Autoclave, internally heated

The experimental apparatus consisted of a 1-liter, stirred autoclave (AC1), used to preheat the solvent-coal slurry, connected to a 2-liter, stirred autoclave (AC2), equipped with an internal heating coil to bring the solvent-coal slurry rapidly to a constant reaction temperature, and a third autoclave (AC3), equipped with a cooling coil to act as a quench vessel (Figure 1). This allowed direct determination of the material lost in... 

The water gas shift reactions were carried out in vertically mounted type 304 stainless steel autoclaves having an internal volume of 700 ml. The autoclaves were heated electrically and... 

As the thickness of the laminate increases, the strength of this thermal spike and the degree of thermal lag during heat-up increases. Figure 8.8 shows the results for a 62.5-mm (500 ply) laminate of the same material. Now the center-line temperature never reaches the autoclave temperature during the first dwell, and the thermal spike during the second dwell is nearly 135°C. The thermal spike is directly related to the release of internal heat during cure. The thermal lag is a manifestation of the low thermal diffusivity of polymer matrix composites. 

Methylenecyclopropane (1 12 g, 222 mmol) was added at — 78 °C to a suspension of Pdfdba) (575 mg, 1 mmol) and an equimolar amount of the appropriate trialkylphosphane in anhyd toluene (6 mL) and placed in a 200-mL stainless steel autoclave cooled to — 78 C under an inert atmosphere of argon. The closed autoclave was heated to 100°C for 18 h with stirring after cooling, all volatile components were condensed off the mixture at 25°C/0.01 Torr and analyzed by GC. Toluene may serve as internal standard. The Pd(acac)2"based catalyst for a reaction on a similar scale was prepared from Pd(acac>2 (183 mg, 0.6 mmol), i-PrjP (96.1 mg, 0.6 mmol) and diethylaluminum ethoxide (156 mg, 1.2 mmol) in anhyd toluene (6 mL). >... 

Autoclave simulation module simulates the variation of autoclave internal temperature and pressure and the vacuum bag pressure with time. Also simulates other parameters associated with structure boundary conditions such as local heat transfer coefficient (HTC). 

For pVTx measurements in highly concentrated electrolyte solutions, Franck s group used a variable volume piezometer designed by Hilbert (1979) and shown schematically in Figure 2.6. The sample is filled in a pure nickel bellows to prevent corrosion and to permit elastic volume changes. This cell is located inside a stainless-steel autoclave immersed in an internally heated, argon-filled vessel. 

Despite the importance of the magnetic properties of expanded fluid mercury, experimental difficulties related to the high critical pressure have prohibited measurements of the static susceptibility except close to r j. As discussed in Sec. 3.2.2, the Faraday method is not readily adapted to use with internally heated autoclaves and the high critical pressure prevents the use of sealed sample cells. Thus measurement of the static, uniform susceptibility of mercury under conditions close to the critical point remains an open challenge to experimentalists. 

An exception to the use of internally heated autoclaves is the measurement of magnetic susceptibilities by the Faraday balance technique described in Sec. 7.3.1. 

Fig. 7.1. Internally heated autoclave for equation-of-state and electrical conductivity measurements on fluids at high temperatures and pressures (Gotzlaff, 1987 Hensel, 1987).

The oldest technology involved in the elastomer blending and vulcanization process is essentially a temperature controlled two roll mill as well as internal mixers followed by an optimum degree of crosslinking in autoclave molds (compression, injection, etc.) in a batch process or in a continuous process such as continuously heated tube or radiated tubes. A few examples of laboratory scale preparation of special purpose elastomeric blends is cited here. 

The use of electric powered steam generators, steam-to-steam heat exchangers, or reboilers to provide steam to steamtables, humidifiers, autoclaves, and for direct injection into the process. Where this type of approach is employed, it generally is necessary to provide a high quality water source to avoid rapid internal deposition of crystalline scales and foulants. 

HPA catalyzed liquid phase nitration was eairied out in a Teflon-lined stainless autoclave of 200 mL equipped with a magnetic stirrer. Reactants and HPA were quantitatively added to the autoclave, which was sealed and heated in an oil-bath. Products were analyzed by GC with OV-101 30 m capillary column and FID detector by using calibrated area normalization and internal standard method. All products were confirmed by GC-MASS analysis. 

A mixture of decalin (bicyclo[4.4.0]decane) isomers (Fluka, >98%) with a cis-to-trans ratio of 2-to-3 was used as a starting material. The experiments were performed in an electrically heated 300-mL stainless steel autoclave (Parr Industries) at 523 K and 2 MPa. The stirring rate and the starting material-to-catalyst ratio were kept at constant values equal to 1500 rpm and 22 (w/w), respectively. The screened catalysts were crushed and the fraction bellow 63 pm was used in the experiments to suppress internal diffusion. 

---