Industrial Silos Research Articles

Non-starter lactic acid bacteria and citrate fermenting bacteria in milk supply chain: Are they easily controlled?

The frequency and possible sources of non-starter lactic acid bacteria (NSLAB) and citrate fermenting bacteria (CFB) at four points of a milk supply chain were evaluated. The relationship between the distance from farms (G1 and G2) to industry with NSLAB, CFB and psychrotrophic bacteria populations was also evaluated. A positive correlation between psychrotrophic and CFB was verified, which points to the need for the correct use of good milking practices to control these bacteria. NSLAB showed a significant increase in the population in raw milk samples collected in industrial silos (4.4 log cfu mL−1). CFB populations showed a significant increase in milk from tank trucks (4 log cfu mL−1). There was no difference between G1 and G2 in microorganisms counts. Even after the pasteurisation process, NSLAB and CFB populations remained high, which points to the occurrence of post-heat treatment recontamination, formation of biofilms and/or the presence of thermoduric microbiota.

ЕКСПЕРИМЕНТАЛЬНЕ ДОСЛІДЖЕННЯ НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ СТІНКИ СТАЛЕВОГО СПІРАЛЬНО-ФАЛЬЦЕВОГО СИЛОСУ

In the context of martial law, Ukraine's agricultural sector is suffering significant losses. By May 2022. Ukraine has already lost almost 13 million tonnes of elevator capacity, some of the grain warehouses have been completely destroyed, and some are in the occupied territories. In this regard, there is a need for elevator capacities, namely, prefabricated, cost-efficient storage capacities. Such structures are exemplified by silos. There are many design solutions for metal silos. However, the rising cost of materials is causing a need to reduce the material intensity of the structure, which is encouraging cylindrical silo manufacturers to search for new types of shell construction. An innovative design of lightweight, industrial silos is a metal spiral-fold silo. The article describes the design of steel spiral-fold silos. The specifics of the spiral-fold silo design, which affects their stress-strain state, are analysed. The characteristics of the silo that was used as a source of samples for the experiment are given. The samples and equipment for the experimental study of a wall of a metal spiral-fold silo are considered. The stages of the experiment are described. The loading of the samples was performed by a central bending load applied in a static mode in the range from 0 kN to 5.5 kN. To determine the relative strains, the structure was unloaded after each loading stage. The analysis of the sample's relative strains which were measured by AVD-4 is made. The character of interaction and deformation of the wall with the folding lock is revealed. The degree of the folding lock opening was estimated. The character of work of the wall and the folding lock in the limit and non-limit states is obtained. A comparison of experimental results with finite element analysis in the LIRA-SAPR software package was performed. The conclusion about the reliable operation of the wall of a spiral-fold silo under operational and increased loads is substantiated

Prediction and validation of the profiles of the top and mixed loading surfaces during discharge from multiple-outlet silos

One of the problems for the efficient operation of large industrial silos is that it is difficult to check the volume of the materials that remain inside the silo at any given time. This problem is more pronounced when materials from two or more sources are stored in a multiple-outlet silo, so that the profile of the mixed loading surface, i.e., the interface between materials from different sources, is not visible. To date, no research addressing this problem has been conducted. Therefore, this study proposes a model to predict the profiles of the top and mixed loading surfaces using the simple kinematic theory and considering the effect of the angle of repose on the shape of the top surface. The accuracy of the proposed prediction model was verified by comparing actual profiles of the top and mixed loading surfaces with those predicted by the model when materials were discharged from a multiple-outlet hopper with discharge sequences varying from the left, central, and right outlets. The results showed that the proposed model adequately predicted the profiles with relatively negligible errors.

Thermophilic Hydrocarbon-Utilizing Bacilli from Marine Shallow Hydrothermal Vents as Producers of Biosurfactants

