Cyclone train

A cyclone train consists of a series of small cyclones (a few cm in diameter) with a progressively lower cut size. Like the cascade impactor, the cyclone train permits on-line measurement of the d3mamically equivalent particle size distribution. The advantage of the cyclone train is that the cyclones can collect more particles than a cascade impactor. 

The cascade impactor and cyclone train also give us the appropriate distribution each captured fraction represents the volume (or actually mass) fraction of solids in the band between the cut diameters of two successive stages. This method also provides us with the dynamically equivalent particle size. 

Standard sampling trains are specified for some tests. One of these standards is the system specified for large, stationary combustion sources (4). This train was designed for sampling combustion sources and should not be selected over a simpler sampling train when sampling noncombustion sources such as low-temperature effluents from cyclones, baghouses, filters, etc. (5). 

Sampling of particulates may be directed at determining the size, size distribution, total mass and/or specific chemical identification. The sampling train usually consists of a probe or inlet, a particulate collector and pump. The pump may be calibrated for flow or a flow measuring device may be included in the train. The particulate collector may consist of one or a combination of devices such as a fitter impinger, cyclone or impactor. 

The product gas is sent to a cyclone to separate any entrained catalyst particles, which are returned to the fluid bed reactor. The synthesis gas is then sent to a heat recovery train. The first exchanger is a process gas waste heat boiler, which has to cool the synthesis gas rapidly to prevent the Boudouard reaction to form carbon deposits on equipment walls and resulting in possible metal dusting (see also the section Application of Synthesis gas). 

Preselectors may be used at the beginning of the sampling train to select for particulates of specific sizes or to separate particles by size. Often, cyclones are incorporated into the sampling train to collect the respirable paniculate fractions. These instruments select for particles less than 10 microns in diameter which can penetrate into the lungs. Cyclones operate by the circular movement of air which has been drawn through an orifice unwanted heavier particles are thrown from the center of the airstream and drop out while lighter particles of the desired size are retained in the airstream and are collected on the filter medium. 

Preheat Train, Crude Heaters, Crude Tower, Atmospheric Flash Tower, Syn Tower, HCC Heaters, Reactor, Kiln, Steam Coils, Air Blower, Cyclone, Main Fractionator, Unsaturated Gas Plant... 

As solids recovery equipment such as cyclones and electrostatic separators is expensive, the flux of solids entrained into the recovery train must be minimized. The column exhaust must thus be located above the TDH. On the other hand, the column must be kept as short as possible to minimize capital costs. In practice, when internal cyclones are used, the exact position above the TDH of the column exhaust to the cyclones will be set by the dipleg pressure balance. 

Once samplers have been trained, they need to be properly equipped. A set of five constant flow-samphng pumps with battery chargers and the needed respiratory collection devices (cyclones) cost around 5,000 to 6,000. These ptunps, equipped with the proper collection filter or device, can be... 

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