Rapidly cyclable foam testing oven

Oven, for example, embodied as a foam tester, can heat and cool circulating gas, and hence, contained sample containers, rapidly. A volume for containing coolant material is provided for cooling the oven volume is provided apart from the oven volume, and the cooling volume is adapted to contain cooling material, at least during operation of the cooling cycle. Optionally, the cooling volume can be closed off from the oven volume when the device is in heating mode and opened when in cooling mode, but preferably, it is not but has a drainable liquid, for example, water, cooling system installed in the cooling volume. The device may have an air plume; preferably however, it has such a plume eliminated with high circulation blowing and mixing of the bath gas, for example, air, provided. Accessories such as a removable drain tray, and so forth, may be added. The exemplary devices are particularly useful for testing for the foaming characteristics of liquids, and the principles of the cooling volume can be applied to cabinet ovens in general. As an option, gel or cooling other than liquid in radiator cooling, for example, solid state cooling, may be employed. Test methodology can include injection of a gas to include a preheated gas, for example, air, into an oleaginous liquid sample, for example, oil or transmission fluid, especially having standardized, predetermined level(s) of contaminant(s).

BACKGROUND TO THE INVENTION 
I. Field of the Invention 
This invention concerns a circulating gas oven, cyclable from heating to 
cooling modes. It is particularly useful for testing the foaming of 
liquids at elevated temperatures. 
II. Description of Arts, Problems, and Needs, Including Information 
Disclosed Per 37 CFR 1.56, 1.97 & 1.99 
As set forth in Selby et al., U.S. patent application Ser. No. 08/782,822 
filed on Jan. 13, 1997, now U.S. Pat. No. 5,824,886, one of the problems 
with liquids, including lubricants, is foam which can form under operating 
conditions. In order to test this, and in the process determine a standard 
property of such liquids, techniques such as the ASTM-D-892 test method 
have been used for some time. In the ASTM-D-892 test method, foaming 
characteristics of lubricating oils are determined at temperatures up to 
ninety-three and one half degrees Celsius. An air bubbling stone is set in 
the sample; the sample is heated appropriately as air is bubbled in, and 
foam characteristics of the sample are observed over a period of time. 
However, with the advent of modern engines, the oils and other lubricants 
which are employed in the engines are made subject to higher and higher 
operating temperatures. Thus, it becomes desirable to test for the 
characteristics of such fluids at or above such temperatures, and among 
such desired tests is a high temperature foaming test, up to and above one 
hundred fifty degrees Celsius. However that may be, currently available 
liquid-filled baths to test for and monitor foam characteristics, and in 
particular as might be encountered at high temperatures, have several 
drawbacks. Among these are included the following: 
1) A lack of an ability to heat and cool quickly. 
2) A lack of ability to see through the bath liquid. 
3) Requirement of more than one bath. 
4) Requirement of frequent bath liquid changes. 
5) Difficulty of handling sample containers coming from the liquid bath and 
coated with hot oil--plus hot cabinetry. 
6) Difficulty of operation. 
In addressing such matters, the aforementioned Selby et al. application, 
which incorporated and claimed the benefit of U.S. provisional patent 
application Serial Nos. 60/012,576 filed on Feb. 29, 1996 and 60/026,429 
filed on Sep. 20, 1996, in brief, disclosed a gas, and especially air, 
bath foam tester having an insulated cabinet with a 
temperature-regulatable volume contained therein; a heater capable of 
heating a gas for the volume; a feature to circulate heated gas in the 
volume; an access system such that sample container(s), each capable of 
holding a liquid sample, is(are) insertable into the volume so that the 
same can be heated therein; and a feature to observe any sample(s) in the 
sample container(s) such that observation can be conducted from outside 
the cabinet--and further wherein cooling can be provided by water or other 
liquid and/or by insert of a cooling device, for example, an insert in 
place of a foam tester sample "carousel" or an insert which may penetrate 
the side of the cabinet. A foam testing protocol was disclosed in which 
the heating mode of the device was alternated with a cooling mode so that 
samples could be tested more quickly in the same device. As well, a 
special pourable sample container was provided thereby. 
As significant as that invention is to the art--and it has commercial 
ramifications as showed by Savant, Inc., Lubrication Technology, "Foam 
Testing Now Available," September 1996, it is not without drawbacks. Chief 
among these is that, according to an ever-present drive to improve 
efficiencies, that foam tester can take longer to cool down between tests 
than desired. 
The following art was cited by the U.S. examiner in the first action in the 
aforesaid '822 application: 
Smith et al., U.S. Pat. No. 2,380,679. This discloses an apparatus for 
testing the foaming characteristics of liquids, more particularly, an 
oil-submersible aerator. 
Groll, Jr., et al., U.S. Pat. No. 3,027,755. This discloses an apparatus 
and method for determining effectiveness of defoamers in foamy systems, 
more particularly, in strippable foamy system, i.e., a fluid system which 
upon agitation results in the production of froth or foam and containing 
one or more components which are to be stripped or removed therefrom, 
e.g., a synthetic rubber lattice produced by copolymerizing unsaturated 
compounds such as 1,3-butadiene and styrene. 
Callaghan et al., U.S. Pat. No. 4,577,491. This discloses a method for 
determining the stability of foam, which includes a sample pressurizing 
vessel connected to a sample injection chamber leading to a sample cell 
linked to a reference cell maintained at constant pressure. 
Lehnert et al., U.S. Pat. No. 5,154,088. This discloses apparatuses and 
methods for incorporating blowing agents into liquids for the production 
of polymer foams and for measuring the volumetric expansion potential of 
mixtures thereof. An apparatus thereof includes a high pressure liquid 
storage and mixing tank. 
Winstead et al., U.S. Pat. No. 5,336,866. This discloses a fabric sample 
treatment apparatus, which is for effecting the controlled and uniform 
heating of a plurality of fabric and dye liquor specimens, and which 
includes a heating chamber having a rotatable sample rack, a radiant heat 
source, multidirectional cooling air vents, temperature measurement 
devices for monitoring chamber and specimen temperature, and control 
equipment. 
Loisel, U.S. Pat. No. 5,465,610. This discloses a device for the 
characterization of the foaming properties of a product which is at least 
partially soluble, which includes a transparent analysis column with a 
porous base to introduce a gas flow, and an automatic measuring system. 
