Kiln Mechanics

L\DATA\Dept150\Polysius Presentations and Training\Polysius Training\Pyroprocessing\Kiln\kiln_mechanics.ppt 140 TEI, 140 CDPage 1

Krupp Polysius Corp.

Rotary Kiln

Mechanical Training



Content:

• Kiln General

• Kiln Inlet Including Seal

• Kiln Outlet Including Seal

• Kiln Shell

• Splined Kiln Tire

• Floating Kiln Tire

• Supporting Roller Station

• Kiln Drives

• Kiln Hood

• Maintenance, Lubrication



POLRO® 2-support rotary kiln



Kiln General



Rotary kiln assembly

1 Rotary kiln shell 7 Guard for rack and pinion drive2 Kiln inlet with inlet seal with lubrication device 3 Tires with fastening 8 Kiln drive

system 9 Kiln outlet with outlet seal4 Supporting roller stations 10 Kiln hood5 Kiln longitudinal guide 11 Clinkering zone cooling (optional)6 Rack and pinion drive



The POLRO 2 - support kiln

• splined tires (cold gap 0.4%)• self-aligning rollers• direct drive via supporting rollers• pneumatically applied inlet and outlet seals• air cooled kiln inlet tray



Process - technological dimensions

Kiln with preheater

Kiln with calciner

10 12 14 15 17L/D ratio

3 - Stations

Number of stations and L / D ratio

2 - Stations

10 12 14 17L/D ratio

3 - Stations

Design of rotary kilns



3 - support kiln versa 2 - support kiln

3-support kiln 2-support kiln

Statically undefined

• possibility of - extreme overload - plastic deformation

• requirement for - etxra safety margin - regular adjustment

Statically defined

• constant support loading

• elastic deformation only

• no sensitivity to misalignment

long enough for process?



Kiln Inlet



“Low-dust” kiln inlet



Air cooled segmented inlet through



Kiln inlet seal

Seal principle



• Slot adjustment between support ring and slide ring

Cardanical fastening

Kiln inlet



Air pressure systemKiln inlet



Kiln Outlet



Kiln outlet sealing



Slide ring

Support ring

Wear ring

Wear ring

Pneumatic cylinder

Cord

Cooling jacket

Principle of kiln outlet sealing



Principle kiln outlet Kiln outlet with dust chute

Kiln outlet



Outlet of kiln Outlet cooling

Kiln outlet



Kiln outlet

Air pressure system



Kiln Shell



Description of the kiln shell calculation basics

The shell is a rotating drum made from rolled steel plates. These shell sections have the same inside diameter but different plate thickness. All sections are welded together.

The shell thickness is a result of some calculations, the so-called Kiln Static.

Basic for the kiln static are some mechanical rules and some limiting factorsfor the shell material, the so-called Design Criteria.

The design criteria for a kiln shell is the Bending Stress.

Different kiln areas have different Loads.



Functions of the kiln shell

• Conveys material

• Guides gas from cooler to kiln

• Creates a constant moving material bed allows heat exchange between gas and material

• Holds the brick lining



Splined Tires



Description and function of the kiln tire

The tire is a steel ring on the outside of kiln shell. It works as an stiffener for the kiln shell. The kiln tires have to carry the kiln weight.

Functions: Transfer load from shell to the rollers

Keeps the shell in a round shape

May transfer torque from roller to tire

Design criteria: Tire bending stress

Ovality in %



Distribution of forces First splined tire in 1950

Splined tires



Principle splined tire Splined fixing

Splined tires



The Floating Shim Plates Form the Connection Between the Tire Teeth and the X-Shaped Retaining Blocks

The Floating Shim Plates Form the Connection Between the Tire Teeth and the X-Shaped Retaining Blocks

Splined tires



Kiln shell ovality Wedge pre-tensioning device

Kiln shell ovality [%]

Floating tire

Kiln Dia. [m]

Splined tire

Splined tires



Splined tire



Floating Tires



Distribution of forces Principle of floating tires

Floating (loose) tires



Steps for radial play reduction

Floating tires



Floating tires



Splined kiln tire Floating kiln tire

Comparison of kiln shell ovalities



Supporting Roller Station



Description and function of a kiln roller

A kiln roller is a steel wheel which is supported on each side. Each tire is supported by two rollers.

Functions: Transfer load from tires to base plate

Supports tires and keeps them in position

Can transfer torque from rollers to tire

Allows rotation

Design criteria: Hertz Pressure

Bearing Pressure



Roller station

1 Base frame

2 Bearing housingassembly

3 Roller and shaftassembly

5 Guide block

12 Oil level indicator



Self aligning roller station for Polro kiln



Kiln Drives



Girth gear drive system

1 Bridge support

2 Bridge plate

3,4 Plate bolts

5 Girth gear

6 Heat shield



Self-aligning pinion

Permitted tilting: ± 10 mm



Electro-hydraulic drive system



Electro-hydraulic drive system



Electro - mechanical drive



Kiln Hood



Kiln hood

1 Lower part of hood2 Upper part of hood3 Suspension door4 Trolley arrangement5 Burner seal6 Inspection port7 Access door8 Sub plate9 Collar segment10 Seal to cooler11 Opening for measuring

socket



Maintenance



Check points of kiln inlet seal:

• Slot between support ring and slide ring

• Thickness of the wear ring

• Visual check of sealing surfaces

• Check for material leakage

• Pre-tensioning of sealing robe

Maintenance kiln inlet



Air pressure net:

• Air pressure for pneumatic-cylinder

• Check of water separator

• Check of lubricator of pressurized air

• Check for leakages

Maintenance kiln inlet

Air pressure system



Check of outlet seal:

(similar to inlet seal), with additional points:

• Graphite lubrication of slide rings

• Function of pendling hatch

• Clearance of dust chute

• Functioning operation of expansion joints

Maintenance kiln outlet



Check of splined tire fastening:

• Check of wedge pre-tension

• Visual check of tire area

• Check of welds

Maintenance splined tires



Check of floating tire fastening:

• Control of relative movement

• Play measurements during stop times

• Control of axial retainers

• Lubrication of slide surfaces

• Check of welds

Maintenance floating tires



Damages at base plates by defficient lubrication

Maintenance floating tires



Maintenance / lubrication points

1 Girth gear

2 Compressor plant

3 Oil atomizer




4 Self-aligning pinion and stock bin

5 Splash lubrication girth gear pinion

6 Pinion bearing

7 Rotary kiln drive




15 Kiln tire

16 Inlet seal

17 Oil atomizer for inlet seal

18 Oil atomizer for outlet seal

19 Cooling air fan

20 Fan for clinkering zone cooling system




21 Supporting roller bearing station I

22 Supporting roller bearing station II

23 Supporting roller bearing staton III

24 Supporting rollerbearing station IV

25 Graphite lubrication equipment




26 Thrust roller

27 Safety thrust roller

28 Slide pin

29 Hydraulic kilns longitudinal guide

30 Graphite lubrication equipment

Documents

Kiln Mechanics