Laboratory combustion chamber

Standard combustion chambers and laboratory combustion chambers ) have been developed for testing the behavior of solid rocket fuels and for the determination of their characteristic properties. 

TRW Systems, Inc., conducted a laboratory-scale incineration study for the U.S. Army from 1973 to 1975 (9). Eleven individual pesticide formulations and three mixed pesticide formulations containing six different active ingredients (chlordane, 2,4-D, DDT, dieldrin, lindane, and 2,4,5-T) were incinerated in a liquid injection incinerator. The experimental apparatus consisted of a fuel atomizer, combustion chamber, afterburner, quench chamber, and scrubber unit. Destruction efficiencies exceeded 99.99% for a minimum 0.4-s residence time at temperatures above 1000°C with 45 to 60% excess air. 

In 1981 the Los Alamos National Laboratory investigated for EPA the thermal destruction of wooden boxes treated with penta-chlorophenol (PCP). The incineration system consisted of a dual-chamber, controlled-air incinerator, a spray quench column, a venturi scrubber, and a packed-column acid gas absorber (11). Destruction efficiencies for PCP exceeded 99.99% for combustion chamber temperatures above 980°C, 20% excess air, and a retention time greater than 2.5 s. For these conditions, TCDD and... 

As a specific example to study the characteristics of the controller, the problem involving four modes of longitudinal oscillations is considered herein. The natural radian frequency of the fundamental mode, normalized with respect to 7ra/L, is taken to be unity. The nominal linear parameters Dni and Eni in Eq. (22.12) are taken from [1], representing a typical situation encountered in several practical combustion chambers. An integrated research project comprising laser-based experimental diagnostics and comprehensive numerical simulation is currently conducted to provide direct insight into the combustion dynamics in a laboratory dump combustor [27]. Included as part of the results are the system and actuator parameters under feedback actions, which can... 

The laboratory furnace, illustrated in Figure 1, has been described in detail elsewhere (19). The combustion chamber design is similar to that of Pershing and Wendt (20). It consists of a vertical cylinder 1.0 m long and 0.2 m inside diameter cast from alumina refractory cement. A series of convective heat exchangers, also 1.0 m long and 0.2 m inside diameter, are mounted directly below the combustor. The combustor is fired at a rate of 8 to 12 Kw, providing a residence time of 1 to 2 seconds in the combustion chamber. 

In a laboratory environmental chamber study of the gas-phase photooxidation of naphthalene and phenan-threne, Sasaki and co-workers (1997b) found two products, 2-nitronaphthalene and 2-nitrodibenzopyranone (XI), that displayed significant genotoxicity in the MCL-5 human cell assay. This finding emphasized the importance of atmospheric reactions in forming mutagens, since the concentrations of such compounds are relatively high in ambient air compared to those expected for nitroarenes directly emitted from primary combustion sources (see Section F). 

Direct evidence may be found both in laboratory and rocket engine experiments that the kinetics of the hvHragnnp/nitrogen tetroxide reaction controls the composition of the reaction products. Even early observations of the reaction of hydrazine and nitrogen tetroxide in rocket combustion chambers contain evidence of the role of chemical kinetics in the production of non-equilibrium combustion products (36). 

The reacting flow test rig was constructed at the Gas Dynamics and Propulsion Laboratory at the University of Cincinnati. The 3D geometry is shown in Fig. 10.8. For better optical observation and laser measurement, the combustion chamber has an octagonal shape with four flat quartz windows. Four... 

Today, combustion catalysts that can operate up to 900-1000 °C have been developed and studied in both laboratory- and pilot-scales. Still, two catalyst features have not been fully developed. To begin with, a catalyst system that can operate above 1000 °C for one year of operation or more. Secondly, a catalyst system that can ignite natural gas at compressor outlet temperatures of approximately 200-400 °C. However, several combustion chamber designs have been proposed that utilize the features of catalytic combustion, but which operate the catalyst module at approximately 500-1000 °C. Here, a homogeneous zone is used to increase the temperature of the gas to the final maximum temperature. These designs are described in detail in Section 5 of this review. 

In this case, an intercalibration study served not only to test the ability of the various laboratories to perform an analysis, it also pointed out the steps in the determination which required further research. The high temperature catalytic oxidation (HTCO) technique has become much more common in this field, with several companies now supplying suitable instrumentation. This technique is not only simpler to run than the older wet oxidation methods, it also allows almost-real-time analyses at sea. The problem of the production of a proper blank, and therefore of a proper reference material for the DOC analysis, has yet to be solved at this time it is being patched by the use of low DOC deep water as a blank, or of water which has passed through the combustion chamber of the analyzer and subsequently condensed. Placing DOC and total nitrogen (TN) detectors in-line has made simultaneous determinations of both quantities on the same sample a routine procedure [53]. 

Data for validating pulverized coal combustion predictions requires accurate information for the reactor parameters shown in Table VI. Data measured in the combustion chamber typically include (1) locally measured values of the gaseous flow field velocity, temperature, and species composition, (2) coal particle burnout, number density, velocity, temperature, and composition, and (3) wall temperatures and heat fluxes. Evaluation should include comparisons with measurements from a wide variety of combustors and furnaces that range in scale from very small laboratory combustors (0.01-0.5 MW) and industrial furnaces (1-10 MW) to large utility boilers (up to 1000 MW). 

In the combustion reaction as carried out in the calorimeter of Figure 7-2, the volume of the system is kept constant and pressure may change because the reaction chamber is sealed. In the laboratory experiments you have conducted, you kept the pressure constant by leaving the system open to the surroundings. In such an experiment, the volume may change. There is a small difference between these two types of measurements. The difference arises from the energy used when a system expands against the pressure of the atmosphere. In a constant volume calorimeter, there is no such expansion hence, this contribution to the reaction heat is not present. Experiments show that this difference is usually small. However, the symbol AH represents the heat effect that accompanies a chemical reaction carried out at constant pressure—the condition we usually have when the reaction occurs in an open beaker. 

We discuss in this section four key aspects of heterogeneous reactions (1) theoretical and experimental structure and reactivity relationships (2) held measurements of relative and absolute PAH decay rates in near-source ambient air and during downwind transport (3) laboratory studies of the photolysis/photo-oxidation and gas-particle interactions with 03 and NOz of key 4- and 6-ring PAHs adsorbed on model substrates or ambient aerosols and (4) environmental chamber studies of the reactions of such PAHs associated with several physically and chemically different kinds of combustion-generated aerosols (e.g., diesel soot, wood smoke, and coal fly ash). Where such data are available, we also briefly consider some toxicological ramifications of these reactions. 

When HPLC is used as part of the analysis, the mobile phase is typically a mixture of methanol and methyl-tert-butyl ether (i.e., 50 50, v/v), although other HPLC solvents for LC/MS using APCI (e.g., water, tetrahydrofuran) can be used. It is important to note that if combustible nonaqueous solvent systems are used, water or a halogenated solvent such as methylene chloride or chloroform should be added to the mobile phase postcolumn to suppress ignition in the ion source. In addition, the APCI source must be vented outside the laboratory and should not allow air into the ionization chamber. A scan range of m/z 300 to 1000 will include the known carotenoids and their most common esters. 

Fig. 2, Laboratory setup for combustion synthesis. 1-reaction chamber 2-sample 3-base 4-quartz window 5-tungsten coil 6-power supply 7-video camera 8-video cassette recorder 9-video monitor 10-computer with data acquisition board 11-thermocouple 12-vacuum pump ...

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