Steam Stripping http://www.jaeger.com/Brochures/steam%20stripping.pdf .

1. Steam Stripping http://www.jaeger.com/Brochures/steam%20stripping.pdf. Stream stripping for water clean-up is essentially a distillation process where the heavy product is water and the light product is a mixture of volatile organics. These organics are present in the feed water, in relatively small concentrations. Since the volatility of the organics is a very strong function of temperature, the high stripping temperature inherent in stream stripping allow for the removal of heavier more soluble organics that are not strippable with air. No off-gas treatment is needed ad the only wastestream generated is a small amount of very concentrated organics.

2. Typical Steam Stripping Applications Benzene removal from wastewaters Sour water (h2O and NH3) stripping Acetone removal/recovery from wastewaters Oxygenate (MTBE. MEK) removal/recovery Removal of chloroform, bromoform and other halogenated organics from water Removal of organics from quench waters Organics recovery from leachates Alcohol (ethanol, propanol, IPA, butanol) removal from water Solvents recovery or removal (tetrahydrofuran, hexane, heptane A wastewater stream is heated and put in intimate contact with steam in a packed or trayed tower. The combined effects of the steam and heat, or temperature cause organic material to transfer from the liquid to the vapor phase. This material is then carried out with the vapor. As contacting proceeds down the tower, the wastewater becomes leaner in the organic material while the vapor phase becomes more enriched as it travels up the tower. The configuration of a steam stripping unit can vary depending on the characteristics of the organic material to be removed, and on what is to be done with it in terms of disposal and recycle. As a minimum, a steamstripping unit will look like the unit depicted in Figure 1. It is important to note that heat recovery from the bottom product is necessary for economical operation. Operations at reduced pressure do not need recovery exchangers, but operate at lower temperatures and larger steam rates. The towers also tend to be a bit larger in vacuum operations.

4. CoFlo™ Tray Operation Jaeger CoFlo™ Tray Structured Packing Jaeger Metal MAX-PAK™

5. Trough Distributor, Model LD4 is generally used in towers with high liquid rates and/or fouling service. Liquid is introduced into the parting box, which distributes the liquid to the troughs which furthers the distribution to the packing. Turndown characteristics can be accomplished through tapered notches sometimes called V-notches or other devices such as drip tubes. Number of parting boxes and troughs are determined by the diameter of the tower, liquid flow, and desired liquid distribution pattern. Orifice Pan Distributor, Model LD1 is manufactured using a flat section or deck with holes for both gas and liquid flow. The gas flows through chimneys which can be round or rectangular. The liquid collects on the deck to a determined level and then flows though holes or drip tubes. Orifice pan distributors must be sealed at the support ledge or positioned on flanges for small diameters. In larger diameters they must be sectioned to pass through a manway

6. Packing Support Plate, Model PS2 is a device used to hold the packing. It generally sits on a support ledge and can be supported additionally with structural beams. The main criteria for a support grating is that it must hold the packed bed in place along with the liquid held up by the packing and it must be designed as to not allow the packing to fall through the openings. Common material used is standard grating which have an approximate 70% open area. Gas Injection Support Plate, Model PS1 is a device used to hold the packing. It generally sits on a support ledge and can be supported additionally by structural beams. There are two design criteria for the gas injection support plate. It must hold the packing and liquid hold-up but also requires an open are greater than the cross sectional area of the tower. The larger open area is accomplished by using slotted or perforated plate that is corrugated or postioned in such a way to allow increased gas flow. Open area ranges from 85% to greater than 100%.

7. Mist Eliminator, Model ME2 are suitable for high liquid load, dirty services and high capacities. Droplet sizes down to 10 microns can be removed. ME2's can be applied in horizontal or vertical up flows and are available in plastics or metals. For installation purposes, the units are made in sections to pass through manways Mist Eliminator, Model ME1 consist of coils or layers of knitted wire mesh held together by top and bottom support grids. The mesh material can be metal or plastic, depending on the application.

8. Random Packings Jaeger Tri-Packs® VSP® Jaeger Rings and Jaeger Saddles Jaeger Cascade Mini-Rings® TOP-PAK® Ceramic Saddles

9. SOME PITFALLS IN STEAM STRIPPING SYSTEM DESIGN. Several aspects of the design of steam stripping systems are very crucial and not immediately obvious. First is the accuracy and reliability of equilibrium data. Steam stripping is a situation where the old reliable Henry's law just isn't applicable due to the broad concentration ranges, high temperatures, extensive interactions between components, and the existence of two liquid phases. The thermodynamic model of choice for steam stripping systems is one based on activity coefficients that can predict immiscibility. No model fits this function better than the NRTL activity coefficient model (non-random two liquid model developed by Prausnitz and co-workers). Pilot and laboratory tests to establish the adjustable parameters in the NRTL model for the mixture in question are advisable, but solubility and vapor pressure data can suffice as a good approximation. Wastewaters can be very fouling, especially when the temperature is raised and inorganic salts precipitate. In typical steam stripping configurations, most of the fouling will occur in the recovery exchanger and design provisions are needed to allow for frequent cleaning. In the absence of a recovery exchanger, the brunt of the fouling will be taken by the stripper itself. In such cases, the use of trays can be a way to avoid plugging even though packings would yield better performance characteristics. The use of sequestering agents is also a good solution for reliable and lengthy operation.

10. Biotechnology Products While many of the plastic packings offered by Jaeger Products can be utilized as biological media in trickling filters, Jaeger Bio-Ring® and Cascade Bio-Ring® offer specific design features for use in fixed film biological filters. These UV-stabilized products offer increased capacity and efficiency to aerobic treatment of wastewater in new installation or as replacement for rock in existing filters. Cascade Bio-Ring® Jaeger Bio-Ring ®