Length Of Tray Research Articles

Evaluating the influence of wrapping turns for a new packaging method called sustainable specific suspension (3S) packaging

3S packaging, which stands for sustainable specific suspension packaging, wraps a product on a piece of cardboard using stretch wrap film. This cardboard is then folded and slipped into a box. The product is protected on all six sides by air if impact forces occur. This research focuses on the number of wraps needed to keep the peak acceleration lower than the maximum acceleration that can be tolerated by the product. A new test method is presented, based on existing drop test methods. It is shown that the protection in one specific shock direction (perpendicular to the tray length) is much more affected by the number of wraps than the other, lengthwise, direction. This allows for a focus on that direction when optimizing the number of wraps. The variation in the measured acceleration peaks and the sudden change in acceleration indicate that the package has reached the protection limits and contact is made between the object and the enveloping cardboard box. Combined with the required degree of protection, one can evaluate whether the object is sufficiently protected.

Effects of press-forming parameters on the dimensional stability of paperboard trays

The dimensional stability of press-formed paperboard trays was investigated during heating and cooling of trays packed with oatmeal. Female mold tool temperature, dwell time, pressing force, and blank holding force were altered in the press-forming of the trays to observe their impacts on the dimensional stability. Dimensional measurements of the trays showed reduced tray width, and the trays exhibited distortions on the tray flange and outer wall. The results showed smaller effects on the tray length, parallel to the machine direction of the material. Improved dimensional stability of the trays was found with a 180 °C female mold tool temperature, a 600-ms dwell time, a 150-kN pressing force, and a 1.44-kN blank holding force. The optimal press-forming parameters were concluded to enhance bonding of the paperboard fibers during the press-forming. The optimization of the press-forming parameters was found necessary to reduce the observed negative response of the material to the challenging environmental conditions in the production of prepared food.

CFD supported performance analysis of an innovative biomass dryer

Abstract In this work, the thermo-fluid performance of a biomass drying chamber with innovative tray configurations has been numerically investigated by solving the governing equations of mass, momentum, energy, and turbulence using Fluent 17. The effect of tray number, tray length, tray arrangement, and hole arrangement on the tray surface has been examined in detail. An enhancement factor has been presented to account for the heat transfer and the associated pressure drop. The results show that both the heat transfer and the pressure drop increase with an increase in tray number and optimum tray number is decided based on the highest enhancement factor. Six different tray arrangements have been examined and it has been found that alternative packed side and rear-front walls arrangement of trays is most effective from the thermo-fluid performance point of view. Based on the hole arrangement investigation, it has been revealed that compared to the inline hole arrangement, the staggered arrangement resulted in higher heat transfer performance with almost no addition to pressure drop. Correlations have been developed to predict the enhancement factor for different tray lengths, tray numbers, and inline and staggered hole arrangements, which help design an efficient and economic biomass drying chamber.

Експериментальні дослідження розподілу питомого завантаження суміші по площі нахиленого лотка

The regularities of specific loading distribution of loose mixture on the area of a working surface of the inclined tray are established in the work. The studies were performed on the experimental setup consisting of a storage hopper and inclined flat trays of different lengths. The material of the study was a grain mixture of winter wheat variety "Myronivska 30". The magnitude of the load was determined using a receiving device, which allowed to obtain the specific load distribution on the width and length of the tray and over time. The specific loading of the tray is uneven in the area of the working surface: the central section is overloaded, and the wall is underloaded. The largest deviations of the specific load at the inlet of the tray, but with length they decrease, approaching a uniform distribution. The specific load profile across the width of the tray is asymmetric and has a local extremum. As the tray length increases, at the certain initial speed and angle, the specific load decreases and the mixture flow slows down. With a constant supply of material from the hopper, there is a gradual accumulation of the mixture in the tray, compaction and growth of the layer, which leads to complete cessation of flow. Uneven loading of the tray occurs due to uneven supply of material from the storage hopper, in which the movement begins. The initial feed varies across the width of the tray and over time, and the nature of the specific load profile formed at the entrance to the tray is preserved for almost its entire length. The movement of the mixture flow in the inclined tray is non-stationary, the specific load varies significantly over the entire surface area and largely depends on the initial conditions of movement. The obtained regularities of specific loading on the working surface area of the tray can be used in the calculation of the modes of loose mixtures movement and substantiation of the equipment parameters for loading the working bodies of machines.

Ex vivo performance comparison of three percutaneous biopsy needle systems.

