Simple Ultrasonic Washer
|Simple Ultrasonic Washer|
The introduction of advanced energy-saving technologies has advanced to the forefront of progress a new device for domestic use - an ultrasonic erasing device. Wash with ultrasound occurs due to the periodic formation in the volume of a liquid of compression-rarefaction waves arising in a practically incompressible medium — water. The linen placed in such liquid is exposed to intensive hydroacoustic influence. Hydroacoustic waves initiate the appearance of microscopic gas bubbles, which contribute to the separation of microparticles of dirt from the volume of washable clothes. With the formation and subsequent collapse (destruction) of gas bubbles, ozone is formed, sterilizing linen. In some cases, with a high energy of ultrasonic oscillations, sonoluminescence can be observed — a luminescence of a fluid, especially noticeable in a darkened room.
The advantage of washing with the use of ultrasonic vibrations is that the laundry is not deformed, does not wear out and is not torn. You can wash even wool products and thin linen. In addition to washing and disinfecting linen, you can process vegetables and fruits designed for preservation, disinfect water. Ultrasonic erasing devices (UZSU) of the "Bionics" type  that have appeared on the market are a compact electrical device weighing 200 g. "Bionics" consists of a network adapter - a power source and the UZSU itself. The device itself in order to preserve the "know-how" is flooded with a compound, and the description of its concept and meaningful characteristics for reproduction is not given. However, having obtained the secondary characteristics obtained by measuring and analyzing device modes, one of the possible UZSU schemes can be presented in the following form (Fig. 1).
UZSU consists of a power source (DA1 chip), two interconnected generators operating at 10 kHz and 1 MHz (DD1 chip), an output stage on a VT1 transistor, and an activator-emitter connected to the device C and D points. The power source in the prototype is made unregulated, designed for the maximum power consumed from the mains - 3 W, which is enough for washing laundry in a liquid volume of 10 ... 25 liters. It seems more appropriate to provide a UZSU with a smooth adjustment of output power. In Figure 1, an adjustable source of stabilized direct current (25 ... 1000 mA) is included in the gap between points A and B.
Figure 2 shows a diagram of a regulated power supply (5 ... 13 V). The generator of pulse packets is made according to the traditional scheme on the DD1 chip and has no features. The nominal values of the RC elements of the high-frequency part of the generator can be adjusted by adjusting the frequency to resonance with the frequency of the ultrasonic emitter-activator. The chip DA1 and the transistor VT1 must be installed on the heat sink plates. The most problematic in the practical implementation of the UZSU is the choice of an ultrasonic emitter-activator and ensuring its waterproofing while at the same time achieving the maximum impact of the energy of ultrasonic vibrations into the environment (liquid). Usually, piezoceramics are used as an ultrasonic emitter - barium titanate, strontium, ferrite or permalloy core emitters, piezoquartz plates (Fig. 3) [2-4], which opens up a wide field for experiment. One of the interesting options for obtaining ultrasonic vibrations is simply the transmission of electric current pulses through water using a system of closely spaced electrodes connected to points A and B of the device. Periodic passage of current pulses between the electrodes will cause acoustic electrostimulated modulation of the solution. Aluminum or graphite can be recommended as electrodes. When washing should be ensured reliable isolation from the mains. The laundry tub (bucket, basin) must be removed from grounded objects and installed on a dry floor. Acoustic oscillations in the erasing solution can be excited in the range of sound frequencies. Experiments have shown that washing in such conditions occurs with an acceptable result compared to the prototype. Features of washing with the use of UZSU - the same washing powder is poured into the washing solution, as in the case of hand washing, the water temperature should be about 65 ° C. The linen should float freely in the solution, occasionally it should be stirred with wooden tongs. It is recommended to lather heavily soiled areas of laundry. The washing process lasts 30 ... 40 minutes or more (depending on the efficiency of the ultrasonic activator). Rinse clothes can also be using the UZSU. It should be noted that the experience of optimal use of the UZSU appears after several washes.