Feed pressure 966 INDEX

Figure 12.9 Volume index as a function of feed pressure feeding an equimolecular mixture. Furnace temperature = 280 °C. CO conversion sets at 90% of the TREC.

Figure 12.10 Volume index as a function of feed pressure with two different feeds.

Silt Density Index (SDI) It is an empirical measurement ASTM Standard D-4189-82, 1987) used for measuring the colloidal fouling potential of RO/NF feed water. It is not a direct measure of the particle concentration, which is more properly measured by turbidity. The SDI value is based on the time required to filter a volume of feed water throu a 0.45 pm filter pad at a feed pressure of 2.1 bar g. The SDI value is calculated from the formula ... 

If the substitute fuel is of the same general type, eg, propane for methane, the problem reduces to control of the primary equivalence ratio. For nonaspiring burners, ie, those in which the air and fuel suppHes are essentially independent, it is further reduced to control of the fuel dow, since the air dow usually constitutes most of the mass dow and this is fixed. For a given fuel supply pressure and fixed dow resistance of the feed system, the volume dow rate of the fuel is inversely proportional to. ypJ. The same total heat input rate or enthalpy dow to the dame simply requires satisfactory reproduction of the product of the lower heating value of the fuel and its dow rate, so that WI = l- / remains the same. WI is the Wobbe Index of the fuel gas, and... 

Precise mandrel indexing required. Simple two-position cross feed on carriage sufficient. Vertical mandrel machine and pressure follower for ribbon sometimes required to preserve ribbon integrity. 

The ability of a feed solution to plug a membrane is determined by the sit density index (SDl) employing a 0.45-pm PVDF microfilter at 30-psi differential pressure (ASTM Standard D-4189-82, 1987). 

The UOP rotary valve has been used in hundreds of Sorbex units across a variety of applications. The purpose of the rotary valve is to simply move the inlet and outlet ports of the net streams (feed, desorbent, raffinate, extract) around the 24 beds in stepwise fashion, creating a semi-continuous countercurrent flow of adsorbent relative to the entry and exit points of the net streams to and from the adsorbent chambers [25]. The rotary valve consists of a rotor plate pressed against a stator plate inside a pressure vessel that indexes the net desorbent, feed, extract and raffinate streams around the adsorbent chambers [26]. An alternative method of moving the inlet and outlet streams around the adsorbent chambers is used in other technologies where multiple automatic on-off valves at each distributor grid inlet are employed [5]. 

MM pressure filtration has tended to become standard practice in many parts of the world as an RO pretreatment, and is designed to reduce the maximum feed-water turbidity below 1 NTU and the silt density index (SDI) below 5. 

HYDROGEN TRANSFER INDEX (HTI1 TEST In this test, 0.5 /xL pulses of 1-hexene feed were carried from a heated sampling valve into a fixed-catalyst bed in a stainless steel reactor by a nitrogen carrier stream at 800 mL/min. (at STP). The catalyst was -250 mesh and diluted with alumina of the same mesh size plus 80-100 mesh acid-washed Alundum. Reactor pressure was controlled by an Annin valve. The effluent stream went to the injector splitter of a gas chromatograph. The reactor conditions included a catalyst temperature of 221°C and 3.45 MPa total pressure. 

The second indirect method is by measurement of the weight of ethylene oxide delivered from the feed containers to the sterilizer. This method assumes no leakage, liquefaction, or polymerization of ethylene oxide in the gas tines connecting the gas source to the sterilizer. It is recommended that the two indirect methods be used in conjunction with each other. The weight loss method ensures that the increase in pressure is in fact due to gas from the ethylene oxide feed container and not from diluent gas or some other source whereas the pressure method provides an ongoing index of gas concentration during the exposure period. Gas makeups should be automated and specified to be drawn from the ethylene oxide feed tanks, not from the diluent gas. Gas makeup may be controlled by pressure switches or by pressure transducers connected to solenoid valves controlling gas flow. 

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