Chambers types

The membranes, of empty chamber type plates, are pressed back to allow cake formation. 

The sizing of pulsation drums is based on the National Advisory Committee for Aeronautics (NACA) Technical Note 2893. The single expansion chamber type has been chosen because of cost, ease of installation, and effectiveness. 

Figure 3.3. Electrode configuration for SEP (a) and for electrochemical promotion (or NEMCA) studies (b). The latter can be carried out using the fuel-cell type configuration (c) or the single chamber type configuration (d).

In the single-chamber type reactor (Fig. 4.1b) all three electrodes (catalyst-working (W), counter (C) and reference (R)), electrode are all in the same chamber and are all exposed to the reactants and products.1 3 In this case the counter and reference electrodes must be made from a catalytically inert (e.g. Au) material for otherwise the catalytic rate on them will obscure the measured (via gas-chromatography or mass-spectrometry, Fig. 4.2) rate on the catalyst-working electrode. 

Figure 4.1. Electrode configuration for NEMCA studies using (a) the fuel cell type reactor and (b) the single-chamber type reactor.

Some characteristics, such as the average particle size, the thickness of stationary phase layer, the chamber type, the application of large amounts of samples, the location and detection of the separated compounds, and the removal of interested compounds by elution or extraction, should be taken into account in PLC. 

The next generation of chambers comprises the horizontal DS chambers (Chromdes, Lublin, Poland) manufactured for plate dimensions ranging from 5 X 10 cm to 20 X 20 cm, depending on chamber type [11,12]. These chambers can... 

The process data from manifold installations can hardly be transferred to chamber-type plants. This applies, practically, also to the process transfer from belljar-type installations to chamber plants. Results obtained in laboratory plants of the chamber type must be analyzed carefully, if they are be transferred to another plant. If the product, the layer thickness of the product and the vials or trays are identical, the following conditions should be observed and compared ... 

All these plants are of the chamber type (see Fig. 1.88 (c)) with cooled and heated shelves and a condenser which can be separated from the drying chamber by a valve. Refrigeration and vacuum systems should be laid out for temperatures and pressures which can be expected under extreme experimental conditions, even if these extreme data may not be used in the production process. Pilot plants for pharmaceutical or medical products should be laid out differently than those used for food. 

Ionization and condensation nuclei detectors alarm at the presence of invisible combustion products. Most industrial ionization smoke detectors are of the dual chamber type. One chamber is a sample chamber the other is a reference chamber. Combustion products enter an outer chamber of an ionization detector and disturb the balance between the ionization chambers and trigger a highly sensitive cold cathode tube that causes the alarm. The ionization of the air in the chambers is caused by a radioactive source. Smoke particles impede the ionization process and trigger the alarm. Condensation nuclei detectors operate on the cloud chamber principle, which allows invisible particles to be detected by optical techniques. They are most effective on Class A fires (ordinary combustibles) and Class C fires (electrical). 

By 1939 a Midget chamber-type polymerization process (20) had been developed that economically employed feed rates as low as 250,000 cubic feet per day, whereas the older units were uneconomical at feed rates below about 2,000,000 to 3,000,000 cubic feet per day. Midget units proved successful because it was found that when operating the polymerization reaction at pressures of 500 pounds per square inch a sufficient amount of feed remained in a dense phase to wash the catalyst clear of most of the heavy polymer, thus extending catalyst life and eliminating catalyst regeneration. 

Figure 12 is a simplified flow diagram of a chamber-type unit. In this instance the feed is taken only from the cracking plant stabilizer overhead although some plants also include the absorber overhead gas in the feed. If a predominantly C3-C4 charge is polymerized the recovery section can be modified to yield a propane stream for liquefied petroleum gas sale as well as butane by the use of a de-ethanizer (if required), a depropanizer, and a debutanizer. 

Figure 12. U.O.P. Catalytic Polymerization Process—Chamber Type...

The type of feed that can be used varies widely. In nonselective polymerization in chamber-type plants a C3-C4 olefin content of about 20 to 25%, is practical. When the olefin content of the fresh feed rises above 25%, enough spent gas of low olefin content must be recycled in order to limit the olefin content of the total feed. Reactor-type plants can employ a higher olefin content in the feed, the exact value depending on the cooling efficiency of the reactor. 

For chamber-type plants the useful catalyst life expected is 100 gallons of polymer per pound of catalyst and about twice that for reactor-type plants (25). The quality of operating procedures can affect the catalyst life to a considerable degree. 

The most important chamber type alkylation units are the UOP type using solid phosphoric acid catalyst for making cumene and ethylbenzene... 

The catalyst was placed in tubes surrounded by a cooling-water jacket in the first units designed for more precise temperature control. It also was found that temperature control within the required precision limits could be obtained in chamber-type units by separating the catalyst into several beds and employing a quench of effluent hydrocarbon low in olefins between the beds. 

Polymerization of olefins from cracked gases today covers a broad range of products from motor fuel to petrochemicals. The petrochemical list is expanding rapidly with many of these products being made from propylene. Figure 1 shows a typical chamber type unit for producing the important petrochemicals, tetramer and cumene. 

Figure 2 shows a typical C3-C4 chamber-type polymerization unit and Fig. 3 shows a typical C3-C4 reactor-type unit. These two units are described in detail in Sec. V. 

Fig. 4. Olefin conversions for chamber type polymerization, Ca-C4 feed.

The U.O.P. Chamber-type unit contains the catalyst in a reactor in which the catalyst is separated into a number of beds. Temperature control is accomplished by quenching between the beds with cold liquid effluent and by recycling spent propane and butane effluent into the reactor feed. This is not a heat-balance operation and a preheater using an outside source of heat is required in addition to the feed-to-products exchanger. A depropanizer and debutanizer are usually used to fractionate the effluent. Figure 2 shows a flow diagram of a chamber type of polymerization unit. 

Prohaska O, Kohl F, Goiser P, Olcaytug F, Urban G, Jachimowicz A, Pirker K, Chu W, Patil M, LaManna J, Vollmer R (1987) Multiple chamber-type probe for biomedical appbcation. Techn Digest Transd 87 pp 1 - 4... 

To detect the incipient stage of fire, ionization-chamber-type sensors are used that analyze the composition of the atmosphere by measurement of its conductance. The ionization rises as the invisible combustion gas concentration rises. 

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