Санкт-Петербург, Политехническая ул., д. 29, Г.З., оф.234, общий отдел: 920-01-97, вакуумное оборудование: 920-71-97
AN OPTICAL DIAGNOSTICS OF SIZE AND SHAPE OF PARTICLES IN FLOWS AND MIXTURES
Fig. 1. Block diagram of the device for measuring size and velocity of moving particles. 1-radiator, .2-focusing lens, 3 – transparent mask, 4- photo sensor, 5- amplifier-detector, 6 – ADC, 7 – PC.
Fig. 2. Working prototype of the device.
The diagnostics is designed for detection, observation and size measurements of solid particles, gas bubbles or droplets moving in liquid, gas or powder flows.
The following diagnostic methods have been developed:
1. Analysis of moving diffraction pattern produced by the particles crossing the light flow. Particles’ size and velocity distributions are calculated from the pulse signals detected by photo sensors. Fig.1 shows the block diagram of the device and the prototype is shown in Fig. 2.
2. Particle photographing by CCD camera combined with microscope. The photographing allows particles shape examining. Digital images processing is employed. Light emitting diode or 2 nanoseconds pulsed laser are used as a flash for photographing of fast particles.
Prototypes of the diagnostic devices have been designed, manufactured and tested.
Inventor’s certificates issued:
1. Kizevetter D.V., Litvak M. Ya., Malyugin V.I. Device for measurements of sizes and velocities of moving particles. #1809303, USSR.-1993.-№14.
2. Kizevetter D.V., Malyugin V.I. Method for measurements of particles’ velocities. #1770911, USSR.-1992.-№39.
Joint patenting, development and manufacturing.
There is no devices measuring both size and velocity distribution at the same time including detection of the particles larger than 100 microns. The method proposed is especially for detection of large particles (several microns) on the background of small particles. At such a condition conventional small angle scattering devices are not accurate.
Photographing is most effective for observation of the complicatedly shaped particles.