us sootblower

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US Sootblowers

© CBPG Clyde Bergemann Power Group - All Rights Reserved

Introduction

Topics to be discussed:

Overview of Clyde Bergemann Inc.

Basic Description/Operation of US Sootblower.

Detailed Description

- Mechanical Components

- Electrical Components


Basic Description

The (US) Sootblower is a long retractable sootblower designed for the cleaning of boiler heating surfaces.

The Long Retractable Sootblower efficiently uses the potential energy in the blowing medium (steam or air) and transforms it almost completely into kinetic energy by means of venturi nozzles.


Basic Description

The blowing element of the long retractable sootblower is the lance tube with two opposed venturi nozzles arranged at the front end.


Basic Description

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.


Canopy

Square rails and angles with bolt-on style gear racks are attached to both sides of the canopy to provide support to the blower carriage, and maintain good pinion clearance.

The bolt-on style gear rack allows for easy removal and installation.

The design of the canopy intentionally gives easy access to all parts that require regular maintenance or repair work significantly reducing maintenance costs.


Carriage Assembly

Over heating the gearbox significantly reduces the life of the lubricant and damages the lubricant seals causing leakage.

This cooler gearbox design also allows a synthetic lubricant to be used, which will last the life of the gearbox, making it virtually maintenance free.


Carriage Assembly

The blower carriage is a unique design that consists of two separate components:

Upper gearbox

Lower spindle housing

This design prevents excessive heat transfer from the hot spindle housing to the blower gearbox.


Rack and Pinion Drive

A roller and pinion are mounted on each side of the output drive shaft resulting in a “balanced design” dual rack and pinion drive, which minimizes wear and tear on the gear racks/pinions.

Side rollers are mounted on the gearbox to guide the blower carriage on the rails.

Roller

Pinion

Side Roller


Drive Shafts

The Carriage has two output drive shafts.

The main output drive shaft provides for translation of the carriage.

A heavy-duty chain is connected to a sprocket on the lower spindle and provides rotation to the lance.

Translation Drive Shaft

Rotation Drive Shaft


Mechanical Components

The main drive motor rotates the main output drive shaft for translation of the carriage.

The main output drive is turned by a worm gear, which results in a locked-train design preventing movement of the carriage due to steam pressure.

The worm gear also provides rotation to the rear gear assembly which allows for rotation of the chain sprocket.


Basic Description

The carriage rides on a balanced dual rack and pinion drive system and is supported by a long steel canopy.

Thereby the two blowing jets ensure a full cleaning coverage along the entire blowing distance.


Basic Description

Sootblowers designed to travel >35 feet are equipped with additional support to prevent damage to the lance and feed tube.

Lance and feed tube support assembly


Basic Description

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 venturi have passed into the boiler and then closes before they reach the boiler wall while returning to the rest position.

Poppet valve

Fixed feed tube


Indexing Sootblowers

To improve the cleaning effect and to reduce erosions, the sootblower is retracted on a different helical path ("indexed") each time the blower is operated.

Indexing is the rotation of the lance tube, w/o forward movement, to achieve a new helix with each run of the sootblower.

Indexing allows the lance tube nozzles to clean a slightly different path (new helix) with every operation of the sootblower allowing 100% of the boiler tube surfaces to be contacted with the cleaning medium.


How Indexing is Accomplished

Indexing is a patented mechanical feature of the Clyde Bergemanngearbox.

When the sootblower reaches the end of its forward travel the carriage actuates the fully inserted limit switch and starts a 0.8 second timer.

The carriage continues to travel forward and hits the front stop block.

When the carriage hits the stop block a clutch slips on the drive pinion in the gearbox which stops forward movement of the carriage but continues to rotate the lance tube.


Basic Description

When the 0.8 second delay timer expires, the carriage retracts to the rest position.

By allowing the carriage to engage the stop block and rotates the lance tube without translation, indexing is achieved and a new helical path for the nozzles to clean.

Controlling the amount of time that the lance tube is allowed to rotate is the key to the operation.

In order to control the amount of time for indexing the sootblower, the front limit switch position must be properly installed.


Basic Description

The typical amount of indexing is generally set to about 1/8th nozzle rotation.


