Pulverizer performance optimization is the first step to a successful combustion optimization program and the inter-relationships of the pulverizers must be considered when attempting to optimize combustion, overall unit performance, operability, reliability, and capacity. Pulverizer capacity seems to be an industry challenge while many units today are undergoing drastic fuel changes. Considering there seems to be a huge disconnect when correlating mill performance with such issues as fuel line distribution, heat rate, NOx and environmental control equipment performance, it is the intent of this technical paper to provide better understanding of how mechanical optimization & tuning of the pulverizers can yield overall improved plant performance. Low NOx firing and/or optimization of the burner belt combustion with a limited amount of furnace residence time is absolutely essential to optimizing plant performance. For example, when pulverizer performance is poor, it is also often related to not only high furnace exit gas temperatures, increased slagging and/or high LOI, but also degrading electrostatic precipitator (ESP) performance from the coarse particle ash. Furthermore, reliability of the boiler (ie. tube leaks, fouling, and slagging) can also be impacted negatively by secondary combustion and consequent super heater and re-heater tube metals overheating and/or wall wastage often occurs from non-optimized fuel distribution being delivered from the pulverizers. Whether the reason for improving mill performance is for the aforementioned items and/or perhaps simply to reduce power generation costs with improved fuels flexibility, the purpose of this case study is to review the basics of vertical spindle mill performance improvements. The data used to support this paper is from a compilation of actual field testing & tuning results. Furthermore, Storm Technologies, Inc. (STI) suggests the aforementioned steps as an effective approach to optimization.

Storm Technologies in cooperation with AES Westover Station implemented a total combustion optimization system approach, including a fan boosted over-fire air system on Unit 13 to reduce the emissions of NOx while also improving and/or maintaining acceptable Carbon in Ash content levels on a daily basis. Implementation of this total airflow & pulverizer performance utilized a fundamental and proven approach to performance optimization and the system has been installed now for over two years and continues to be successful. The results of this systems modifications was up to 60% NOx reduction and payback in months by reducing the need for NOx credits and simultaneously improving unit performance, reliability and fuels flexibility. All of the goals of this program were accomplished and the technical success of this project is once again the results of applying a systematic and comprehensive approach addressing fundamental opportunities for improvement. The benefit of this total combustion optimization project was not only NOx reductions, but also reliability and “fuels flexibility”. Furthermore, foresight in this system was the ability to improve boiler efficiency, heat rate and reduce rates of ammonia when and/or if SCR or SNCR is installed. Since the installation of the FBOFA System it should be noted that AES Westover has been able to consistently attain between .25–.30 lbs/mmBtu NOx and single digit carbon in ash levels with no negative effects of the system installed. The goals of this project were as follows: 1. NOx Reduction from >.54lb/mmBtu (full load) – to ≤ 0.32 lb/mmBtu; 2. Flyash Carbon Content less than 10%; 3. Minimal slagging; 4. Operations with a minimum of 2% Oxygen to maintain a “slag friendly” furnace without exceeding the NOx limits; 5. Maximum Load Capability; 6. Maximum Fuel Flexibility; 7. Total Combustion Optimization & Performance Preservation.

South Carolina Electric and Gas (SCE&G) Wateree Station is a pulverized coal fired power generation facility consisting of two Riley supercritical units (3,549 psi 1,005/1,005°F, 2,850 klb/hr) and two General Electric G2 tandem compound four flow three casing reheat steam turbines.

Introduction: Single or multiple cavernous hemangiomas involving the lips can be disfiguring and are subject to traumatic hemorrhage and ulceration. Furthermore, the cavernous hemangiomas may increase in size over time. The lip is a unique body tissue because of the vermilion color. Thus, surgical removal of lesions involving the vermilion borders present esthetic concerns.Case Presentation: A 51-year-old male presented with a chief complaint of a "red-blue puffy" and protruding lower lip of several years duration. Clinical examination revealed four raised soft tissue lesions ranging from 0.4 to 1 cm in diameter. Similar lesions were noted on the dorsal tongue surface. All lesions blanched on palpation but were not pulsatile. The preliminary diagnosis was cavernous hemangioma. Given the range in size, distribution, and esthetic concerns, the two largest lip lesions were surgically excised and the smallest was ablated by carbon dioxide laser irradiation. A small lesion involving both lips at the commissure was not treated because of lack of esthetic and functional concerns.Conclusions: Treatment was successful in that no complications were incurred and the esthetic result was pleasing to the patient. This case demonstrates that laser ablation of a cavernous hemangioma with good hemostasis is possible and should be considered a viable treatment option. Clin Adv Periodontics 2015;5:110-115.