Estudio de la influencia de las ventosas en transitorios hidráulicos con aire atrapado

Las operaciones de llenado y vaciado de agua de una instalación conllevan el desplazamiento de grandes cantidades tanto de agua como de aire. Este tipo de operaciones, así como las posibles alteraciones de la presión del fluido durante el funcionamiento normal de la instalación, son algunas de las posibles causas por las cuales pueden aparecer bolsas de aire atrapado en la misma. El aire atrapado en un sistema de distribución de agua reduce la capacidad de trasporte de la misma al tiempo que puede ocasionar desperfectos en la instalación y en los diferentes elementos y accesorios, tales como, contadores de agua, válvulas, etc. Además, en los transitorios hidráulicos con aire atrapado se pueden llegar a generar sobrepresiones superiores a la sobrepresión de Allievi. También es cierto que, en ocasiones y bajo determinadas circunstancias, las bolsas de aire atrapado pueden actuar como colchón y atenuar la sobrepresión que se alcanza en un transitorio hidráulico. Los dispositivos que se utiliza generalmente en las instalaciones de distribución de agua para eliminar o admitir aire en las conducciones son las ventosas. Las ventosas convencionales abren y cierran automáticamente, de modo que no se puede actuar externamente para modificar su funcionamiento. Actualmente existen manuales como el de la American Water Works Association (AWWA) o los catálogos de algunos fabricantes basados en la experiencia acumulada a lo largo del tiempo que son una especie de guía sobre como seleccionar el diámetro adecuado de la ventosa y su ubicación óptima en la instalación. Sin embargo, no existe ninguna normativa firme al respecto, por lo que el finalmente el usuario es la persona que debe tomar la decisión que considere más oportuna. De este modo, los parámetros determinantes a la hora de seleccionar la ventosa más adecuada para un uso concreto en una instalación son el diámetro nominal de la ventosa y su coeficiente de descarga y admisión. A menudo, los fabricantes proporcionan vaCarlos Alberola, MDM. (2007). Estudio de la influencia de las ventosas en transitorios hidráulicos con aire atrapado [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1929Palanci

Towards Competencies os Sustainability in Engineering Degrees: Project based service-learning experiences

Comunicació presentada al 13th International Conference on Society & Materials, SAM13 (Pisa, 20-21 May 2019)In the present work, a series of collaborative service-learning (SL) experiences carried out in the Universitat Jaume I de Castelló and University of the Basque Country will be presented. These experiences have been developed with in undergraduate courses,bachelor thesis and master thesis. The work points out how these experiences can serve as a toolf or teaching coordination at various levels: horizontal coordination with in a year in one degree, coordination between different degrees orinter-university coordination. The potential of these experiences makes them a very powerful methodological tool that can help not, only the students and the extra curricular agents involved, but also the teaching itself

Analysis of the waste selective collection at drop-off systems: Case study including the income level and the seasonal variation

There are several factors which have an influence in the selective collection of the municipal waste. To define a selective collection system, the waste generation pattern should be firstly determined and these factors should be analyzed in depth. This paper tries to analyze the economic income level and the seasonal variation on the collection and the purity of light-packaging waste to determine actions to improve the waste management plan of a town. In the first stage of the work, waste samples of the light-packaging containers were collected in two zones of the town with different economic characteristics in different seasons during one year. In the second stage, the samples were characterized to analyze the composition and purity of the waste. They were firstly separated into four fractions: metals; plastic; beverage cartons; and misplaced materials. The misplaced fraction was in its turn separated into cardboard, rubber and leather, inert waste, organic matter, paper, hazardous waste, clothes and shoes, glass and others. The plastic fraction was separated into five types of plastics and the metal fraction into three. In the third stage, the data have been analyzed and conclusions have been extracted. The main result is that the quality of the light-packaging fraction collected in these zones during both seasons were similar. This methodology can be extrapolated to towns with similar characteristics. It will be useful when implementing a system to collect the waste selectively and to develop actions to achieve a good participation in the selective collection of the waste

Cuaderno de problemas resueltos de Proyectos de Ingeniería

Área de Proyectos de Ingeniería. Departamento de Ingeniería Mecánica y Construcción. Codi d’assignatura: EX103

