Ran Qiu Zhang

Bio: Ran Qiu Zhang is an academic researcher from Fudan University. The author has contributed to research in topics: Signal processing & Signal conditioning. The author has an hindex of 1, co-authored 1 publications receiving 59 citations.

On-line continuous measurement of particle size using electrostatic sensors

Abstract: The development of a reliable, cost-effective instrument for on-line particle sizing remains a challenging area worldwide. This paper presents the design and evaluation of a new electrostatic sensor combined with a novel digital signal processing algorithm for the on-line continuous measurement of the mass median size of particles in a dilute-phase pneumatic suspension. Key design aspects of the constituent elements of the sensor, including a wire-mesh electrode, signal conditioning electronics and digital signal processing algorithm are described. Experimental results obtained using a typical range of particulate materials demonstrate that, under constant mass flow conditions, the processed output of the sensor is capable of indicating the mass median particle size with a relative error no greater than 15%. A critical appraisal of the technique, including advantages and limitations, is also included.

Recent Developments in Smart Drying Technology

Abstract: With advances in computer, control, and sensing technologies, it is now possible to design smart dryers for certain products. In this article, a generalized definition of smart (or intelligent) drying technology is proposed and discussed. Recent developments in smart drying technology for fresh foods are reviewed. Such technology can be cost-effective in detecting and monitoring various food quality parameters which vary with time of the drying process, thus controlling the conditions of drying and producing high-quality products. Some important categories of smart drying technology are listed and discussed; these include biomimetic systems, computer vision technology, microwave dielectric spectroscopy, near infrared reflectance (NIR) spectroscopy, magnetic resonance imaging (MRI), ultrasonic techniques, electrostatic sensor technology, and control systems for the drying environment. Several applications of these smart drying technologies are analyzed. Key factors leading to the success of smart drying te...

Characterization of Electrostatic Sensors for Flow Measurement of Particulate Solids in Square-Shaped Pneumatic Conveying Pipelines

Abstract: Theoretical analysis of an electrostatic sensor with square-shaped electrodes for installation on a pneumatic conveying pipeline is reported in this paper. In comparison with ring-shaped ones, the square-shaped electrodes are more difficult to analyze because of the four sharp corners. Based on a mathematical model of the electrostatic sensor, induced charge on the electrode and hence the induced current are derived. Sensitivity distribution and frequency response of the sensor are consequently identified. Additionally, effects of the geometric dimensions and attributes of charged particles on the characteristics of the sensor are investigated. Experimental work was performed on a purpose-built particle flow test rig in order to verify the modeling results. Suggestions on the improvement of the electrostatic sensor design are also given.

Process analytical technology: application to particle sizing in spray drying.

Abstract: The purpose of this research was to explore the possibility of employing PAT for particle sizing during spray drying with the use of an in-line and at-line laser diffraction system. Microspheres were made using maltodextrin and modified starch as wall material and size results obtained using PAT compared with those determined with off-line laser diffraction and light microscopy. Median particle size results were highest for in-line laser diffraction, followed by at-line and off-line laser diffraction and finally light microscopy. This was due to the presence of agglomerates which were measured as discrete microspheres in the in-line set-up. At-line and off-line laser diffraction gave results more closely correlated with individual microsphere sizes due to agglomerate breakdown during the measurement process. Light microscopy allowed direct observation of the particle morphology, however, its use for particle sizing was tedious and sample size was much smaller compared to laser diffraction. Although PAT was found to be an efficient and convenient tool, careful data interpretation was needed taking into account the cohesiveness of the material measured. The at-line set-up appeared to be more suitable in this particular application.