SU1702101A1 - Method for removing dust from chamber bottom of waste-heat boiler - Google Patents

Abstract

The invention relates to metallurgy and can be used to remove sludge dust from the bottom of a waste heat boiler, exhaust gases from furnaces. The aim of the invention is to improve the reliability of the waste heat boiler by reducing air suction. A method for removing sludge dust from the bottom of the chamber the utilization boiler includes moving the settling dust in cyclic-counter flows to the discharge opening 6 with the accumulation of dust above it, opening the discharge opening after the accumulation of dust above it in excess of m its opening time for consumption, 2 yl

Description

The invention relates to metallurgy and can be used to remove precipitating dust from the bottom of a recovery boiler located in the process chain for cooling and cleaning gases derived from continuous-smelting furnaces, mainly autogenous smelting, in particular, smelting furnaces in a liquid bath (Vanukov furnace) .

The purpose of the invention is to increase the reliability of the recovery boiler by reducing air suction

FIG. 1 shows the camera section; in fig. 2 is a section A-A in FIG. one.

The device comprises a waste heat boiler 1 with a bottom 2, over which a screw 3 is installed, having two oppositely directed screw surfaces 4 and connected to a drive 5. At the meeting point of the screw surfaces 4 in the bottom 2, a discharge opening 6, blocked by a valve 7, is made.

The method for removing settled dust from the bottom of the recovery boiler is as follows.

Dust in the recovery boiler 1 settles on the bottom 2. The screw surfaces 4 of the auger 3 connected to the drive 5 move it from the ends of the recovery boiler 1 to its middle, where a hole 6 is made at the meeting point of the dust conveyed by the screw 3. Collecting dust from the bottom 2 and moving it to the discharge opening is carried out cyclically, in opposite flows, which allows accumulating excess dust (a pile) over the discharge opening 6, which, reaching the size of a certain portion, completely blocks the discharge opening 6. Then the dust unloads through the discharge opening Excess dust provides a complete overlap of the discharge opening during unloading and thereby prevents the ingress of air into the waste heat boiler 1.

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The unloading process is carried out cyclically, with simultaneous movement of dust from the bottom 2 of the recovery boiler 1 to the discharge opening, which ensures the supply of new portions of dust to completely block the discharge opening 6, which prevents air from leaking. By reducing the amount of incoming dust into the discharge opening 6 to the extent that air can be allowed to drain into the waste heat boiler 1, the valve 7 covers the discharge opening 6. The accumulation of sludge dust over the discharge opening 6 begins again and the process repeats.

The use of cyclical operation also significantly reduces the energy costs of the drive 5 mechanisms that create counter-transport flows of precipitated dust.

The operation of the valve 7 may be dependent on a time relay or a weight sensor.

PRI me R. In the waste-heat boiler installed behind the smelting furnace in each bath (Vanyukov's furnace), dust is collected from the bottom and moved to the discharge opening is cyclically, counter-flow, for which utilization of auger 3 installed 2 above the boiler oppositely directed helical surfaces. 4. The temperature of the gases leaving the melting unit at the inlet to the waste-heat boiler is 1100-1200 ° C, and 380–420 ° C at the exit from it. The dust content of the gases at the inlet is up to 12.5 g / m3, the gas consumption through the waste-heat boiler, on average. 58500m 7h Therefore, for 1 hour, about 740 kg of dust passes through the waste-heat boiler. About 25–30% of the dust (mainly the cope fraction) is deposited in the recovery boiler, which is about 200 kg. With the length of the waste-heat boiler 23 m, about 8-9 kg of dust accumulates in 1 h per 1 m length. Within 1-1.5 hours, a heap of dust, approximately 0.4 "0.4" 0.4 m or 0.06-0.07 m3, is collected by cycling around 3-5 s augers above the discharge opening. On average, Dust unloading (opening of the valve), taking into account the pressure difference between the outside and inside the waste-heat boiler, takes 15–20 s, with the valve closing being advanced, i.e. It begins to block the opening 6 before the time of discharge of dust, and this ensures that the discharge hole 6 that is being transported by the dust is permanently blocked, and, accordingly, the impossibility of air leaks when removing the dust.

During the unloading of dust (15-20 s) with maximum performance, the screw 3 is working, ensuring transportation

almost all accumulated dust accumulated in its turns to the discharge opening 6 at the meeting point of the flows. After that, the cycle including the listed operations with their temporal characteristics is repeated, namely: for 1-1.5 hours, by turning on 3-5 from the screw 3, the dust is collected by opposing streams and accumulates over the discharge opening 6 to a certain amount ( 0.07 m3). Then, at the meeting point of the flows through the discharge opening 6, which is opened by the gate, the dust is unloaded for 15–20 s. With this in

Continuing the unloading time, new portions of dust are fed in opposite directions by screw 3 to the discharge opening 6. Before the dust is completely unloaded (10–15 s, from the beginning of the discharge of dust), the valve begins to open the discharge opening 6 and the dust discharge cycle ends here.

As a result of the use of this method, the reduction and actually elimination of air suction due to the constant blocking of the discharge orifice with dust or a valve is achieved, stability of the composition of the waste gases of the melting unit, POSUJANTRS, their temperature and high concentration due to

elimination (decrease) of air suction. This in turn ensures a stable and reliable process for obtaining elemental sulfur or sulfuric acid from the exhaust gases, and tekhe increases the service life of the equipment used in these processes.

The elimination of air leakages significantly increases the reliability of the boilers utilization by preventing the formation of specimens, reduces the labor required for cleaning the dust discharge leaks and the bottom of the heat recovery boiler from specs, and consequently the coefficient increases.

the resulting products are reduced environmentally harmful emissions into the atmosphere.

Claims (1)

Invention Formula The method of removing settled dust from the bottom of the chamber of the recovery boiler, which consists in moving the settling dust in cyclical stream to the discharge opening, periodically opening it and discharging dust through it, in order to increase the reliability of the recovery boiler by reducing air suction, when moving dust accumulate over the discharge opening, and opening the discharge opening is carried out by the person, exceeding its consumption during the time from: hardly accumulating dust over it about the quantity of the crucible A j --3fcJ g //. / , / l / 7 ////// ъ ™ b Shig.1