The exploitation of thermophilic hydrocarbon-utilizing bacilli could provide novel environmentally friendly surfactants. In this work, 80 thermophilic bacilli isolated from shallow hydrothermal vents of the Eolian Islands (Italy) were screened for their ability to utilize hydrocarbons and produce biosurfactants (BSs). Among them, 15 strains grew with kerosene or gasoline (2% v/v) as the only carbon and energy source, and most of them were positive to the methylene blue agar as prescreening assay for BSs production and displayed emulsifying activity. The cell-free supernatants (CFSs) from two selected strains, Bacillus licheniformis B3-15 and Bacillus horneckiae SBP3, were both surface active and able to emulsify different hydrocarbons and vegetable oils. BSs from B3-15 (910 mg L−1) and SBP3 (950 mg L−1) were chemically different surfactin-like lipopeptides, with specific mineral-, castor- and crude oil removal ability from the cotton matrix. CFSs from the 15 thermophilic strains, which harbor both lipolytic and surfactant abilities, could be suitable for industrial-based applications and environmental issues, such as oil recovery and removal from polluted areas or surfaces, (e.g., oil pipelines, bilge tankers, or industrial silos), whereas the crude BSs, as high-value compounds, may be used in different fields of application, as detergent, cosmeceutical, and pharmaceutical industries.

Assessment of Structural Behavior, Vulnerability, and Risk of Industrial Silos: State-of-the-Art and Recent Research Trends

This paper presents a literature compendium about the main studies on the structural behavior, vulnerability, and risk of industrial silos, as one of the most important players of different industrial processes. This study focuses on the main scientific works developed in the last decades, highlighting the more notable issues on circular steel silos as the most widespread typology in practice, such as the content–container complicated interaction, the structural and seismic response, and the several uncertainties in the design and assessment processes. Specifically, this paper proposes a near-full state-of-the-art on (i) the behavior of silos under different kinds of loads, ordinary and extreme, (ii) the effects of imperfections and the interacting structures (e.g., ring beams, supporting structures), (iii) the stored material properties, the relevant uncertainties and the impact on the silo behavior, (iv) the possible failure modes given by the focused structural configuration and the stored materials, and (v) assessment and risk mitigation strategies. Throughout the text, some considerations are provided in order to summarize the more recent research trends about steel silos and to highlight the still open issues on the risk and vulnerability reduction of these kinds of structures.

Changes in phytosterol contents during rape seed storage under conditions simulating industrial silos

During seed storage in tall silos the low layers of rape seeds are exposed to static pressure exerted by the upper layers. This may cause deformation and damage of seeds found in the lower layers and losses of biologically active compounds. The aim of this study was to simulate under laboratory conditions the actual ecosystem found in industrial plants and to evaluate the effect of not only the temperature and moisture content, but also static pressure on degradation of phytosterols contained in rape seeds in the course of storage. Changes in phytosterol levels were assessed using GC-MS. During storage in all samples of seeds (7–16% moisture content) under the adopted conditions of overpressure (20–60 kPa) and temperature (25–35 °C) the total content of phytosterols decreased by 3–57%. The smallest losses in the total phytosterol contents (3–4%) were recorded during storage of seeds with a 7% moisture content, irrespective of the applied storage temperature (25–35 °C) and overpressure variants (20–60 kPa). The greatest losses of phytosterols (43–57%) were observed during storage of seeds with a 16% moisture content at a temperature of 35 °C, while the higher the applied overpressure, the greater these losses were. The study showed that the greatest influence on sterol content during storage was increased seed moisture, and subsequently the temperature and the pressure. Experimental results also showed that for seeds with higher moisture contents (13 and 16%) an increase in storage temperature from 30 to 35 °C intensifies losses of individual phytosterols much more markedly that an increase in temperature from 25 to 30 °C. Moreover it was observed that overpressure over 20 kPa enhanced losses of investigated phytosterols.

Managers Fail to Innovate and Academics Fail to Explain How

I am stunned by the failure of so many organizations to create the capability for generating streams of new products and services over time. Organizations capable of ongoing innovation can create more profits, more value, more employment, more growth, and more adaptability to transformations in technologies and markets (BCG study of investor returns). Generating streams of innovation is even more important now, especially for organizations in emerging economies, because industrial transformations and global grand challenges (Ferraro, Etzion, & Gehman, 2015) demand continuous innovations in products, programs, business processes, and strategies. For example, digitalization is transforming business models from vertical industrial silos such as consumer goods, materials, or financials to horizontal platforms that orchestrate networks, create technologies, and provide services (think Amazon, Alibaba). New markets and technologies emerge unpredictably but will produce major economic and social changes. Emerging economies more directly face grand challenge complexities of poverty, water scarcity, inequality, and climate changes. Innovations in emerging economy organizations are also very complex, since they often include innovations in sales, distribution, and business models along with rigorous product design and development processes.

