scholarly journals Production Methods for Regular Aggregates and Innovative Developments in Poland

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1429
Author(s):  
Tomasz Gawenda

The aim of this article is to present possibilities of producing aggregates with an increased content of regular particles in some well-known examples, as well as to present previously unused methods of aggregate production. Traditional aggregate production systems require the use of three or four grinding stages (depending on the particle size of the feed), but fine fractions contain approximately 10% irregular grains on average. The conducted research has shown that in innovative patented technological systems, it is possible to obtain regular aggregates with a share of irregular grains below 3%. The separated irregular aggregates can be crushed again or used for other purposes. The advantages of such inventions include less grinding stages, reduced dust, and lower energy consumption. Regular aggregates also have benefits compared to typical ones. The analyzed aggregate products from various mines showed that regular aggregates have better properties, for example, higher resistance to grinding and abrasion. This article also describes the advantages of using such aggregates for concrete or other applications.

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  


2020 ◽  
Vol 10 (22) ◽  
pp. 8055
Author(s):  
Sergey A. Stel’makh ◽  
Evgenii M. Shcherban’ ◽  
Anatolii I. Shuiskii ◽  
Al’bert Yu. Prokopov ◽  
Sergey M. Madatyan ◽  
...  

The paper studies the influence of the geometric parameters of the mixer on the mixing process, the construction of the mixing body, its location in the mixer bulk, and the mixer shape and geometry. The technique of calculating the power spent on mixing the foam concrete mixture is described. The effects of the ratio of the mixture height to the mixer diameter, the number and width of reflective partitions, and the shape of the conical part of the mixer on the homogeneity of the foam concrete mixture and the power consumption are considered. The optimal ratios of the foam concrete mixture height to the mixer diameter have been determined. Moreover, the optimal range of the ratios of the partition width to the mixer diameter has been established, in order to obtain a homogeneous foam concrete mixture throughout the volume with lower energy consumption. The optimal values of the angle of the mixer conical part for the preparation of a foam concrete mixture have been determined.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1603
Author(s):  
Ernesto Olvera-Gonzalez ◽  
Nivia Escalante-Garcia ◽  
Deland Myers ◽  
Peter Ampim ◽  
Eric Obeng ◽  
...  

Different strategies are reported in the literature for energy saving in Closed Plant Production Systems (CPPS). However, not reliable evidences about energy consumption with the use of pulsed LED light technique in lighting system available in Plant Factory and Vertical Farm. In this work, three key points to determine the effects of pulsed LED light versus continuous LED light are presented: (1) A mathematical model and its practical application for stabilizing the energy equivalence using LED light in continuous and pulsed mode in different light treatments. (2) The quantum efficiency of the photosystem II was used to determine positive and/or negative effects of the light operating mode (continuous or pulsed) on chili pepper plants (Capsicum annuum var. Serrano). (3) Evaluation of energy consumption with both operation modes using ten recipes from the literature to grow plants applied in Closed Plant Production Systems, different Photosynthetic Photon Flux Density at 50, 110, and 180 µmol m−2 s−1, Frequencies at 100, 500, and 1000 Hz, and Duty Cycles of 40, 50, 60, 70, 80, and 90%. The results show no significant statistical differences between the operation modes (continuous and pulsed LED light). For each light recipe analyzed, a pulsed frequency and a duty cycle were obtained, achieving significant energy savings in every light intensity. The results can be useful guide for real-life applications in CPPS.


Author(s):  
Rima Tedjini ◽  
Raquel Viveiros ◽  
Teresa Casimiro ◽  
Vasco D.B. Bonifácio

Mechanosynthesis is an emergent green technology that proceeds under solventless or vestigial solvent conditions. Major advantages relay in waste reduction and lower energy consumption, without compromising or enhancing reaction conversion....


2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Lelia Murgia ◽  
Giuseppe Todde ◽  
Maria Caria ◽  
Antonio Pazzona

Dairy farming is constantly evolving towards more intensive levels of mechanization and automation which demand more energy consumption and result in higher economic and environmental costs. The usage of fossil energy in agricultural processes contributes to climate change both with on-farm emissions from the combustion of fuels, and by off-farm emissions due to the use of grid power. As a consequence, a more efficient use of fossil resources together with an increased use of renewable energies can play a key role for the development of more sustainable production systems. The aims of this study were to evaluate the energy requirements (fuels and electricity) in dairy farms, define the distribution of the energy demands among the different farm operations, identify the critical point of the process and estimate the amount of CO2 associated with the energy consumption. The inventory of the energy uses has been outlined by a partial Life Cycle Assessment (LCA) approach, setting the system boundaries at the farm level, from cradle to farm gate. All the flows of materials and energy associated to milk production process, including crops cultivation for fodder production, were investigated in 20 dairy commercial farms over a period of one year. Self-produced energy from renewable sources was also accounted as it influence the overall balance of emissions. Data analysis was focused on the calculation of energy and environmental sustainability indicators (EUI, CO2-eq) referred to the functional units. The production of 1 kg of Fat and Protein Corrected Milk (FPCM) required on average 0.044 kWhel and 0.251 kWhth, corresponding to a total emission of 0.085 kg CO2-eq). The farm activities that contribute most to the electricity requirements were milk cooling, milking and slurry management, while feeding management and crop cultivation were the greatest diesel fuel consuming operation and the largest in terms of environmental impact of milk production (73% of energy CO2-eq emissions). The results of the study can assist in the development of dairy farming models based on a more efficient and profitable use of the energy resources.


