Discharge mechanism

Solids Discharge The type of discharge mechanism utilized is dependent upon the necessity of sealing the atmosphere inside the fluidized-bea reactor and the subsequent treatment of the sohds. The simplest solids discharge is an overflow weir. This can be used only when the escape of fluidizing gas does not present any hazards due to... 

FIG. 18-124 Operating principles of a roll-discharge mechanism. (Schweitzer, Handbook of Separation Techniques for Chemical Engineers, p, 4-40, Copyiight 1979 hy McGraw-Hill, Inc, Used with peimission of McGraw-Hill Book Co,)... 

Feed and Discharge Feed and discharge arrangements for ball and rod mills depend on their mode of operation. Various feed and discharge mechanisms are shown in Fig. 20-34. 

FIQURE A-2-6.5. Step by Step discharge mechanism producing long discharge with relatiuely low voltage. 

There is a risk of environmental hazard from toxic, flammable or volatile cakes specially secured discharge mechanisms may be incorporated. 

S The slurry arms for cake washing and smoothing S The cake discharge mechanism... 

A cake discharge mechanism that can be either a scraper, belt, roll and in rare cases a string discharge. Blow is applied only to filters with scraper and roll discharge mechanisms but not to filters with a belt or string discharge,... 

Selecting the suitable mechanism largely depends on the release characteristics of the cake from the filter media. Scraper discharge mechanisms generally tend to suit cakes that release readily whereas roller discharge mechanisms are best suited for cakes that exhibit thixotropic behavior. 

Sludge discharge systems should allow for easy automation and variation of volumes discharged. Mechanical scraper tip speed should be less than 1 m with speed variation of 3 1. 

In the case of charged powder entering a silo, the Maurer discharge mechanism continuously dissipates charge as shown in Fig. 10. The details of this mechanism—thresholds, inlet flow requirements, etc.—are not as well-documented or understood as they should be. 

The theoretical result for a slow discharge mechanism followed by a fast recombination reaction is F/4RT for this ratio. The discrepancy is not too serious, because the predicted value depends upon an observed Tafel slope of 2RT/F and the value obtained on iron is about twice this, which would correspond to the lower value for, dlogg/dV observed on Fe. 

The rate-determining step is the surface combination of C0ads with OH to give a carboxylic group. The remarkable slope of 120 mv, so easily confused with a discharge mechanism, can be interpreted if these adsorptions are Tempkin in type, in terms of the mechanism equations 12-15, if the 9 dependence is relatively small (equation 16). 

A typical string discharge mechanism is shown in Figure 7.20. 

Figure 7.20. String discharge mechanism on a filter handling silica gel...

Figure 15. Schematics showing various discharge and charge mechanisms of battery electrodes, which serve as examples of the battery electrode charge/discharge mechanisms discussed in the text.

Figure 17. Discharge mechanism of a Zn—Mn02 cell. From top to bottom, various stages of the discharge reaction are depicted. On the Zn side, the local change of the pH alters the composition of the discharge product.

Figure 18. Discharge mechanism of a Li—SOCij ceii. The cell can operate until the surface of the carbon cathode is fully covered by electronically insulating LiCI and S discharge products. The Li—SO2 cell is also a soluble cathode system with a cell construction similar to that of the Li—SOCI2 cell. It follows a similar discharge reaction where the reaction product is L1S204.

Ikoma et al. carried out a detailed investigation to study the self-discharge mechanism and contribution of separators.They used nonwoven fabric made of conventional polyamide (FA), FF (with surfactant), and a nonwoven fabric whose main material was sulfonated-FF (hydrophilic) as separators. When nonwoven fabric made of chemically stable sulfonated-FF is used as a separator instead of a conventional polyamide separator, the self-discharge rate of the NiMH battery was strongly depressed, to the same level as that of NiCd battery. 2 >o-242.243... 

The origin of the deep localized states in the mobility gap that control the dark decay has been attributed to structural native thermodynamic defects [12]. Thermal cycling experiments show that the response of the depletion time to temperature steps is retarded, as would be expected when the structure relaxes toward its metastable liquid-like equilibrium state. As the structure relaxes toward the equilibrium state, t(j decreases further until the structure has reached equilibrium. The only possible inference is that must be controlled by structure-related thermodynamic defects. The generation of such defects is, therefore, thermally activated. We should note that because the depletion discharge mechanism involves the thermal emission of carriers... 

Extruders can be broadly classified (14,15) as screw and cylinder extruders, based on the feed mechanism that transports the wet mass towards the die and further based on the die configuration and discharge mechanisms. Figure 3 shows extruders of varying scales from lab to production while Figure 4 shows schematics of the various configurations of extruders used in the pharmaceutical industry. A comparison of attributes of various types of extruders is shown in Table 2. 

The name Leclanche cell is given to the familiar primary system consisting of a zinc anode, manganese dioxide cathode and an electrolyte of ammonium chloride and zinc chloride dissolved in water. The alternative designation zinc-carbon ceir is broader and includes the so-called zinc chloride system which, due to a different electrolyte composition, is characterized by a different discharge mechanism. The Leclanche cell may be written as... 

The discharge mechanism of the Leclanche cell is complex and not all the details are yet fully understood. The basic process consists of oxidation of zinc at the anode to form zinc ions in solution ... 

It is believed that the discharge mechanism involves the formation of an intermediate lithium intercalation compound in which both lithium and fluorine are situated between the carbon layers of the graphitic structure. The carbon formed is graphitic and improves the cell performance as the discharge progresses, leading to a high cathode utilization - close to 100% for low currents. The lithium fluoride precipitates. 

Again the actual cell reactions are very complex and the compositions of some of the ternary intermediates are only known approximately. The discharge mechanism is considered to proceed in three main steps ... 

Other contributions to the polarization are activation polarizations (nact) caused by inhibition of the passage of ions through the phase boundary which may arise in the discharge mechanism. Films on the electrode may also contribute (e.g. oxide, metal already deposited, impurity) by offering a resistance to current flow differing from the bath resistance (ohmic polarization, Tlohm)- Hence the observed overvoltage is given by... 

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