Pneumatic Feeding System Research Articles

Experimental Evaluation of Mechanical Properties, Thermal Analysis, Morphology, Printability, and Shape Memory Performance of the Novel 3D Printed PETG‐EVA Blends

AbstractPolyethylene terephthalate glycol (PETG) is a novel amorphous shape memory polymer with excellent printability for 4D printing. In this article, ethylene‐vinyl acetate (EVA) is used as a biocompatible and non‐toxic copolymer to improve plasticity and shape memory performance of PETG. PETG‐EVA blends are prepared and 3D printed using a melt mixing method and an upgraded fused deposition modeling (FDM) with a pneumatic feeding system. The results of the thermal analysis show that the blends exhibit two tan‐delta peaks, each related to their components, and morphology images confirm that they are biphasic and immiscible with good compatibility. The morphology of both EVA10 and EVA30 matrix droplets is observed, with the droplets being larger for EVA30. The use of a pneumatic feeding system, along with the ability to control the output melt flow, results in the best printing ability for EVA30, with minimal microholes between the grids and interlayer cracks. The tensile strength of PETG‐EVA blends ranged from 25.38 to 20.14 MPa, with the highest tensile strength achieved for EVA30. The shape memory performance of all three blends is similar; with shape recovery exceeding 90% in 20 s. Blends with higher EVA content exhibited faster shape recovery within the first 10 s.

Polyhydroxyalkanoate production from animal by-products: Development of a pneumatic feeding system for solid fat/protein-emulsions.

Fat-containing animal by-product streams are locally available in large quantities. Depending on their quality, they can be inexpensive substrates for biotechnological processes. To accelerate industrial polyhydroxyalkanoate (PHA) bioplastic production, the development of efficient bioprocesses that are based on animal by-product streams is a promising approach to reduce overall production costs. However, the solid nature of animal by-product streams requires a tailor-made process development. In this study, a fat/protein-emulsion (FPE), which is a by-product stream from industrial-scale pharmaceutical heparin production and of which several hundred tons are available annually, was evaluated for PHA production with Ralstonia eutropha. The FPE was used as the sole source of carbon and nitrogen in shake flask and bioreactor cultivations. A tailored pneumatic feeding system was built for laboratory bioreactors to facilitate fed-batch cultivations with the solid FPE. The process yielded up to 51 g L-1 cell dry weight containing 71 wt% PHA with a space-time yield of 0.6gPHA L-1 h-1 without using any carbon or nitrogen sources other than FPE. The presented approach highlights the potential of animal by-product stream valorization into PHA and contributes to a transition towards a circular bioeconomy.

Experimental Study on the Stability of Pneumatic Cut Tobacco Feeding System

According to the process performance of cigarette machines system, the device was established to measure the stability of pneumatic cut tobacco feeding system, which was signified as the flow deviation coefficients of branch circuits. The state and process of pneumatic feeding system were simulated respectively by shutting one branch, and then it paid close attention to the changing of flow rates or velocities in other branch circuits. The flow deviation coefficients were calculated with the experimental data, and the results shown that shutting down one branch, the flow deviation coefficients of other branches is always below 12%.The results will do some benefits to the design of cut tobacco pneumatic conveying system in the engineering application.

Pneumatic feeding system for low-temperature deposition manufacturing based on system identification

Low-temperature deposition manufacturing (LDM), which is based on the principles of additive manufacturing, can preserve biological activity by fabricating custom pore-sized three-dimensional (3D) scaffolds. Appropriate extrusion velocity is significant to the fabrication of ideal macro-porous structures, which prevents collapse between layers and over-accumulation of material. This paper: proposes a new pneumatic feeding system consisting of an air source and valves; focuses on combinations of mathematical delay models of the first order and least squares identification; and describes the construction of a model of pressure and extrusion velocity by analysing the process of pneumatic material feeding. Our tests confirmed the time series used to adjust the desired pressure via opening and closing valves to change the feeding velocity using the parameters of our model. Furthermore, we verified that gelatin scaffolds could be formed by LDM, and over-accumulation and decrease overlap had been solved to some extent using our time series.

Feed pellet distribution in a sea cage using pneumatic feeding system with rotor spreader

In modern salmon farming feed is commonly transported to the cages and distributed over the surface by means of a pneumatic conveying system. Airspeed in the feeding system is used to spread the feed, although high airspeed causes pellet breakage. Thus, knowledge about how airspeed affects spreading of feeds of different pellet sizes is necessary in order to optimise the feeding routines at salmon farms.The aim of this study was to describe the surface distribution of feed pellets in sea cages when using a pneumatic feeding system with a rotor spreader. Feeds with three different pellet sizes were used and two different spreader types were tested, both with different orientations of the top unit. The spreader test was carried out with three different airspeeds of the feeding system. The test was carried out in an outdoors square steel cage (24m×24m) with the rotor spreader positioned in the centre of the cage. Styrofoam boxes were used to collect the pellets. The boxes were positioned in a row on each side of the spreader, referred to as two opposite directions. The results showed that the pellets were distributed unevenly over the cage surface. One direction had higher spatial pellet densities and less area covered with feed pellets. The opposite direction showed a more dispersed pattern and longer spreading distance. Depending on airspeed, spreader and tilting of the top unit, between 18% and 80% of the cage surface was covered with feed pellets and spatial pellet densities between 0gm−2 and >200gm−2 were measured. Increasing airspeed gave a longer spreading distance of pellets, measured from the centre. The effect of airspeed was more pronounced for spreader direction with dispersed spreading. Also, with increasing airspeeds the areas with high spatial pellet densities were decreased for both directions, indicating a more uniform spreading with higher airspeeds. The pellet distribution for the different pellet sizes was similar. Spreader type and tilting significantly affected pellet distribution.

The Pneumatic Feeding System of Electrospinning Based on Numerical Simulation and System Identification

Electrospinning, which is a technology to make nano fiber, has quite high requirements of the speed of feeding. In order to solve the unstable phenomenon, salivation, and achieve the stability of quality, numerical simulation is used to compute the nozzle exit pressure and exit velocity, while recursive least squares is used to identify of the results of the simulation. At last, PID algorithm and recursive least squares methods are combined together to form a model for the feeding system controller. And the pneumatic device and pressure sensor are used to build electrospinning feeding system. Finally, experimental verification PEO solution is used to verify this method, no drooling electrospinning phenomenon happens

Analysis of pellet degradation of extruded high energy fish feeds with different physical qualities in a pneumatic feeding system

The aim of the present study was to investigate degradation of three commercial high energy extruded salmonid feeds, differing in physical quality, during pneumatic conveying in a feeding device at different airspeeds (25, 30 and 35ms−1) and feeding rates (9, 18 and 36kgmin−1). The physical quality of the feeds, with a diameter of 12mm, was measured as existing quality, DORIS value, hardness and durability index. Significant differences in the formation of small particles among the feeds were observed during pneumatic conveying. Increasing air speed (ms−1) increased the formation of fractures (particle size 2.4–10mm) and fines (particle size<2.4mm). Increasing the feeding rate (kgmin−1) had the opposite effect, causing a reduction in formation of fracture and fines. Despite the significant differences in physical quality among the diets, no good correlations were found between physical quality parameters and pellet degradation during pneumatic conveying. DORIS value, hardness and durability index could therefore not be used to predict the degradation of pellets during pneumatic conveying.The overall conclusion from the experiment was that the three feeds varied in degradation pattern during pneumatic conveying, and the pellet degradation was highest at high airspeed and at low feeding rate. None of the measured variables for physical feed quality could be used to predict the pellet degradation pattern in the feeding system.