Cleaning systems types

Mechanical Cake Removal. This method is used in the American version of the dynamic filter described under cross-flow filtration with rotating elements, where turbine-type rotors are used to limit the cake thickness at low speeds. The Exxflow filter, introduced in the United Kingdom, is described in more detail under cross-flow filtration in porous pipes. It uses, among other means, a roUer cleaning system which periodically roUs over a curtain of flexible pipes and dislodges any cake on the inside of the pipes. The cake is then flushed out of the curtain by the internal flow. 

The latest installations incorporate a waste heat boiler in the off-gas cleaning system to recover sensible heat from the rotary kiln off-gas. There is sufficient sensible heat in the off-gas from the SL/RN process to generate 500 to 700 kWh/t of DRJ, depending on the type of reductant used. 

An air valve, sometimes called the air-activated valve, is widely used for automated food handling operations. Although electronic or electric control boxes may be a part of the system, the valve itself generally is air-activated, and is more reflable than other types. Air-operated valves are used for in-place cleaning systems, and for the transfer and flow control of various products. 

There are many types of cleaning systems and equipment, for example ... 

Electrostatic precipitators have been used in various gas-cleaning applications almost for a century. During the past decades, a large number of modifi cations to electrostatic precipitators have been developed, the nn.ist common being duct and pipe types. The utilization of electrostatic precipitation extends from small household air cleaners up to huge industrial gas-cleaning systems. 

In Germany approximately 80 rendering plants, spread all over the land, process more than 800 000 t of raw material per year. Five plants in northern Germany were chosen with different size and different air cleaning systems, table 1. These chosen air cleaners are of the common types in rendering plants. The attempt to include also a bioscrubber and an activated carbon filter failed due to frequent breakdowns. 

Several dry-cleaning systems using CO2 as a solvent have been proposed and are currently under development. As the topic is mainly concerned with the definition of a cleaning process for industrial or commercial applications, the literature refers to several patents which differ in type and performance of the washing machines. 

Allylimidates underwent a clean Claisen-type rearrangement in the presence of 5 mol % palladium chloride (equation 28),40 as did allyl carbamates39 and S-allylthioimidates (equation 29).41 This S to N rearrangement has found application particularly in the synthesis of pyrimidines, systems for which thermal S to N allylic rearrangements were generally ineffective (equation 30).42 Finally, 0-allyI S-methyl dithiocarbonates cleanly underwent palladium(ll)-catalyzed O to S allylic transposition (equation 31 ).43... 

Cleaning systems must be designed in such a way that cross-contamination of the effective medicinal contents of the products is precluded. For this reason, CIP systems of types 2 and 3 are recommended. 

Insoluble pigment soils, such as clays or other particulate solids, are removed during cleaning from the fiber surfaces with the help of surfactants. In both cleaning systems, surfactants incorporate this type of soil into the micelles to form relatively stable suspensions to prevent the redeposition of soil onto the textile (12). 

Figure 7 is a phase diagram for the V-Ca-O system. Figure 8 shows a schematic diagram of the CVD apparatus. For cleaning a Type 304 SS chamber was heated to 850°C within 1 hr. while purging with 99.999% argon and was then cooled. 

System Type. The three basic types of SCF cleaning systems are the direct system, in which supercritical carbon dioxide (SCCO2) is the only cleaning solvent, the single-cycle system, in which the SCCO2 is mixed with a cosolvent and the dual-cycle system in which the parts are exposed separately to cosolvent and supercritical carbon dioxide. 

Cleaning systems that are designed for maximum flexibility (removal of different types of contaminants) are often supplied with multiple separators in a series/parallel combination, each operating at different pressures for selective separation. Such refinements can add significant cost to the system. 

A general scheme of a waste water treatment plant is presented in the example shown in Figure 7.3. The scheme presented in Figure 7.3 is a very general presentation of the possible water cleaning system in the refinery. Depending on the amount of water and the type of contaminants, it can look different than what is shown in Figure 7.3. However, the pool-collectors and collectors for technical water, which were not described previously, are always part of every scheme of... 

Off-gas purification. As a high-temperature process, any type of vitrification process will have to have a very effective off-gas cleaning system. In fact, besides the remote operation and maintenance technique, off-gas treatment will be among the most important waste-processing problems to be solved. The off-gas may contain volatile fission products, such as ruthenium and cesium, as well as aerosols and dust. Multistage systems will be required with wet and dry cleaning procedures to obtain an off-gas sufficiently clean for release to the atmosphere. 

---