DE907923C - Slag grate for melting chamber firing of water tube boilers - Google Patents

Description

Slag grate for melting chamber firing of water tube boilers To avoid the accumulation of fly ash and slagging of the heating surfaces the greatest possible separation of the liquid slag particles in the melting chamber aimed at by water tube boilers. For this purpose, in particular, the impact effect when slag particles hit the slag bath or the melting chamber walls exploited. Slag grates have also been arranged through which the flue gas flow is broken down into partial flows upon exit from the melting chamber. The slag grates are formed from pipes carrying water or steam. To get the best possible excretion To achieve this in the slag grate, several rows of pipes are arranged one behind the other. The rows of pipes are offset from one another so that the slag particles DuTch steps through the alleys in one row and collides with the pipes in the next row etc. Both uncovered and insulating pipes are used as cinder pipes Pipes surrounded by a protective layer.

The melting chamber is opposed to the cooling one by the sleeping grate Effect of the downstream, connected heating surfaces shielded, so that even with partial loads the temperature required for the liquid slag discharge in the melting chamber is available. The slag grate is located between the high-temperature melting chamber and the colder downstream heating surfaces. The one adhering to the slag trap pipes Slag will kept liquid by radiation from the melting chamber and the. Contact with the smoke gases emerging from the melting chamber. On the the side facing away from the melting chamber in the radiation and flow shadow of the pipes the slag can solidify. when the cooling through the slag grates The coolant flowing through and the colder downstream heating surfaces are too large will. Around. a sufficient precipitation of the slag particles contained in the flue gases when exiting the melting chamber zti, it is necessary to use several pipe grinders ini slag grate to be connected in series. But this is not possible because of the cooling of the slag and the resulting clogging of the slag grate.

It is therefore suggested to keep the liquid slag flowing away give a twist to the vertical or almost vertical slag fan, so that, in addition to their movement parallel to the pipe axis, they also move in the tangetitialc-i direction makes around the pipe. In this "" way, it becomes in the radiation or flow shadow cooled slag returned to the Raucligasstrom and heated again, and the initial seizure of the slag and clogging of the slag grate is avoided.

The movement of the slag around the slag collecting tube is according to the invention achieved in that the surface of the tubes is formed helically. In the case of insulated pipes, the surface of the insulating surface is single and multi-threaded Helical lines are formed, and in the case of non-insulated pipes, two or more: _ rc tubes helically wound around each other.

As an example of the subject of the Eriindtii @ «is in Ab-h. i and 2 shows a slag grate, which is in the pipe arrangement of a forced-flow boiler is switched on.

Fig. I shows a section of the sclilii (-enity catching grid in the front view and Fig. 2 in side view.

The water or steam is drawn through the pipe grinders via the distributor i. 1 and 5 pressed into divider 3. After the Durclimixing has taken place, the coolant flows through the rows of tubes 6 and; into the collector 2. The ones emerging from the melting chamber Flue gases flow through the rows of pipes a, g, 6 and; in the horizontal direction. the Pipes in rows 1 and 6 lie one behind the other. while the pipes in rows 5 and 7 are in the aisles of rows 4. and 6. For better circulation to achieve the smoke gases zti, the pipe screws are consecutive ears wrapped in the opposite sense. The pipes in rows .1 and 6 have a left-hand twist and the drill g and; Right twist. In addition, the pipes are the consecutive Rows of tubes in the H (') lie staggered so that at the greatest width of the Rolirs, .arauben of rows .1 and 6 the smallest width of rows 5 and; is, and uingekelirt.

The viscous slag adhering to the slag collecting pipes flows not straight down, but follows the helical windurig of the pipes. As a result, the liquid slag stays in the radiation or Ströintnigsscli.attf ° ti limited in time and the slag kept liquid. From the lower distributor 3 the slag drips into the slag bath.

The helical pipes not only get the slag flowing off kept liquid, but also a better circulation of the smoke gases and thus a better separation of the slag is achieved. The length of the screw turns can be adapted to the toughness of the slag. In all kinds of ways the connection of the slag fan rolire with each other can be seen in the given Adjust conditions to a large extent.

Claims (3)

PATENT TABLES: i. Slag collecting grate with pipes inclined vertically or diagonally downwards for melting chamber firing of water rolir boilers, characterized in that the surface of the slag collecting pipes is designed in a helical shape so that the liquid slag can still move in tan when it flows away from the pipes, in addition to being parallel to the pipe axis .gential direction. 2. Sclilackenfangrost, tiacli claim i, characterized in that at insulated cinder pipes cover the surface of the insulation as a helix is trained. 3. slag grate according to claim i, characterized in that two or more bare pipes are helically wound around one another. Slag collecting grate according to one of Claims 1 to 3, characterized in that: @ the direction of rotation of pipe screws lying next to or behind one another is opposite is.