Materials In Bins Research Articles

Would You Like Wood or Plastic? Bin Material, Sanitation Treatments, and Bin Inoculum Levels Impact Blue Mold Decay of Stored Apple Fruit.

Blue mold, caused primarily by Penicillium expansum, is a significant postharvest disease of apples. It not only causes economic losses but also produces mycotoxins that contaminate processed fruit products, which contributes to food waste and loss. Previous research has shown that packing and storage bins harbor Penicillium spores and that steam and hot water efficiently reduce spore inoculum levels. However, studies using wooden and plastic bins regarding their ability to harbor spores, the effect of chemical sanitation treatments on spore levels, and the impact of rinsate from treated bins on apple fruit decay have not been investigated for the Mid-Atlantic area (Okull et al. 2006; Rosenberger 2009). We evaluated different sanitation treatments (chemical and physical) to reduce P. expansum inoculum levels on wooden and plastic bins. We determined that wooden bins bound P. expansum spores four orders of magnitude higher than plastic. When both bin types were treated with steam (wooden) or sterile hot water (plastic), Thyme Guard, or Academy, all treatments resulted in significantly (P < 0.05) lower spore levels compared to untreated controls. Although, plastic bins retained lower numbers of spores after inoculation with contaminated spore rinsate and required much higher concentrations of P. expansum spores in rinsate to retain spores at levels that would lead to decay on apple fruit. Overall, we demonstrated that plastic bins retain fewer spores than wooden bins and that both can be sanitized by various physical or chemical treatments. We envision that our findings will be applicable in the future as the techniques implemented in this study were used to investigate industry-relevant questions. Our goal is that the research techniques and findings become feasible with advancements in technology and/or accompany other shifts in existing processes in commercial pome fruit packing and storage facilities.

Abrasion wear resistance of wall lining materials in bins and chutes during iron ore mining

The wear problem on the internal lining of bins and chutes needs to be addressed before any significant efficiency gains during iron ore mining operations. This study aims to investigate the factors determining the wear resistance of common lining materials used in iron ore mining operations. A purposely designed experimental system was utilised to quantitatively assess the wear resistance of a suite of wall lining materials against an iron ore abrading medium, from which a wear rate for each liner is determined. Results suggested that the hardness of a lining material can be utilised to indicate its abrasion wear resistance. From experimental results, prediction models of the service life of selected lining materials in bins and chutes are also obtained.

Pack Factor Measurements for Corn in Grain Storage Bins

Shelled yellow corn is commonly stored in concrete or corrugated steel bins. Granular materials compact under their own weight, primarily due to particle rearrangement, leading to an increase in bulk density and a change in volume when stored. Reliable grain pack factors are needed to estimate storage capacities and to accurately monitor grain inventories. A science-based model (WPACKING) of pack factors is available that uses the differential form of Janssen’s equation and takes into account the variation in density caused by pressure variation with height and moisture content of the grain and accounts for the effects of grain type, test weight, bin geometry, and bin material. However, this model needs to be compared to field data over a wide range of conditions to ensure robust prediction accuracy. The objective of this research was to determine the field pack factors and bin capacities for on-farm and commercial bins used to store corn in the U.S. and compare them to predictions of the WPACKING program. Bin inventory measurements were conducted in concrete bins with depths up to 31.4 m (114.8 ft) and corrugated steel bins with diameters up to 32.8 m (156 ft). These values were also compared to the techniques used by the USDA Risk Management Agency (RMA) and the USDA Farm Service Agency, Warehouse Branch (FSA-W). The differences between predicted and reported mass were -4.54% (maximum underprediction) to +4.53% (maximum overprediction) for WPACKING, -2.69% to 4.97% for the RMA method, and -3.33% to + 5.67% for the FSA-W method. The absolute average difference was lowest for the WPACKING model (0.90%) compared to the RMA and FSA-W methods (1.61% and 1.86%, respectively). WPACKING had less than half as many prediction differences above 1% (13 out of 51 bins) as did the RMA and FSA-W methods, which had 29 out of 51 and 33 out of 51, respectively. The RMA and FSA-W methods do not take into account the variations in pack factor due to bin type and moisture content of the stored grain.

