Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
  • F28G3/00—Rotary appliances
  • F28G3/16—Rotary appliances using jets of fluid for removing debris

Definitions

• the invention relates to a soot blower for cleaning heating surfaces in a heat exchanger with the features of the preamble of claim 1.
• the smoke gases in the heat exchanger which are produced when solid, liquid or gaseous fuels are combusted, are connected to the lance tube of the sootblower via the nozzles and can penetrate into it.
• the mostly aggressive and hot gases cause damage due to corrosion or pollution.
• a harmless, gaseous flushing medium for example air
• a barrier medium for example air
• the purge air and sealing air are taken from a central blower in heat exchangers, especially in power plants that are equipped with a large number of sootblowers, and distributed to the individual sootblowers.
• a complex pipeline system is required for this. Because of the mostly low pressure level of the central blowers used, relatively large line cross sections are often required in order to keep the friction losses low.
• a separate control element is required in front of each soot blower in order to ensure that the required air volumes are distributed as evenly as possible to ensure the different friction losses due to the different pipe lengths to the individual soot blowers.
• the connections on the sootblower valve and / or on the wall box must be made flexible due to the thermal expansion of the heat exchanger and the movement of the sootblower caused thereby.
• a procedural requirement of many manufacturers and operators of heat exchangers is, moreover, that the amount of air introduced per sootblower should remain as small as possible and should not exceed a maximum value even in the case of frequently occurring pressure fluctuations on the flue gas side.
• the invention has for its object to simplify the known system for supplying the soot blower with flushing and blocking medium.
• the central blower and the complex air distribution system can be dispensed with, since the purge and sealing air can be generated on each soot blower by a separate compressor.
• This compressor and the distribution pipes on the soot blower are designed so that each soot blower always receives the required amount of purge air and sealing air. The necessary rough setting can be made at the manufacturer.
• FIG. 1 is a side view of a soot blower according to the invention
• Fig. 2 shows the detail Y of FIG. 1 and
• Fig. 3 shows the detail Z of FIG. 1 for another embodiment of the invention.
• the soot blower shown has a lance tube 1 which is provided with nozzles 2 at its front end.
• the lance tube 1 is connected to a gear carriage 4 which is driven by a motor 3 and which can be moved together with the lance tube 1 on a stationary mounting rail 5.
• the motor 3 also sets the lance tube 1 in a rotational movement, so that the nozzles 2 perform a helical movement overall.
• the end points of the travel path of the lance tube 1 are each determined by a fixed limit switch.
• the lance tube 1 can be moved through an inlet opening into a heat exchanger, the wall of which is indicated by a wall tube 6.
• the inlet opening is surrounded by a wall box 7 for sealing against the outside atmosphere. This is in the retracted state
• the displaceable lance tube 1 surrounds a stationary inner tube 8, the rear end of which has a connection for a blowing medium, for example steam.
• the amount of the blowing medium is regulated via a sootblower valve 9 arranged on the sootblower.
• the inner tube 8 is provided with a connection 10 for a flushing medium, for example air.
• the purge air connection 10 is above the valve seat of the soot blower valve 9, d. H. arranged in the flow direction of the blowing medium behind the soot blower valve 9, via the purge air connection 10 and the inner tube 8, the lance tube 1 is supplied with purge air which emerges from the nozzles 2.
• a check valve 12 is arranged in a scavenging air line 11 leading to the scavenging air connection 10 and is set such that the blowing medium cannot penetrate through the scavenging air line 11 after the soot blower valve 9 has been opened.
• the wall box 7 is provided with a connection 13 for a blocking medium, for example air.
• the sealing air connection 13 is connected via a flexible line 14 to a sealing air line 15 laid on the soot blower.
• the pressure of the purge air and the sealing air is above the gas pressure prevailing in the heat exchanger.
• the purge air and the sealing air are generated by a device which is specific to each soot blower and which is formed by a compressor 16 which is attached to the soot blower.
• the compressor 16 is connected to the soot blower in the workshop into one unit. In doing so, too the electrical connection cables for driving the compressor 16 and for the motor 3 of the soot blower drive are routed to a central terminal box and are electrically secured there.
• the compressor 16 is arranged in the vicinity of the soot blower valve 9;
• An air line 17 is connected to the outlet of the compressor 16, which leads to a knee stitia8.
• the sealing air line 15 branches off from the elbow 18 0 to the sealing air connection 13 on the wall box 7 and the purge air line 11 branches off to the purge air connection 10.
• a safety valve 19 is provided in the air line 17, the response pressure of which corresponds to the design pressure of the compressor 16.
• the compressor 5 is preferably an embodiment which has a delivery volume that is largely independent of the level of the counter gas pressure on the flue gas side. Compressors operating according to the displacement principle, such as piston and rotary piston compressors, can be used.
• this design can only be selected if the smoke-side overpressure is low, so that it can be accepted that no sealing air is emitted during the blowing operation of the soot blower.
• the check valve 12 is in fact closed and the compressor 16 is switched off or blows off via the safety valve 19.
• separate purge air connections 10 and sealing air connections 13 must be provided, as shown.
• the compressor 16 is arranged directly on the wall box 7.
• the sealing air connection 13 is rigidly connected to the wall box 7.
• the air blown into the wall box 7 can simultaneously serve as sealing air and purge air and ensure that the flue gases cannot escape from the heat exchanger into the open or can penetrate into the soot blowers.
• the knee 18 must be provided in the air line 17 with a branch to the purge air line 15, as shown in FIG. 3.
• a separate purge air and sealing air supply is also necessary in those soot blower types in which the nozzles 2 of the blowpipe remain in the heat exchanger even when the sootblower is not in operation, ie the sootblower valve 9 is closed.
• a task of the purge air and the sealing air can be selected according to each of the embodiments shown in FIGS. 2 and 3.
• the control of the compressor 16 can be operated in such a way that the compressor 16 runs continuously, that is to say also during the soot blower operation with the soot blower valve 9 open and the check valve 12 closed. Any overpressure that builds up is discharged via the safety valve 19.
• the control is preferably carried out in such a way that the compressor 16 is turned off when the soot blower is in operation.
• the switch-on and switch-off pulses for the electrical drive of the compressor 16 are picked up by the contactors of the sootblower control, which are controlled by the limit switches of the sootblower.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Incineration Of Waste (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6216125

Family Applications (1)

Country Status (7)

Families Citing this family (6)

Citations (5)

Family Cites Families (5)

• 1983
  • 1983-12-06 DE DE19833343992 patent/DE3343992A1/de active Granted
• 1984
  • 1984-09-01 DE DE8484110433T patent/DE3461338D1/de not_active Expired
  • 1984-09-01 EP EP84110433A patent/EP0148997B1/de not_active Expired
  • 1984-09-01 AT AT84110433T patent/ATE23630T1/de not_active IP Right Cessation
  • 1984-10-31 CA CA000466765A patent/CA1259002A/en not_active Expired
  • 1984-12-05 JP JP60500241A patent/JPH0686927B2/ja not_active Expired - Fee Related
  • 1984-12-05 WO PCT/EP1984/000390 patent/WO1985002673A1/de unknown
• 1985
  • 1985-02-21 IN IN148/MAS/85A patent/IN163540B/en unknown

Patent Citations (5)

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