Mullen, U.S. Pat. No. 5,597,950. This discloses surfactant monitoring by 
foam generation, a device of which detects the formation of foam with a 
light beam or conductivity measurement. 
Arthur H. Thomas Co., Philadelphia, Pa., 1974 Parts Catalog, page 102. This 
discloses glass beakers. 
The following art was initially cited by the U.K. examiner in a search 
report dated May 22, 1997 in British patent application No. GB 9704236.0 
corresponding to the aforesaid '822 application: 
Lunick, U.S. Pat. No. 4,356,967. This discloses a laboratory incubator 
chamber system, which includes an air-tight sealed compartment for 
providing an incubation chamber and a sealed control compartment for 
housing electronic circuitry. 
Selfridge et al., U.S. Pat. No. 4,572,427. This discloses a controlled 
atmosphere enclosure, which is an incubator having a housing defining a 
thermally insulated chamber with a controlled gas atmosphere. Sensing 
devices are in a gas recirculation path outside the incubator chamber. The 
gas atmosphere circulates from a chamber outlet in an upper portion of the 
chamber, through the recirculation path, returning to the incubator 
chamber through an inlet in a lower portion of the chamber. Included in 
the recirculation path are a recirculation blower, a filter, a carbon 
dioxide sensor, and a humidifier. 
European patent application publication No. 0 252 738 A2. This discloses a 
foam meter, which includes a thermostatically controlled column open at 
one end with a mesh at the other end. 
U.K. patent specification No. 1,186,105. This discloses a humidity cabinet, 
which includes a plurality of moisture-proof compartments for samples to 
be tested, each compartment having a door which can be opened or closed as 
desired, a fan in each compartment, a common drive means for the fans 
located outside the compartments, and a timing device controlling the 
operation of the fans. 
U.K. patent specification No. 1 313 970. This discloses an apparatus for 
laboratory testing of sustained release drugs, which includes a heatable 
chamber, means for accurately controlling the temperature in the chamber 
and including a mercury bulb thermometer located within the chamber, a 
relay operating switch connected to a heat source for the chamber, and a 
rotatable wheel-shaped device located within the chamber and supporting a 
number of elution bottle housings. 
U.K. patent application No. GB 2 157 833 A. This discloses testing oil for 
emulsion formation, which includes a test rig--meant to simulate engine 
operating conditions so as to determine the propensity of various oils to 
form water-in-oil emulsions in the rocker covers of the engine--in which 
heated oil and heated saturated air, or raw steam, are directed by 
delivery pipes onto an inclined test plate disposed inside a cabinet and 
cooled. 
U.K. patent application No. GB 2 169 086 A. This discloses an apparatus for 
testing of fluids, especially for physical characteristics or 
susceptibility of process fluids, e.g., oil, to foam or form an emulsion, 
which includes a rotor with at least one arcuate and preferably 
transparent pipe segment that can transport the test fluid at various 
speeds during the rotation. 
SUMMARY 
The present invention provides in a foam tester including an insulated 
cabinet with a temperature-regulatable oven volume contained therein; a 
heater capable of heating a gas for the oven volume; a feature to 
circulate heated gas in the oven volume; an access system such that sample 
container(s), each capable of holding a liquid sample, is(are) insertable 
into the oven volume so that the same can be heated therein; and a feature 
to observe any sample(s) in the sample container(s) such that observation 
can be conducted from outside the cabinet--and wherein a cooling feature 
is provided to cool down the oven volume in the insulated cabinet--the 
improvement which comprises a cooling volume apart from the oven volume 
for containing coolant material, optionally, which can be closed off from 
the oven volume when the device is in heating mode and vice versa, 
preferably, however, which is not, but has a drainable liquid cooling 
system installed therein. In one particular embodiment, gel cooling may be 
employed; in another, high volume blowers circulate oven air, which can be 
cooled by a water-cooled radiator, and the need for an air plume within 
the oven volume is obviated with suitable ports. Test methods can include 
injection of preheated gas into an oil sample, especially having 
standardized, predetermined level(s) of contaminant(s). 
In general, the invention is useful in providing heating and cooling cycles 
in gas circulation ovens. It is especially useful in testing liquids for 
foaming at elevated temperatures. 
Significantly, the present oven can heat and cool circulating gas, and 
hence, contained foam tester sample containers, rapidly, and accordingly, 
another major step forward is made in the art, in particular as pertains 
to that of foam testing of liquids. Many if not all of the aforementioned 
problems in the art are addressed, and much if not all of the same is 
ameliorated or overcome. Preferred plumeless foam tester embodiments of 
the invention are highly developed for simple, efficient operation. The 
foam tester may be employed to operate sample testing cycles without the 
removal of samples from the tester between tests and with high efficiency 
suitable for high volume applications in the modern testing laboratory. 
Cooling is most efficiently provided. Ease of operation is significantly 
enhanced. 
Numerous further advantages attend the invention.

ILLUSTRATIVE DETAIL 
The invention can be further understood by reference to the present detail, 
which may be read in conjunction with the accompanying drawings. The same 
is to be taken in an illustrative and not necessarily limiting sense. 
The specification of the aforementioned patent application of Selby et al., 
Ser. No. 08/782822, is incorporated herein by reference. 
The oven of the invention is a gas, especially air, bath. Preferably, 
ambient pressure is employed, which may include a slight overpressure 
wrought by intake blower(s) and/or a slight underpressure wrought by 
exhaust blower(s). 
In reference to FIGS. 1-5, cabinet oven 1000 is embodied as a foam tester. 
