Liquid injection

In this method, the polyurethane is assisted in the flow by the application of gas pressure to the surface of the material. Parts where there is a long flow are particularly suited to this method. 

The air ahead of the flow of polyurethane must be removed, and other vents in the parts must also be used. Applying a vacuum ahead of the polyurethane will also help the flow and will help prevent trapped air. Typically, pressures of 0.4 to 0.8 MPa are needed. The lower the viscosity, the lower the pressure required. 

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Liquid injection incinerators. This t3q)e of incinerator has a cylindrical refractory-lined combustion chamber mounted verti-... 

Liquid-Injection Molding. In Hquid-injection mol ding (LIM), monomers and oligomers are injected into a mold cavity where a rapid polymerization takes place to produce a thermoset article. Advantages of these processes are low cost, low pressure requirement, and flexibiHty in mold configuration. Conventional systems, such as isocyanate with polyol, release Htfle or no volatiles. The generation of substantial volatiles in the mold is obviously undesirable and has represented a significant obstacle to the development of a phenoHc-based LIM system. A phenoHc LIM system based on an... 

Liquid Injection. Liquid injection units are the most common type of incinerator today for the destmction of Hquid hazardous wastes such as solvents. Atomizers break the Hquid into fine droplets (100—150 microns) which allows the residence time to be extremely short (0.5—2.5 s). The viscosity of the waste is very important the waste must be both pumpable and capable of being atomized into fine droplets. Both gases and Hquids can be incinerated in Hquid injection units. Gases include organic streams from process vents and those from other thermal processes in the latter case, the Hquid injection incinerator operates as an afterburner. Aqueous wastes containing less than 75% water can be incinerated in Hquid injection units. 

Liquid injection. Add volatile liquid so that the latent heat of vaporization equals excess energy. 

For areas where cooling water is either scarce or not available, direct liquid injection may be a possibility. The liquid coolant should be injected near the discharge end of the compressor to minimize lubricant dilution. Alternatively, the liquid can be flashed in a separate exchanger and used to cool the lubricant. While the cooling may appear to decrease the power to the compressor, the net effect is an increase in the power due to the additional weight flow of the extra refrigerant needed to perform the cooling. 

F01 Liquid Injection R23 Metals Recovery - Acid Leaching... 

F11 Rotary Kiln with Liquid Injection Unit R24 Metals Recovery - Reverse Osmosis... 

F01 Liquid Injection R26 Metals Recovery - Solvent Extraction... 

Applicability/Limitations Liquid injection incineration can be applied to all pumpable organic wastes including wastes with high moisture content. Care must be taken in matching waste (especially viscosity and solids content) to specific nozzle design. Particle size is a relevant consideration so that the wastes do not clog the nozzle. Emission control systems will probably be required for wastes with ash content above 0.5 percent (particulate control) or for halogenated wastes (acid gas scrubbers). 

Residuals Produced Liquid injection incinerators produce ash which may require application of a post treatment technology prior to disposal. The byproducts from the emission control devices may also require further treatment prior to disposal. 

Solid wastes arc disposed of by two basic methods. The first is by some type of dumping or landfill procedure the second is by incinerating (burning) the waste. This section focuses on incinerators, namely the rotary kiln, liquid injection, fuidized-bed, and multiple-hearth dc ices, which are the four types... 

Liquid injection incinerators are currently the most commonly used type of incinerator for hazardous waste disposal. A wide variety of units are marketed today, mainly horizontally and vertically fired types a less common unit is the tangentially fired vortex combustor. 

As the name implies, the liquid injection incinerator is confined to hazardous liquids, slurries, and sludges with a viscosity value of 10,000 SUS (Saybold universal seconds) or less. This limitation reflects the requirement that a liquid waste be converted to a gas before combustion. This change is brought about in the combustion chamber and is generally expedited by increasing the waste surface area through atomiziition. An ideal droplet size is... 

The key to efficient destruction of liquid hazardous wastes lies in minimizing unevaporated droplets and unrcacted vapors. Just as for the rotary kiln, temperature, residence time, and turbulence may be optimized to increase destruction efficiencies. Typical combustion chamber residence time and temperature ranges arc 0.5-2 s and 1300-3000°F. Liquid injection incinerators vary in dimensions and have feed rates up to 1500 gal/h of organic wastes and 4000 gal/h of aqueous waste. 

Internal liquid injection into the diffuser passage is used in a few applications for direct contact cooling. The quantity and quality of the liquid must be carefully controlled. 

Type case (horizontally split, vertically split). Cooling—diaphragm cooled, external intercoolers, liquid injection in case (this should be selected only on recommendation of manufacturer). 

The values for polytropic conditions represent an uncooled compressor, that is, no internal diaphragm cooling, no liquid injection, and no external coolers for the pressure range being considered. 

However, since the suction gas to the compressor would then be hotter than its normal slightly superheated condition, the compressor may overheat and the discharge gas become too hot for correct and safe working. This form of capacity reduction is usually combined with a liquid injection valve, thermostatically operated, which introduces liquid also into the suction to keep it cool. The fitting of dual interdependent controls of this sort, both of which have inherent fail-unsafe possibilities, should be approached with caution. 

Figure 9.7 Capacity reduction by hot gas injection, with compensating liquid injection...

The typical TP encapsulation process is an insert injection molding or liquid injection molding operation. The insert, a coil, or an integrated circuit, for example, is placed in a mold equipped with either fixed spider type supports or retractable pins or other features to support it when molten TP is injected. 

The micro-channels are sensitive not only to inlet geometry but also to the method of gas-liquid injection. 

B. Residual liquid injection Same as above, followed by injection Most pegmatite and carbonatite veins... 

In addition to standard liquid injection there are many GC accessories which can provide different methods of sample introduction to the column, such as HS, SPE, SFE, TD, TG, Py, etc. Examples of such GC-FTIR devices are TD-GC-FT1R (with a cryostat interface) and PyGC-FTIR. 

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