BUSCADOR RECOLECTA

The drying process of paper has many production parameters that can influence both the energy consumed and the characteristics of paper produced. It was found that most of the previous studies conducted on this process assume that the conditions of the facilities are always appropriate. The control of the variables associated with air circulating inside the drying hood is essential to obtain a paper with adequate quality and obtain low ratios of energy consumption and CO2 emissions. This article proposes a new indirect method based on the study of the enthalpy of the airflows inside the production hall and thermographic images that helps to analyze the maintenance state of the enclosure hood drying section in a general process, whereby it can also estimate the emissions and energy losses. The combined use of sensors and equipment has helped to identify energy losses and potential savings in CO2 emissions. The developed method is applied to a paper manufacturing plant that has ratios of energy consumption and CO2 emissions very close to the product benchmark set by the European Authorities. The study corroborates that it can be identified as a significant energy loss in paper making drying process. Analyzing facilities that are in apparently good maintenance conditions, leaks are evident. These energy losses are very significant compared with the theoretical energy consumption, and it can affect the paper moisture profile., The authors would like to acknowledge the financial support of the Spanish Ministry of Economy and Competitiveness, Project DPI2014-58007-R.

The machining with compressed air cooling has been identified as an environmentally conscious process. Its good performance has been achieved in materials as titanium alloys or aluminum alloys, but composites have not been explored. This work presents a first study related to evolution of thrust forces during the tapping process in reinforced polyamide with glass fiber, in particular PA66-GF30, when the tool cooling is considered. The experimental methodology was carried out by tapping operations in plates of PA66-GF30, using a drilling center. The experimental tests were executed using compressed air cooling by means of a vortex-tube cooling, in dry. Taps are of high-speed-steel with cobalt as base material and with coating; their geometry and dimensions are M12x1.75 mm. Outcomes obtained confirm that the methodology is appropriate in the tapping process of PA66-GF30. The tool cooling provides a reduction of thrust forces, although it is conditioned by type of tap and the coating.