Технические науки/6.Электротехника и
радиоэлектроника
K.t.n. Ritter D.V.,
Student Magzumov
T.H.,
Magistrant Latypov S.I.
The North Kazakhstan state
university after M. Kozybaev, Petropavlovsk
Microwave power systems in wireless devices and the
system
Microwave installation, Chair nent for this article of interest, occupy
mainly UHF range, covering frequencies from 400 to 2500 MHz. In this frequency
range of operation of the plant with access to the broadcast (connected,
television, radar systems), as well as working with no output (various
industrial and technological systems).
Variety of industrial and technological systems using microwave is
extremely large. This includes a variety of industries, including agriculture,
medicine, industry and others. For agricultural research focuses on the study
of germination, increase yields, accelerated fermentation, pest control, seed
treatment, quality control of products for gene modification. The extensive
studies carried out in medicine to study the effect of microwave on
bioorganisms, thawing of organs and tissues after cryopreservation. In
industry, the microwave is used to accelerate the process of polymerization
resins, processing of timber, petroleum products [1, 2], etc.
Important in this case is the fact that the presence of any microwave
generator and power split device volume: space, enclosed area irradiated
object, etc. Depending on the power demand effects of microwave oscillations is
chosen, and the choice of frequency determined by the purpose of installation.
Domestic microwave ovens so the frequencies in the range of 2450 
50 MHz, and
industrial installations 435.92 
0.88 MHz and 915 
25 MHz. In this
context, the purpose of the microwave device depends largely instrument power distribution
at the site.
Domestic microwave ovens require a small enclosed space, which
concentrates the electromagnetic field.
Installation agricultural demand or energy concentration in small areas
(research on seed treatment, pest control) or its distribution over the length
and width of a farm planting.
Industrial plants are also very diverse in scope and application of the
irradiated surfaces. Thus, the heating of the bitumen in the tank requires the
emitter of microwave energy directly to them, while open containers of them
requires heating in certain areas, specify the width and length of bitumen.
The situation is similar when drying. Most often, it is dried by the
group method in the form of parties. Dried material using microwave energy devoted
a large number honors [3, 4]. The focus of the work is to provide an efficient
heat treatment of timber, regardless of the initial moisture content of the
cross-section, low energy and economic costs in the implementation of the
process of drying.
Drying by microwave energy is carried in the chamber, which is placed in
the prepared stacks of wood. The camera offers the microwave radiation, and
coolant. Irradiation of the material is evenly opposite sides of the stack. For
perfection Ania processing using various manufacturing operations and control
modes. Such operations include changing the coolant flow direction relative to
the material stack, ensuring dispensing microwave power with the power of a
heater to regulate, in turn, flow of coolant; execution modes vlagoteplovoy
processing and others. When drying consider rock geometry and humidity of
processed wood products.
When drying account physical phenomena underlying the process. Thus, the
moisture moves in the fibers of the wood parts more heated in less heated, and
also from the more humid local volumes to a less humid (dry). Such movement of
moisture requires a uniform heating of the material, to prevent internal and
external injuries.
A regime of uniform heating of the material is not easy and is usually
provided by an increase in the number of microwave oscillators.
Note that for a typical large round timber uneven moisture distribution
over the cross section that the microwave drying leads to thermal underheating
central layers of wood, and overheating of the outer layers.
To supply microwave radiation into the chamber usually use aperture horn
antennas, which are placed end to end camera.
Wood sizes vary widely and therefore drying chamber shall take into
account the size of the material. Increasingly require rapid drying of small
width of long samples of wood. In normal industrial applications it is not
possible for a number of reasons.
Consider the basic technical units that make it possible to implement
this process. The whole process of microwave heating can be divided into
exposure, drying and heating, although the exposure is accompanied by moisture,
ie drying, and the latter is accompanied by heating. Therefore, in each case,
are the measure of the time of exposure and the level of the irradiated
power. From the process of the traditional heating with microwave oven
heating is throughout the volume of the same time. Naturally, the microwave
effect on organic and inorganic materials to a large extent depends on their
electrical properties. So they released capacity depends on the frequency and
the dielectric loss tangent. For large values of tan are more
affected by the conductive properties of the object, so start playing the role
of the field penetration depth. On this basis, with a large thickness of the
irradiated sample will be manifested more skin effect.
References
1. Gareev FH Microwave drying process - the energy of round timber. N E26V3/347 Posted 20.04.2005.
2. Patent number
2199064 F 26 B 3/347, H 05V6/64 Russia Set to dry dielectric materials. Microwave energy. / FH Gareev Filing Date 17.04.2001 Date 20.02.2003.
3. Gareev FH Nontraditional
timber drying: vacuum and microwave / / Timber Industry -2004 - № 5-P.62-65.
Informations about authors / Сведения об авторах
|
Surname / Фамилия |
Ritter / Риттер |
|
Name / Имя |
Dmitry / Дмитрий |
|
The organisation, post / Организация, должность |
The
North
Kazakhstan
state
university
after
M. Kozybaev, The teacher /
Северо-Казахстанский государственный университет им. М. Козыбаева, преподаватель |
|
The address / Адрес
|
Kazakhstan, the
city
of
Petropavlovsk, street Jumabaev
115,
apartment
601
/ Республика Казахстан, город Петропавловск, улица Жумабаева 115, квартира 601,
почтовый индекс 150000 |
|
The electron
address of the author / Электронный адрес автора |
|