As in the foam tester of the '822 application, in general, the foam tester 
1000 of the present invention can be equipped with similarly operating 
features, as follows: 
______________________________________ 
Feature Identity Number 
______________________________________ 
Housing, cabinet 10 
Top outside, e.g., 3/64- to 1/16-inch metal such as 
11 
Al, steel, to include stainless steel (preferred) 
Insulation, e.g., CERWOOL ceramic fiber, or a 
13 
high-temperature glass fiber 
Inside wall, e.g., 3/64- to 1/16-inch metal such as 
14 
aluminum (Al), steel, to include stainless steel 
Cabinet part top 
15 
Top access opening, e.g., an about 10-inch diameter hole 
16 
Cabinet outside wall, e.g., 3/64- to 1/16-inch metal such 
17 
as Al, steel, to include stainless steel (preferred) 
Tempered glass window, e.g., with four panes 
18 
Outside window gasket 19 
Oven volume 
20 
Oven volume rear wall 21 
Inside window gasket 22 
Oven floor, e.g., Al sheet 23 
Perforate circulation stack or air plume, e.g., Al, steel 
24 
Floor drain, e.g., as hole for air plume in oven floor 
27 
Side channels, for heating elements and so forth 
28 
Insertable carousel, member to hold sample container(s) 
30 
Outside, top, e.g., 1/4-inch thick KYDEX plastic layer, 
31 
or other heat-resistant material 
Insulative core, e.g., melamine, or 5/8-inch 
32 
heat-resistant foam 
Lower layer, e.g., Al with TEFLON polytetrafluoroethylene 
33 
mechanically or adhesively fastened thereto, or a 
heat-resistant phenolic laminate 
Fasteners, e.g., six nut and bolt type 
34 
Sample cylinder holes, e.g., six 
36 
Support rods, e.g., six TP314/304L ASTM A269 stainless 
37 
steel, or Al 
Carousel base, e.g., Al with TEFLON polytetrafluoroethylene 
38 
mechanically or adhesively fastened thereto, or a 
heat-resistant phenolic laminate 
Sample cylinder cups in carousel base, e.g., six 
39 
Front panel area 
40 
Air flow gages, e.g., Gilmont 150 mm GF-5531-2217 ball type 
41 
Main on/off switch 
44 
Main fuse 
45 
High-temperature (T) cut-out system indicator panel light 
48a 
High-T cut-out control device, e.g., a WATLOW-92 unit 
48b 
with manual reset feature 
Automatic oven volume heater heating on/off switch 
49 
Inlet for providing air or other gas for sample foaming 
52 
Electric supply cord, e.g., Carol 12/3 type SJOW-A (UL) 
54 
90-degree C., P-123-70-MSHA, CSA type 90-degree C., FT2 
Oven lights, e.g., two 55 
Cabinet bottom, e.g., 1/8-inch thick painted steel 
60 
Screw-type, height-adjustable feet, e.g., four (in corners) 
61 
Lower back access panel, e.g., perforated aluminum (Al) 
62 
Heater, e.g., dual - electric resistance finned strip type 
65 
Positive pressure plenum, including side channels 
69 
Sample container,. e.g., 1000-mL graduated cylinder type 
80 
Bubbling wand assembly for generating foam in test sample 
85. 
______________________________________ 
The foam tester 1000 also can include features such as the following: 
The cabinet 10 can also hold drain tray assembly 57. The assembly 57, for 
example, made of stainless steel, can be hollow and include pan bottom 
57b, top drain hole 57d which may have a rubber gasket about its 
circumference, handle 57h, drain tray pan drawer support rails 57r mounted 
to the bottom 60 of the cabinet 10 on and into which the tray pan 57p may 
be slid in and out, and drain tray pan side 57s, top 57t (with the drain 
hole 57d therein through which liquids spilled inside the oven volume 20 
may be drained) and width 57w (on the front of which the handle 57h is 
positioned). Also, protruding from the cabinet 10 on a side thereof is 
radially symmetric, scallop-edged handle 59, for example, of a hard 
plastic, which an operator can rotate so as to open and close internal 
door 159 for controlling the passageways employed in heating and cooling 
cycles; the handle 59 and door 159 are connected to rotatable axle 150, 
which can be mounted directly or indirectly to the housing 10 and equipped 
with an overcenter action to help insure that the door 159 stays either in 
closed or open position. Rather than being of aluminum, the lower back 
access panel 62 as well as the entire back panel can be stainless steel 
with louvers or punchouts, and it may be essentially flat with the entire 
cabinet deeper to accommodate suitable blowers and so forth. As shown in 
FIG. 4, the overcenter action can be provided by eccentric member 151 
mounted to the axle 150, which member is pivotally connected about an 
upper end of elongate compression spring loaded member 152 pivotally 
mountable directly or indirectly about a lower end thereof to the housing 
10; upon contact by the member 151 switch 155 such as a micro-switch or 
proximity switch can activate a circuit so that the heat on/off switch 49 
cannot turn on heaters with the door 159 in its open, i.e., cooling air 
entry, position; the door 159 may have a "beaver tail" or V-shape feature 
to extend it as far as it can go into the V-shaped floor defined in part 
by groove 123 of negative pressure plenum 167. As well with the housing 
10, gas egress ports 153a & 153b on housing top 15 provide independently 
monitored, heated gas, for example, air, for carrying by separate conduits 
(not illustrated) such as TYGON flexible plastic tubing to one or more, 
for example, three, bubbling wand assemblies 85. 
The oven volume 20 can have thermocouple 48c, for example, mounted on the 
rear wall, which is part of the over-temperature and control system, and 
sends signals to the high-temperature cut-out control unit 48b, which 
shuts the heating down if the temperature becomes too high and signals the 
high-temperature cut-out system indicator panel light 48a, which lights up 
when the cut-out value is reached. Also, the volume 20 can be defined in 
part by imperforate wall sections 121i, for example, as provided by about 
3/64-inch to 1/16-inch thick sheet aluminum, which can make up top, front 
and rear of the two side oven volume walls; open wall sections 121o, for 
example, two opposing about 2-inch wide by 61/2-inch tall openings in the 
upper portions of the oven volume side walls, which basically are cut out 
sections to provide illumination and installation access for the lights 
55, and air circulation orifices; and perforate wall sections 121p, for 
example, 3/64-inch to 1/16-inch thick sheet aluminum having about 1/4-inch 
to 3/8-inch holes therein such as obtainable as PERFMETAL perforated metal 
sheets, which can make up the upper near-front (immediately rearward of 
the openings from open wall sections 121o) and upper rear side oven wall 
sections, each, say, of an about 4-inch width by 61/2-inch height. Rolling 
ball carousel supports 125 can be mounted on the oven volume floor 23 and 
these can greatly facilitate rotation of the carousel 30. Also present are 
imperforate lower side walls 126, for example, of 3/64-inch to 1/16-inch 
thick sheet aluminum, behind which can be placed insulating tiles 128, for 
example, of ceramic, so as to ameliorate "hot spots" from the heaters 65. 
