SU1218258A1 - Air preheater - Google Patents

Description

The invention relates to a heat exchange technique and can be used in fuel combustion plants operating on flue gases.

The purpose of the invention is to increase operational reliability by reducing the possibility of destruction of the heat exchange tubes.

In Fig.1 schematically shows the proposed heater; 2 a fourth heat exchange section, a longitudinal section; on fig.Z section aa in figure 2.

The air heater contains sequentially installed in the U-shaped gas duct 1 the main first second, third, fourth heat exchange sections 2-5 and the additional section 6 installed between the main first and second sections 2 and 3. The first main section 2 and the additional section 6 are made of different pipes. By air, the second and third main sections 3 and 4 are connected in parallel, the second section 3 being anticipated to the first section 2, and the additional section 6 is connected to the third section 4. Sections

2 and 6 are connected to a common consumer 7 of heated air. Sections

3 and 4 are connected in series to the main heat exchanger section 5 connected via air to an air source 8. Section 5 is made in the form of a duct 9 divided by a horizontal wall 10, in which heat transfer elements 11 are fixed, to a gas and air cavity 12 and 13, respectively, and the air cavity 13 is divided by a vertical partition 14 into successively connected by air sections 15 and 16.

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The operation of the described air hopod-Grevetel is as follows.

The cold air with dust from the source 5 through the duct enters the cavity 13 of section 5 through the hole in the wall and then the air is directed into the space between the heat transfer elements 11, skirting the partition 14. The air contained in the air about the elements 11 and during the rotation of the air around the partition 14 falls out of the air flow and settles at the bottom of the cavity

15 to 13, from where it is periodically removed as it accumulates, and the air cleared of air and heated to 20-60 ° C enters section 3 and 4 through the duct, where it is heated before

20 higher temperatures. The air movement path in section 3-5 passes along a horizontal straight line, which is the axis that divides the air cooled part of section 325 5 in half, which allows even heat transfer from pipes to air along their entire length without local overheating. and pipe integrity problems. Heated in sections

30 4 air up to 150-200 ° C through the duct enters the consumer 7 through section 6, and from section 3 through section 2 to the same consumer 7. Due to dust deposition in section 35, abrasive is prevented

wear of pipes of sections 2-6, which prevents depressurization of these pipes and, accordingly, overflows of heat exchanging media. Performance

40 of an additional section 6 of the U-shaped pipes allows for reliable compensation of the thermal elongations of the pipes in the most stressed zone — at the inlet of the hot heating zone.

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Claims (1)

An AIR HEATER containing the first, second, third and fourth heat-exchange sections respectively sequentially installed in the U-shaped duct, the first of which is made of U-shaped pipes, the second and third sections being connected in parallel through the air, characterized in that, with In order to increase operational reliability by reducing the possibility of destruction of the heat exchange pipes, the second section is upstream through the air of the first section and between them in the duct there is an additional section of U-shaped pipes connected by air behind the third section, and the fourth section is made in the form of a duct, divided by a wall with heat transfer elements into gas and air cavities, the last of which is divided into series-connected compartments. >