The aim of this study is to identify the micro-mechanical characteristics that define biopsy performance in normal ex vivo animal organs. Three biopsy systems with differences of needle external diameter, tray height and effective tray length were assessed. Sampling was performed in porcine liver and kidneys with commercially labelled 14G, 16G and 18G, using 2-cm throw needle systems. Five samples were obtained per needle size and per organ, and the experiment was repeated twice for a total of 90 biopsy cores. Samples were analysed and compared in terms of macroscopic aspect, sample length, weight and tissue architecture. The system with the longest effective needle tray (system A) has shown significant superiority (p < 0.001) versus the other systems regarding the mean weight of tissue obtained for all needle sizes. Furthermore, the 14G needle of system A has shown superiority regarding the number of portal spaces and the 16G regarding the length of kidney fragments obtained. The outcomes obtained with the different biopsy systems were not equal. The micro-mechanical characteristic that appears to influence the quantity and quality of the obtained tissue is the effective needle tray length and not the needle external diameter or the needle tray height. This information should be taken into account in the future design of biopsy needle systems, particularly when potentially used in the assessment of biomarkers and the characterisation of tumour micro-environment. • The amount of obtained tissue mass is not the same among percutaneous biopsy needle systems. • There are different micro-mechanical characteristics that condition the amount of obtained tissue. • The micro-mechanical characteristic that offers more tissue mass for the same calibre is the effective length of the needle tray.

Hybrid centrifugal spreading model to study the fertiliser spatial distribution and its assessment using the transverse coefficient of variation

Studying centrifugal spreading by carrying out field or in-door experiments using fertiliser collection trays is tedious and labour intensive. This is particularly true when several implementation methods need to be compared, numerous replications are required or fertiliser sample characterisation is required. To circumvent cumbersome experiments, an alternative approach consists in performing in silico studies. In order to reach this objective, a hybrid centrifugal spreading model is designed by combining theoretical fertiliser motion equations with statistical information. The use of experimental measurements to characterise fertiliser properties, outlet velocity, angular mass flow distribution and spread pattern deposition, ensure a realistic calibration of the model. Based on this model, static spread patterns and transverse distributions are computed for a virtual twin-disc spreader. The number of fertiliser granules used to compute a spread pattern is deduced from the target application rate while the granule properties and their motion parameters are randomly selected from pre-established statistical distributions. This Monte Carlo process reproduces the random variability of fertiliser spread pattern depositions. Using this model, simulations demonstrate the mean and standard deviation of CV value decrease with the application rate. The CV mean value also decreases with the collection tray surface, while the standard deviation decreases with the collection tray length. Mathematical relationships are deduced from simulation results to express the mean and standard deviation of the CV as functions of the application rate and collection tray surface or length. The simulation model is also used to compare spreader test methods and study the influence of some fertiliser particles properties on the transverse distribution.

Set point identification of a tribocharging process for mixed granular solids

Identification of the optimal operating conditions is a critical issue for the industrial application of tribocharging techniques. The aim of this paper is to formulate a set of recommendations regarding the choice of tray length, vibration amplitude and material feed-rate values for a vibratory-type tribocharger. The study was carried out on a laboratory vibratory feeder with granular plastics originating from waste electrical and electronic equipment. Several one-factor-at-a-time experiments followed by a composite factorial experiment were performed based on a two-step strategy: 1) identifying the domain of variation of the controlled variables; 2) finding the best choice of the set point.

Distortion analysis of pulsed terahertz signal measured with spectral-encoding technique

The principle of the spectral-encoding technique, one of the single-shot techniques for measurement of arbitrary pulsed terahertz (THz) signals, or T-rays, is demonstrated theoretically and through simulation. For single-cycle input THz pulse (bipolar wave form), THz signal could be retrieved faithfully under certain conditions, while for the multicycle input case, the THz signal cannot be retrieved without any distortion. However, there is an optimal length of the chirped-probe-pulse, corresponding to the characteristic time of the multicycle THz field, to minimize the distortion in the retrieved THz signal. Three main possible sources of distortions from both bipolar and multicycle THz signals are analyzed systematically. The first distortion originates from the mismatch of the optimal duration Tco of the chirped-probe-pulse and the T-ray length T. The second one is relevant to the spectrum bandwidth of the probe pulse. The third one occurs when the modulation depth k⪡1 is not satisfied. It comes from the neglect of the quadratic term of the modulation depth k, which reflects the strength of the THz signal in the retrieving process. Possible strategies are proposed to reduce these distortions.

CFD Simulation of Hydraulics of Sieve Trays with Gas Mal-Distribution

A transient three-dimensional, two-fluid computational fluid dynamics (CFD) model is developed in the Eulerian framework to predict the hydraulics of sieve trays, especially with gas maldistribution. For this purpose, an algorithm is developed to explain the hole-gas velocity and pressure drop terms along the liquid flow path length. An important modification to the previous CFD works is the use of variable, position dependent, gas superficial velocity for calculation of interphase drag term along the tray. The flow path length of tray was divided into a number of sections; gas-superficial velocity, hydraulic parameters and drag coefficient were obtained for each section. This modification has an important effect on the simulation results and causes faster convergence and better predictions of tray hydraulics. The results are in good agreement with experimental data. Model results obtained in this study have revealed that the effect of hydraulic gradient is significant for high liquid path length and may create non-uniform gas flow. This paper describes how the inlet flow maldistributions can be included in CFD simulation of sieve trays. The results of simulations with non-uniform gas velocity distributions are presented, and compared against experimental data from literature. The results are in good agreement with experimental data.