Calorimeter description

The reversibility and efficiency of this heat pump can be calorimetrically simulated, when using the absorption vapour device which is described in the "calorimeter description" chapter. Its use is illustrated by the following example ... 

Various flow calorimeters are available connnercially. Flow calorimeters have been used to measure heat capacities, enthalpies of mixing of liquids, enthalpy of solution of gases in liquids and reaction enthalpies. Detailed descriptions of a variety of flow calorimeters are given in Solution Calorimetry by Grolier [17], by Albert and Archer [18], by Ott and Womiald [H], by Simonson and Mesmer [24] and by Wadso [25]. 

De Haven [127] gives an overview of the results of accelerating rate calorimeter (ARC) experiments. The ARC was described in Section 2.3.2.3. As mentioned in the previous description, care must be taken in scale-up of results from experiments with relatively high phi-factors. For direct simulation of plant operating conditions, a phi-factor of 1.0 to 1.05 is required. As stated in [127], a decrease in the phi-factor from 2.0 to 1.0 increases the adiabatic temperature rise by a factor of 2, but the maximum self-heat rate increases by a factor of 20. Later in Chapter 3 (Section 3.3.4.6), an example of scale-up of ARC results is given. 

Dunkle s Syllabus (1957-1958) Shock Tube Studies in Detonation (pp 123-25) Determination of Pressure Effect (144-45) Geometrical and Mechanical Influences (145-48) Statistical Effects of Sensitivity Discussion on Impact Sensitivity Evaluation (148-49) Pressure in the Detonation Head (175) Temperature of Detonation (176) Charge Density, Porosity, and Granulation (Factors Affecting the Detonation Process) (212-16) Heats of Explosion and Detonation (243-46) Pressures of Detonation (262-63) A brief description of Trauzl Block Test, Sand Test, Plate Dent Test, Fragmentation Test, Hess Test (Lead Block Crushing Test), Kast Test (Copper Cylinder Compression Test), Quinan. Test and Hop-kinson Pressure Bar Test (264-67) Detonation Calorimeters (277-78) Measurements... 

As was already mentioned, experimental determinations of heat of explosion and of heat of detonation are conducted in steel or special alloy cylindrical vessels of strong construction, known as "constant volume explosion bomb calorimeters and as "detonation calorimeters . To the brief description of such calorimeters (bombs), which is given in Vol 2 of Encycl, p Cll-R, the following may be added ... 

Start test at RT and program to 250°C. Ignition temp is interpreted to be the point at which the exothermic degradation begins, point A of Fig Et 19. Peak degradation temp is indicated by point B Note Description of "Calorimeter, Calorimetry Calorimetric Determinations is given in Vol 2 of... 

Parr calorimetric bombs and calorimeters are very much in use in the US. These bombs are cylindrical in shape and are provided with covers which can be securely closed against leakage. Detailed descriptions of experimental procedures using Parr oxygen bombs and Patr calorimeters... 

The reactivity value is obtained by using the peak temperature of the lowest differential thermal analysis (DTA) or differential scanning calorimeter (DSC) exotherm value as shown in column 2 of Table VI. Alternatively, it can be obtained from a qualitative description of the instability (or... 

Heat flux calorimeters are bioreactors equipped with special temperature control tools. They provide a sensitivity which is approximately two orders of magnitude better than that of microcalorimeters, e.g. [33,258]. The evaluation and description of microbial heat release is based on a heat balance heat yields and the heat of combustion of biological components are central parameters for quantification [70]. Measurements obtained so far have been used to investigate growth, biomass yield, maintenance energy, the role of the reduction degree of substrates, oxygen uptake [414] and product formation [272]. 

The type of calorimeter and the method of calculating the heats of adsorption from the experimental data were essentially the same as described in previous papers (I, 4, 10). Two calorimeters of the same design were used, one employing a filler made of copper as described by Dry and Beebe (4) and the other a filler of aluminum. (A drawing and brief description of this calorimeter will be supplied on request addressed to the authors at Amherst College.) In one run for nitrogen adsorption on the bare surface we employed a liquid nitrogen trap to prevent contamination of the sample in the calorimeter by condensed mercury. Data from all runs on the various calorimeters and samples checked within the accuracy of the experiments. 

Once the heat capacity of the calorimeter is known, the value of any quantity of heat transferred to it, as the result of a chemical reaction, for example, can be readily determined by equation (3.1). Similarlj, the heat capacity of any substance can be found from the amount of heat it transfers to a calorimeter the change in tcmperatiire of the substance must also be known. In actual practice various devices are used to improve the accurac of the results, but the foregoing description indicates the fundamental principle involved in modern calorimetric work. 

Figure 4.9. Vertical section of the high-temperature calorimeter Setaram. See text for description.

The Copper Calorimeter.—The first description of this apparatus was given by W. Nemst, F. Koref, and F. A. Lin-demann (36) detailed instructions for its use were given later by Koref (60), who has carried out a large number of valuable measurements with it. The work was then continued by A. S. Russell (79a) and Ewald (99) the latter, in the examination of ammonium compounds, discovered the remarkable fact that there is here a transient decrease of specific heat with rise of temperature over a certain range, which points to internal rearrangements in the ammonium radicle. 

The vacuum calorimeter described by Schwers and me has been further developed recently in a few respects by Gunther (107), who used it for many important measurements reference may therefore be made to the description given by Gunther for a more detailed account. The vacuum calorimeter has been used by Eucken (105) with marked success to determine the specific heats of gases at constant volume, and also for the measurement of heats of evaporation, heats of fusion, and heats of transformation at low temperatures (cf. also Chapter V). 

For the two fundamental thermodynamical functions (total and free energy) U and A are always used U signifies the heat developed in a process, or, in other words, the total amount of heat which can be measured in a calorimeter, and A the corresponding maximum work supplied in isothermal processes. This method of description, which frequently differs in sign from that hitherto customary, seemed to me advantageous for the following reasons —... 

OIT is a relative measure of a material s resistance to oxidative decomposition. It is determined by the thermoanalytical measurement of the time interval of exothermic oxidation of a material at a specified temperature (typically between 140 and 210°C) in an oxygen atmosphere. The procedure employs a differential scanning calorimeter (DSC). It is very practical to use an automatic sample, that is a carousel, which typically holds 50 specimens, and descriptions for 65 specimens can be programmed into the instrument before the runs. For low OIT numbers (less than... 

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