A chimney is required for every device that generates thermal energy and uses in its process solid, liquid or gaseous fuel ... In simple terms, for all types of furnaces and boilers, except for electric ones. In the process of fuel combustion, combustion products are formed, which must be discharged into the atmosphere.
This is usually done by means of a chimney.
Previously for bricks were most often used for chimney construction, and a solid metal pipe was used in the construction of baths.
Currently, one of the most affordable and popular chimneys in private construction is a sandwich chimney.
The main advantages of these chimneys are their high performance characteristics, as well as the fact that you can do the installation of a sandwich chimney with your own hands without involving specialists.
Sandwich chimney consists of:
To increase the reliability of connections, clamps are sometimes used.
So why is such a construction of a sandwich chimney necessary?
Firstly , in the area of the chimney located next to the heater, high temperatures occur and the walls of the chimney will become very hot, which will lead to a fire hazard and also a touch hazard.
In a sandwich chimney, only the inner pipe will be heated, since the outer one is separated by a layer of insulation, then the heating will be insignificant. And there will be no danger of fire and injury.
Secondly , the thermal conductivity of the metal is very high and in the sections of the chimney far from the heater, the exhaust gases will cool down quickly, which will lead to a decrease in draft.
Also, due to the temperature difference, condensation is actively formed, which subsequently leads to an increased formation of soot and clogging of the chimney, as well as to the passage of corrosive phenomena.
Chimneys, consisting of one chimney, are dependent on external conditions, sandwich chimneys, unlike them, are not subject to such phenomena.
Material of which the chimney is made
The chimney selection procedure can be divided into several stages.
The first parameter will be the material from which the chimney is made. With all the external similarities, there are many products on the market made from low-quality materials.
Pay particular attention to the material from which the inner tube is made. In the technical documentation for the chimney, it should be noted from which stainless steel grade the pipe is made. If there is no mark, then this is a direct sign of poor-quality products.
How to determine the diameter of the inner pipe? The diameter of the inner pipe, as , is usually selected based on the heat output of the boiler or furnace.
For a furnace :
5 kW, a pipe with a diameter of 158 mm is used,
The next important parameter is the thickness and material of the thermal insulation layer.
The best material for thermal insulation is non-combustible basalt wool and with a high coefficient of thermal resistance.
The thickness of the insulation will depend on the temperature of the flue gases.
It is different for different types of boilers. So for:
The next step in choosing a chimney will be be the choice of the layout.
There are two main schemes:
The advantage of the layout of the chimney inside the room is that the impact from outside is minimized, respectively, and the formation of condensation will be minimal.
The disadvantage of is that it is a very technological and complex process that requires careful planning, requires penetration through all floors and roofs.
With an external location of the chimney on the outer wall, only one penetration is required, while the rest of the chimney is attached to brackets, which reduces labor intensity during construction, which is a plus of .
The downside of is that the chimney will be exposed to external influences, as a result of which condensation will form.
The flue assembly always starts from the boiler.
When installing an external chimney , an adapter is put on the boiler outlet, pre-lubricated with a heat-resistant sealant, the working temperature of which is up to 1500 degrees. Then everything is fixed with a clamp.
When installing an internal chimney , it is necessary to install an intermediate section in the form of a single-wall pipe, the installation of a sandwich-chimney at once is not allowed. With a passage through the wall after the branch pipe, mount horizontal section , the length of which should not be more than a meter. A slight slope must also be provided.
For the passage through the wall, a hole is made outside, usually 400x400 millimeters. A passage block filled with thermal insulation is installed in the opening, through which a sandwich pipe is passed.
Next, install the vertical part of the chimney.
There are two methods of pipe installation:
Smoke connection when a pipe with a wider socket is worn on the narrow part of the pipe.
The smoke rising through the chimney, in this case, has no obstacles and freely escapes.
The downside of is that a gap is formed with this fastening. The resulting condensate directed upwards, flowing down the pipe wall, will penetrate into the gap. As a result, the thermal insulation will become damp and the efficiency and properties of the sandwich chimney will deteriorate.
To avoid this effect, pipes are connected by condensate when a bell is put on the narrow part.
With this connection, drops of condensate freely slide down the chimney, without falling on the thermal insulation. To ensure tightness from smoke, the connection of the outer pipe is coated with sealant and secured with a clamp.
When assembling a sandwich chimney, a smoke connection is used on a horizontal section, and a condensate connection on a vertical section.
When installing a sandwich chimney inside the room, the main difficulty is the device for passing the chimney through the ceilings and roof.
To do this, use pass-through node , which is attached to the ceiling from below.
It can be either box-shaped or cylindrical, filled with thermal insulating material (most often it is mineral basalt wool or expanded clay). The pass-through unit is also closed from above with a metal plate.
When crossing the roof, an opening in the roof is first cut, then a chimney is installed and fixed in the center of the opening. Then a conical roof is put on the pipe, which is attached to the roof. And the end of the work will be installation of the head .
Although at first glance it seems that there is nothing complicated in the installation of a sandwich chimney - you need to have a clear idea and primary skills in working with chimneys.
The work must be done carefully and carefully, because the chimney is one of the most dangerous things in the house that can cause a fire.
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Posted By: Work Style |10, Nov 2020
Posted By: Work Style |10, Nov 2020
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