Autoclave venting

The leaching reactions are exothermal. Temperature in the autoclave is kept at about 140-160 with cooling coils (closed cooling water circuit) and the pressure is 15-16 bar. The autoclave vent gases are directed to the gas scrubbing system. 

The autoclave is not the only component of an LDPE plant which may be exposed to a decomposition. Local hot spots in a secondary compressor may initiate a decomposition reaction consequendy it is necessary to protect these units from serious overpressure by pressure relieving devices and to release the products of the decomposition reactions safely. The problem of the aerial decomposition referred to eadier has been largely overcome by rapidly quenching the decomposition products as they enter the vent stack. 

Great care is needed in the design of autoclaves and sterilization cycles because of the requirement for the presence of moisture. The autoclave must be loaded to allow complete steam penetration to occur in all parts of the load before timing of the sterilization cycle commences. The time required for complete penetration, the so-called heat-up time, varies with different autoclave constmction and different types of loads and packaging materials. The time may not exceed specific limits in order to guarantee reproducibility and, for porous loads, saturated steam. The volume of each container has a considerable effect on the heatup time whenever fluids are sterilized. Thermocouples led into the chamber through a special connector are often employed to determine heatup times and peak temperatures. The pressure is refleved at the end of each sterilization cycle. Either vented containers must be used or... 

After the hydrogen absorption ceases, the autoclave is cooled, vented, and the reaction mixture is filtered to separate the catalyst. The filtrate is then heated on a steam bath at 60-80 mm pressure to remove the dioxane. The less volatile residue consists of 1,933 parts of crude dithioglycerol, a viscous oil. 

Instead, membrane filtration may be used to sterilise the nutrient in this experiment. This can be accomplished by drawing the nutrient from a mixing jar and forcing it through an in-line filter (0.2 p,m pore size) either by gravity or with a peristaltic pump. The sterilised medium is fed into an autoclaved nutrient jar with a rubber stopper fitted with a filtered vent and a hooded sampling port. 

They may also be required in industrial applications where they become part of venting systems on fermenters, centrifuges, autoclaves and freeze-dryers. Certain types of filter (membrane filters) also have an important role in sterility testing, where they can be employed to trap and concentrate contaminating organisms from solutions under... 

The substrate, catalyst and solvent were placed into a glass liner equipped with a magnetic stir bar. The liner was placed in a 250 mL steel autoclave that was then charged at r.t. first with N2, then with H2. The reaction mixture was stirred at r.t. until the hydrogen consumption ceased, after which the H2 was vented, the autoclave flushed with N2 and the reaction mixture filtered off on glass filter. The solution was evaporated and the products crystallized and filtered. The crystalline mixture contained the hydrochloride salt of diamino resorcinol and aniline In order to separate completely diamino resorcinol and aniline, the product mixture has to be recrystallized from hydrochloric acid solution. 

Batch Experimental Apparatus and Methods. The activity of the rhodium catalyst was tested in a 125 mL reactor with a pressure rating of 3000 psi at 350°C and a pressure relief valve that is rated for 1500-2200 psi. If the pressure valve releases, the gaseous contents of the autoclave are safely vented through a 1/4" stainless steel line and the liquid/vapor content in the autoclave is collected in a metal container and the vapor vented out through the hood. The reactor was heated in a silicone oil bath with a digitally controlled heat/stir plate. 

Autoclave steam sterilization is a well-established and widely used procedure. Normally, steam enters through the top of the chamber (Fig. 9). Being lighter than air, it remains at the top of the chamber but steadily and continuously drives the air out of the chamber through the bottom vent throughout the sterilization cycle. The velocity of steam entering the... 

At the completion of a run, the autoclave was cooled by electric fan to room temperature and the autoclave gases were vented through gas meter and analyzed by gas chromatography. Liquid portions of the samples were subjected to gas chromatographic analysis to determine the composition of products. 

Oxidation of the durene derivative to benzenehexacarboxylic acid (mellitic acid) in an autoclave is normally effected in stages, initially by heating at 80-104°C with the vent open to allow escape of the evolved gases. Subsequent heating to a higher temperature with the vent closed completes the reaction. On one occasion omission of the first vented heating phase led to explosive rupture of the autoclave at 80° C. 

Other types of equipment available to investigate the gas evolution are various autoclave tests (Section 2.3.3.2), isoperibolic autoclave tests (Section 2.3.1.2), and closed Dewar tests (Section 2.3.2.2). Mass flux data are also required in designing any vent facilities (Chapter 3). 

From the autoclave testing, it is concluded that in case of a runaway, the substance produces a significant quantity of gases. The end stage of the runaway will certainly result in a thermal explosion. The venting evaluation should be conducted by the test methods and calculation procedures described in Chapter 3. 

In a typical experiment, the appropriate IL (2.0 ml), the iridium complex 11 (3 X 10 mmol) and the substrate 8 (11 8 = 500 1) were loaded under argon in a window-equipped stainless steel autoclave (V = 12 ml). The reactor was then pressurised with H2 and the desired amount of CO2, followed by heating under stirring to 40 °C for a standard reaction time of 22 h. The products were collected for GC and HPLC analysis by extraction of the IL phase with hexane after cooling and venting, or alternatively isolated by CO2 extraction. Representative results are summarised in Table 3. 

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