 18 from the immersion freezer 10. In the past this 
has been done by opening the immersion freezer 10, thus exposing the 
person collecting samples to the liquid cryogen, vaporizing cryogen and 
upsetting the entire freezing process. It has also been possible in those 
freezers where there is an exhaust duct at the exit end of the immersion 
freezer to open a clean-out door on the exhaust and take samples in that 
manner. In other installations it is possible to open the covers of the 
after treatment apparatus adjacent to the immersion freezer exit with the 
same resultant exposure to the liquid and gaseous cryogen. 
It has been discovered that a safe method of sampling involves installation 
of a sample port 30 and sample collector 32 as shown in FIGS. 1 and 2. The 
sample port FIG. 2 includes a generally rectangular shaped body 34 and a 
top flange 36 and a bottom flange 38, the flanges 36, 38 being adapted to 
fix the port 30 into the top of the freezer as shown in FIG. 2. The bottom 
flange 38 is placed onto the port after it is installed in the freezer 10 
through a suitably prepared aperture. The entire port 30 can be welded 
into place or otherwise fastened to the top of the freezer 10 as is well 
known in the art. Slidably disposed within the port 30 is the sample 
collector 32 which is in the form of an elongated box 40 having a flange 
42 and a handle 44 so that the sample collector 32 can be slideably 
inserted inside of the port 30 as shown in FIG. 2. Sample collector 32 
includes in the housing a large aperture 46 disposed proximate the end 48 
of the sample collector that is inserted into the freezer 10. The aperture 
46 is fabricated above the end 48 of the sample collector 32 housing 40 so 
that a dam 50 is created and thus a pocket in the bottom of the sample 
collector 32. 
In use sample collector 32 is introduced into the port 30 so that the 
aperture 46 faces the conveyor 18 and is disposed with the bottom 48 below 
the reversing roller 19 of the conveyor 18 so that product 17 falling from 
conveyor 18 to conveyor 24 will be trapped in the pocket created by the 
dam 50 of sample collector 32. Sample collector 32 can be quickly removed 
from the freezer and the samples checked for degree of freezing as shown 
by the arrow 56 and ghost image in FIG. 2. A pin 52 and wire layer 54 are 
included for positioning sample collector at the proper position inside 
freezer 10 in the up or out of service position to block the sample port 
to prevent air from entering or cold cryogen gas to escape from the 
freezing apparatus. 
Using a device according to the present invention permits the operator to 
collect samples without opening the freezer, without coming in contact 
with the liquid cryogen, without being exposed to vaporize liquid cryogen 
and without upsetting the freezing parameters of the entire system. 
Having thus described my invention what is desired to be secured by Letters 
Patent of the United States is set forth in the appended claims.