Electrostatic precipitator performance and trace element emissions from two Kraft recovery boilers

Fine particle emissions from combustion sources have gained attention recently due to their adverse effects on human health. The emission depends on the combustion process, fuel, and particulate removal technology. Particle concentrations at Kraft recovery boiler exits are very high, and the boilers are typically equipped with electrostatic precipitators (ESP). However, little data are available on the ESP performance in recovery boilers. Particle concentrations and size distributions were determined at two modern, operating recovery boilers. In addition, we determined the fractional collection efficiency of the ESPs by simultaneous measurements at the ESP inlet and outlet and the particulate emissions of trace metals. The particle mass concentration atthe ESP inlet was 11-24 g/Nm3 at the two boilers. Particle emissions were 30-40 mg/ Nm3 at boiler A and 12-15 mg/Nm3 at boiler B. The particle size distributions had a major particle mode at around 1 microm. These fume particles contained most of the particle mass. The main components in the particles were sodium and sulfate with minor amounts of chloride, potassium, and presumably some carbonate. The ESP collection efficiency was 99.6-99.8% at boiler A and 99.9% at boiler B. The particle penetration through the ESP was below 0.6% in the entire fume particle size range of 0.3-3 microm. Trace element emissions from both boilers were well below the limit values set by EU directive for waste incineration.     

Challenges in integrating requirements management with PLM

Nowadays, requirements management (RQM) is mostly not included in the current structures of product lifecycle management (PLM) systems, although RQM has become a critical activity throughout the PLM. Customer requirements with all related product information need not only be integrated with each other, but with all processes and stakeholders involved through the related business functions of product lifecycle. In this paper, we examine the various challenges of RQM, especially related to PLM. Company-specific challenges are identified, when integrating RQM with PLM in a case company acting in the automotive industry. The objective of this study is to find out how product-related information on customer requirements could better be utilised and integrated with PLM. We propose a new integration framework according to which the challenges at different integration levels are categorised. As a final conclusion, the study shows the core points where and how the concepts of PLM and RQM should be developed, as to create requirements integrated solutions for extended products and systems through the lifecycle.     

Effect of fuel injection pressure on a heavy-duty diesel engine nonvolatile particle emission

The effects of the fuel injection pressure on a heavy-duty diesel engine exhaust particle emissions were studied. Nonvolatile particle size distributions and gaseous emissions were measured at steady-state engine conditions while the fuel injection pressure was changed. An increase in the injection pressure resulted in an increase in the nonvolatile nucleation mode (core) emission at medium and at high loads. At low loads, the core was not detected. Simultaneously, a decrease in soot mode number concentration and size and an increase in the soot mode distribution width were detected at all loads. Interestingly, the emission of the core was independent of the soot mode concentration at load conditions below 50%. Depending on engine load conditions, growth of the geometric mean diameter of the core mode was also detected with increasing injection pressure. The core mode emission and also the size of the mode increased with increasing NOx emission while the soot mode size and emission decreased simultaneously.     

Phase State and Deliquescence Hysteresis of Ammonium-Sulfate-Seeded Secondary Organic Aerosol

The phase state of secondary organic aerosol (SOA) has an impact on its lifetime, composition, and its interaction with water. To better understand the effect of phase state of SOA on climate interactions, we studied the SOA phase state and the effect of its history and report here the phase state and the humidity-induced phase hysteresis of multicomponent-seeded SOA particles produced in a large, continuously stirred tank reactor. We determined the phase state of the particles by their bounced fraction impacting on a smooth substrate in a low-pressure impactor. The particles were composed of ammonium sulfate ([NH₄]₂SO₄) seed and a secondary organic matter (SOM) shell formed from oxidized α-pinene or isoprene. The ammonium sulfate (AS) seed dominated the deliquescence of the α-pinene SOM multicomponent particles, whereas their efflorescence was strongly attenuated by the SOM coating. Particles coated with isoprene SOM showed continuous phase transitions with a lesser effect by the AS seed. The results agree with and independently corroborate contemporary research.