Reducing the seismic vulnerability of existing elevated silos by means of base isolation devices

Industrial silos are used for storing a huge range of different materials. In the last decades, many of these structures were damaged by natural events, among which the earthquakes were the most significant. Indeed, numerous industrial plants have been built in the territories with high seismicity risk. Most of these plants have been designed and built before the latest updates of the seismic design codes took place, hence their current seismic reliability is questionable. In order to avoid future economic, life-safety and environmental troubles that can be caused by the collapse of these non-building structures, specific retrofitting solutions should be developed and implemented urgently. This paper shows the feasibility of the seismic isolation solution on a typical case study. Seismic vulnerability of an existing industrial steel silo system has been investigated, and a retrofitting solution has been proposed making use of the curved surface single sliding pendulum devices. Incremental dynamic analysis method has been used to compare the performance of the original and the retrofitted solutions. Structural benefits of the seismic isolation solution have been quantified in terms of inelastic deformations, base shear, inter-story drifts and isolator displacements. The seismic behaviour of the original and the retrofitted structure has been compared by means of fragility curves.

Slip-stick excitation and travelling waves excite silo honking

Silo honking is the harmonic sound generated by the discharge of a silo filled with a granular material. In industrial storage silos, the acoustic emission during discharge of PET-particles forms a nuisance for the environment and may ultimately result in structural failure. This work investigates the phenomenon experimentally using a laboratory-scale silo, and successfully correlates the frequency of the emitted sound with the periodicity of the mechanical motion of the grains. The key driver is the slip-stick interaction between the wall and the particles, characterized as a wave moving upwards through the silo. A quantitative correlation is established for the first time between the frequency of the sound, measured with an electret microphone, and the slip-frequency, measured with a high-speed camera. In the lower regions of the tube, both the slip-stick motion and the honking sound disappear.

Degradation of tocopherols during rapeseed storage in simulated conditions of industrial silos

Abstract The investigations consisted in laboratory simulation of conditions prevailing in the real ecosystem in an industrial rapeseed storage facility. The aim of the study was to assess the impact of temperature, moisture, and static pressure on degradation of tocopherols contained in rapeseed. Rapeseed varieties with high oil content were analysed in the investigations. Samples of seeds with 7, 10, 13, and 16% moisture levels were stored at a temperature of 25, 30, and 35°C in specially designed airtight pressure silos for storage in controlled conditions. During the storage, the seeds were subjected to overpressure in the range of 20-60 kPa. The seeds were stored in these conditions for 28 days. It was demonstrated that primarily moisture induced the greatest loss of the total content of tocopherol and its α-T and γ-T homologues, followed by temperature and, to a lesser extent, pressure. In addition, the results obtained showed that, in the case of seeds characterised by higher moisture levels (13 and 16%), an increase in the storage temperature in the range of 25-30°C rather than 30-35°C intensified tocopherol loss more efficiently.

English

Dairy farmers strive to meet industry quality standards, the industry focuses on the quality of the raw material for higher yield and quality of dairy product. The aim of this study was to evaluate the influence of bulk transportation, storage and milking system on the quality of refrigerated milk. Overall, 548 samples of refrigerated milk were collected, 312 from bulk tanks (individual and collective) and (manual and mechanical milking), 143 from tank cars and 93 from industrial silos. Mean values ​​of proximate composition, somatic cell count (SCC) and total bacterial count (TBC),  were compared in relation to different milking systems (manual and mechanical), type of producer (individual and collective) for these comparisons and for physicochemical analyses, total bacterial count and somatic cell count in different collections, the Tukey test at 5% significance level was used. It was observed that 40% of milk samples from bulk tanks, 69.93% of samples from tank cars and 62.36% of samples from industrial silos had SCC over 500,000 SC / ml. There was an increase of TBC from the bulk collection of milk on the farm up to the arrival of milk in the processing industry. Refrigerated milk stored in individual or collective bulk tanks obtained by manual or mechanical milking had to be adjusted to standards required by Normative Instruction number 62 of December 2011. Education and training measures such as hygienic milk collection, cleaning of milking equipment, proper implementation of mastitis control programs and refrigeration of the post-milking raw material must be adopted aiming at improving the quality of refrigerated milk.   Key words: Somatic cell count (SCC), total bacterial count (TBC), protein, fat, non fat solids. &nbsp

Quality assessment of raw milk according to type of milking and of conditions of transport and storage

