Laboratory foam test

The degree of foaming tendency may be checked by laboratory foaming tests, but it is difficult to predict what effect a given degree of foaming may have on tray capacity. 

Flame Resistance. Traditionally, small-scale laboratory flammabiUty tests have been used to initially characterize foams (38). However, these do not reflect the performance of such materials in bulk form. Fire characteristics of thermal insulations for building appHcations are generally reported in the form of quaHtative or semiquantitative results from ASTM E84 or similar tunnel tests (39). Similar larger scale tests are used for aircraft and marine appHcations. 

Repeated membrane failures during the early part of the 12-kW plant 500-hour DMMP run prevented effective control of water balance and levels of silver and organic material in the catholyte system. After laboratory-scale testing from October 11 to October 21,2001, AEA concluded that the failures resulted from foaming or pockmarks in the lattice structure of the PTFE support in the Nafion membrane and that the pockmarks formed only if the membrane came into contact with the cathode. 

Cell size and uniformity are also important variables when studying foams. However, space limitations preclude discussions of these variables herein. Other surfactant properties critical to the success of an EOR process are surfactant adsorption and thermal stability. These questions, under study in our laboratory, are not considered in the short-term one atmosphere foam test experiment and therefore will not be discussed herein. 

Work previously reported has shown very significant reductions in gas mobility when in situ generated foam was used in laboratory core tests. Using unconsolidated core models, investigators measured ten to several hundredfold decreases in gas mobilityThe effectiveness of foam for mobility control is vitally dependent on the choice of the surfactant used. Early tests using 1% ammonium lauryl sulfate were not totally successful in demonstrating foam effectiveness. ... 

Foam Separation by Dispersed Air Flotation Cell Chemical Reagents for Adsorptive Bubble Separation Laboratory Foam Separation Tests Engineering Applications... 

Engine Oil Aeration an engine test which complements the laboratory 1.3 foaming test . 

A researcher is spraying decontamination foam in a laboratory to test the neutralization of chemical weapons. 

Faikne of an amine solution foaming test. Bacon (1987) mcommends that the foam height and break time as measured by the standard Dow foam test be less than 200 ml and 5 seconds, lespectivdy. Smith (1979A, B) describes laboratory and field foaming tests... 

Laboratory experiments using rodents, or the use of gas analysis, tend to be confused by the dominant variable of fuel—air ratio as well as important effects of burning configuration, heat input, equipment design, and toxicity criteria used, ie, death vs incapacitation, time to death, lethal concentration, etc (154,155). Some comparisons of polyurethane foam combustion toxicity with and without phosphoms flame retardants show no consistent positive or negative effect. Moreover, data from small-scale tests have doubtful relevance to real fine ha2ards. 

Flammability. The results of small-scale laboratory tests of plastic foams have been recognized as not predictive of their tme behavior in other fire situations (205). Work aimed at developing tests to evaluate the performance of plastic foams in actual fire situations continues. All plastic foams are combustible, some burning more readily than others when exposed to fire. Some additives (131,135), when added in small quantities to the polymer, markedly improve the behavior of the foam in the presence of small fire sources. Plastic foams must be used properly following the manufacturers recommendations and any appHcable regulations. 

Miscellaneous chemicals are used to modify the final properties of rigid polyurethane foams. Eor example, halogenated materials are used for flammabihty reduction, diols may be added for toughness or flexibiUty, and terephthalate-based polyester polyols may be used for decreased flammabiUty and smoke generation. Measurements of flammabihty and smoke characteristics are made with laboratory tests and do not necessarily reflect the effects of foams in actual fire situations. 

There are many laboratory methods for testing the relative merits of one defoamer against another. It is a simple matter to measure foam height as a function of time to compare the performance of various foam surfactants and defoamers. Unfortunately, this simplicity has led to a wide variety of methods and conditions used with no standard procedure that would make the measurement of foaminess as characteristic of a solution as its surface tension or viscosity. It has been suggested that the time an average bubble remains entrapped ia the foam is such a quantity (49), but very few workers ia the defoamer iadustry have adopted this proposal. Ia practice, a wide variety of methods are used that geaerally fall iato oae of five maia categories ... 

Also, other dependent variables associated with CO2-foam mobility measurements, such as surfactant concentrations and C02 foam fractions have been investigated as well. The surfactants incorporated in this experiment were carefully chosen from the information obtained during the surfactant screening test which was developed in the laboratory. In addition to the mobility measurements, the dynamic adsorption experiment was performed with Baker dolomite. The amount of surfactant adsorbed per gram of rock and the chromatographic time delay factor were studied as a function of surfactant concentration at different flow rates. 

The experiments initially conducted were designed to test the performance of the apparatus by determination of the effect of pressure on the viseosity/quality spectrum of a typical foaming agent when it flows through a straight capillary tube. The method used is based on a technique recently developed in the laboratories(7) for this purpose, at atmospheric pressure,... 

Experimental Materials. All the data to be presented for these illustrations was obtained from a series of polyurethane foam samples. It is not relevant for this presentation to go into too much detail regarding the exact nature of the samples. It is merely sufficient to state they were from six different formulations, prepared and physically tested for us at an industrial laboratory. After which, our laboratory compiled extensive morphological datu on these materials. The major variable in the composition of this series of foam saaqples is the aaK>unt of water added to the stoichiometric mixture. The reaction of the isocyanate with water is critical in determining the final physical properties of the bulk sample) properties that correlate with the characteristic cellular morphology. The concentration of the tin catalyst was an additional variable in the formulation, the effect of which was to influence the polymerization reaction rate. Representative data from portions of this study will illustrate our experiences of incorporating a computer with the operation of the optical microscope. 

An annual inspection should be made of foam concentrates and their tanks or storage containers for evidence of excessive lumps or deterioration. Samples of concentrates should be sent to the manufacturer or qualified laboratory for quality condition testing. 

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