Gravity cooler

The rate of air delivery by the cooling fan can be adjusted by manual control of the inlet vanes. Such adjustment, however, is necessary only in the event of major changes in the rate of clinker output from the kiln. If the kiln is to be run at reduced output for a long period, one or more compartments of the gravity cooler can be shut off in order to save electric power consumption. 

Separate dust coiiection systems are needed only for grate coolers in so far as there is a surplus of exhaust air and no after-cooling in a gravity cooler is employed. The exhaust air design conditions for dust collectors intended for operation with... 

The gravity cooler, or "g" cooler, can serve only as an after-cooler for dealing with clinker which has already been cooled to about 500° C and in which the coarser lumps have been crushed to a size that the cooler can accept. 

When fluids heat unevenly, the hot part of the fluid tends to rise with respect to the cooler part of the fluid because of differences in density. The flow is driven by gravity, and distorts resolution in electrophoretic separations. 

FIG. 12-91 Vertical gravity-bed cooler with louvres. (Sprout, Waldron Co.)... 

Circulatory systems often use an intermediate header tank, from which the bearings are supplied by gravity. The complete system may comprise, in addition and according to the size of the installation, heat exchangers or coolers, filters, strainers, settling tanks, centrifuges and other purifying equipment. 

The gas, condensate and woter mixture ex the Production Cooler then flows to the Production Separator where the vapour and liquid streams are separated. A horizontal API type gravity separator was specified for this service to ensure that any liquid slugs are processed reliobly with minimum liquid carry over in the outlet gas stream. More compact proprietary designs were reviewed but were not considered to be sufficiently reliable particularly at high turndown or with highly fluctuating liquid production rates. 

The interpretation of the Li abundance gap using a diffusion model has been questioned because of the observed absence of abundance anomalies of heavy elements in F stars (Boesgaard and Lavery 1986 Thevenin, Vauclair and Vauclair 1986 Tomkin, Lambert and Balachandran 1985) where Be has been observed to be underabundant. Such anomalies had been predicted on account of the diffusion calculations in the absence of any mass loss (Michaud et al. 1976, Vauclair et al. 1978b). It has recently been shown that even a very small mass loss was sufficient to reduce considerably any expected overabundance in F stars. On Fig. 2c of Michaud and Charland (1986), it is shown that a mass loss rate of 10 15 Mo yr-1 is sufficient to keep the Sr overabundance, below a factor of 1.5 while Sr would be expected to be more than 100 times overabundant in the absence of mass loss (Michaud et al. 1976). The presence of even a very small mass loss rate considerably limits any overabundance when the radiative acceleration and gravity are close to each other as is the case for heavy elements in stars cooler than Teff = 7000 K. The same small mass loss rate reduces the Li overabundance in stars of Teff = 7000 K or more where Li is supported. As shown in Fig. 4 of Michaud (1986), the same mass loss rate of 10 15 Mo yr 1 eliminates the Li overabundance of a factor of 10 expected in the absence of mass loss at Teff = 7000 K. It has now been verified that the presence of mass loss cannot increase the Li underabundance that diffusion leads to beyond a total factor of 30 underabundance. 

As shown in Fig. 18.23, dry liquid feed containing olefins and isobutane is charged to a combined reactor-settler. In this example, the reactor uses the principle of a differential gravity head to circulate through a cooler before contacting a highly dispersed hydrocarbon feed in the reactor pipe. The hydrocarbon phase, generated in the settler, is sent to a fractionator, which separates LPG-quality propane, isobutane recycle, n-butane, and alkylate products. A small amount of dissolved catalyst is also removed from the propane product by a small stripper tower. 

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