Declaración ambiental según ISO 14025: una oportunidad para informar de los aspectos ambientales de los servicios de gestión de residuos

Type III Environmental Declarations as set out by standard UNE-ISO 14025 (2007) are a voluntary instrument that organizations can use to foster the demand for and supply of systems that have a lower impact on the environment. They are based on an independent verification of Life-Cycle Assessment (LCA) data corresponding to the system under study. As a result, a series of environmental indicators are made public for various impact categories (climate change, ozone layer depletion, acidification, eutrophication photochemical oxidation, abiotic depletion, etc.) as well as the consumption of resources, emissions and waste generated. Environmental Declarations are based on a set of operational rules known as Product Category Rules (PCRs) that establish the specific norms, requirements and guidelines for conducting LCA studies and obtaining environmental indicators. These rules are specific for each system/product category. In 2008, RCPs were published for the “waste management services” category. The purpose of this paper is to shed light on the PCRs established for these services, the guidelines for carrying out the study on the corresponding LCA and the key environmental indicators and additional information to be included in the environmental declaration itself. Some examples of companies that already have this declaration will also be presented. Key words: environmental declaration, product category rules, waste management systemLas Declaraciones Ambientales (DA) tipo III enmarcadas en la norma UNE-ISO 14025 (2007) son un mecanismo voluntario que las entidades pueden utilizar para fomentar la demanda y el suministro de aquellos sistemas que causan una menor repercusión sobre el medio ambiente. Se basan en una verificación independiente de los datos de análisis del ciclo de vida (ACV) del sistema objeto de estudio. Como resultado, se hacen públicos una serie de indicadores ambientales para diferentes categorías de impacto (cambio climático, reducción de la capa de ozono, acidificación, eutrofización, formación de oxidantes fotoquímicos, reducción de recursos, etc.), además de los consumos de recursos, emisiones y residuos generados. Las DA se apoyan en un conjunto de reglas operativas conocidas como Reglas de Categorías de Producto (RCP), en las que se establecen las pautas específicas, requisitos y guías para el desarrollo de los estudios de ACV y la obtención de los indicadores ambientales. Estas reglas son específicas para cada categoría de sistema/producto. En el año 2008 se publicaron las RCP para la categoría “servicios de gestión de residuos”. El objeto de este artículo es dar a conocer cuáles son las RCP establecidas para estos servicios, las indicaciones para la realización del estudio de ACV correspondiente y los indicadores ambientales clave e información adicional a incluir en la propia declaración ambiental final. Así mismo se presentarán algunos ejemplos de empresas que disponen ya de dicha declaració

The determination of waste generation and composition as an essential tool to improve the waste management plan of a university

When many people work in organized institutions or enterprises, those institutions or enterprises become big meeting places that also have energy, water and resources necessities. One of these necessities is the correct management of the waste that is daily produced by these communities. Universities are a good example of institution where every day a great amount of people go to work or to study. But independently of their task, they use the different services at the University such as cafeterias, canteens, and photocopy and as a result of their activity a cleaning service is also needed. All these activities generate an environmental impact. Nowadays, many Universities have accepted the challenge to minimize this impact applying several measures. One of the impacts to be reduced is the waste generation. The first step to implement measures to implement a waste management plan at a University is to know the composition, the amount and the distribution of the waste generated in its facilities. As the waste composition and generation depend among other things on the climate, these variables should be analysed over one year. This research work estimates the waste generation and composition of a Spanish University, the Universitat Jaume I, during a school year. To achieve this challenge, all the waste streams generated at the University have been identified and quantified emphasizing on those which are not controlled. Furthermore, several statistical analyses have been carried out to know if the season of the year or the day of the week affect waste generation and composition. All this information will allow the University authorities to propose a set of minimization measures to enhance the current management

