Rotary lock

There are several types of volumetric feeders in addition to the rotary lock feeder. These include a roll-type feeder (Fig. 2). a tray feeder (Fig. 3. and a bell feeder (Fig. 4). 

Preheater. Figure 2 is a schematic of the preheat section. Ground raw shale is allowed to slide into or is pneumatically transported (a minimal volume flow) into the lower part of the preheater. A standpipe of shale serves as a resistance seal to purging gas and allows the preheater to be pressurized by transporting gas. Although a slide valve near the bottom of the standpipe should provide adequate flow control for the shale, a flapper valve, screw feeder, or rotary lock may be considered as options. 

A reciprocating pump driven by a variable speed drive is used in the short line between the storage tanks and the mixer. By adjusting the speed, the desired ratio of sodium to peroxide can be maintained in the mixer. Normally, sodium will not exceed about 10% of the charge to the mixer. Sodium peroxide enters the mixer by gravity from the surge bin through a rotary lock. 

Vortex dryers are characterized by a spiral flow of a particle-gas suspension due to tangential entry of the gas stream into the dryer chamber. Wet material is fed directly into the drying chamber by a screw feeder or nozzle atomizer, or dispersed with the drying medium (air, inert gas, superheated steam, etc.). After performing several spiral trajectories, the particulate material leaves the dryer with an exhaust gas. Alternatively, it may be separated from the gas within the dryer and further discharged via a rotary lock. 

The powder is filled by means of pneumatic conveying into the silo. The powder is discharged by means of a screw conveyor to an intermediate container, from where it is fed by a rotary lock into another pneumatic conveyor, which transports the powder into another silo. 

The rotary lock, star or feeder valve and the screw conveying discharge device, shown in Figs. 11.1.1a and 11.1.1b and 11.1.2, are two devices often used to seal against high differential pressures existing between the cyclone and the underflow. These devices are very suitable for some cyclone applications such as the flour mill application shown in Fig. 11.1.3. However, rotary valves do require motors that render them unsuitable for use inside of vessels... 

F Rotary lock valve discharge into hopper with vent line to overflow... 

Option F.— This last option, which utilizes a rotary lock valve on the cyclone underflow line is a very effective way of preventing hopper aeration gas and entrained solids from flowing back up the cyclone. Like Option B, the... 

FIOR Process. In the FIOR process, shown in Figure 5, sized iron ore fines (0.04—12 mm) are dried in a gas-fired rotary dryer. A skip hoist dehvers the dry fines to lock hoppers for pressurizing. The fines pass through four fluidized-bed reactors in series. Reactor 1 preheats the ore to 760°C in a nonreducing atmosphere. Reactors 2, 3, and 4 reduce the ore at 690—780°C. At higher (ca 810°C) temperatures there is a tendency for the beds to defluidize as a result of sticking or hogging of the reduced material. 

Pressure drop in the system may be computed by methods described in Sec. 6. To prevent excessive leakage into or out of the system, which may have a total pressure drop of 20 to 38 cm of water, rotary air locks or screw feeders are employed at the solids inlet and discharge. 

The negative system usually sucks on a cyclone and/or filter/receiver mounted above the receiving storage hopper or bin. Solids are usually sent down to the hopper with a rotary air lock feeder. Air is sucked into the transfer pipe or duct at the pickup end of the sy.stem. A variety of feeders can be used to introduce solids into the flowing air stream such as rotary air lock feeders, pan-type manifolds under rail car hoppers, paddle-type rail car unloaders, screw conveyors, etc. 

Even though 15 psi is possible from a blower, most positive-pressure systems are limited to 10-12psi differential pressure because of limits of the rotary air lock feeder valves (deflections in shaft and bearings and increased blowback air). 

Another version of the dewatering screw that has been used successfully in a number of installations (Figure 40) consists of an inclined screw with a box-like back end and an internal overflow weir. The drive is usually a variable-speed motor reducer. Rotary air lock fitted with a variable-speed drive is typically used as shown in Figure 37 in connection with the plain receiving tank and an inclined screw conveyor. Materials of construction can be chrome-plated cast iron or nickel-hard casing. The rotary valve is made of hard faced tips or stainless steel replaceable blades. 

The kelly bushing attaches the kelly to the rotary table. It locks into the master bushing and transfers the torque produced by the table to the kelly. There are two types of kelly bushings [16] ... 

The seal shown back in Figure 56.4 depicts a typical friction drive or single-coil spring seal unit. This design is limited in its use because the seal relies on friction to turn the rotary unit. Because of this, its use is limited to liquids such as water or other non-lubricating fluids. If this type of seal is to be used with liquids that have natural lubricating properties, it must be mechanically locked to the drive shaft. 

Recently a new type of proton assisted recoupling experiments has been developed for coherence transfer where rf irradiation is taking place on all involved rf channels. This embraces the homonuclear proton assisted recoupling (PAR) [45, 140, 141] and the later resonant second-order transfer (RESORT) [142] experiments, as well as the heteronuclear proton assisted insensitive nuclei (PAIN) cross polarization [44] experiments. In PAR and PAIN, spin-lock CW irradiation is applied on both passive ( H) and active spins (13C, 15N) without matching rotary resonance conditions. In RESORT a phase alternation irradiation scheme for the passive spins is used. 

Rotary air lock (active) Extinguishing barrier (active) Explosion protection valve (passive or active)... 

Cyclone. The first element in the system for DTS gaseous effluent is the cyclone provided to separate large particulate matter that could rapidly plug the downstream candle filters. This element is not required in the system for MPT gaseous effluent. Separated particulate matter is discharged into a steel container through a rotary air lock. The particulates are processed in the MPT to ensure 5X decontamination. 

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