Machine rotary

A second method is the iso-conic partitioning method (Nan Wang 2008) that resembles the isophote method, but it generates isolines, called equi-space contour lines, on a surface that refer to small variation of the machine rotary axes. Figure 17 shows curves that are equidistant in regard of machine rotations. Similar, these isolines are not tool path curves, but some of them can be used as guide ways for tool paths. 

Fig. 4-11 illustrates, the 4-stage cycling of the rotary turntable machine. Rotary turntable machines are available with from two to twelve stations, platen sizes up to 24 in. by 29 in., with vertical clamp design and clamping pressures from 385 - 880 tons. The clamping mechanism is fully hydraulic. Shot capacities range from 26 - 267 oz. Machines are also available with metered shot control that permits injection of a different shot... 

Horizontal rotary machines employ multiple molds in a horizontal plane on a rotary turret. As each mold approaches the extmder die exit, it opens to accept the parison and then closes. The parison is then blown into the bottle shape. The extmder must extmde on an intermittent basis or be intermittently withdrawn to provide a parison for each passing mold. 

The Bucher-Guyer horizontal rotary press is a highly automated batch process machine that requires no press aid. The press consists of a horizontal hydrauhc ram inside a rotating cylinder containing many flexible rods covered with a knitted synthetic fabric. The rods have serrated surfaces to allow juice which passes through the fabric to flow to the discharge ends. Hydrauhc pressure is apphed for a preset time, the ram is retracted, and the cylinder is rotated to break up the press cake. This cycle is repeated several times before the press cake is removed from the cylinder and the press is cleaned (16). Juice yield for this horizontal rotary press is 84% with secondary water addition it is increased to 92% (15). 

It was concluded in 1975 that centrifugal secondary compressors with a dehvery pressure of 200—250 MPa (29,000—36,000 psi) would be feasible for ethylene capacities of more than 100,000 kg/h. However, in order to replace the primary compressor with a centrifugal machine, it would be necessary to increase the throughput to 200,000-250,000 kg/h (176). Rotary machines have yet to be used in LDPE plants. 

Tablet Press. The main components of a tablet compression machine (press) are the dies, which hold a measured volume of material to be compressed (granulation), the upper punches which exert pressure on the down stroke, and the lower punches which move upward after compaction to eject the tablets from the dies. Mechanical components deflver the necessary pressure. The granulation is fed from a hopper with a feed-frame on rotary-type presses and a feeding shoe on single-punch presses. A smooth and even flow ensures good weight and compression uniformity. Using the proper formulation, demixing in the hopper is minimized.

Single-punch machines produce approximately 100—150 tablets per minute. Depending on numbers of die per punch units, standard rotary presses can produce 5000 tablets/min, and even more with a double-sided rotary press. The newest high speed presses can achieve 12,000 tablets/min. 

Many users consider rotaiy compressors, such as the Rootes -type blower, as turbomachines because their behavior in terms of the rotor dynamics is very close to centrifugal and axial flow machineiy. Unhke the reciprocating machines, the rotary machines do not have a veiy high vibration problem but, like the reciprocating machines, they are positive displacement machines. 

Screw-Type This type of rotary compressor, as shown in Fig. 10-80, is capable of hancmng capacities up to about 4.248 X lO" m m (25,000 fF/min) at pressure ratios of 4 1 and higher. Relatively small-diameter rotors allow rotative speeds of several thousand rev/min. Unhke the straight-lobe rotary machine, it has male and female rotors whose rotation causes the axial progression of successive sealed cavities. These machines are staged with intercoolers when such an... 

The alternative method of sample extrac tion is termed the ctoss-sti eam samphng method, or ci o.s.s-belt when used in conjunc tiou with a belt conveyor. Sample extraction typically take place with a belt conveyor in motion. However, with a rotary table-feeder conveyor, extractions are made with the table stopped. A cutter can perform extractions by this means from a machined flat surface with neghgible... 

Applications include electric motor drives for conveyors and other material handling equipment such as stacker reclaimers, crushers, haulages, ball mills, cranes, hammer mills, rotary dryers, centrifuges, reciprocating pumps, winches, fans and wire drawing machines. 

Larger compressors, normally above 150 to 200 horsepower, have forged steel crankshafts. Cast crankshafts are used in medium-size machines. Crankshafts should have removable balance weights to compensate for rotary unbalance as well as reciprocating unbalance. The crankshaft should be dynamically balanced when above 800 rpm. 

Straight-lobe compressors, or blowers, as they are commonly called are low-pressure machines. The feature unique to these compressors is that the machines do not compress the gas internally as do most of the other rotaries. The straight-lobe compressor uses two rotors that intermesh as they rotate (see Figure 1-7). The rotors are timed by a set of gears. The lobe shape is either an involute or cyclodial form. A rotor may have either two or three lobes. As the rotors turn and pass the inlet port, a volume of gas is trapped and carried between the lobes and the outer... 

The role of quality in reliability would seem obvious, and yet at times has been rather elusive. While it seems intuitively correct, it is difficult to measure. Since much of the equipment discussed in this book is built as a custom engineered product, the classic statistical methods do not readily apply. Even for the smaller, more standardized rotary units discussed in Chapter 4, the production runs are not high, keeping the sample size too small for a classical statistical analysis. Run adjustments are difficult if the run is complete before the data can be analyzed. However, modified methods have been developed that do provide useful statistical information. These data can be used to determine a machine tool s capability, which must be known for proper machine selection to match the required precision of a part. The information can also be used to test for continuous improvement in the work process. 

The drying of the curd is completed by passing through a rotary drier such as the Pillet-Bordeaux. In this machine the curd passes down a chute with hot air running counter to the direction of flow of material. Strict temperature control is essential, the maximum discharge temperature being below 65°C. If such control is not made then the resin will be dark in colour. 

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