De Souza J.B.,Cinar Brazil Ltda |
Abbas T.,Cinar Ltd.
ZKG International | Year: 2015
Most cement plants have limitations in terms of co-processing due to flow stratification leading to lower fuel burnout/calcination, high CO/NOx and build-ups. The identification of flow stratification is extremely difficult and requires elaborate in-flame and 3-D mapping of the temperature and major gas species to quantify the air-fuel mixing pattern and mixedness levels. In this paper, a mineral interactive computational fluid dynamics (MI-CFD) model encompassing combustion and mineral interactions is used to visualise intricacies of calciner internal aerodynamics and its effect on meal calcination levels and fuel burnout. Modelling results provide a cost-effective way to reduce flow stratification, which leads to the implementation of low-cost solutions.
Abbas T.,Cinar Ltd.
ZKG International | Year: 2012
Two case studies where coal and natural gas were replaced with precoke and AFR thermal substitution are presented. In the first study, a detailed MI-CFD modeling campaign was initiated with the emphasis on visualization of the effect of various calciner improvement designs. The injected petcoke particles were observed to penetrate slightly more into the upward directed flow of kiln gases in the base case as compared with the lower injection case. The temperature distribution within the chamber showed that the exit temperature is in good agreement with plant measured data. In an another case study shows the MI-CFD representation of a modification of riser duct chamber height by 3 m to improve combustion and calcination levels. The results showed that the combined effect of lowering the petcoke burners and extending the height of the precalciner by 3 m has only a marginal effect on char burnout and calcination levels as shifting the burners.
Cookie Jar Entertainment Inc. and CINAR Corporation | Date: 2004-03-24
Paper goods and printed publications, namely, books in the field of childrens entertainment, picture books, comic books, coloring books, magazines in the field of childrens entertainment, newsletters in the field of childrens entertainment, trading cards, and stationery. Clothing, namely, t-shirts, sweatshirts, sweatpants, pants, shorts, jackets, coats, mittens, gloves, undergarments, shoes, bathing suits, pajamas, vests, pullovers, bath robes, belts and hats. Toys, namely stuffed toys, plush toys, dolls and accessories therefore, action figures and accessories and play sets therefore, electronically operated educational and entertainment activity puzzles and games, board games, card games, drawing games, jigsaw and manipulative puzzles, toy vehicles, yo-yos, playing cards. Entertainment services, namely, production and distribution of live-action and animated motion pictures and television programs for others; videotape production; providing online information in the field of childrens education and entertainment via a computer network.
Nance G.,GCC |
Abbas T.,Cinar Ltd. |
Lowes T.,Cinar Ltd. |
Bretz J.,Cinar Ltd.
IEEE Cement Industry Technical Conference (Paper) | Year: 2011
In an effort to reduce production costs, the cement industry is using more and more alternative fuels and raw materials (AFRs) than ever before. Some successful examples show thermal substitution rate (TSR) as high as 90%. Generally, a higher than 20-30 TSR requires detailed analysis of not only combustion aspects of AFRs, but also their impact on emissions, kiln stability and clinker quality. Usually those conditions that provide a more optimum combustion environment both for plants using conventional fuels as well as those using AFRs or a combination of the two mean an increase in NOx emissions. Implementation of traditional low-NOx techniques can have a negative impact on CO/VOC emissions as well as increase deposit build-up potential and cause kiln instabilities. Several alternative NOx reduction methods are available and have been applied within the cement industry. These methods include Selective Non-Catalytic Reduction/Selective Catalytic Reduction (SNCR/SNR) and can provide NOx reduction efficiencies of 40-80% respectively, without significant negative impact on CO/VOC emissions, but at the same time add significant cost to clinker production. © 2011 IEEE.
Akhtar S.S.,Holcim Inc. |
Ervin E.,Holcim Inc. |
Raza S.,Cinar Ltd. |
Abbas T.,Cinar Ltd.
IEEE Transactions on Industry Applications | Year: 2016
In the North American energy market, natural gas (NG) prices have been gradually decreasing during the past several years, primarily due to advances in shale gas extraction techniques. The availability of cheaper NG, while seen as an attractive short-term fuel switching option, is viewed with caution by most cement plants due to long-term procurement concerns. Also, due to traditionally higher NG prices, cement plants have invested heavily into solid fuels, including storage, grinding, handling, and dosing systems - often achieving high thermal substitution rates (TSRs) of solid alternative fuels and raw materials (AFRs). As a result, a wealth of knowledge has been acquired on firing solid fuels, including some of the more difficult ones, e.g., higher sulfur petcoke and bigger size AFRs, where operational issues such as build-ups, emissions, and production losses have been and are being minimized. Switching to gas firing, however, requires readaptation of combustion and process guidelines for a fuel which, although in principal, is easier to burn, but has relatively lower radiative heat transfer and sharper burning characteristics than coal. As such, the plants, which have switched to NG firing, have observed inconsistent trends in production, energy, and emission performance, mainly due to the lack of sufficient information on combustion/process interactions of the two fuel types required for cost-effective optimization. An NG flame ignites earlier, releases intense heat but lacks dissipation of heat as compared with a solid fuel flame, thereby requires plant specific adjustments. This paper presents actual results of NG firing trials at selected cement plants along with mineral interactive computational fluid dynamics (MI-CFD) predictions, subsequent to validation from the plant data, on four kiln and four calciners. Recommendations are also made to improve and optimize NG firing by taking into considerations of the combustion and mineral interactions. © 2015 IEEE.