FLUE GASES CLEANING FROM NITROGEN OXIDES BY ADDITIONAL OXIDATION OF NO TO NO2 AND ABSORPTION

Experimental researches of operational characteristics of laboratory samples of two types of packing for the direct contact heat exchanger have been carried out, - Raschig ceramic rings and the developed construction with using the ribbon of amorphous metal alloy. The metal alloy packing slightly surpasses the ceramic one by the basic operational heat engineering parameters, and contributes to oxidation of the NO to water-soluble NO2, which enables to remove more of the latter by absorption with water and, as a result, to reduce the emissions of nitrogen oxides to the environment after contact apparatus by 35 % more efficiently than with using the ceramic packing.

Experimental investigation of the heat and mass transfer phenomena in a counterflow wet cooling tower with foam ceramic packing

This article deals with an experimental investigation of coinstantaneous heat and mass transfer phenomena between water and air in a counterflow wet cooling tower filled with a new type packing named “FCP-08.” The packing consisted of foamed ceramic corrugated board with sine waves, surface retention groove is 1.0 m high, and it has a cross-sectional test area of 0.68 m × 0.68 m. This investigation is focused mainly on the effect of the water–air mass flow ratio on the heat and mass transfer characteristics of the cooling tower, for different inlet water temperatures. The results show that the cooling water range, [Formula: see text], and the cooling tower efficiency, [Formula: see text], decrease with the increase in water–air mass flow ratio, [Formula: see text]. Meanwhile, the heat rejected by the cooling tower, [Formula: see text], increases with the increase in the water mass flow rate. The cooling characteristic coefficient, [Formula: see text], slightly decreases with the increase in water–air mass flow ratio and the value is obviously higher than that of other packing investigated before. The relationship between the cooling characteristic coefficient and water–air mass flow ratio is obtained by linear fitting. The comparison between the obtained results and those found in the literature for other types of packing indicates that cooling performance of the tower with foam ceramic packing is better.

Application of Cyclone Gas Cap Water Washing Device in Ultra Clean Discharge Treatment Technology of Exhaust Gas

Exhaust gas treatment device of coal fired boiler has been upgraded with ultra clean discharge treatment technology, and the new cyclone gas cap washing device is applied in the second half of the desulfurzing tower systm.This new water scrubbing tray system is composed with water sprays, ceramic packing, cyclone gas cap and independent water tank, which is proven by field tests, has exceling effect on exhaust gas treatment, and can decrease concentration of aerosol in exhaust gas to below 5mg/Nm3 which is lower than the state discharge standard.

Experimental Study and Performance Analysis of Ceramic Packing Cooling Tower Using Taguchi Method

Deterioration of the packing material is a major problem in cooling tower. In this experimental study, ceramic tile is used as packing material. The experimental study was conducted in a forced draft cooling tower. Cooling tower operating parameters were optimized using Taguchi approach. The application of Taguchi method is assessing maximum cooling tower effectiveness for the Forced draft counter flow cooling tower using ceramic packing. An experimental study has been carried out for Taguchi’s L9 orthogonal array. According to the Orthogonal array, the trail was performed under different inlet conditions of flow rate of water, air and Inlet water temperature. Signal-to-noise ratio (S/N) and regression were carried out in order to determine the effects of process parameters on cooling tower effectiveness. Finally, confirmation tests verified this reliability of Taguchi method for optimization of forced draft counter flow cooling tower performance with sufficient accuracy. Confirmation experiment was d o n e using optimum combination showed that cooling tower effectiveness was found by experiment is closer to the predicated value.

Degradation of pCBA by catalytic ozonation in natural water

The catalytic effect of commercially available ceramic Raschig rings versus stainless steel rings (known to be oxidant resistant) at different water qualities, for the decomposition of ozone and the hydroxyl radical formation have been investigated by using an ozone bubble column. Para-chlorobenzoic acid (pCBA) has been used as a model pollutant since it has been reported to be an ideal compound for ozone AOP studies because it displays slow reaction rates with ozone, but rapid oxidation kinetics with the OH radical. While the ozone was quite stable when the stainless steel rings were used as a packing media, the ceramic media enhanced the decomposition of the ozone. Nevertheless, the water quality was found to significantly affect the ozone stability. Indeed, in addition to high pH, both NOM and TIC lowered the ozone concentration in the system. When considering the degradation of pCBA, the ceramic packing rings, as high pH and NOM, increases its rate constant which is correlated to the higher decomposition of ozone and consequently to higher formation of hydroxyl radicals. In contrast, TIC decreased the degradation rate of pCBA even if it decomposes the ozone which is due to its scavenging effect.

De Novo VOC From Regenerative Thermal Oxidizers

Regenerative thermal oxidizers are used extensively for the abatement of volatile organic compound (VOC) emissions from process vent streams. Due to the unique heat storage and convection properties of the ceramic packing utilized, they are especially well suited for applications with high flows and dilute concentrations of organic vapors. However, packed-bed devices such as these are known to be vulnerable to interstitial plugging when processing vent streams that contain particulate matter in addition to the VOC. In this paper, the authors postulate a new failure mode that involves relatively small concentrations of organic solids in the vent stream, and that may lead to serious performance deficiencies long before interstitial plugging becomes problematic. Specifically, we assert that “De Novo VOC” can be generated from organic particulate matter that adheres temporarily to the bed and is revaporized when the flow is reversed, causing a significant decrease in the apparent destruction efficiency of the abatement device. In this theoretical treatment, the spatial and temporal response of a hypothetical thermal bed is compared against the phase-change and combustion characteristics of a common organic solid, in order to estimate particle loading levels that may pose immediate compliance problems for users of these systems. Although experimental data are not available to corroborate the conclusions reached herein, the authors contend that routine carryover of small amounts of organic particles from a collection device (e.g., baghouse) to the thermal destruction system can create high exhaust VOC levels, and may eventually lead to hostile fires in the beds. As a means of mitigating against such failures, the authors recommend that an inlet particulate loading limit be implemented for all regenerative thermal oxidizer installations.