A gap 27a may be provided between the lower portion of the oven volume 
rear wall 21 and the oven volume floor 23 to provide an alternate passage 
for spilled liquids to drain. Thermocouple 147, for example, also mounted 
on the rear wall, which is part of a process temperature control system, 
and which sends its signals to a process control system device. 
The carousel 30 can be equipped with handle 135, preferably which is 
centrally located, for example, a radially symmetric, scallop-edged of a 
hard plastic. This aids the operator not only in insertion and removal of 
the carousel 30 into and from the oven volume 20 but also in positioning 
the carousel 30 with the sample cylinders 80 therein for better sight 
alignment by facilitating rotation of the same in preparation for or 
during test runs. 
The front panel area 40 also can include as the two gas flow gages 41, left 
side flow gage 41a (communicating with features 153a and 170a) and right 
side flow gage 41b (communicating with features 153b and 170b); first 
timer 42a and second timer 42b, for timing test runs and so forth; lower 
fan opening 143a with fan for drawing in outside air to cool inside 
instruments in the wiring volume, and upper vent 143b to permit hot air to 
exit from the wiring volume; in conjunction with the high-temperature 
cut-out control system, an over-temperature reset switch 48d, for example, 
one controlled by lock and key, working in conjunction with the WATLOW-92 
unit 48b; "check blower" indicator light 56, which lights up when a preset 
low pressure differential between the positive and negative plenums 69 & 
167, respectively, is reached so as to indicate if one of the blowers 66a 
or 66b is inoperative or operating at less than proper capacity; filter 
frame assembly 58 which holds a spun air filter between front and back 
imperforate metal sheets held by its edge frame, the same able to be 
fastened to the front panel 40, for example, by two screws; first timer 
starting push button switch 142a, which starts the timer 42a, and second 
timer starting push button switch 142b, which starts the timer 42b; 
process control system device 146, for example, a WATLOW-981 unit, which 
can control test run temperature and may monitor or control other test 
data. Heating cycle indicator light 149 lights up when the heating cycle 
on/off switch 49 is set at its "on" position when the heaters 65 are 
energized; and cooling cycle on/off switch 151a and cooling cycle 
indicator light 151b lights up when the cooling cycle on/off switch 151a 
is at its "on" position--and the internal door 159 is in its "open" 
position to permit cooling air to enter inside the hot oven. 
Workings of the foam tester 1000 also include a thermostat (not 
illustrated) in the noted wiring volume so as to communicate to the system 
and the fan 43a an over-temperature situation in the wiring volume such 
that the fan 43a operates even though the main power switch 44 is in the 
"off" position; suitable circulation blowers 66a (left) & 66b (right), for 
example, Dayton model number 5M064A, 1/20-horsepower, 
3000-rotations-per-minute, 115-volt, 60-Hertz, 2.9-ampere, class "B" 
impedence-protected pusher blowers, with the left pusher blower set to 
rotate in the counterclockwise direction when viewed from the front and 
the right pusher blower set to rotate in the opposite (clockwise) 
direction. Other speeds and types of blowers 66 may be employed. Negative 
pressure plenum floor drain crease 123 leads spilled liquids to hole 127 
and associated conduit, which leads the spilled liquids to the drain tray 
pan drain hole 57d and the drain tray pan 57p for removal as may be 
needed. Imperforate sliding doors 129 such as of a metal, for example, 
aluminum, about the top, center of the side walls of the oven volume 20 
are provided in pairs and can be adjusted to cover or uncover portions of 
the perforate wall sections 121p making up the upper near-front and upper 
rear side oven wall sections so as to regulate air flow and ameliorate 
temperature differentials in the oven volume 20 during heating cycle test 
runs. For example, on both sides of the oven volume 20, the sliding doors 
129 can be adjusted to leave an about 3/4-inch wide portion of the 
perforate wall sections 121p making up the upper near-front side oven wall 
sections, and an about 1/2-inch wide portion of the perforate wall 
sections 121p making up upper rear side oven wall sections, which can 
reduce temperature differentials in the oven volume 20 from an about 
30-degree to 40-degree Fahrenheit value as can be found with the foam 
tester of the '822 application to a maximum of an about 6-degree to 
7-degree Fahrenheit value initially in a heating cycle, i.e., when "cold," 
to a mere about 3-degree to 4-degree Fahrenheit value when the foam tester 
1000 operates later in the heating cycle, i.e., when the device is "warmed 
up." Thermocouples 147h may limit temperature of the heaters 65. 
Further workings of the foam tester 1000 include cooling plenum 158 and 
special negative pressure plenum 167. The cooling plenum 158 such as made 
of metal, for example, aluminum, can be generally in the form of a cube or 
a rectangular boxlike interior bounded by side walls 158a (left) and 158b 
(right); floor 158c; rear wall 158d, which can be considered to be the 
other side of a part of negative pressure plenum front wall 167e and also 
contain the hole 167h; and top 158e, which can be considered to be the 
underside of a part of the oven floor 23. The negative pressure plenum 167 
such as made of the same metal as the cooling plenum 158 can have its 
drain crease 123 in part defining its inverted house-shaped interior, 
which is bounded by slanting bottom walls 167a (left) and 167b (right), 
which may be considered to define a sort of "invert roof"; side walls 167c 
(left) and 167d (right); front wall 167e; rear wall 167f; gap 167g between 
the floor 167a and rear wall 167f, especially about the crease 123 so as 
to provide drainage to hole 127 for any spilled liquids; front wall hole 
167h which can communicate with the cooling plenum 158 when the door 159 
is opened--otherwise, when the door 159 is closed the hole 167h is sealed 
from the cooling plenum 158; and top 167i, which also can be considered to 
be the underside of a part of the oven floor 23. The venturis of the 
blowing motors 66 mate with the rear wall 167f equidistant from a vertical 
midline thereof which intersects the crease 123 and about central in each 
left and right section formed thereby. In operation, when the door 159 is 
closed, the foam tester 1000 is in its heating mode, and the gas such as 
air is sucked down through the air plume 24 into the negative pressure 
plenum 167 by the blowing motors 66; from thence, the gas is blown and 
thus flows to the positive pressure plenum 69, side channels 28, oven 
volume 20 and back down through the air plume 24. When the door 159 is 
opened, the foam tester 1000 is in its cooling mode, and a gas, preferably 
air, can be sucked by action of the motors 66 through the filter 58 into 
the cooling plenum 158 preferably so as to be cooled by cooling device 
290, from thence to the negative pressure plenum 167, and thence to the 
positive pressure plenum 69 and the oven volume 20 with or without the 
carousel 30 and sample containers 80 to cool the same; an extended "beaver 
tail" door 159, shaped generally like a "home plate" in baseball, can 
cover the hole 27 to as much as about ninety to ninety-five percent of its 
total cross-sectional area, which is highly. effective in providing 
cooling air to the oven volume 20 and contents; exhaust of the cooling air 
which is forced into the oven volume 20 may be provided by removal of a 
sample container 80 from the carousel 30 or by an external vent emanating 
from the oven volume 20 to the surrounding atmosphere. 
