Rec Tractable Soot Blower

RKS RETRACTABLE SOOT BLOWER DESCRIPTION The RKS sootblower is a long retractable sootblower designed for the cleaning of boiler heating surfaces. This sootblower uses the potential energy in the blowing medium (steam or air) and transforms it almost completely into kinetic energy by means of venturii nozzles. The result is the best cleaning effect possible. The extra large cross flow sections avoid high-pressure drop inside the sootblower and high noise emissions. All components of the RKS sootblower are built for trouble free operation in the tough environment of a power boiler or similar applications. Normal travel speed is 76”/min. An optional hi speed gearbox is available at a travel speed of 98”/min. The unit may be mounted vertically or horizontally. When mounted vertically, a brake is required. The blowing element of the long retractable sootblower is the lance tube with two opposed venturii nozzles arranged at the front end. The lance tube is helically inserted into the flue gas pass, and then returned to the rest position by means of the gear-motor driven carriage. Thereby the two blowing jets ensure a full cleaning coverage along the entire blowing distance. The blowing medium is fed to the lance tube via the poppet valve and the fixed feed tube. The poppet valve is mechanically opened once the venturii have passed the boiler wall, and again closed before they reach the rest position again. To improve the cleaning effect and to reduce erosions, the sootblower is retracted on a different path ("indexed") each time the blower is operated. Because the lance tube is fully retracted from the furnace and cooled through the blowing medium, the long retractable sootblower can

be used in areas with higher flue gas temperature than any other sootblower type. However, it is important that the blower design conditions are being met at all times and that proper cooling is maintained. The cleaning effect of the Sootblower depends generally on the following: a. Size of of the venturii venturii being used used as determined by the inside diameters of the venturii. b. Pressure of the blowing medium medium in front of the venturii. c. Distance between the location location of the venturii and the boiler tube. d. Type of contamin contamination ation (slaggi (slagging ng or fouling conditions, etc.) The blowing pressure of the RKS sootblower has to be carefully monitored to prevent insufficient cleaning (blowing pressure probably too low!) and to avoid excessive erosions on boiler tubes (blowing pressure probably too high!). With steam being used, it is very important to properly design and operate the steam supply to avoid condensate blowing, which could cause severe damage to boiler and sootblower. It is important that all safety precautions are strictly enforced, especially the steam supply and the electrical supply precautions before any maintenance or repair work is performed. The major components in the RKS include the canopy, the traveling carriage, lance and feed tube, poppet valve, wallbox, blower suspension and electrical components. Each of these components will be briefly described in the following paragraphs. The canopy is a formed 1/4" (6.35mm) carbon steel or optional stainless steel structure providing rigid support and protection for the blower components. This Section 2 – Product Overview

Copyright © 2003 Clyde Bergemann, Inc. Applications Standards Handbook

RKS RETRACTABLE SOOT BLOWER DESCRIPTION canopy design intentionally gives easy access to all parts that require regular maintenance or repair work. The solid front plate provides a surface to mount the lance tube support bearings and, at the same time, shields the blower against corrosive attack. Square rails and angles with weld-on style racks are attached to both sides of the canopy to provide support to the blower carriage, provide a mounting surface for the rails, and maintain good pinion clearance. A removable top cover at the rest position allows replacement of the gear-motor through the top of the canopy while leaving the lance hub housing, lance and feed tube, as well as the poppet valve in place. The blower carriage consists of three separate components: the lance hub assembly, the gearbox and the electric motor. The lance hub housing contains the lance hub, which is supported by two special roller bearings and sealed by two double lip Viton oil seals. Because the lance hub housing is a separate component from the gearbox, heat transfer from the cleaning medium to the blower gears is avoided. The electric motor is directly mounted to the fully enclosed spur and worm gear that has two output drive shafts. The axial drive shaft for the lance tube insertion and the rotary drive shaft for the lance tube rotation. The selflocking characteristic of the worm gear ensures that the carriage will not travel in case the motor looses power. Several different travel speeds are available for proper cleaning coverage. The blower carriage is well guided in the canopy rails by a set of vertically and horizontally arranged rollers. The lance tube is flanged to the rotating lance hub, which also takes up the stuffing box packing. The lance tube of the RKS is designed to meet the specific requirements of each