Basic Description


SealPackTM

The SealPackTM is a spring loaded packing cartridge assembly that provides continuous pressure on the packing gland.

The SealPackTM seals the packing against the feed tube as it rotates and travels with the carriage, thus eliminating the need for maintenance personnel to repeatedly adjust the packing gland.


SealPackTM

On a recent study, the SealPackTM extended the life of a set of packing to 18 months of operation on a recovery boiler.

This significantly reduces the maintenance costs associated withsootblower packing and will have an even greater effect on a power boiler application.


Poppet Valve

The blowing medium is fed through an externally adjustable poppet valve.

The pressure of each individual sootblower can easily be adjusted while in operation, eliminating the need to shutdown, isolate, and tag out the blower.

The supply line pressure can also be adjusted independent of the valve opening by using the SmartControl system, offering additional control over the cleaning intensity.


Poppet Valve Components

Guide Bushing

Valve Stem Pressure Disk

Valve Seat

Valve Plug Nut

Valve Plug

Roll Pin

Guide Bushing Washer

Gasket


Poppet Valve Components

Valve stem

Packing

Packing Gland

Lock Plate Weldment

Lock Angle Packing Nut

Valve Spring

Adjustment Nut

Lock Nut


Poppet Valve Operating Mechanism

When the blower carriage starts inserting, the poppet valve is opened by the valve latch and arm assembly.

A pin attached to the carriage actuates the poppet valve.

Poppet Valve Pin Attachment Bolts Poppet Valve

Valve Latch Optional Center Support Pin


Vent Valve

The purpose of the vent valve is to scavenge air into the sootblower when the sootblower is idle.

The negative pressure boiler will supply the suction pressure.

The operating pressure of the sootblower seals the opening during operation.

Vent Valve


A threaded plug is supplied on the opposite side of the vent valve.

The threaded plug is a standard location for monitoring the blowing pressure downstream of the seat and for a seal air/scavenging air connection.

A pressure gauge can be installed to check the sootblower operating pressure.

Clyde Bergemann recommends a permanent installation of a pressure gauge for ease of pressure verification without working on the sootblower.

Verification of Pressure


Wallbox Options

Depending on the furnace pressure conditions, two types of wallboxes are available:

Negative pressure

Positive pressure


Negative Pressure Wallbox

A negative pressure wallbox is supplied for furnaces with a reliable negative gas pressure condition.

A spring loaded floating plate seals the boiler opening sufficiently and still provides proper lance tube clearance.


Positive Pressure Wallbox

For positive flue gas conditions a positive pressure wallbox with sealing air connection is recommended to avoid gas leaks from the sootblower wall openings.


Blower Suspension

The front plate of the sootblower has two arms extending away from the sootblower.

The arms have a threaded hole that line up with the two pivot holes (bosses) that are located on the sootblower wallbox.


The rear of the sootblower has a slotted plate that is used to support the back of the sootblower.

A pin is inserted through two hanger rods and the slotted plates to support the rear of the sootblower.

Blower Suspension


Electric Motor

The electric motor is mounted directly to the gearbox.

The blower carriage assembly is driven by a 2 HP (230/460V, 3 phase, 60Hz, 1800RPM) electric motor.

The electric motor power is supplied through a four wire S.O. cable that is guided by the E-Chain trailing device.


Limit Switch

The US Sootblower's travel is constrained by a single limit switch on the carriage.

The limit switch is activated by a flag bolted on the rear (rest position) and front (full insert) of the canopy.


Limit Switch

The limit switch’s motor power supply can be accessed in an electrical box that is mounted to the side of the sootblower housing.

The limit switch and motor cables are wired to terminal strips in an electrical box to facilitate connection at the plant.


P-Chain


P-Chain Photos


Control Panel


Basic Description

The blowing pressure of the US 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 couldcause severe damage to boiler and sootblower.


Normal Operation

In the event that certain areas are not sufficiently cleaned, those responsible sootblowers may be addressed individually.

Since the sootblower’s blowing jets often have an erosive effect if dust or ash is present, it is recommended to regularly check the surfaces for erosion, and reduce the blowing pressure if damage is found.

us sootblower

Documents

overview of clyde bergemann

blower carriage

rights reservedrack

main output drive shaft

main drive motor

output drive shafts

blower gearbox

cooler gearbox design