Top Charging Car Automatic Control System Based on PLC

In view of the furnace top charging car ore bin automatic distributing problems, This article puts forward a kind of high reliability, stable performance of automatic material distributing control system ,The system uses wireless communication technology、Ore bin material level detection technology and High reliability of PLC control technology, Achieving material distributing car accords to the need of ore bin for charging, Making material distributing more rational and effective, reduce labor intensity and improve the level of automation for production.`

A method to detect diphenylamine contamination of apple fruit and storages using headspace solid phase micro-extraction and gas chromatography/mass spectroscopy

Analysis of headspace concentrations of diphenylamine using solid phase micro-extraction (SPME) was examined for its suitability to detect DPA contamination and off-gassing in apple (Malus domestica) fruit, storage rooms and storage materials. Four SPME fibre coatings including polydimethylsiloxane (PDMS, 100μm), PDMS/divinylbenzene (PDMS/DVB), Polyacrylate (PA) and PDMS 7μm were evaluated. The average limits of detection and of quantification for head space DPA ranged from 0.13 to 0.72μgL−1 and 0.42 to 2.35μgL−1, respectively. Polyacrylate was identified to be the most suitable and compatible fibre for DPA analysis in apple samples, because of its high sensitivity to DPA and low fruit volatile interferences. SPME techniques were further applied to study contamination of DPA in apples, storage rooms and packaging materials. DPA was found in the air of storage rooms containing apples that were not treated with DPA. Wood and plastic bin material, bin liners, and foam insulation all adsorbed and off-gassed DPA and could be potential sources of contamination of untreated apples.

CFD-Based Analysis of 1-MCP Distribution in Commercial Cool Store Rooms: Porous Medium Model Application

1-Methylcyclopropene (1-MCP) is a synthetic plant growth regulator used commercially to delay ripening of fruits. 1-MCP (SmartFreshTM) is applied in gaseous form (as a fumigant) in the cool store room. This paper uses a porous medium computational fluid dynamics model to numerically analyze the distribution of 1-MCP in cool store rooms for apple fruit. The effects of air circulation, room shape, and bin material were investigated. Dose calculation based on filling density was explored. The 1-MCP distribution in commercial cool stores, under room cooling condition, was uniform irrespective of room shape. Rooms filled with fruit in wooden bins deplete 25 % more of the active substance than rooms filled with fruit in plastic bins. The calculated dose increases linearly with the amount of fruit in the cool store (filling density). Hence, this study suggests that dose prescription based on filling density is feasible.

DEPLETION OF 1-MCP BY 'NON-TARGET' MATERIALS DURING STORAGE

We tested the sorptive capacity of a number of non-target materials found in apple (Malus × domestica Borkh.) storage rooms on their capacity to remove 1-MCP from the storage atmosphere and thereby compete with the fruit for the active compound. Further, we evaluated the impact of temperature and moisture. Non-target materials included bin construction materials [high density polyethylene (HDPE), polypropylene (PP), weathered oak, non-weathered oak (Quercus sp.), plywood, and cardboard] and wall construction materials (polyurethane foam and cellulose-based fire retardant). Each piece had an external surface area of 76.9 cm 2 . We placed our 'non-target' materials in 1-L mason jars and added 1-MCP gas to the headspace at an initial concentration of approximately 30 μl·L -1 . Gas concentrations were measured after 2, 4, 6, 8, 10 and 24 h. The concentration of 1-MCP in empty jars was stable for the 24-h holding period. Little to no sorption was detected in jars containing dry samples of HDPE, PP, cardboard, polyurethane foam, or fire retardant. Inclusion of plywood, non-weathered oak, and weathered oak lead to a loss of 10, 55, and 75 percent of the 1-MCP after 24 hours. Using dampened materials, no sorption resulted from the inclusion of HDPE, PP, polyurethane foam, or the fire retardant. However, the rate of sorption of 1-MCP by dampened cardboard, plywood, weathered oak, and non-weathered oak increased markedly, resulting in a depletion of approximately 98, 70, 98 and 98 percent, respectively. For oak bin material, the rate of sorption was not impacted by temperature, and increasing the surface area by approximately 100% only marginally increased the rate of sorption. When dampened oak bin material was included with apple fruit in a proportion similar to that found in fruit storage, 80% depletion occurred in 5 hours compared to approximately 24 hours for fruit alone. The data suggest that in situations where 1-MCP levels can be compromised by wooden and cardboard bin and bin liner materials, but not by plastic bin materials or typical wall construction.