Notably also in the foam tester 1000, air or other gas for making foam in 
liquids in the sample containers 80 through use of the wands 85 is 
provided with two separate but equal systems of conduits: The air or other 
gas enters through conduit fitting 52 from pressure supplied by a pump or 
as from bottled gas, and the conduit is divided into two separate conduits 
(dashed lines - - - & dotted lines . . . ) inside the cabinet 10; the air 
or other gas passes therethrough and into respective flow gages 41a & 41b, 
and then into tempering conduits 170a & 170b in the side channels 28 above 
the-heaters 65 of the foam tester 1000, where the air or other gas is 
heated, and from thence it is directed to respective gas egress ports 153a 
& 153b on the housing top 15. Each side of this foam-producing gas system 
has a total of about six feet of 1/4-inch copper tubing being provided as 
coiled tempering conduit lengths 170a or 170b. Thus, the conduits are the 
same lengths from features 52 to 153a & 153b to provide for more 
reproducible foam generation in testing. As well, the foam tester 1000 has 
cooling motors 174 for cooling the blowers 66, but the cooling motors 174 
may be eliminated such as when self cooling blowers, for instance, totally 
enclosed fan cooled blowing motors, are employed for the blowing motors 
66. 
Any suitable cooling unit or type of cooling may be employed with the foam 
tester 1000. Thus, cooling units such as disclosed by the '822 
application, or other cooling units, may be employed. Alternatively, 
ambient air may be employed without chilling, but chilling is preferred 
for faster cycle times unless a chilled ambient air is employed such as 
during winter, and the cooling unit may embrace the cooling device 290, 
which can be removably inserted or permanently installed in the cooling 
plenum 158. 
Advantageously, the cooling unit 290 employs gel cooling. For example, as 
depicted in FIGS. 6 & 7, gel tube assembly 291 may include copper tube 292 
with a copper cap 293 on a first end of the tube 292 permanently attached 
such as by soldering, and with a copper part 294 permanently attached to a 
second end of the tube 292, which part 294 includes male threads 
accessible from the outside, i.e., the part 294 is a male to female 
adapter. Cap 295 with complementary female threads can seal the assembly 
291 after freezer pack type gel 296 is inserted into the tube 292, and the 
gel 296 may be of any suitable variety, typically being a composition 
containing propylene glycol, water, a thickener such as corn starch, color 
and a bactericide, as available with units used in common picnic coolers. 
Optionally, cellular resilient material 297 may be employed for absorbing 
the force of expansion associated with freezing water. A plurality of such 
filled, capped tube assemblies 291 may be arranged in perforated housing 
298, for example, of aluminum, which may have handles 299. The unit 290 
with filled gel tube assembly(ies) 291 is cooled, usually to freezing, 
inserted into the plenum 158 of the oven 1000, and air or other carrying 
gas is circulated thereby to cool the same as it is introduced into other 
parts of the oven 1000. 
As another alternative, the cooling device 290 may be a solid state cooling 
unit such as so-called ferro-electric unit, which operates on the Peltier 
effect. For instance, as depicted in FIG. 8, alternate, solid-state 
cooling device 290a has Peltier effect chips 290b arranged in a suitable 
housing provided with electric power so that cold sides 290c of the chips 
290b face each other and hot sides 290d face each other to form separate 
cold and hot channels 290e and 290f, respectively, with the cold channels 
290e perpendicular to the hot channels 290f. The device can be set up so 
that air is drawn in through the cold channels 290e to be cooled in the 
plenum 158 for providing cool air to cool the appropriate parts of the 
oven 1000. Simultaneously, air is drawn across through the hot channels 
290f to be expelled on a side of the oven 1000 where the same will not be 
drawn in the front, or where ever the intake is for the air to be cooled. 
The foam tester 1000 is amenable to automation. For example, solenoids may 
provide communication between flow gage 41a and timer 42a and between flow 
gage 41b and timer 42b so as to work with a programmable device such as an 
electronic programmable logic controller or mechanical sequencer or 
combination of relays producing a circuit commonly referred to as relay 
logic. 
Accessory features may be added, deleted or modified. 
The oven of the invention is made to any suitable dimension. For example, 
the foam tester 1000 includes dimensions, in inches (")--which may be 
considered to be approximate--as follows: 
______________________________________ 
Feature Identity 
Dimensions 
______________________________________ 
Cabinet 10 21" wide .times. 21" deep .times. 25" tall 
Cabinet 10 plus feet 61 
21" wide .times. 21" deep .times. 26" to 27" tall 
Window 18 5-3/4" wide .times. 13" tall 
Window panes 18a & 18d 
1/4" thick 
Window panes 18b & 18c 
1/8" thick 
Oven volume 20 
11-1/4" wide (top) to 10-3/4" (bottom) .times. 
13-1/4" deep .times. 15-3/4" 
tall 
Stainless st./Al plume 24 
3/64" to 1/16" thick, 3" diameter .times. 
