When the black liquid follows from a pipe with the specific smell, formed as a result of subsidence of water steams and steams of resinous substances on chimney walls, it means that in a pipe the condensate which impregnates in due course an oven laying through was formed, it becomes crude, draught decreases, and the laying quickly collapses. Stains from furnace lateral aspect delete, cutting down a brick and plastering such places a cement mortal. Often a laying replace new. Heavy smells allocated with a condensate do impossible residing at the house. The condensate from many reasons is formed, after all even in the driest fuel always there is a moisture small amount. Besides, hydrogen containing in fuel, incorporating to oxygen, also forms water.
Smoke gases with low temperature and any quantity of water in the form of steam pass on furnace and pipe channels, cooling them. Adjoining to cold walls of a pipe, they settle on them in the form of drops which flow down downwards.
That water available in hot gases evaporated is better, the temperature of the last should be raised. On good nagretyh pipe walls the settled drops of a moisture quickly evaporate. Normal temperature of gases before an exit in a pipe 120... 140°С, and at an exit from a pipe in atmosphere not more low 100°С. From practice of operation of furnaces it is known that if smoke gases at an exit in a pipe, i.e. At vjushki, have temperature nearby 250°С condensate it is never formed, draught in furnaces improves, furnaces quickly heat up, consuming thus less fuel.
To Define temperature of leaving gases it is possible in the elementary way - by means of dry luchiny which put across an aperture vjushki during a fire chamber. If through 30-40 mines or a bit later to take out luchinu and to scratch out from it a soot it is possible to judge temperature of gases. Colour luchiny does not vary at temperature in limits 150°С. If luchina turns yellow to colour of a crust of a white loaf, the temperature means has reached to 200°С and if became brown, colours of a crust of rye bread the temperature has risen to 250°С. Turned black luchina specifies in temperature 300°С and when it is carbonized the temperature rises to 400°С.
This data says that at a fire chamber of the furnace the temperature of gases should be regulated so that at vjushki it was in limits 250°С. In the summer the condensate is formed in a small amount or it is not present at all. We will consider principal causes of formation of a condensate.
The Big role is played by the sizes of the grid-iron lattice, correctly lifted under and the device of a hearth at the Russian furnace, the sizes of the channel, a thickness of walls, length and chimney height, temperature of its heating, humidity of applied fuel, temperature of gases leaving a pipe and superfluous quantity of flues in the furnace.
The chimney Height should be not less than 5-6 m, considering from level zolnikovoj chambers or poda the Russian furnace, a thickness of a laying of walls of a pipe - in 1/2 bricks (120 mm). More thin walls of a pipe quickly heat up and quickly cool down that leads to condensate formation.
Various cracks in a pipe and the furnace through which cold air gets, also promote cooling of gases and condensate formation. When section of a laying of a pipe (flue) more demanded for the given furnace, smoke gases rise on it very slowly, and cold external air cools them in a pipe. For strengthening of draught of a wall of a flue should be smooth. All roughnesses in a pipe promote decrease in draught and detain on itself soot.
Skilled stove-makers tell that sometimes for draught improvement in furnaces it is necessary to shift a pipe, reducing the sizes of a flue, lowering or lifting a pipe on a roof. To do it it is necessary some times, before reception of satisfactory result. In places of narrowing of a flue follows stesyvat right angles for maintenance of smoother transition of gases.
Draught in a pipe also is influenced by a wind. At a horizontal direction of a wind about a pipe there is a depression of air and gases leave a flue is better, are as though exhausted from it. If the wind blows from top to down it overturns gases in a pipe and draught decreases to a minimum.
For reduction of harmful influence of a wind by gases leaving a pipe inclined planes of pipes mow down or arrange metal caps-umbrellas with oblique planes. Hitting about them, the wind deviates the initial direction and does not get to a pipe. Besides, the cap protects top of a pipe and its wall from namokanija and washing out by rain waters. In crude pipes draught decreases.
The Big role is played also by process of combustion of fuel. The tree ignites at temperature not more low 300°С, coal at 600°С. Normal process of burning proceeds at more heat: a tree - at 800... 900°С, coal - at 900... 1200°С. Such temperatures provide continuous burning provided that air (oxygen) arrives without interruption in potrebnom for burning quantity. When it gets too much, toplivnik it will be cooled, and burning to worsen, as for good burning the heat is necessary. It is not necessary to heat the furnace, holding opened a fire chamber. At full combustion of fuel colour of a flame straw-coloured, and a smoke white or nearly so the transparent. In this case soot is not postponed almost on walls of channels of the furnace and a pipe. At insufficient giving of oxygen in the furnace there is an incomplete combustion of fuel, fire wood decays or burns with a dark red flame, and from a pipe there is a black smoke which carries away with itself not burnt down smallest particles of fuel (soot). In this case on walls of channels of the furnace and in a pipe soot settles and quickly litters them.
In beskanalnyh furnaces with big internal teplovosprinimajushchimi surfaces hot gases give to them a lot of heat, and leave in a pipe strongly cooled that leads to formation of the big condensate.
For rise in temperature of leaving gases such furnaces should be reconstructed, reducing internal teplovosprinimajushchie furnace surfaces, arranging small windows-apertures from toplivnika only in last or in last and penultimate flues.
For reorganisation of such furnaces assort a part of a laying from forward or other party, it is frequent from two parties, and after correction the repaired place should differ nothing from earlier executed laying.
For example, when in the furnace is available seven flues to liquidate a condensate, one or two of them - last and penultimate - disconnect, blocking above or below that raises temperature of departing gases.
These channels can to be disconnected, and to arrange from toplivnika furnaces to them small windows-apertures with section approximately 50x50 mm. The square window is heavy and inconvenient for spreading in a brick. Therefore it is simple stesyvajut or chop off a brick on the one hand in the necessary quantity. This way reliable, it raises temperature of departing gases to norm as streams of hot air from toplivnika get to channels and lift in them temperature.
Here the basic recommendations about struggle against condensation of steams of water and steams of resinous substances on walls of flues.