Problemas resueltos de análisis de riesgos en instalaciones

Enginyeria Industrial. 369: Seguretat i Anàlisi de RiscosBeing able to define which products are creative and which are not in a totally objective way with just one rater is of great importance. Accordingly, this study was conducted with the aim of identifying which methods of evaluating product creativity respond best to the requirements established for a method, namely, it must be useful, objective and simple to apply in enterprises. Likewise, this work also seeks to determine their shortcomings and the possible modifications or adaptations needed to correct them. To accomplish this goal, three known methods of evaluating creativity were analysed and applied to five products in order to determine their creative value, by means of a single rater. The findings are validated by evaluating creativity through questionnaires answered by experts in order to obtain a set of reference values for each parameter that creativity depends on. The analysis of the results, both graphically and numerically, reveals a tendency of the different metrics to display similar results, although they do not coincide in absolute terms due to the different scales and formats used for each metric. The conclusions show the most common shortcomings when it comes to evaluating creativity and, therefore, being able to propose global improvements that should be implemented in order to create a metric for objective creativity

Analysis of refuse-derived fuel from the municipal solid waste reject fraction and its compliance with quality standards

The final disposal of the Municipal Solid Waste is still a problem in many countries. The lack of space, the generation of leachate, and the emission of greenhouse gases as well as the requirements of the new legislation on waste dissuade the administrations involved from using the landfill option as a possible means of final disposal of MSW. The terms of the European Legislation on waste management and energy encourage member states to develop waste recovery techniques before sending it to a landfill. Therefore, member states have introduced source separation and mechanical-biological treatment to separate biodegradable recovery fractions (organic, paper-cardboard, plastic packaging, and glass) from the reject fraction, which is afterwards disposed of in landfills. One of the main aims of this study is to analyse the energy recovery properties of the reject fraction from a biological-mechanical treatment plant in Spain. For this purpose, this work presents a physical and chemical characterization of waste reject fraction from a real mechanical-biological treatment plant as well as the metal and halogen content. Additionally, the quality standards of the refused derived fuel processed at the laboratory and the atmospheric emissions of this type of fuel have been determined

Methodology to design a municipal solid waste generation and composition map : A case study

The municipal solid waste (MSW) management is an important task that local governments as well as private companies must take into account to protect human health, the environment and to preserve natural resources. To design an adequate MSW management plan the first step consist in defining the waste generation and composition patterns of the town. As these patterns depend on several socio-economic factors it is advisable to organize them previously. Moreover, the waste generation and composition patterns may vary around the town and over the time. Generally, the data are not homogeneous around the city as the number of inhabitants is not constant nor it is the economic activity. Therefore, if all the information is showed in thematic maps, the final waste management decisions can be made more efficiently. The main aim of this paper is to present a structured methodology that allows local authorities or private companies who deal with MSW to design its own MSW management plan depending on the available data. According to these data, this paper proposes two ways of action: a direct way when detailed data are available and an indirect way when there is a lack of data and it is necessary to take into account bibliographic data. In any case, the amount of information needed is considerable. This paper combines the planning methodology with the Geographic Information Systems to present the final results in thematic maps that make easier to interpret them. The proposed methodology is a previous useful tool to organize the MSW collection routes including the selective collection. To verify the methodology it has been successfully applied to a Spanish town

Influence of the Municipal Solid Waste Collection System on the Time Spent at a Collection Point: A Case Study

Waste management plans pay attention to municipal solid waste (MSW) collection systems. It represents a significant portion of waste management as it involves a great economic cost and environmental impact. For these reasons, many researchers have studied the optimization of collection routes, analyzing factors that make them more efficient and sustainable, for example, the overall distance traveled and the time spent on the route. Collection times depend on factors such as the speed of the truck, time at traffic lights or time spent on loading and unloading the waste. The loading and unloading times play an important role in the measurement of the total time of the route. Moreover, there is scarce information in the literature about measuring the real-time spent on the trip. All those times are necessary to optimize the total route time. However, it is difficult to obtain this information directly as it depends on parameters such as the type of truck. The aim of this work is to propose a methodology to define all the times involved in the waste collection process. Once they are well defined, they have to be measured in some cases or calculated in others. This works also presents a case study to validate the proposed methodology with an extensive fieldwork to measure those times that can’t be calculated in the waste collection process. The work presents the results of a study of the time spent at a collection point in six MSW collection systems using different types of collection trucks and bin designs. We have determined how the characteristics of the system affect the time spent at a collection point. Additionally, the times for the six models have been established. Finally, we have determined the influence of the collection model in the duration of the activity. Under certain conditions, times can coincide even though the models are different