Bubble volume measurement

Breath alcohol testing is accompHshed by a number of techniques. The oldest rehable procedure involves bubbling a measured volume of deep-lung air containing alcohol through an acidic solution of potassium dichromate, Deep-lung air is the last portion of expired breath. It is collected in... 

Calibrate the detector tube pump for proper volume measurement at least quarterly. Simply connect the pump directly to the bubble meter with a detector mbe in-line. Use a detector mbe and pump from the same manufacturer. Wet the inside of the 100 cc bubble meter with soap solution. For volume calibration, experiment to get the soap bubble even with the zero ml mark of the buret. For piston-type pumps, pull the pump handle all the way out (full pump stroke) and note where the soap bubble stops for bellows-type pumps, compress the bellows fully for automatic pumps, program the pump to take a full pump stroke. 

In any study on bubble formation, the measurement of bubble volume is of primary importance. The bubbles formed at a nozzle ascend through the liquid column and rupture at the surface of the liquid. During their ascent,... 

In these methods the volumetric flow corrected to the nozzle tip, Q, and the frequency of bubble formation, /, are directly measured. The bubble volume is then calculated. These methods have a number of limitations. 

Even with the above-mentioned limitations, the indirect methods constitute the simplest way of evaluating bubble volumes from single nozzles, and hence are most extensively used. As these methods involve a knowledge of the two quantities Q and f the ways of measuring each of them are separately discussed below. 

This device has been successfully employed for measuring bubble volumes when the chemical reaction between a gas and a liquid is being studied (V2). The conditions under which the gas is measured are converted to the conditions of pressure, temperature, etc. existing at the nozzle tip. 

Tate s law makes use of bubble formation in the measurement of the surface tension of a liquid, and hence the fact that surface tension influences the bubble volume is obvious. At flow rates tending to zero, the bubble volume is such that the upward force due to buoyancy is balanced by the downward force of surface tension. So, an increase in surface tension should... 

Quenched at Base — At2yp m-

Bubble Volumes y basy r " Known from (Sizes) - Measured v-— Flow Thickness... 

The conductivity probe technique has been applied successfully to gas-phase measurements in a slurry bubble column. The presence of solids does not appreciably change the gas-phase characteristics for a volume fraction of solids less than 5 percent. The radial distribution functions of gas holdup and interfacial area increase significantly from the wall to the center of the column. The average Sauter mean bubble diameter is greater than the Sauter mean bubble diameter measured near the wall. 

If Cq is known as a function of the capillary number and the surfactant properties, the functional form of the frequency and bubble volume can be approximated from the linear results. However, a model for Cq in constricted angular tubes does not exist. If one assumes that snap off occurs as soon as the thread becomes axisymmetric, then the base state thread radius is approximately the half width of the channel at the point snap off occurs. The experimental observations of Arriola and Ni along with the theoretical predictions of Ransohoff and Radke indicate that snap off takes place very near the constriction neck. Therefore, the radius of the bubbles formed should be slightly larger than the half width of the constriction neck. In fact, approximating Cq by the constriction half width, one observes from equations 14 and 15, that the snap off frequency and bubble volume are independent of the liquid flow rate once the critical liquid flow rate has been exceeded. Ni measured the dependence of snap off on the bubble velocity, the velocity of... 

A major factor in fluidized bed behavior is the interaction between the gas flow from individual orifices and the particle and gas mixture within the bed. The jet penetration and the subsequent bubble formation have an important influence upon solids and gas mixing and, ultimately, upon the usefulness of the bed for reactor purposes. While flow visualization data are available at ambient pressures and temperatures, the natures of jet penetration and bubble development at high pressures and temperatures are not easily measured. Typical data on bubble size and bubble velocity at ambient conditions are shown, represented by the small size symbols, in Figure 2. It is well known that bubble volume can be correlated as a function of gas volumetric flow rate ( ) and that bubble velocity is related to the size of the bubble radius ( ). Such semi-empirical correlations are indicated as solid lines in that figure. 

A quantitative comparison between the numerical model and experimental data can be made using those measurements of bubble volume and bubble rise velocity. The calculated values of bubble volume and bubble rise velocity for both ambient and high pressure conditions and also for some complex geometries such as the Westinghouse Cold Flow 30 cm diameter semi-circular model, are shown as large symbols in Figure 2. The specific geometries and flow conditions for the calculations are listed in Table I. 

Bend the needle to invert the syringe, displace air bubbles and measure the required volume of liquid. 

The equivalent bubble diameter d, defined as the diameter of a spherical bubble with a volume equal to the average bubble volume, is often used as a measure of bubble size. A representative relation for the equivalent bubble diameter in a three-dimensional bed with B particles supported by a perforated plate distributor was given by [134] ... 

APPARENT PARTICLE DENSITY is when the volume measured includes closed pores or bubbles of gas within the particle. This density is measured by gas or liquid displacement methods like the liquid or air pyknometers (see below). 

The dynamic surface tensions of aqueous solutions of pt-BPh-EOlO at five concentrations are shown in Fig. 5.31, obtained from complementary bubble pressure and drop volume measurements. The curves show the typical course of y(log rj-behaviour for a diffusion... 

In the standard version of the MPTl measuring cell the dead time is of the order of 70-80 ms. To decrease down to 10 ms it is necessary the decrease the length of the capillary 1 and the volume of detaching bubbles. The bubble volume can be controlled by the distance between the capillary tip and the electrode located opposite to it (cf Fig. 5.12). For different lengths of the capillary reproducible and accurate bubble formation was possible under the conditions summarised in Table 5F.1. 

The experimental measurements produced concentration-time plots of ethylene oxide and ethylene glycol in the liquid phase, as shown in Figure 8.18. The physical picture of this reaction/reactor system is most closely approximated by the plug-flow gas phase, well-mixed batch liquid phase. The appropriate relationships to model this system are given in equations (8-176) to (8-178), (8-183), and (8-188). The bubble volume is variable, and the nature of the variation changes with the extent of conversion (i.e., concentration of glycol in the liquid phase), however, the pure oxide gas phase allows yg = l. The modified equations specific to this reactor are then... 

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