GAS HEATING ремонт ноутбуков ;nokia n8 купить;велосипеды киев THE CHARACTERISTIC OF HEATING FURNACES
Oven heating
serves for maintenance in separate premises of settlement temperature of air.
Fluctuations of temperature of air in premises for the period between fire chambers
should not exceed ±3 °С In premises of industrial and auxiliary appointment of
fluctuation should not exceed ± 3 °С during working hours. The average temperature
of external surfaces of furnaces in inhabited and public buildings should not
exceed 90 °С.
Furnaces should have high to. The small dimensions, a smooth
external surface to provide safety of using with them. It is desirable, that furnaces
were factory manufacturing.
Heating furnaces depending on a design and a
scope are divided:
1) on a thermal capacity - on heatcapacious and notheatcapacious;
2)
but the scheme of movement smoke a lawn - on channel, mixed:
3) under the form
- on rectangular, round and angular;
4) on height - on one-storeyed and many-tier;
5)
on a material - from a brick, in a metal case and without it, a tile, tiles, in
a skeleton and without it, national teams block, metal;
6) to destination -
heating and otopitelno-cooking. The greatest distribution have received brick
heatcapacious.
Furnaces. Heat such furnaces periodically one
or two times a day. The furnace file accumulates heat and gives then to its heated
up premise. And теплоотдача these furnaces at a periodic fire chamber it is non-uniform
in time owing to what in heated premises considerable fluctuations of temperature
within days are observed.
At
a continuous fire chamber heatcapacious furnaces with use of gas fuel the uniform
temperature indoors during all time is reached, increases them to. The item service
life raises, the daily schedule of gas consumption is levelled.
Neteploemkie furnaces are characterised by high warming up of walls and
their fast cooling after the fire chamber termination. In practice they have not
received a wide circulation.
In existing designs of the heating furnaces created
for burning of firm fuel, specificity of burning of the gas fuel possessing a
number of features, as from the point of view of technology, and safety was not
considered.
At gas use in heating furnaces important not only to achieve its
full burning, but also as much as possible to increase return of heat to walls.
It promotes alignment of temperature of air on height of a heated premise it is
located in the bottom part of the furnace. Besides, furnaces with the bottom warming
up give economy of fuel to 15 % in comparison with furnaces of the top warming
up.
Intensive warming up of the bottom zone of the furnace at gas burning can
be reached or installation in the top part lattices from fire-resistant bricks,
or a direction of a stream of products of burning from to the furnace basis. The
specified ways of an intensification of heating of the bottom zone can be carried
out at furnace major repairs when remain without change се external walls.
The
system of flues of the heating furnaces translated on gas fuel, should: to provide
depression in any part of the furnace and the minimum hydraulic resistance to
pass with a burning product; to possess high ability and in regular intervals
to distribute heat on a file of the furnace with primary warming up of its bottom
zone.
 Let's
consider, how flues heating furnaces with multiturn consecutive channels in the
top passes meet these requirements can be created (i.e. pressure above atmospheric).
If in a furnace laying there are cracks products of incomplete combustion can
arrive in a heated premise that is extremely dangerous. It is necessary to carry
to lacks of multiturnaround system of flues also the big hydraulic resistance
created by descending branches, and non-uniform heating of walls of the furnace.
Non-uniform heating is caused by that walls of the gases of channels first on
a course heat up much more strongly, than the last.
The system of flues with
one ascending channel and several parallel опускными channels is deprived lacks
of multiturnaround system, on for the big furnaces of an eye is not suitable,
as at such system of flues the top part of the furnace more strongly gets warm
and the bottom is much worse. There is it because the hottest gases from go to
the top part of the furnace, and the bottom is washed already by colder gases.
Beskanalnye furnaces type are characterised by insignificant hydraulic
resistance on a course of smoke gases and uniform warming up on laying perimetre.
However it is necessary to carry strong warming up of the top zone to lacks of
such system of flues in comparison with bottom and formation under a cap of superfluous
pressure.
Furnaces with system of consecutive horizontal smoke channels, despite
simplicity of a design, possess by insufficient warmly heat-sink ability (at small
length of horizontal channels) and non-uniformly get warm on perimetre.
In
furnaces with channels of direct-flow type hydraulic resistance is insignificant,
as in them are absent channels and sharp turns of a gas stream. The furnace laying
gets warm in regular intervals, and intensive heating of the bottom zone is easily
reached by placing in the top part топливника nozzles from шамотного a brick.
In the furnace with channels of direct-flow type depression as movement of products
of burning coincides with action of carrying powers is always supported.
Thus, from the considered schemes of channels of furnaces it is necessary
to give preference to the scheme of direct-flow type which is recommended to be
applied in all again under construction gas furnaces. However at re-equipment
of existing furnaces on gas fuel (considering their features) can be applied and
other systems of smoke channels.
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