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Grzegorz Borsuk, Jacek Wydrych and Bolesław Dobrowolski

Abstract

Rotary kiln installation forms a very complex system, as it consists of various components which affect cement production. However, some problems with particle settling are encountered during operation of tertiary air installation. This paper reports on the results of a study into gas-particle flow in a tertiary air duct installation. This flow was calculated using Euler method for air motion and Lagrange method for particle motion. The results in this paper demonstrate that study focus on the tertiary air installation is a practical measure without the analysis of other processes in the rotary kiln. A solution to this problem offers several alternatives of modifying the inlet to the tertiary air duct. As a result of numerical calculations, we demonstrate the influence of geometry of a rotary kiln modification on the number of large particles transported in the tertiary air duct. The results indicate that in order to reduce large particles, rotary kiln head geometry needs to be modified, and a particle settler should be installed at its outlet.

Open access

Grzegorz Borsuk, Bolesław Dobrowolski, Grzegorz Nowosielski, Jacek Wydrych and Jerzy Duda

Abstract

Clinker burning process has a decisive influence on energy consumption and the cost of cement production. A new problem is to use the process of decarbonization of alternative fuels from waste. These issues are particularly important in the introduction of a two-stage combustion of fuel in a rotary kiln without the typical reactor-decarbonizator. This work presents results of numerical studies on thermal-hydraulic phenomena in the riser chamber, which will be designed to burn fuel in the system where combustion air is supplied separately from the clinker cooler. The mathematical model is based on a combination of two methods of motion description: Euler description for the gas phase and Lagrange description for particles. Heat transfer between particles of raw material and gas was added to the numerical calculations. The main aim of the research was finding the correct fractional distribution of particles. For assumed particle distribution on the first stage of work, authors noted that all particles were carried away by the upper outlet to the preheater tower, what is not corresponding to the results of experimental studies. The obtained results of calculations can be the basis for further optimization of the design and operating conditions in the riser chamber with the implementation of the system.

Open access

Aneta Strachecka, Grzegorz Borsuk, Jerzy Paleolog, Krzysztof Olszewski, Milena Bajda and Jacek Chobotow

Abstract

Body-surface chemical compounds were studied in 1-day-old nest workers and foragers both in Buckfast and Caucasian bees. The workers of these two age-castes were sampled twice in each of two consecutive years. Body-surface lipids were determined by means of gas chromatography, with a GCQ mass spectrometer. Protein concentrations and activities on the body surface were examined in bee cuticle rinsings obtained from worker bees according to the methods of Lowry, of Anson, and of Lee and Lin. Protease and protease inhibitor activities were determined. Polyacrylamide gel electrophoresis was performed. Caucasian bees, particularly foragers, had more lipids, but Buckfast bees (two age-castes) had more proteins on their body surfaces. A total of 17 alkane types (C17 - C33), 13 alkene types (C21 - C33), 21 esters (C12 - C32), and a phenol (C14) were detected in both races. Alkene C33 was detected only in Caucasian bees. More alkanes, esters, and phenols were found in Caucasian 1-day-old nest workers and foragers than in these age-castes of Buckfast bees. The protein concentration and protease inhibitor activities were lower in Caucasian bees that had higher protease activities. These values corresponded with specific numbers and widths of the electrophoretic bands.

Open access

Aneta Strachecka, Grzegorz Borsuk, Krzysztof Olszewski, Jerzy Paleolog, Mariusz Gagoś, Jacek Chobotow, Agnieszka Nawrocka, Magdalena Gryzińska and Milena Bajda

Abstract

Three groups of caged bees were fed with sugar syrup (the control), sugar syrup supplemented with amphotericin B (AmB) in a dose of 0.5 mg/ml, and sugar syrup with AmB in a dose of 0.25 mg/ ml. Amphotericin B shortened the life span of the bees and reduced the level of global DNA methylation compared to the control, however, it increased the body-surface protein concentrations. In the hindguts of the bees, there were found AmB deposits. Honeybees appear to be a useful model for studying the side effects of anti-fungal AmB therapy. Among other things, epigenetic changes and senescence acceleration are considered to be the side effects of the therapy.