4. Metal cutting. Equipment and tools for oxygen cutting
For
metal and use the following types
welding: oxygen, oxygen-flux,
plasma-arc, arc with an electrode
and others. The most widespread
oxygen and plasma cutting, which
subdivided into dividing, purpose
which is to separate one part of the metal
from the other, and superficial (fire),
the purpose of which is to cut off a layer of metal.
Process
oxy-fuel cutting
based on the combustion of metal in the environment
oxygen, at which the flame brings
metal to the combustion temperature, and powerful
a jet of oxygen burns it and removes
the formed slag. Quantity
heat released when burning metal
large enough. This allows hot
flowing slag to warm up the lying
below metal layers (more than 1 mm).
Metal,
subject to oxygen cutting, must
meet the following conditions:
temperature
metal ignition in oxygen
must be below its temperature.
melting. This condition is satisfied
steel containing up to 0.7% carbon.
General cutting of metals with a large
carbon content is not possible. That
the same happens when cutting alloyed
steels,
with an increase in the content of impurities
cutting conditions worsen even at low
carbon content;
temperature
melting of metal oxides should be
below the melting point of the main
metal. Cast iron and non-ferrous metals
satisfy this condition, and
therefore, in the usual way
are cut;
cut
metal must have a minimum
thermal conductivity.
For
cutting uses the same equipment,
as for welding, except for the torch,
instead of which the cutter is used
(fig.4.5).
Figure 4.5.
Oxygen cutter
V
cutter structurally integrated
heating part and cutting.
The heating part is similar to the welding part
burners. The cutting part is made up of
additional tube 4 for supply
cutting oxygen. The mouthpiece contains
two concentric
openings for the outlet of the heating
flame 1 and cutting jet 2. Mouthpiece
cutter 3 forms a right angle with the barrel.
When replacing acetylene with other fuels
gases in the cutter increase the cross section
injector channels and mixing chamber.
Hand cutting due to irregularity
torch movement and cutting vibration
jet does not provide high quality
cut surface, so the cut cavity
mechanically processed.
By
purpose cutters are divided into
universal, allowing to produce
separation cutting of various shapes
in any direction, and special,
intended for certain
operations (for cutting holes, etc.),
as well as for surface cutting.
Atmospheric injection gas burners
Our organization provides a full range of services for the installation, adjustment, maintenance, repair of burners of any type
Burners are divided into two types - atmospheric (injection) gas burners and blast gas burners with a closed combustion chamber.
An important difference between gas boilers from each other is not in the appearance of the device, but in the design of the gas burner. Before choosing a boiler, it is important to decide: what kind of burner it will have, consider the principle of their operation, device features, advantages and disadvantages. What to prefer and why?
Atmospheric (injection) gas burners. Device.
Air supply as in a conventional gas stove. They are also called "gas burner for a boiler with an open combustion chamber."The gas burner in these devices is a tube, in the walls of which there are holes for the gas to escape. Gas, mixing with air from the room, ignites. Atmospheric burners are considered simpler models.
Atmospheric (injection) gas burners. Operating principle .
In an atmospheric (injection) gas burner, gaseous fuel is supplied through the ejector, which, thanks to draft, draws air from the surrounding space, then this mixture enters through the holes into the combustion chamber, where it ignites. close to atmospheric, carried out by the energy of the air jet. In full mixing burners (all the air necessary for combustion is mixed with gas) operating on medium pressure gas, a short flame is formed, and combustion is completed in a minimum furnace volume. Only a part (40-60%) of the air required for combustion (the so-called primary air) enters the injection gas burners of partial mixing, which is mixed with the gas. The rest of the air (the so-called secondary air) enters the flame from the atmosphere due to the injecting action of gas-air jets and rarefaction in the furnaces. Unlike medium pressure injection gas burners, low pressure burners form a homogeneous gas-air mixture with a gas content above the upper ignition limit; these gas burners are stable in operation and have a wide heat load range.
In general, the principle of operation is similar to industrial hearth models. With such combustion, torches with a rather low temperature flame are formed above the holes in the chamber. This design is the simplest, and reliable enough, which allows it to be used on all types of boilers, from cheap to expensive.
Atmospheric (injection) gas burners. Advantages.
good mixing of gas and injected air and maintaining, within certain ranges, the calculated ratio of their quantities when the burner heat output changes.
The main disadvantages of burners with a single gas nozzle are:
significant length, especially at high thermal power: the need for a strict coincidence of the axis of the nozzle with the axis of the burner; high noise level, and low-pressure burners - a significant length of the flame and the dependence of secondary air on the rarefaction in the furnace.
Our contacts
The specialists of our organization will perform installation, adjustment, maintenance, verification of gas-using equipment of any type and volume in the city of Dnipro and the Dnipropetrovsk region.
To carry out the work, we have all the relevant documents issued by state bodies, as well as certified by state control bodies, laboratories.
+380 63-852-66-89 +380 96-669-11-03
Feedback form. (Ask a question, leave your coordinates, send a message - and we will contact you as soon as possible.)
