Chang You Li

A Study on Dynamic Simulation of Litchi Pitting Process Based on ANSYS / LS-DYNA

To study the dynamic mechanical changes in litchi pitting process and improve the accuracy of litchi pitting, this paper established a 3-D solid assembly model of litchi, fixture and tool and conducted the finite element discrete of the model by using ANSYS / LS-DYNA software. In addition, the deformations and stress states of litchi’s multi-layer structure under the effects of tool and fixture were simulated and calculated by the LS-DYNA971 solver. The results showed that the deformations and stresses of litchi’s multi-layer structure changed with the increase of cutting depth, and appeared the maximum amplitude out of sync. When the litchi was gonna cut through, the stress amplitude of fruit pulp was the maximum among litchi’s multi-layer structure and the stress amplitude of fruit pulp was the minimum. Pulp would reach its maximum stress when cutting through the litchi, and because of its low strength, the breakage was prone to occur. The stress of fruit stone was large in the initial stage, and big fruit stone was easily led to the breakage for its overlarge stress. In pitting process, the deformation and slippage of litchi would take place with fixture clamping and tool pitting, so this is a complex dynamic deformation process. This study is urgent to make more comprehensive and systematic researches.

The Transformation Properties of Aroma Components in Banana Drying Process

To obtain high-quality dried banana, by means of solid-phase micro-extraction, GC-MS, the total ion chromatogram (TIC) changes with time of banana aroma in different drying stages were analyzed. With searching in NISI Willy Database, the aromatic components of above samples were obtained. By classifying the types of the aroma components, the changes of its total number and the classification of substances were compared. A result was drawn that types of total aroma and its main ingredient changed slightly in its normal drying, and substances of esters had high content and the most species. But while drying to the anhydrous state, the main component material isoamyl butyrate transferred to furfural, and Aldehydes, ketones, furans substances increased significantly. These changes were associated with the physical diffusion of material components, biochemical synthesis and chemical decomposition. The results provide a basis for high-quality and high-efficiency banana dryer design.

Intermittent Microwave Drying of Litchi: Drying Kinetics and Quality Formation in Color Difference

In order to reveal the characteristics of thermal transmission and drying quality on the litchi’s multilayer structure, the peel and flesh that separated from fresh fruit were dried with the whole fruit by microwave radiation in three kinds of tempering intermittent HT0101, HT0505 and HT1010. Their characteristics of dehydration and the changes of color difference in drying process were compared. The results showed that microwave drying had influences on the capability of dehydration and the quality of color difference in different interval. The influence of HT0505 was more significant, while the other two conditions, in which there were only a small amplitude of cross and fluctuation, were approximate. In the same conditions of microwave drying, the capability of dehydration of peel and flesh separated was better than that of whole fruit, and the dehydration speed of peel was the fastest. As to color difference, the changes of peel and whole fruit were smaller and much easily to tend to stable. The change of the color difference on the flesh was obvious and finally tended to stable. The further research still needed the further study on biochemical effect during the transformation of quality.

A Parting Surface Design of Multi-Cavity Mold Based on Pro/E Surface Technique

Parting surface design is the key to mold design. Taking mold design of a component as an example, this paper introduces the implementation of a parting surface design of complex multi-cavity mold supported by the surface technique of Pro/E software.

Banana Microstructure Changes during Oven Drying Process

To learn about banana microstructure changes on affecting moisture dehydration performance and its quality during oven drying process, this experiment chose scanning electron microscopy to observe the microstructure changes on outer surface, inner surface and cross section of banana peel and its flesh during drying process, in order to examine the relationship between dehydration performance and its microstructure shape and microstructure pore structures changes. The results showed that during drying process, all surfaces of banana peel and its flesh endured shape deformation from regularly to irregularly. Microstructure shrank evenly in beginning, while became conglomerate later, appeared to be significantly distortion and breakage. Microstructure pore quantity and area showed great changes, those average diameter over 10um pore numbers increased steadily, while pore area just reduced in beginning and then increased rapidly afterwards. As banana microstructure shape and pore shrinkage and deformation increased greatly, which also increased the resistance of moisture evaporating greatly. This may be an important reason that cause banana drying speed and quality decreased, it is an urgent problem that needs to be solved during fruit and vegetable drying process and storage.

