Thermalization chamber

Evaporation of the mustard agent was performed in desorbers (fig. 2) mounted in thermal chamber (fig. 3). 

Figure 3. Thermal chamber. 1. Thermal chamber 2. Desorber 3. Silica gel cartridge 4. Flowmeter 5. Thermo relay 6. Fan 7. Contact thermometer 8. Air distributor 9. Drying column 10. Air distributor 11. Water pump.

Decontamination of the treated samples with mixture of air and vaporized ammonia was conducted in a thermal chamber (fig. 3) with flows of purified dry air and evaporated ammonia through desorbers. Ammonia was produced form crystalline ammonium hydrogen carbonate. An evaporator filled with a 10% solution of hydrogen carbonate is heated to 80°C and subsequently assembled to the system for purified dry air. 

Fig. 1.1. Details of the high-frequency iaser evaporation source. Shown are the rotary motor, which drives the planetary gear assembly for turning the target, and the thermalization chamber with exchangeable expansion nozzie. The iaser-produced plasma expands into this thermalization chamber. A heiium gas puise is then introduced by a piezo-driven pulsed valve and synchronized with the iaser puise into the same volume. The metal-gas mixture then expands through the nozzie into the vacuum leading to cluster formation. In contrast to conventional sources, the laser beam is coaxial to the molecular beam axis. The bellow is used to aiign the source along the optical axis of the ion optics...

Samples were melt pressed in a vacuum laboratory hot press (Carver Press, Model C) at 160°C for 30 min. The molded films were then allowed to cool to room temperature under vacuum. A dual temperature chamber for the melt crystallization experiments consists of two large thermal chambers maintained at the melt temperature (Ti = 160°C) and the crystallization temperature (Ts = 81°C, 83°C, 86°C, 89°C, 92°C or 96°C). After 5-10 min at Ti, the copper sample cell was transferred rapidly ( 2 s) to the other chamber by means of a metal rod connected to a pneumatic device. A detailed description of the arrangement of the sample and of the two detectors used to measure WAXS and SAXS simultaneously has been provided previously [32]. Each polymer sample within the copper cell was 1.5 mm thick and 7 mm in diameter and was contained between two 25 im thick Kapton films. The actual sample temperature during crystallization (T2) and melting (Ti) was monitored by means of a thermocouple inserted into the sample cell. The crystallization temperature was usually reached 120 s after transfer without overshooting. Under isothermal conditions the fluctuations in the sample temperature are less than 0.5°C. Unless stated otherwise, all references to time are times elapsed after transferring the sample to the crystaUization chamber. 

After passing through diaphragm D1 the cluster ions enter a thermalization chamber (4 cm diameter, 30 cm long), whose temperature can be varied between 50 K and 700 K. For the 35 K experiment a shorter tube was employed [16]. The helium buffer gas transfers this temperature to the clusters. The clusters undergo about 10 to 10 collisions with the helium atoms before leaving the thermalization tube. Detailed analysis shows that a shorter aggregation tube would be sufficient [18, 19]. 

Multipurpose thermal chamber (Heating/cooling, aging)... 

The size distribution of the cluster beam can be tuned by the delay of the He pulse, its gas background pressure and is dependent on the geometry and distance between nozzle and thermalization chamber [2, 8, 18]. For smaller cluster sizes the He pressure (in the cluster source chamber) needs to be higher than for bigger ones [19]. The kinetic energy distribution upon impact is measured by... 

A third system designed to clear the process hurdles tlmt were present in the medicinal chemist s approach was one which used a GC as a thermal chamber. The approach used by e medicinal chemist (Scheme 3) in producing the... 

Dynamic Mechanical Analysis determines the elastic modulus (storage modulus), viscous modulus (loss modulus) and damping coefficient (Tan 5) as a function of temperature. The test specimens dimension was 3 mm X 13 mm x 20 mm and was the same for those used in the Izod impact test but without a notch. The test specimens were clamped between the movable and stationary fixtures, and then enclosed in the thermal chamber. The frequency, amplitude, and a temperature range of25-220°C were set-up for the material. The analyzer applied torsional oscillation to the test sample while slowly moving through the specified temperature range of 25-220°C. 

Where there is a temperature difference between the object to be weighed and the surrounding air, air currents will be induced close to the object s surface (12). These can be significant if extreme accuracy is required. Objects should be allowed to reach thermal equiHbrium in the laboratory before weighing. Just as important, the balance should be designed to minimize the temperature rise inside the weighing chamber. In extreme cases, the object should be placed inside the chamber until it reaches thermal equiHbrium before weighing. Needless to say, drafts must be avoided. 

Aluminum-containing propellants deflver less than the calculated impulse because of two-phase flow losses in the nozzle caused by aluminum oxide particles. Combustion of the aluminum must occur in the residence time in the chamber to meet impulse expectations. As the residence time increases, the unbumed metal decreases, and the specific impulse increases. The soHd reaction products also show a velocity lag during nozzle expansion, and may fail to attain thermal equiUbrium with the gas exhaust. An overall efficiency loss of 5 to 8% from theoretical may result from these phenomena. However, these losses are more than offset by the increase in energy produced by metal oxidation (85—87). 

The Calcimatic is a patented kiln of Canadian origin that is radically different from other kiln types. It consists of a circular traveling hearth of variable speed, supported on two concentric tiers of rollers. Kiln feed of 12.7 mm is fed onto the hearth in a 2.5—10 cm bed from a preheater chamber. The kiln is usually fired with natural gas or fuel oil, although the option of using pulverized coal has also been developed. After great interest, resulting in sales of many units throughout the world, the popularity of the Calcimatic has ebbed because of disappointment in the unit s mediocre thermal efficiency. 

Thermal Process. In the manufacture of phosphoric acid from elemental phosphoms, white (yellow) phosphoms is burned in excess air, the resulting phosphoms pentoxide is hydrated, heats of combustion and hydration are removed, and the phosphoric acid mist collected. Within limits, the concentration of the product acid is controlled by the quantity of water added and the cooling capabiUties. Various process schemes deal with the problems of high combustion-zone temperatures, the reactivity of hot phosphoms pentoxide, the corrosive nature of hot phosphoric acid, and the difficulty of collecting fine phosphoric acid mist. The principal process types (Fig. 3) include the wetted-waH, water-cooled, or air-cooled combustion chamber, depending on the method used to protect the combustion chamber wall. 

Fig. 3. Thermal phosphoric acid processes (a) wetted-waH combustion chamber (b) air-cooled combustion chamber (c) water-cooled combustion...

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