Search Results

You are looking at 1 - 10 of 28 items for

  • Author: R. Dańko x
Clear All Modify Search
Open access

R. Dańko

Abstract

The idea and experimental verification of assumptions of the integrated recycling process of matrices of uniform self-hardening moulding sands with synthetic resins, leading to obtaining moulding sands matrix of expected quality - is presented in the hereby paper. The basis of the presented process constitutes a combination of the method of forecasting averaged ignition losses of moulding sands after casting and defining the range of necessary matrix reclamation treatments in order to obtain its full recycling. Simultaneously, the empirically determined dependence of dusts amounts emitted during the reclamation process of the matrix from the given spent sand on the ignition loss values (which is the most proper assessment index of the obtained reclaimed material quality) was taken into account. The special experimental stand for investigations of the matrix recycling process was one of the elements of the conceptual approach and verification of its assumptions. The stand was equipped with the system of current on-line control of the purification degree of matrix grains from organic binder remains. The results of own investigations, allowing to combine ignition loss values of spent moulding sands after casting knocking out with amounts of dusts generated during the mechanical reclamation treatment of such sands, were utilized in the system.

Open access

A. Fedoryszyn and R. Dańko

Abstract

The study investigates the key aspects involved in the flow of the air-sand stream from the machine chamber and in the core box filling in the core shooting and core blowing processes.

The prevailing tendency to manufacture thin-walled castings with intricate channel structures has become the major determinant of castings quality and production rates. An important parameter of most core sand used in the shooting processes is the ability to eject from the machine chamber and the core-box filling capability. These properties are the key factors determining the feasibility of manufacturing intricate cores and the process efficiency. The research work outlined in this study focuses on establishing the performance criteria of core sand ejection from the machine chamber and of core box filling and sand compaction.

The results given below were obtained for several new-generation core sand types, containing organic and inorganic binders, and designed to be used in hot-box, warm box and warm air processes.

Open access

R. Dańko, M. Holtzer and J. Dańko

Abstract

The after reclamation dusts originated from various foundry plants, applying moulding sands with organic binding agents, mostly resins, are characterised by different properties in dependence of the used binders, reclamation systems, spent sands overheating degree and the efficiency of the system dedusting the reclaimed material operating in individual foundry plants.

In the article the results of investigations of physicochemical properties and thermal utilisation possibility referring to six kinds of after reclamation dusts generated in the mechanical reclamation process of spent moulding sands with furfuryl resins and six other kinds of after reclamation dusts obtained from reclamation process of spent moulding sands with alkaline resins have been presented. All tested dusts originated from various Polish foundry plants of cast iron and cast steel applying the mechanical reclamation process of moulding sands with resins, obtained from different producers.

Open access

R. Dańko and J. Dańko

Abstract

The aim of the hereby paper is to present the developed model of determining the volume and surface porosity based on the main fraction of polifractional materials, its experimental verification and utilisation for the interpretation of effects accompanying the formation of a moulding sand apparent density, porosity and permeability in the blowing processes of the core and moulds technology.

Open access

R. Dańko, J. Dańko and M. Skrzyński

Abstract

The cumulative results of investigations of the possibility of using the reclaimed materials after the mechanical, thermal or mechanical-thermal reclamation for making cores by means of the blowing method in the alkaline CO2 technology, are presented in the paper. Three kinds of spent sands: with furfuryl resin, bentonite and alkaline phenolic resin, obtained from the foundry, were subjected to three kinds of reclamation: mechanical, thermal and combined mechanical-thermal, applying for this aim adequate experimental devices. The obtained reclaims were assessed with regard to the degree of the matrix liberation from the determined binding material. Reclaims of moulding sands with binders of the form of resin were assessed with regard to ignition loss values and pH reaction, while reclaims of moulding sands with bentonite with regard to the residual clay content and pH value. In all cases the results of the performed sieve analyses were estimated and the average characteristic diameter dl was determined. The reclaimed matrix was applied as a full substitute of the fresh high-silica sand in typical procedures of preparing core sands used for making shaped samples for bending strength investigations, Rg u.

Open access

J. Dańko, R. Dańko and M. Skrzyński

Abstract

The paper, especially dealt with problems of reclamation of used furan sand, carried out in new, vibratory sand reclamation unit REGMAS developed by researches from AGH-University of Science and Technology, Faculty of Foundry Engineering in Cracow (Poland). Functional characteristics of reclamation unit as well as the results of reclamation of used sand with furfuryl resin are discussed in the paper. The quality of reclaim was tested by means of the LOI and pH value, dust content in the reclaim and at least by the the quality of the castings produced in moulds prepared with the use of reclaimed matrix.

Open access

R. Dańko, J. Dańko and J. Stojek

Abstract

Experiments of filling the model moulds cavity of various inner shapes inserted in rectangular cavity of the casting die (dimensions: 280 mm (height) × 190 mm (width) × 10 mm (depth) by applying model liquids of various density and viscosity are presented in the paper. Influence of die venting as well as inlet system area and inlet velocity on the volumetric rate of filling of the model liquid - achieved by means of filming the process in the system of a cold-chamber casting die was tested. Experiments compared with the results of simulation performed by means of the calculation module Novacast (Novaflow&Solid) for the selected various casting conditions - are also presented in the paper.

Open access

M. Skrzyński, R. Dańko and J. Kamińska

Abstract

The results of investigations of the reclamation of spent moulding and core sands, originated from one of the Polish foundry plants, are presented in the paper. Four mixtures consisting of two types of spent sands (spent moulding sand and spent core sand) were subjected to the regeneration process. Each tested mixture consisted of an inorganic type spent moulding sand and of an organic type spent core sand. Proportions of mutual fractions of spent moulding and core sands in mixtures was 70%-30% and was representative for the waste sands from the foundry, from which these sands originated.

Open access

R. Dańko

Abstract

A proper management of sand grains of moulding sands requires knowing basic properties of the spent matrix after casting knocking out. This information is essential from the point of view of the proper performing the matrix recycling process and preparing moulding sands with reclaimed materials. The most important parameter informing on the matrix quality - in case of moulding sands with organic binders after casting knocking out - is their ignition loss. The methodology of estimating ignition loss of spent moulding sands with organic binder - after casting knocking out - developed in AGH, is presented in the paper. This method applies the simulation MAGMA software, allowing to determine this moulding sand parameter already at the stage of the production preparation.

Open access

R. Dańko

Abstract

Modern investigation methods and equipment for the quality estimation of the moulding sands matrices with organic binders, in their circulation process, are presented in the paper. These methods, utilising the special equipment combined with the authors investigation methods developed in the Faculty of Foundry Engineering, AGH the University of Science and Technology, allow for the better estimation of the matrix quality. Moulding sands systems with organic binders require an in-depth approach to factors deciding on the matrix technological suitability as well as on their environmental impact. Into modern methods allowing for the better assessment of the matrix quality belongs the grain size analysis of the reclaimed material performed by means of the laser diffraction and also the estimation of the moulding sand gas evolution rate and identification of the emitted gases and their BTEX group gases content, since they are specially hazardous from the point of view of the Occupational Safety and Health.