Research on the Highly Energy-Efficient Conversion and Utilization Path of Solar Energy Demand Type

In order to promote the highly energy-efficiency utilization level of solar energy demand type, this paper, based on the average radiation within the solar radiation spectrum range and application requirement analysis of quantum theory, investigated the technical bottleneck and solution on the highly energy-efficient storage and conversion of solar energy demand type. Studies showed that the key to highly energy-efficiency utilization was to synthetically promote the utilization rate of energy conversion in each solar area. It could make direct conversion and utilization of solar energy in accordance with easy-preserved type foods, electrical power, fuel and other forms of energy demand, and then conversion route of energy utilization could be cut down and energy losses in the process of transmission could be decreased. Making full use of energy of solar spectrum visible light area to increase the plant photosynthesis, or using catalysis to change the Fermi lever and minimum work function of photocell battery module stripping to strengthen the photo electricity conversion rate could further enhance the conversion rate of highly-efficiency utilization of solar energy demand type. The study was involving multi-field of knowledge, and still need to be integrated innovation with further theoretical research.

Diffusion Model of Heavy Metal Loss in Mining Area and its High Efficient Prevention and Cure

In order to high efficiently prevent and cure the diffusion of heavy metal loss in mining area, this paper investigated the main ways of heavy metal loss, built the diffusion model of its non-steady-state and uniform loss, and solved the model by integration, a time-varying function on the path of heavy metal loss which diffused into soil and runoff waters in the mine area was acquired, and a method of efficient prevention and cure was obtained. The results shows that the continuous existence of heavy metal in the mining area will aggravate and increase the regional pollution of soil and runoff waters, among them, the diffusion speed of heavy metal loss dissolved into runoff waters due to soil erosion in mining area will be faster and the hazard will be lager, there exists a high pollution concentration in the estuarine of new waters which the runoff flowed into. The effective recovery of heavy metal residue and waste liquid in mining area, and the decrease of discharge concentration is the important ways to effectively reduce the improvement costs of heavy metal pollution area and improve the harnessing effect, if further combing the restorations of engineering plants and bacteria improvement for heavy metal polluted area, which would be more efficient and rapid, and suitable for research and spread.

Sampling Device for Grain Moisture on-Line Inspection

Concerning the nonuniformity problem when sampling in current single grain moisture on-line inspection devices, this paper designed a new grain sampling device by analysing the physical property parameters of grains. The design of the sampling device is optimized by combining computer mode and physical experiments. In condition of ensuring single grain sampling, fixed the structure parameters of sampling rollers for South grains and North-east grains. The structure parameters of South grain sampling roller groove is length 18mm, width 2.5mm, depth 3mm. The structure parameters of North-east grain sampling roller groove is length 15mm, width 4mm, depth 4mm.

Research on Corn Drying Process under Temperature Gradient

Using a special Test-Bed, the temperature and the grain moisture content variation in different locations was measured continuously, under the condition of maintaining a large temperature difference between two terminals of grain layer. The results show that the temperature gradient can enhance corn-drying process, and there are two modes of the promotion: 1. The temperature difference direct drive the moisture migration; 2. The temperature difference can generate air convection, and accordingly promote the drying rate. However, the speed of moisture migration originated from air convection was much higher than driven by temperature gradient.

Application of Wireless Data Transmission Technique in Drying Equipment

The application of online detection technology for grain moisture is one of the most effective ways to improve the quality of grain drying. The online detection system for grain moisture consists of three parts: online remote module of ingoing grain moisture (charging), online remote module of outgoing grain moisture (discharging), and the host controller. It adopts JZ873 wireless transparent transmission module to realize the wireless data communication among various modules, and to formulate the communication drive. In practice, this system has characteristics such as flexible use, reliable data transmission, and it is more suitable for those testing and control conditions where it is inconvenient to wiring.