application. The standard lance material is 3 1/2" O.D. (4" optional), high tensile quenched and tempered chrome moly alloy steel with full penetration butt welded collar for a safe connection to the lance hub. The lance nozzle is made of a high temperature, heavy wall (.219"), 310 stainless steel investment casting. Two venturii are used as required for proper cleaning. The lance tube support is designed to keep the lance tube close to the center of gravity for deflection compensation. The fixed feed tube ensures proper packing sealing while the lance tube is inserting or retracting. The feed tube is connected to the poppet valve via an easy removable split ring and a clamp plate. The standard feed tube is 304 stainless steel, 2 3/8" O.D. All feed tubes are ground finished to ensure a long packing life. The blowing medium is supplied through an automated poppet valve, which has a standard ANSI 600 R.F. flange connected to the blowing medium piping. The valve seat is threaded for easy replacement without the necessity of removal and machining of the poppet valve. Three different seat/cone sizes are available to match the line pressure. The valve stem is sealed off by means of the pure graphite valve stem packing. The switching travel is adjustable to suit the actual requirements by relocating the trip pin in the trip bar. The valve control location is easily accessible for adjustments and maintenance work. The pressure from the supply line can be independently adjusted with respect to the valve opening via the pressure control disc. Two threaded plugs are supplied in the poppet valve casting to monitor downstream blowing pressure and to connect a steam purge line if necessary. Section 2 – Product Overview


RKS RETRACTABLE SOOT BLOWER DESCRIPTION Depending on the furnace pressure conditions, two types of wallboxes are available: a. A n ne egative pr pressure wa wallbox is is supplied for furnaces with reliable negative gas pressure condition. The spring loaded floating plate seals the boiler opening sufficiently and still provides proper lance tube clearance. b. For po positive flflue ga gas co conditions a positive pressure wallbox with sealing air connection is recommended to avoid gas leaks from the sootblower wall openings. For temporary removal of the lance tube, high pressure aspirating air can be applied to seal off the openings. The front plate of the RKS is connected to the boiler wall via the pivoting front suspension, supplied together with the wallbox to be mounted to the boiler wall sleeve. At the rear end of the sootblower a second support provides suspension from the structural steel of the boiler. The suspension allows the front end to follow the

horizontal and vertical expansion of the boiler. Generally, for steam blowing, the sootblower is declined towards the boiler in operating condition to ensure proper drainage of the lance and feed tube. The RKS traversing operation is contained by two limit switches at the rest and reverse position. These limit switches are activated by a trip pin or flag located on the lance hub housing. The slotted limit switch bracket located on the canopy accomplishes limit switch adjustment. The electric motor power for the blower carriage drive is supplied through a four wire SO cord which is carried by the E-Chain system. The voltages of the limit switches and motor power supply can be controlled in a NEMA 4 terminal box for field connection. Generally, a NEMA 4 push button station is provided for manually control the sootblower during maintenance work. The motor starter, with overload protection required for sootblower operation, can be individually mounted in a NEMA 4 starter box or in a common central starter cabinet.

Section 2 – Product Overview


RKS RETRACTABLE SOOT BLOWER SPECIFICATIONS Housing

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1/4” Thick Cold Rolled Steel

Motor

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1.5 H.P. (230/460V, 3 phase, 60 Hz, 1800 RPM), TEFC

Lance

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3.5”/4”/5” O.D. Alloy – T11 Standard 4130, 17-22sa or Stainless for higher Temp. Applications

Nozzle Indexing

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Through Timer in PLC or Local Enclosure.

Feed Tube

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Type 304 Stainless Steel

Nozzle Head

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Carbon Steel, ASTM A216 Grade WCB or

Valve Body

Alloy, ASTM A217 Grade WC6 Plug

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Seat

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RC-50H 5/ 5/8” Pitch

Side Bars

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Straight Bar, Nickel Plated

Bushings

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Rollers

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Nickel Plated

Pins

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Limit Switches

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Heavy Duty, NEMA 4 – Other Options Available

Electrical Box

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NEMA 4 Standard – Other Options Available

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Term Termin inal al Stri Strips ps and and Inse Insert rt/R /Ret etra ract ct Pus Pushbut hbutto tons ns

Lance Rotation Chain

Comp Co mpon onen ents ts

Options Include -

Integrally Mounted Motor Starter Cabinets

Wiring – Box Conductor

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16 AWG for Power

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16 or 18 AWG for Control

Insulation

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(THHN) or (MTW) 90ºC Rated

Sheath

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Stranded Copper

Cable Sheath

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Stranded Copper

Wiring

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3 & 5 Conductor NEC type MC, 14 AWG Stranded (Class B)

Wiring – Cable

annealed copper, 90ºC, 600V, flame-retardant.



RKS RETRACTABLE SOOT BLOWER SPECIFICATIONS

Lubrication

Coating

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Spindle Bearings – CBI Grease

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Gearbox – CBI Oil

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Galvanized as Standard

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Primer Base wi with Ac Acrylic or En Enamel Pa Paint as Option

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Color lor: Standa ndard Blue (Any Color Availab lable as Option) on)

- Chain/Rack – CBI Spray













Rec Tractable Soot Blower

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