Copyright 2015 American Association for Aerosol Research     

The effects of operating conditions on emissions from masonry heaters and sauna stoves

Emissions from masonry heaters and sauna stoves were studied. In the sauna stove the production of organic gaseous carbon (OGC) at 10 gC kg^?1 (per kilogram of fuel), carbon monoxide (CO) at 55 g kg^?1, fine particle mass (PM₁) at 5 g kg^?1 and number emissions (N) at 1.8 × 10¹⁵ kg^?1 was higher than in other measured appliances. In a modern technology masonry heater with a unique grate, the emissions were very low: 0.4 gC kg^?1 OGC, 14 g kg^?1 CO and 0.7 g kg^?1 PM₁. Conventional masonry heaters, using small logs, clearly produced higher emissions when compared to using large logs. Doubling the fuel load caused emission factors to increase by up to 4- times (OGC), except for the number emission, which decreased from 4.0 × 10¹⁴ to 2.0 × 10¹⁴ kg^?1. From the conventional masonry heater 90% of the PM was emitted during the firing phase. Its combustion process is different to that in stoves or conventional open fireplaces. The insufficient supply of air, due to too fast pyrolysis, and increased ash release, due to the high combustion temperature, are the main parameters which cause high particle and gas emissions in masonry heaters and sauna stoves.     

The effect of positive feedback on industrial housekeeping and accidents; A long-term study at a shipyard

The experiments aimed to determine the effects of performance feedback on housekeeping behavior and consequently, on injuries over a longer period of time, and also to assess the validity of well-known Heinrich's axioms with respect to accident causation. The study was conducted at two production halls of a shipyard. Nine performance targets were set for housekeeping performance. An observation method was developed to measure performance. After we determined the baseline, feedback on performance was given by posting the results of each observation round as a large graph on the wall. The housekeeping index was significantly improved in both halls after the feedback was started. The effect persisted throughout the two-year follow-up period. Accidents were reduced by 70–90%, much more than expected merely on the basis of improved housekeeping. The effect of feedback on accidents persisted for the three-year follow-up period. The possible mechanisms are discussed.     

The status of trace elements in staple foods from the former Federal Republic of Germany I. Contents of 11 trace elements

In representative samples of bread cereals and cereal products from the former Federal Republik of Germany (FRG) the status of 11 trace elements was analysed in 1989. It is demonstrated that the results are quite representative for the former FRG as compared with results published in the previous 15 years. The sampling technique for staple foods is explained. A number of certified standard reference materials were used to validate the analytical methods employed.

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Spurenelementgehalte in Grundnahrungsmitteln der BundesrepublikI. Gehalte von 11 Spurenelementen

Zusammenfassung In repräsentativen Proben von Brotgetreide und Getreideprodukten aus der Bundesrepublik werden die Gehalte von 11 Spurenelementen für das Jahr 1989 analysiert. Es wird gezeigt, daß die Ergebnisse repräsentativ für die alte Bundesrepublik sind, wenn man sie mit den Ergebnissen aus den vergangenen 15 Jahren vergleicht. Die Probennahmetechnik für die Herstellung von Grundnahrungsmittelproben wird erklärt. Zertifizierte Standard-Referenz-Materialien wurden verwendet, um die Ergebnisse der Analysen abzusichern.

     

An empirical analysis of spreadsheet calculation

Spreadsheet calculation is a powerful tool in simple administrative data processing. Formulae in spreadsheets have similar forms to expressions in traditional programming languages, but the implementation of control structures is totally different. This paper contains an analysis of 101 spreadsheets made and used in business and government. The analysis concerns general properties, such as cell contents and referencing, the role of input, output and computation, and the different ways iteration is implemented. Finally some effects of expertise are studied. The results show that less than half of the available functions are really used, only one cell in 25 contains computation, and iteration is implemented in at least four different ways. Formulae are found to differ in their contents from expressions of programming languages, as control structures are implemented differently in these systems. Summation with a constant skip is suggested to be included in the set of functions of spreadsheet calculation.