SU8488A1 - Screen type boiler for pulverized fuel - Google Patents

Description

The existing designs of steam boilers are poorly combined with furnaces for burning dust and fuel, the volume of which far exceeds the volume occupied by the boiler itself. In addition, irichdits take measures to energetically cool the walls of the firebox, which otherwise would quickly collapse from the high temperatures that characterize pulverized fireboxes. In boilers of the so-called screen type, these inconveniences are eliminated by creating a furnace inside the boiler itself, transferring most of the heat by radiating a burning torch directly to the boiler tubes surrounding the combustion chamber from all sides. Such boilers are designed to achieve a greater volume of flue space vertical and very difficult to manufacture.

The proposed horizontal screen-type boiler is designed to eliminate the listed disadvantages.

In FIG. 1 shows a longitudinal section of the proposed boiler; FIG. 2 is the same cross section; FIG. 3-microdial section of the modified boiler; FIG. 4, 5 and 6 variants of the lower drums.

Dust fuel flows through pipe 1 (Fig. 1) to the fan 2, which simultaneously sucks the air through channels 3, thoroughly mixes the dust with this air and throws it through the ring channel 4 into the inside of the furnace. The fan is protected from radiant heat by the screen 21. Such a torus-injector fan, in addition to intensive mixing of air with dust, creates a vortex (turbulent) movement of this mixture inside the combustion chamber. The first part of the furnace 5 is a short cone-shaped ignition chamber, the furnace 6 itself is placed inside the boiler, which limits the top and bottom of the torso to two drums 7 and 8, and with side-rows of tubes 9 arranged in a checkerboard pattern so that All radiant heat was perceived by the walls of the tubes and did not reach the bricking. The combustion chamber 6 is an almost regular cylinder with a diameter of about 4-7 meters. This shape of the chamber is well suited to the vortex motion of the flame and excludes dead angles. Here, the radiant heat from the burning torch is absorbed and intense vaporization takes place. A large number of tubes 10 (Fig. 2), all of which together form a shield impermeable to heat rays, are rolled into the back of the drums.

And, thus, the superheater 11 (Fig. 1) is protected from burning, located behind the cat. “This last bundle of tubes fills the entire cross section of the furnace, so. that the gas must pass between the house and the

The boiler is combined with a superheater 11 (Fig. 1) and an air preheater 18 and is one compact unit with them and a furnace. The remaining internal vertical walls and horizontal walls, the channels 19 can be used to supply air to the firebox, which leads to a minimum of heat loss to the surrounding. A fan 20 is used to drain the flue gas through the flue gas. The air is sucked through the air preheater and the channels can be produced by the fan 2, which plays the role of a nozzle or a special fan.

In order to preserve the entire length of the drum for flaring the side-wall tubes, the rear screen can be formed by tubes 21 (Fig. 3) flared in two horizontal chambers or drums 22 arranged perpendicular to the main drums 7 and 8. In the same drums the tubes 23 of the additional heating surface of the boiler can be expanded, absorbing heat from the flue gases by means of contact (convection) and thus lowering the temperature of the flue gases at the entrance to the air preheater 18 to the desired values s. A superheater 24 may be located between the front rows of tubes of such a drum, which represent the screen, and the rear bundle of tubes. To circulate, the boiler is supplied with tubes 12, lying around: masonry and; connecting the top drum to the bottom drum. For greater preservation of the drums, the lower part of the upper drum 7 is protected with a suspension arch made of refractory bricks 13, and the lower drum 8 is protected with refractory plates 14 lying on the drum. The removal of ash occurs between the pipes through the funnels 15. To protect the ash funnels of unburned fuel particles or coke from the ash plugs, the gaps between the pipes, in the front part of the boiler, are laid down by small bricks. The boiler is suspended at the two ends of the upper drum on the clamps 16, mounted on an iron frame, and equipped with a conventional sucker, 17.

For fuel, during combustion of which liquid slags are formed, which can fill the lower drum 8 and the lower part of the tubes 9, the entire lower part of the boiler can be made in a somewhat different way. Instead of one drum 8, the tubes are flared in two drums 25 (Fig. 4), with some of the left side tubes 26 rolling in the right drum and vice versa. These crosswise intersecting tubes 26 form a lower screen for the granulation of slags, and these tubes are located at a distance sufficient for free passage of the slags. Instead of the two lower drums, two cylindrical chambers 27 (Fig. 5) can also be used with holes for flaring tubes. In the same boxes, both the heating tubes 9 and the circulation tubes 12 are rolled, and the space between the circulation tubes and the heating tubes is filled with a light lining 28 consisting of iron outer sheets lined with fireclay plates or refractory bricks.

Instead of each of these boxes of relatively larger diameter or complex cross-section, 2 RL boxes 29 (Fig. 6) of normal construction, used for securing, ionic horizontal water tube boilers can be used.

The subject of the patent.

1. A screen type boiler for pulverized fuel consisting of upper and lower drums connected by rows of tubes separated to form a combustion chamber, characterized by the use of the end of the combustion chamber 6 (Fig. 1 and 2) of tube bundle 10, rolled into the end portions of the drums 7 and 8 of the boiler and the combustion products leaving the furnace for heating, for which pipes the chimneys are located, including the superheater 11 and the air preheater 18.

2. Variation of the boiler described in paragraph 1 (FIG. 3), characterized in that instead of a bundle of pipes 10 at the end of the chamber 6 there are installed pipes 21, rolled into additional transverse drums 22 and 22, connected behind the superheater by an additional bundle of pipes 23.

3. The modification of the boiler described in paragraphs 1 and 2 as applied to combustible fusible ash, characterized by the use of two 25 or 27 (Fig. 4 and o) lower headers instead of one common drum, with the aim of forming a gap for dip between the lower intersecting ends of the pipes 26 ash.

4. Variation of the boiler described in paragraph 3, characterized in that the collectors 29 (FIG. 6) are made in the form of flat boxes.

FIG. 2