Silo emptying in aspect of the non-desctructive detection methods application

The paper presents results of concentration measurements in non-cohesive sand during free flow in rectangular and cylindrical silos using different non-invasive methods like thermography, X-ray photography, X-ray tomography and electrical capacitance tomography. The effect of the initial bulk solid density and roughness of silo walls on the concentration changes were investigated. Advantages and disadvantages of all presented methods were outlined. The possibility of application of the Electrical Capacitance Tomography (ECT) for observation the porosity changes of the bulk solid was pointed out

Measurement of dynamic pulsations in bulk solid during silo discharging using ECT method

Paper will focus on the results of tests with the slender cylindrical silo emptied both gravitationally and in controlled manner. The influence of the initial density, wall roughness, height and velocity on the emptying process will be presented. During tests values of the vertical and horizontal accelerations on the silo wall were measured, the effect of the outlet velocity and level of the dynamic effects were compared. Results will be presented in the form of continuous graphs, which allow to analyse the entire process in simpler way comparing to tomographic images form. It is a better form of presentation in order to work out settings for process control, as well

Monitoring of solids behaviour during gravitional flow in rectangular silo

This paper is focused on the application of Electrical Capacitance Tomography (ECT) to gravitational flow of bulk solid in rectangular silo investigation. In order to measure the materials distribution inside a vessel, a dedicated, spatial 16 electrode sensor is designed. Reconstructed images are presented in 3D domain space. The investigated silo model consists of rectangular bin and a cone-like hopper section. The flow behaviour of material (friable sand) is studied for two silo model configurations having different lower section slopes. The slope angle is a silo geometrical parameter affecting the type of the flow regime - mass or funnel type

An algorithm to generate high dense packing of particles with various shapes

Discrete Element Method (DEM) is one of available numerical methods to compute movement of particles in large scale simulations. The method has been frequently applied to simulate the cases of grain or bulk material as the major research issue. The paper describes a new method of generating high dense packing with mixed material of two different shape used in DEM simulation. The initial packing is an important parameter to control, because have influence on the first few seconds after start the simulation. Some-times when the material in silo is arranged with loose packing before the start, the particles move downward gravity. These changes between the start and the first few seconds in simulations act strongly on the results at the end of a discharging process in silo. At the initial simulation time it is important to prepare proper packing with mixed material, in order to make sure that the particles will not move due to gravity action. This solution is a necessary step to integrate in the simulation procedure in order to compare later the computer simulation with experimental measurements of material discharge in a silo

Traceability of raw materials in silos in an anode plant

Carbon anodes, regularly consumed in primary aluminum production, are made of calcined petroleum coke, coal tar pitch, and recycled materials. The properties of calcined coke depend on the source of crude oil and the calcination conditions. Similarly, pitch properties depend on the coal tar source and the manufacturing process. Different calcined coke and pitch mixtures are commonly used in anode manufacturing to meet various regulations and/or due to economics and availability. This makes it hard to maintain the anode quality. Calcined coke and pitch are placed in silos and used when required for production. It is hard for the industries to track the source of raw materials used in their daily recipes. This article presents an approach to trace back the details of the use of particulate raw materials with a custom-made software, which takes into account the type (mass flow or funnel flow) of silos. Such tracking can help identify the causes of problems and maintain/improve anode quality

A review of current techniques for the evaluation of powder mixing

Blending a mixture of powders to a homogeneous system is a crucial step in many manufacturing processes. To achieve a high quality of the end product, powder mixtures should be made with high content uniformity. For instance, producing uniform tablets depends on the homogeneous dispersion of active pharmaceutical ingredient (API), often in low level quantities, into excipients. To control the uniformity of a powder mixture, the first required step is to estimate the powder content information during blending. There are several powder homogeneity evaluation techniques which differ in accuracy, fundamental basis, cost and operating conditions. In this article, emerging techniques for the analysis of powder content and powder blend uniformity, are explained and compared. The advantages and drawbacks of all the techniques are reviewed to help the readers to select the appropriate equipment for the powder mixing evaluation. In addition, the paper highlights the recent innovative on-line measurement techniques used for the non-invasive evaluation of the mixing performance

Emergency condition of the ceramic facade of a residential building

The paper presents a description of the technical condition of the ceramic cladding of a residential building, the technical condition of which deteriorated significantly after only a few years of operation. The analysis of the influence of the applied design and working solutions on the façade failure frequency was analyzed. The article presents a conceptual solution to bring the building to the proper technical condition in terms of defects and damage to the facade

Technical conditioning of the repair work of modernist Gdynia tenements

W artykule przedstawiono przykłady rozwiązań konstrukcyjno-materiałowych przedwojennych wielorodzinnych budynków mieszkalnych realizowanych w Gdyni na terenie dzielnicy Działki Leśne, które obecnie, w czasie prowadzenia prac remontowo-modernizacyjnych, powodują powstawanie znacznych utrudnień wydłużając czas robót budowlanych oraz generując dodatkowe koszty. Na przykładzie fundamentów, stropów oraz murów zewnętrznych omówiono koncepcje projektowe umożliwiające usunięcie części występujących usterek.In the paper examples of solutions of structural-material prewar multi-occupied residential buildings carried out were presented in Gdynia in the district of Woody Plots which at present, during conducting renovation-modernization works cause coming into existence of considerable impediments extending the time of building work and generating extra costs. On the example of foundations, of ceilings and outside walls design concepts were discussed enabling to remove the part of appearing defects

Building modernization located in the conservation protection zone in the aspect of technical conditions

The paper presents a description of the technical condition of the building after many years of operation and analyzes the impact of the current use and the lack of regular periodic repairs on the technical efficiency of the building. The influence of the technical solutions applied during the construction of the building on the current limitations related to the planned, target change in the way of use was discussed. Variant conceptual solutions for the modernization of the building were also presented, taking into account the preservation of its historic character