Effectiveness of 1-MCP treatments on ‘Bartlett’ pears as influenced by the cooling method and the bin material

Wooden bin-stored ‘Bartlett’ pears ( Pyrus communis L.) were hydrocooled (HC) or forced-air cooled (FAC) and immediately treated or not with 1-methylcyclopropene (1-MCP) for 24 h. 1-MCP gas concentrations used were 0, 0.3 or 0.6 μL L −1 (called 0, 0.3 and 0.6, respectively). Fruit were subsequently kept at 20 °C for 20 d or stored at −0.5 °C and 95% RH for 60, 90, 120 or 150 d. After cold storage, fruit were kept at 20 °C for up to 16 d for further ripening. In another experiment, pears stored in wooden bins (W) or plastic bins (P) were all hydrocooled, treated or not with 0.5 μL L −1 1-MCP (called 0.5 and 0, respectively), stored at −0.5 °C and 95% RH for 0, 30, 60, 90 or 120 d, and transferred to 20 °C for further ripening. In FAC pears, increasing 1-MCP concentrations usually resulted in delayed increases in ethylene production and lower ethylene production rates, as well as delayed softening. In contrast, HC-0.3 pear firmness did not differ from that of HC-0 fruit after cold storage. Generally, HC-0.3 pears displayed higher ethylene production and lower firmness values than FAC-0.3 pears after a 7-d exposure to 20 °C, regardless the length of cold storage. FAC-0.6 pears always showed lower ethylene production rates and higher flesh firmness values than HC-0.6 fruit. Soluble solids concentration was not consistently affected by 1-MCP. FAC-0.3 and HC-0.6 fruit showed higher titratable acidity values than HC-0 fruit after 0, 60, 120 and 150 d of cold storage plus 7 d at 20 °C. Effectiveness of 1-MCP treatments on HC pears was influenced by the bin material; P-0.5 pears were firmer than W-0.5 pears after 7 d at 20 °C, regardless the length of the cold storage. HC-0.5 fruit exposed to −0.5 °C for 90 d reached eating quality (firmness ≤23 N) by day 7 if placed in W, and by day 21 when stored in P. Results and previous evidence suggest that wet wooden bin material may represent a major though unpredictable source of 1-MCP sorption that could bind a significant percentage of the 1-MCP applied. When used at relatively low doses 1-MCP partial removal by wet wooden bins can compromise the application effectiveness for controlling ethylene action.

Depletion of 1-MCP by ‘non-target’ materials from fruit storage facilities

The sorption of 1-methylcyclopropene (1-MCP) by a number of ‘non-target’ materials found in apple ( Malus × domestica Borkh.) and pear ( Pyrus communis L.) fruit storages was measured as a function of time, temperature, and moisture content. Materials included bin construction materials [high density polyethylene (HDPE), polypropylene (PP), extensively- and slightly-weathered oak ( Quercus sp.), weathered fir ( Abies sp.) plywood, and cardboard] and wall surface materials (polyurethane foam and cellulose-based fire retardant). Bin construction materials test pieces had an external surface area of 180 cm 2. We placed ‘non-target’ materials in 1-l glass jars and added 1-MCP gas to the headspace at an initial concentration of approximately 30 μl l −1. Gas concentrations were measured after 2, 4, 6, 8, 10, and 24 h. The concentration of 1-MCP in empty jars was stable for the 24-h holding period. There was little to no sorption by HDPE, PP, polyurethane foam, or fire retardant. However, plywood, cardboard, slightly-weathered oak, and extensively-weathered oak absorbed 16, 18, 55, and 75% of the 1-MCP after 24 h. Moistening the test material increased the rate of sorption of 1-MCP for cardboard, plywood, weathered oak, and non-weathered oak, resulting in a depletion of approximately 98, 70, 98, and 98%, respectively, in 24 h. For oak bin material, the rate of sorption was not impacted by temperature and increasing the surface area by approximately 100% only marginally increased the rate of sorption. When moistened oak bin material was included with apple fruit in a proportion similar to that found in fruit storage, 90% depletion occurred in 6 h compared to approximately 80% in 24 h for fruit alone. The data suggest that 1-MCP levels can be compromised by wooden and cardboard bin and bin liner materials, but not by plastic bin materials or wall surface materials commonly used in Michigan.

Contamination of Apple Fruit with Diphenylamine During Storage

Apple fruit are treatmented with diphenylamine (DPA) in the form of a postharvest dip to prevent the development of storage scald. However, DPA residues have been detected on apples not treated with DPA, which is problematic in markets where DPA residues are not acceptable. The objective of this study was to identify sources of DPA contamination and evaluate the effectiveness of ozone to reduce contamination. Concentrations of DPA in the atmosphere of commercial storage rooms was monitored during the storage season and the adsorption of DPA onto wood and plastic bin material, plastic bin liners, foam insulation, and apple fruit was assessed. DPA was sampled from headspace with solid phase micro extraction using 65 μm polyacrylate micro fibers and analyzed using GC-MS. The effectiveness of gaseous treatments of 300 and 800 ppb ozone to reduce DPA contamination on apple fruit and bin material was also determined. DPA was found to volatilize from treated apples and bins into the storage room air, where it was adsorbed onto storage room walls, bins, bin liners and other fruit. DPA was found in the atmosphere of storage rooms containing apples that were not treated with DPA. Wood and plastic bin material, bin liners, and foam insulation all had a high affinity for DPA and were determined to be potential sources of contamination. Ozone reacted with DPA and following gaseous ozone treatments, off-gassing of DPA from wood and plastic bin material and bin liners was reduced. However, ozone was not effective in removing all DPA in contaminated materials and was ineffective in removing DPA from contaminated apples. Due to the pervasive and persistent nature of DPA, fruit should be handled and stored in facilities where DPA is not used to prevent contamination of fruit.

