Water heating: the distribution of temperatures along the height of the fire tube during the operation of the samovar on a charcoal is as follows: the highest temperature in the region of the burning center, that is, below; The upper part of the flame tube is heated less.

For heating and boiling water, this temperature distribution is optimal in height. The hotter and therefore lighter water rises, in full accordance with Archimedes' law, and its place is taken by the cold and heavier, from the upper layers of the reservoir.

Thus, due to natural convection, the liquid circulates intensively, mixes and evenly heats up throughout the volume. The efficiency of the St. Petersburg samovar on coal is not less than 70%.

When the samovar is fired with wood, the distribution of temperatures along the height of the flame tube is obtained by another. The most strongly the flame tube heats up in the zone of narrowing, that is, in the upper part of the heat exchanger; In the lower part of the furnace it is not hot at all, so that the heating of the water takes place mainly at the lid of the samovar. Heated and lighter water is so above and remains, and convection does not arise.

E.E. Greylich. By its means

When the St. Petersburg samovar, translated into firewood, begins to hiss and splatter from under the lid with hot drops, this does not mean that the water boiled. The liquid in the bottom area and filling the cup through the tap can be a little warm. The thermal conductivity of the water is low, and without convection it heats up slightly.

Low temperatures in the flame tube lead to the fact that tar and condensate actively pollute the furnace of the samovar are actively extracted from the wood. The efficiency of the samovar on wood is close to 15%.

Technique of safe operation of samovar

The samovar tank is always filled with water in full, otherwise with local overheating, thin-walled joints made with tin-lead solder can disintegrate.

Before the kindling of the samovar, the grid is closed with several large pieces of coal. Unlike coal, the need for temperature is relatively low for ignition of wood. Prepare a beam of ray, better birch, light and lower the flared torch into the flame tube.