2018 ◽  
Vol 10 (9) ◽  
pp. 3248 ◽  
Author(s):  
Dong Tian ◽  
Min Zhang ◽  
Xuejian Wei ◽  
Jing Wang ◽  
Weisong Mu ◽  
...  

This paper compares the difference in energy consumption in different sub-patterns and features of energy consumption structures used in protected grape production systems using statistical data. Then, spatial characteristics between different production modes based on geographic information systems are also analyzed. The results reveal that the types of energy consumption include steel, iron wire, water, chemical fertilizer, pesticides, electric power, organic fertilizer, plastic films, and labor. The total energy consumption for protected grape production was 210,534.3 MJ ha−1 in 2011, 211,504.6 MJ ha−1 in 2012, and 222,571.8 MJ ha−1 in 2013. From the perspective of cultivation modes, early ripening production and late ripening production consumed more energy than rain-shelter production; in terms of facility types, the total energy input of both vinyl tunnels and solar greenhouses were always higher than rain-shelter greenhouses. Indirect and non-renewable energy consumption were higher than that of direct and renewable energy, which accounted for 90% of energy consumption. Spatial analysis showed that the values of Moran’s I were all positive for the three years, which means protected grape input had a positive spatial autocorrelation. Therefore, we should adjust the energy input structure and choose more sustainable production modes to improve the sustainability of the production of protected grapes.


Author(s):  
Nagisa Onoda ◽  
Shota Ishiguchi ◽  
Osamu Nakabeppu

We are studying the effects of thermal moisture swing air-cleaning method on removal of suspended particulate matter, SPM. This method continuously humidifies sample air with heating and dehumidifies it by cooling, in a channel. It was experimentally demonstrated that the thermal moisture swing method reduces SPM suspended in sample air. The experimental result showed reduction of SPM above 10 nm in particle size, and the removal ratio increased with intensifying the thermal moisture swing. The SPM removal mechanism of this method was theoretically estimated. The estimation suggests that the reasons for the SPM reduction are suction flow accompanying condensation and thermophoresis. These phenomena would transport SPM to cooling wall of the dehumidifier. Also, diffusional deposition and gravitational sedimentation would transport SPM to the wall of the channel. And, the transported particles are separated from the air with adhering on the wall. We estimated the effects of these phenomena on SPM removal using simple model and energy consumption. The estimation qualitatively agreed with the experimental result.


Author(s):  
Gülferah Çorapçıoğlu

Purpose The purpose of this paper is to ensure the preservation and sustainability of traditional water mills in Turkey with their original function and to allow these water mills to become heritage for future generations. Design/methodology/approach The study is the original examination of one sample water mill to be conserved, that is chosen from 11 water mills that were determined after the investigation of water mills in of Antalya, in Mediterranean Region. A preliminary study was first performed using the external observation method on 11 horizontal wheel water mills. The water mills to be accorded the highest priority with regards to conservation were selected based on their characteristics. Restoration techniques were then proposed to ensure the sustainability of the traditional production systems while retaining their original function. Findings The decision of water mill with the highest priority of conservation is based on the analysis of “structural damage,” “all seasons accessibility” and “supporting environmental factors.” This water mill was used primarily for grain production and is located on the Doyran River in Antalya. Current circumstance of the sample mill is analyzed, restoration techniques for the purpose of conservation and creation of recreational sites and that enable the presentation of traditional production methods are suggested. Social implications This paper includes implications for the contribution to the region’s cultural identity by developing the region’s infrastructure for cultural and ecological tourism and by ensuring the continuation of traditional production methods and craftsmanship. Originality/value This paper brings a new approach to the identification of water mills and the decision of the water mills to be conserved as a result of field studies.


2018 ◽  
Vol 7 (3) ◽  
pp. 1861
Author(s):  
Neveen Y. Azmy ◽  
Rania E. Ashmawy

Windows play a significant role as they largely influence the energy load. Although there are many studies on the energy-efficient windows design, there is still a lack in information about the mutual impact of windows’ size, position and orientation on the energy loads. In this paper, the effect of different window positions and orientations on the energy consumption in a typical room in an administrative building that is located in the hot climatic conditions of Cairo city, Egypt is considered. This case study has been modeled and analyzed to achieve good environmental performance for architectural space, as well as assessing its impact on the amount of natural lighting required by using the Energy Plus program. The study concludes that the WWR (Window Wall Ratio) 20% square north-oriented upper  opening consumes 25% lower energy than the rectangular 3:1 opening in the lower west-oriented façade. The upper openings are the highest in terms of light intensity, as they cover about 50% of the room area. The WWR 30% rectangular north-oriented upper 3:1 opening consumes 29% lower energy than the rectangular lower 3:1opening in the façade. Regarding light intensity, the upper openings are the best for natural lighting as the light covers more than 60% of the room area.                                                                                                                                                               


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