Grain Bin Loads as Affected by Grain Moisture Content and Vertical Pressure

ABSTRACT A computer technique has been developed to esti-mate the wall pressures and average bulk densities of materials in bins. The Janssen approach is utilized where the material properties and k-values are allowed to vary within the bin as functions of the vertical pressure on the material and the moisture content.

Stresses developed by cohesionless granular materials in bins

This paper is concerned with the determination of stresses developed by a cohesionless granular material obeying a Mohr-Coulomb yield criterion during slow continuous mass flow in bins and hoppers. Exact numerical solutions for the stress fields are obtained by the method of characteristics for several bin configurations. A simpler but more approximate approach based upon the method of integral relations is developed. The simpler integral method has the advantage that it can average through stress discontinuities, thus circumventing the difficulties arising in the exact method of characteristics. Good agreement is found between the simple integral analysis and exact numerical computations for the stress fields.

Stress discontinuities in cohesionless particulate materials

In the examination of problems concerned with limit equilibrium, situations arise where abrupt changes in stresses occur in the stress field. These are conveniently idealized as discontinuity surfaces. In this paper the cohesionless particulate material is assumed to obey a Mohr-Coulomb yield criterion and consideration is given to a particular quasi-static situation of a moving retaining wall. The boundary conditions are chosen such that the existence of a stress discontinuity surface is necessary in order to satisfy the static equilibrium equations within the context of the limit equilibrium analysis. The problem is analogous to one encountered in connection with the mass flow of cohesionless granular materials in bins. Solutions for the stress field are obtained. Experimental observations of the failure surfaces generated in glass beads and sand are compared and found to be in agreement with the predicted slip lines.

Flow Patterns of Granular Materials in Flat-Bottom Bins

Bins with flat bottoms and multiple openings are commonly used in industry to store granular solids because of their lower cost and because they occupy smaller vertical space than bins with a singular hopper outlet. However, in many flat-bottom bins the live capacity is much smaller than the bin volume because the spacing of openings does not permit the flow patterns above the openings to intersect. A theory has been developed to predict the boundary of the flow patterns that occur in these bins when circular openings are used, and experimental results in a small-scale bin have been found to agree closely with the theory. Boundaries of flow patterns are a function of the effective angle of friction of the material, the diameter of the opening, and the head of material in the bin. In general, the flow patterns expand outward from the edge of the opening, and become almost vertical near the top of the bin. Results of this study make it possible to determine which materials can be satisfactorily stored and which opening designs must be used to achieve adequate live-storage capacity in flat-bottom bins.

Theory of the Formation of Arches in Bins

The flowing of the granular materials in bins is governed, particularly in the case of small ratios of aperture diameter to particle size, by the constant formation and breaking down of arches, known as dynamical arches. In unfavorable circumstances the arches may become stable and the aperture clogged. By building up a mechanical model of the arch the fields have been found in which a stable and a dynamical arch, respectively, may be formed, enabling a bin to be judged with respect to the danger of stable arch formation. A stable field allows of studying the interaction of arch stresses and deformation of materials starting from the stress curve of the arch as a function of the curvature, and from the curve of deformation of the material as a function of the stress. It is, therefore, possible that the elasticity of the material diminishes the stable field or even reduces it to zero. In the case of nonelastic materials, the collapse of the arch may be introduced by making the lower part of the aperture wall elastic. Stable arches can now be prevented from forming by choosing the elasticity of the resilient aperture wall in such a way that if the stress increases the wall expands sufficiently to cause the required collapse. The theory underlying this solution enables the elasticity constant and the required expansion to be calculated.

Gravity Flows of Ideally Plastic Materials Through Slots

Experimental evidence shows that plasticity theory is a suitable framework for analyzing the flow of bulk materials in bins and hoppers. It thus serves as a rational guide for the collection of requisite design data including the distribution of stress and velocity throughout the moving mass of material.