Research on the causes of change in production and milk composition in the primary sector of production, transport and storage are important aspects and serve as a tool for improving the quality of raw materials and dairy products, since the consumer market is more demanding and growing demand. The objective of this paper was to evaluate the quality of milk depending on the type of milking and conditions of transport and storage. Between December 2010 and May 2011, samples were collected fresh milk directly from dairy herds and stored in refrigerated raw milk cooling tanks, insulated tanks and industrial silos. The electronic analysis (SCC, TBC and centesimal composition) were performed at the Laboratory of Milk Quality. It was used for statistical analyzes the statistical package ASSISTAT. The hand milking resulted in raw milk and raw milk refrigerated for best quality, which demonstrated the need to implement measures aimed at improving the hygienic quality of milk milked mechanically. The milk stored in silos industrial TBC showed higher compared to the milk stored in isothermal tank, however, both showed high microbial counts, which suggests the use of storage conditions conducive to microbial proliferation, inappropriate hygiene procedures and equipment of temperature and time above the storage required by Brazilian law. Produce raw material quality, according to current standards, resulting in higher yield and quality of dairy products, a situation that benefits industry and consumers.

Transient natural convection and heat transfer during the storage of granular media

Transient heat transfer in an originally isothermal cylinder filled with a porous medium after sudden change of wall temperature is studied experimentally and computationally. Lab-scale experiments with water as the interstitial fluid are used in order to imitate the conditions prevailing in large, air-filled industrial silos. The proposed model assumes isotropy of the porous medium, local thermal equilibrium between the phases, Darcy flow and applicability of the Boussinesq approximation. Its predictions are in satisfactory agreement with the experimental results. Simulations reveal the role of dimensionless parameters like the modified porous media Rayleigh number and the cylinder aspect ratio. A criterion for neglecting the influence of natural convection on heat transfer is established.

Theoretical and experimental testing of a scaling rule for air current segregation of alumina powder in cylindrical silos

Air current segregation (ACS) is one segregation phenomenon that has been identified to contribute significantly to the separation of fines (particles < 42 µm) from coarse material during the filling of industrial silos. This paper describes investigations of ACS for alumina powder based on experiments conducted in an industrial silo, in the laboratory and by computation, using the commercial computational fluid dynamics code Fluent. For the industrial silo, the extent of ACS has been measured using the accumulation of fine material at the wall as an indicator. Based on these results, modifications to the feeding system were undertaken which showed that ACS is promoted if the material is fed in a dilute form. Experiments in the laboratory confirmed this effect visually. In order to be able to compare numerically the extend of ACS, a segregation index has been developed. It was found that a dilute particle jet leads to more ACS than dense particle jet. The effects of solids feeding rate and air extraction rate on ACS have been investigated in the laboratory silo and the results clearly show that low solids feeding rates promote ACS. It was further found that an increase in the air extraction rate has a mild effect in suppressing ACS. These effects were confirmed by the Fluent simulations, which showed an unexpectedly good agreement with the experiments.

Partitioned Distinct Element Method Simulation of Granular Flow within Industrial Silos

A method for performing discrete element simulations of granular flow and pressures within industrial silos is presented. Special attention is devoted to complex problems involving large numbers of particles and sophisticated boundary conditions due to the presence of inserts. The proposed method consists of partitioning the silo into layers that are analyzed sequentially, and in determining stresses and velocities at the virtual interlayer boundaries. The method is first validated by simulating the discharge of a single insert hopper containing 20,000 particles, performing both a simulation of the whole silo and a multilayer partition. The results show a small discrepancy in the displacement fields produced by the two simulations. Then the discharge of an industrial silo containing 170,000 particles with several inserts of different size and shape is simulated. The relevance of the stress and velocity fields obtained confirms the feasibility and the efficiency of the procedure. The method allows for managing huge numbers of particles with a limited memory capacity and a gain of computational time that may be significant depending on each particular case.

Systems for electrostatic evaluation in industrial silos

AbstractWhile a primary strategy for avoiding ignition during silos filling lies in control of the ignition energy of the suspension, it may also be possible to control the energy of on‐bed brush discharges created during filling. Two instrument systems are described for investigations in operational, full‐scale process equipment. A discussion is made of the effective energies of brush discharges, the effects of process variables on static, and types of charge neutralizer that have been used or proposed. The instrument systems allow pragmatic, in‐plant evaluation of the effects of process variables and the benefits of any charge neutralizer system that is used.