14-1/2" tall 
Side channels 28 
1-3/4" wide .times. 13" deep .times. 15-3/4" 
tall 
Carousel 30 15-15/16" diameter .times. 17-1/2" tall 
Sample cylinder holes 36 
2-5/8" diameter circular holes in top 
and lower layer, 2-1/2" holes in 
foam 
Carousel support rods 37 
3/8" diameter .times. 15" tall 
Carousel base 38 
15-15/16" diameter .times. 1/4" tall 
Sample cylinder cups 39 
2-9/16" diameter .times. 3/16" deep 
Hollow drain tray pan 57p 
8" wide .times. 16" deep .times. 11/16" high, with 
3/4" hole center 14-3/4" from 
front 
Filter frame assembly 58 
8-3/8" wide .times. 1/2" deep .times. 7-1/2" tall 
Sliding doors 129 
Each 8" wide .times. 6-1/2" tall 
Cooling plenum 158 
8" wide .times. 8" deep .times. 8" tall 
Lower pressure plenum 167 
12-1/2" wide .times. 5-3/4" deep .times. 5" tall, 
in general, at sides; 5-3/4" tall 
at 
front center & 6" tall at rear 
center. 
______________________________________ 
In reference to FIGS. 9-21, cabinet oven 1001 is embodied as a plumeless 
foam tester. 
In general, the plumeless foam tester 1001 does not have an air plume such 
as found in the foam tester 1000 (24); however, the device 1001 includes a 
cooling volume apart from the oven volume for containing coolant material. 
Nonetheless, the cooling volume of the plumeless foam tester 1001 is not 
physically closed off from the oven volume when the device is in heating 
mode as in the foam tester 1000; rather, the plumeless foam tester 1001 
has a drainable liquid cooling system installed in a gas-conducting 
passageway which leads to and is in communication with the oven volume. 
The same passageway or volume, with the cooling liquid drained from the 
cooling system, serves as a heating passageway when the plumeless foam 
tester 1001 is in heating mode. 
As in the foam tester of the '822 application, in general, the plumeless 
foam tester 1001 of the present invention can be equipped with analogous 
features, as follows: 
______________________________________ 
Feature Identity Number 
______________________________________ 
Cabinet housing 10 
Outside wall, e.g., of 1/4-inch thick KYDEX thermoplastic 
11 
Insulation around oven volume, e.g., of woven glass fiber, 
13 
one inch in thickness with an aluminuin foil skin 
Inside oven volume wall, e.g., of aluminuin sheet metal 
14 
Cabinet top, e.g., of L-50 fiber-based epoxy composite 
15 
(Polycomposites) some 1/4-inch thick 
Top access opening, about ten inches in diameter 
16 
Cabinet outside wall, e.g., of stainless steel 
17 
Outside window gasket 19 
Oven volume 
20 
Inside window gasket 22 
Center hole in oven volume floor to lower plenum 
27 
Insertable sample carousel 30 
Carousel outside, top, e.g., of the 1/4-inch L-50 material, 
31 
with insulative core, and lower, inside layer of 
ULTEM-1000 polyetherimide resin with a 332-degree 
Fahrenheit rating 
Handles, e.g., two, each of stainless steel 
35 
Sample cylinder holes, e.g., six 
36 
Support rods, e.g., six, each of stainless steel 
37 
Carousel base, e.g., of aluminum with large center hole 
38 
communicating with large center hole in oven floor 
from lower plenum (being further present underneath 
the base, however, for spinning the carousel on the 
oven floor, a low profile ball bearing turn table 38b, 
e.g., a 9-inch round McMaster-Carr Supply model-6031K21 
turn table with a 4-1/2 - inch center hole, carbon-steel 
ball bearings in a track near the outside perimeter of 
the turn table, and a 750-pound load capacity rating) 
Sample container receiving cups in base, e.g., six 
39 
Front panel area 
40 
Gas, e.g., air, flow gages, e.g., Gilmont 150-mm ball type 
41 
Left hand gas, e.g., air, system gage 
41a 
Right hand gas, e.g., air, system gage 
41b 
Main on/off switch 
44 
Main fuse (rear mounted) 45 
High temperature cut out light 
48a 
High temperature cut out control device, e.g., a 
48b 
WATLOW-92 unit 
Overtemperature key reset switch 
48d 
Inlet for providing air or other gas for sample foaming 
52 
Electric supply cord 54 
Cabinet bottom, e.g., 1/4-inch thick painted steel 
60 
Cabinet feet, e.g., four height-adjustable screw-type 
61. 
______________________________________ 
As in the foam tester 1000 hereof, in general, the plumeless foam tester 
1000 can be equipped with like features, as follows: 
______________________________________ 
Feature Identity Number 
______________________________________ 
Drain tray assembly 57 
Heat-insulating tile 128 
Heat-insulating tile installation line mark (FIG. 20) 
128m 
Gas egress ports for heated gas, e.g., air, for foaming 
153 
Independent left hand side gas system egress port 
153a 
Independent right hand side gas system egress port 
153b. 
______________________________________ 
The plumeless foam tester 1001 also can include features such as the 
following: 
Multi-pane, heat-insulating, wide-range-of-view window 318 includes wider 
inner window 318i, for example, with two panes, and narrower outer window 
318o, for example, with two panes. Silicone sealant/adhesive is used for 
each pane. Air is present between the panes. A capillary tube extends from 
within the confined volume to atmosphere in between each pane to relieve 
heat induced pressure but prevent moisture form being inhaled upon 
cooling. 
In general, oven volume housing 320 defines the oven volume 20, which is 
composed of oven volume cage walls, for example, of aluminum sheet metal: 
rear wall 321r, two imperforate side walls 321s, and top 321t. The inside 
window 318i completes the definition of the oven volume 20, generally 
speaking. The rear wall 321r is imperforate, save blower intake opening 
321o with grill. The top wall 321t is also imperforate, save the carousel 
access hole 16. Advantageously, defining the carousel access hole 16 can 
be heat-insulative, low-friction material 316, for example, such as of 
suitable plastic, e.g., of Teflon polytetrafluoroethylene. Oven volume 
floor 23, for example, made of aluminum, includes the center hole 27; 
front circulation holes 324f, for example, two in number, each with an 
about 7/8-inch diameter placed (on center) about one inch from the inside 
boundary of the inner window 318i and about 19/16 inches from the nearest 
side wall 321s; and rear circulation holes 324r, for example, four in 
number and all with an about 7/8-inch diameter, one set of two of which 
(e.g., left hand side set) having a first hole placed (on center) about 
19/16 inches from the inside boundary of the rear wall 321r and about 
29/16 inches from the nearest side wall 321s and a second hole placed (on 
center) about 29/16 inches from the inside boundary of the rear wall 321r, 
and the other set of which (e.g., right hand side set) being a mirror 
image thereof. Each of the holes 27, 324f & 324r are open to and in 
communication with positive pressure plenum 369. The oven volume housing 
320 is connected to, but set off from, the cabinet housing 10 by sets of 
set-off post fasteners 321f which secure the same through a series of 
heat-insulating set-off posts 321b (bottom) and 321t (top). Lights 355, 
shining through the inner window 318i, are placed within the cabinet 10 
but outside the oven volume 20 so as to illuminate the same. 
