Seymour Calvert

Particle collection in cyclones at high temperature and high pressure.

We thank W. T. Edmondson, D. P. Larsen, and I. Ahlgren, respectively, for the use of unpublished data for Lake Washington, Shagawa Lake, and lakes Norrviken, Edssjon, and Oxundasjon. We also thank R. J. Allan for providing a preprint of his study of Canadian prairie lakes. We benefited from discussions with S. C. Chapra, B. R. Forsberg, E. Smeltzer, and E. B. Swain, and from the participants in the workshop on phosphorus-chlorophyll relationships (40). We also appreciate critical reviews of the manuscript by D. E. Canfield, D. P. Larsen, and K. H. Reckhow.

Flux Force/Condensation Scrubbing

Considerations for the engineering design of flux force/condensation (FF/C) scrubbers are reviewed. Fine par-ticulate removal in multiple sieve plate FF/C scrubbers is predicted, using mathematical design models. Results of experimental studies of two multiple sieve plate scrubbers for the removal of submicron particles are given. The published experimental data on FF/C scrubber performance are summarized. A preliminary analysis of the economics of FF/C scrubbers, compared to the conventional high energy scrubbers, defines the most favorable operating conditions for the application of FF/C scrubbers.

Gas sorption by a suspension of activated carbon in water.

rn Gas scrubbing by suspensions of adsorbent particles in liquids offers the advantages of high capacity, fluid handling, and inexpensive solvent losses. Reported herein are the results of adsorption capacity for carbon dioxide, butane, and propane on wet-activated carbon. Also reported are the results of mass transfer efficiency for carbon dioxide, methane, propane, butane, n-hexane, ethylene, trichloroethylene, benzene, toluene, butyl alcohol, amyl alcohol, and acetone sorption by suspensions of activated carbon in water. The efficiency results agree with those predicted by a mathematical model. Solubility of the transferring component in water is the major factor affecting transfer rate. Adsorption capacity may be as high for wet-activated carbon as for dry, depending on the gas.

Entrainment Separators for Scrubbers

Liquid entrainment separation was studied experimentally for packed bed, knitted mesh, zigzag baffle, tube bank, and cyclone type apparatus. Primary collection efficiency data compare well with theoretical predictions but re-entrainment of the collected liquid did not agree with theoretical models. Separation efficiency, drop size, and pressure drop data are presented.

Inertial impaction of fine particles at high temperature and high pressure

Abstract The results of a theoretical and experimental study of inertial impaction at high temperatures and high pressures are presented. Some theoretical uncertainties in predicting the drag force on a small particle ( μ m) at very high gas temperatures are those related to the momentum transfer between the particle and high temperature gas molecules. Experimental data indicate that conventional inertial impaction models can be used for predicting particle collection at high temperature and pressure without substantial error.

Engineering Design of Fine Particle Scrubbers

A concise, quantitative picture of the state of the art of particle scrubbing is presented in the form of performance prediction methods. A new relationship between the particle diameter collected at 50% efficiency and scrubber pressure drop for several of the most common scrubber types is a design tool of great utility. Scrubber capability for the collection of submicron particles by diffusion is described in a graph for several scrubber types.

Aerosol Sampling with a Side Port Probe

Abstract A most important consideration in determining particulate concentration in a gas stream is that of obtaining a true sample. This report describes an experimental investigation of a side port probe and a conventional sampling probe for obtaining aerosol samples from a duct. Sampling bias for both types of probe was determined experimentally over a wide range of test conditions using monodispersed aerosols from 0.5 to 10 microns in diameter. Sampling bias was shown to be a function of the inertial impaction parameter and duct to probe velocity ratio. Experimental results are presented. Operational limits over which a sampling probe can be used are shown as a function of the permissible sampling error.

Performance of gas-atomized spray scrubbers at high pressure

A large number of coal gasification processes being developed propose to use Venturi scrubbers for particulate removal at high pressures. Theoretical predictions based on existing Venturi models indicate that Venturi scrubber performance will deteriorate severely in these high gas pressure applications. An exploratory theoretical and experimental program was performed to study the effect of gas pressure on Venturi scrubber performance. Experiments were done on a 0.47 m/sup 3//s (1000 acfm) pilot scale Venturi scrubber operating at pressures up to 10 atm. Efficiency-pressure drop relationships were established for the Venturi at different gas pressures. Experimental results confirmed that the performance of the Venturi scrubber deteriorates with increasing pressure. An engineering design model was developed. The model predicted a pressure drop which is close to that measured and a penetration higher than measured. More data are required to further refine and develop a reliable engineering design model for high pressure Venturi scrubbers.

Removal of Small Particles from Air by Foam in a Sieve-Plate Column

Particle collection by foam produced on sieve plate apparatus was studied in a 3 x 3 in. sq column and in a 2 in. diam circular column. Experimental data have been obtained for silica test dust, glass beads, sulfur aerosol, polystyrene beads, and extensively for methylene blue aerosol. A new technique utilizing the Goetz aerosol spectrometer was developed and was used to obtain the collection efficiency as a function of particle diameter. A correlation was developed based on inertial mechanism. In this correlation the collection efficiency is expressed as a function of inertial parameter and foam density. The pressure drop in the operating range varied from 2 to 4 in. of water.

Spray Charging and Trapping Scrubber for Fugitive Particle Emission Control

The control of fugitive process emissions (FPE) with Spray Charging and Trapping (SCAT) scrubber was evaluated both theoretically and experimentally. The SCAT uses air curtain and/or jets to contain, convey, and divert the FPE into a charged spray scrubber. Experiments were performed on an 8000 cfm bench-scale spray scrubber to verify the theory and feasibility of collecting fugitive particles with charged water spray. The effects of charge levels on drops and particles, nozzle type, drop size, gas velocity, and liquid/gas ratio on collection efficiency were determined experimentally. The results of the experiments and the comparison between theory and data are presented. An air curtain was developed for conveying the FPE to the spray scrubber, deflecting the crosswind, and containing hot buoyant plume. The design and air flow field for the air curtain are presented.