The positive pressure plenum 369 can have, in general, portions including 
special lower, narrow-height, transverse plenum 369t and special rear, 
vertical plenum 369v. The holes 27, 324f & 324r to the oven volume 20 
preferably are in direct communication with the lower plenum 369t, and the 
lower plenum 369t is open to and in communication with the rear plenum 
369v. Preferably, in general, the interior of the lower plenum 369t is 
void of solid features, but the interior of the rear plenum 369v contains 
gas/air heater 365 and gas/air cooling radiator 390. 
The heater 365 is any suitable for the job. Advantageously, however, the 
heater 365 is composed of a plurality of heaters, for example, two, one 
with a 725-watt element, e.g., a Vulcan model #OSF1510-725B) and the other 
with a 475-watt heater element, e.g., a Vulcan model #OSF1510-475B), 
which, together, are highly effective in and adapted to commonly 
encountered 20-amp electric service. The heater 365 can be mounted below 
circulation blower 366 and above the radiator 390. 
The blower 366 is a high-volume gas/air blower, preferably of the 
squirrel-cage variety. For example, a 500-cubic feet per minute (cfm) to 
700-cfm capacity squirrel-cage arrangement, e.g., a model #1-1548 squirrel 
cage blower supplied by York Electric, can be provided as the blower 366. 
The blower 366 can be mounted on brackets 366b through its bearing 
housing, the bearings of which, for example, can be AMI bearings rated to 
a 372-degree F. temperature. The blower can be driven by electric motor 
366m which, through heat-resistant pulley 366p, for example, such as an 
adjustable Acculink V-groove fiber-reinforced rubber variety having a 
280-degree F. rating, drives heat-insulative blower shaft 366s, for 
example, of G-11 fiber-epoxy material. The intake for the blower 366 is 
the gas/air passing through the blower intake opening 321o from the oven 
volume 20, and, from the blower 366, the gas/air is forced into the rear 
plenum 369v, from there to the lower plenum 369t, and from there to the 
oven volume 20. The presence of the heater 365 and radiator 390 as well as 
fins included therewith causes increased turbulence in the plenum 369 and, 
in conjunction with the entry holes 27, 324f & 324r and impetus of the 
high-volume blower 366 itself, assists in an even temperature distribution 
in the oven volume 20 through dynamic convection without a plume. Be that 
as it may, it has been found that with the high-volume, turbulent flow of 
air in the oven volume 20, occasioned from the features in the device 
1001, a strictly even or uniform value of temperature in the oven volume 
20 is not critical for obtaining highly reproducible foam test data in the 
device 1001. 
The radiator is any suitable for the job. Advantageously, however, the 
radiator 390 is a liquid-cooled radiator, from which the cooling liquid 
can be drained when the device 1001 is in heating mode and through which 
the cooling liquid can be pumped when the device 1001 is in cooling mode. 
For example, the radiator 390 can be a water-cooled unit, e.g., a Peerless 
model #3660-0-12 unit, with metal cooling fins which contact the gas/air 
passing thereby in the plenum 369. Such a radiator may be in a radiator 
system which can include cooling water ingress port 391, water exit port 
392, and water vapor escape port 393, each, for instance, made of a 
suitable heat-insulating material such as of heat-insulative plastic, for 
example, of Kynar nylon composite, which has a 285-degree Fahrenheit (F.) 
rating. In conjunction with the radiator 390 and ports 391, 392 & 393, are 
water input lines 391i, for example, of copper tubing; water drain lines 
392d, for example, of copper tubing; pressure relief valve 391/2r, e.g., 
set to a 125-p.s.i. (pounds per square inch) value; and water vapor escape 
line 393v, for example, of copper tubing. The system is controlled by two 
solenoids, a first one 391/2s, which controls liquid water flow lines, and 
a second one 393s, which controls the vapor escape line. The solenoids are 
programmed to be either the first open and the second closed (cooling 
mode) with water, for example, from the tap, entering the port 391 cool 
and exiting the port 392 carrying off heat, or the first closed and the 
second open (heating mode) with draining of the radiator 390 as well as 
escape of any left over water accelerated and facilitated through the open 
vent port 393. 
Separate but equal gas/air tempering lines include tempering coils 370a & 
370b, for example, of 3/16-inch inside diameter and 1/4-inch outside 
diameter copper tubing coiled helically seven times or so with a helical 
radius of about two inches for a distance of about a foot more or less, 
inside the oven volume 20. This arrangement is most efficient in the 
tempering of the gas, for example, air, which enters through the coupling 
52, travels through separate lines, and, so separated, passes through the 
insulation 13 and side wall 321s to the coils 370a or 370b to be heated, 
and then, so tempered, passes out the side walls 321s and to the proper 
gas egress port 153a or 153b. The tempered gas/air is employed to generate 
foam in the sample in the sample container 80. 
Front gages and signal lights can include, in addition to the main switch 
44, the high temperature cut-out light 48a and the overtemperature cut-out 
key reset switch 48d, for example, display-transmission module 342, e.g., 
an ATM-20 unit (NAIS), for providing visual messages to the operator as 
well as providing the input signals to a programmable logic controller 
(PLC); main power indicator light 344; sequence selector switch 345, which 
permits the operator to select between preprogrammed test runs; 
temperature control unit 346, e.g., a WATLOW-988 device; and cooling 
switch 347, which permits the operator to turn on the cooling function. In 
the device 1001, the main switch 44 controls electrical power to the 
components of the unit, i.e., the module 342, lights 355, blower 366, and 
so forth. A wiring volume, in addition to the high temperature control 
48b, contains microprocessors and other regulatory instrumentation, and it 
is cooled during use by warm air exiting upper side cooling vent 343a and 
being drawn into the wiring volume by a blower motor through lower side 
cooling vent 343b. Internal cabinet components are cooled through air 
entering vent 343c and being forced by blower motor 374 onto such items as 
the oven volume insulation 13, lights 355, motor 366m and so forth, and 
from thence out louvered, stainless steel back panel 362. 
Resistive temperature device (RTD) couple 346c, for example, a WATLOW 
4-inch RTD, which can be located in the front of the lower plenum 369t, 
provides input to the temperature controller 346 for effective temperature 
control of the oven volume bath. Thermocouple 348c, located in the upper 
portion of the rear plenum 369v, generally between the heater 365 and 
blower 366, provides the input for the temperature cut-out control unit 
48b. 
Most notably, with the oven volume 20, hole 27, 324f & 324r, heater 365, 
blower 366, plenum 369, radiator 390 and so forth arrangement, heating and 
cooling cycle times in the device 1001 can be quite astoundingly fast. For 
example, heating cycle (24-degree Celsius (C.) to 150-degree C. oven 
volume temperature) times as short as fourteen minutes, or less, and 
cooling cycle (150-degree C. to 10-degree C. oven volume temperature) 
times as short eighteen minutes, or less, have been attained with 
regularity. This compares most favorably with any foam tester device, to 
include even the device 1000, which has a relatively fast cycle time of 
about half an hour to heat and half an hour to cool, and is a definite 
practical improvement in kind over even the foam tester devices of Selby 
et al., Ser. No. 08/782822. 
Moreover, with the aforesaid arrangement, the device 1001 can provide for a 
highly uniform heating and temperature distribution within the oven volume 
20, notwithstanding the fact that the same need not be exactly uniform. 
For example, a heat and temperature distribution in the foam testing mode 
has been found to be at a 150.+-.3-degree C. value, or better. This 
compares most favorably with the air plume containing foam tester devices, 
to include the device 1000. See, infra. 
Advantageously, the device of the invention, especially, for example, the 
device 1001, is made to CE (European) standards. 
Dimensions of the device 1001 may vary. Nevertheless, for example, the 
following dimensions, which may be considered to be approximate, can be 
found with the foam tester of FIGS. 9-21: 
______________________________________ 
Feature Number Dimension 
______________________________________ 
10d (FIG. 13) 24 inches (61 cm) 
10h (FIG. 11) 18-1/2 inches (47 cm) 
10r (FIG. 19) 3-3/4 inches (9-1/2 cm) 
10v (FIG. 18) 8-1/4 inches (21 cm) 
10w (FIGS. 13 & 18) 
24 inches (61 cm) 
10/61h (FIG. 11) 19-15/16 inches (50-1/2 cm) 
20d (FIG. 19) 12 inches 30-1/2 cm) 
20h (FIG. 18) 14-15/16 inches (38 cm) 
20/369w (FIG. 19) 
12 inches (30-1/2 cm) 
30x (FIG. 17) 1-1/2 inches (3-3/4 cm) 
40c (FIG. 19) 9-1/2 inches (24 cm) 
40d (FIG. 19) 3 inches (7-1/2 cm) 
40e (FIG. 19) 11-3/4 inches (29-3/4 cm) 
318d (FIG. 19) 1-3/4 inches (4-1/2 cm) 
318wi (FIG. 19) 9-1/2 inches (24 cm) 
318wo (FIG. 19) 6 inches (15-1/4 cm) 
369d (FIG. 17) 15-3/4 inches (40 cm) 
369h (FIG. 17) 1 inch (2-1/2 cm). 
______________________________________ 
In actual testing, methodology can include injection of a gas to include a 
preheated gas, for example, air, into an oleaginous liquid sample, such as 
known in the art or disclosed in the aforementioned application of Selby 
et al., where, in general, pristine oil samples are subject to foam 
testing. However, for alternative foam testing, it may be desirable to 
introduce one or more contaminant(s) into the sample, especially so that 
the same has a standardized, predetermined level(s) of contaminant(s). For 
example, water may be introduced to an oil sample in the form of a liquid 
before it is heated and air is bubbled through to produce the foam, or, as 
a preferred alternative, water may be introduced in the gaseous phase. The 
water vapor may be provided before or during foaming such as by 
introduction by steam or air which has been moistened by bubbling it 
through liquid water in an enclosed flask. Other contaminants which may be 
introduced include fuel, carbon and/or metal particles, 
silicone-containing anti-foaming agents, and so forth and the like. 
Accordingly, foam testing can be correlated to the presence of the 
contaminant(s) in an actual oil sample as found, for example, in internal 
combustion engines, or in automatic transmission fluids, and so forth, 
where air contact, combustion by products, wear and tear and other sources 
of contamination may affect an oil in use. 
Accordingly, the oven of the invention, for example, embodied as a foam 
tester, can heat and cool circulating gas, and hence, contained sample 
containers, rapidly. A volume for cooling the oven volume is provided 
apart from the oven volume, and the cooling volume is adapted to contain 
cooling material, at least during operation of the cooling cycle. 
Optionally, the cooling volume can be closed off from the oven volume when 
the device is in heating mode and opened when in cooling mode, but 
preferably, it is not but has a drainable liquid, for example, water, 
cooling system installed in the cooling volume. The device may have an air 
plume; preferably however, it has such a plume eliminated with high 
circulation blowing and mixing of the bath gas, for example, air, 
provided. Accessories such as a removable drain tray, and so forth, may be 
added. The exemplary devices are particularly useful for testing for the 
foaming characteristics of liquids, and the principles of the cooling 
volume can be applied to cabinet ovens in general. As an option, gel or 
cooling other than liquid in radiator cooling, for example, solid state 
cooling, may be employed. Test methodology can include injection of a gas 
to include a preheated gas, for example, air, into an oleaginous liquid 
sample, for example, oil or transmission fluid, especially having 
standardized, predetermined level(s) of contaminant(s). 
CONCLUSION 
The present invention is thus provided. Parts and subcombinations may be 
interchanged from one embodiment to another, and further, may be practiced 
without regard to other parts, subcombinations or combinations, in the 
practice of the invention, and numerous adaptations and modifications can 
be effected within its spirit, the literal claim scope of which is 
particularly pointed out as follows: