Top Banner for Wood Drying Notes

Timber Kiln Drying Equipment

 

The commonest type of timber drying kilns are “heat and vent” type “compartment kilns” which dry timber in batches:

Heat and Vent timber kilns

These can be categorised by the location of the fans used to circulate the air. Thus there are:

Overhead Fan type timber kilns:-

Longitudinal shaft type (below): utilising a number of fans on a longitudinal, driven shaft.

Diagrams showing operation of longitudinal and cross shaft design kilns.

Diagrams showing operation of longitudinal (above) and cross shaft design kilns

Cross shaft type (above):- this type is the most popular in UK. One or more fans is used to circulate the air through the stickered stack of timber.

A 3m3 capacity overhead cross-shaft fan type timber kiln.

Above: A 3m3 capacity overhead cross-shaft fan type kiln. The air entry/ exhaust ducts are just visible in the back wall of the kiln, on either side of the air circulation fan.

 

Side Fan type: these are also popular:-

Drying timber showing fan at side of timber stack.

Construction of Timber Drying Kilns

 

Originally, compartment kilns were built of brick (cavity-wall), but these suffered from mortar degradation due to the acids released from the wood. Nowadays, they are usually constructed from double skinned sheet aluminium or steel, well insulated with glass wool. From a point of view of energy conservation it is imperative that there are good seals around the doors. The fans can be external or internal.

Kilns should always be run full to reduce air "short-circuiting” and not passing through the stack of timber.

Next Page: Benefits of Kiln Dried Timber production compared to Air Seasoning Timber

Button Link to Home Page

HOME

Privacy Policy and Website Terms of Use

Cookie Policy

Contents

Reasons to Dry Timber: An Introduction to Timber Drying

 

Timber Drying - Fundamentals Concepts and Definitions

 

Factors controlling the Drying of Wood

 

The Structures of Softwoods and Hardwoods and their effect on Wood Drying

 

An Introduction to the Air Seasoning of Timber

 

Layout of a Timber Drying Yard

 

Design of Stacks in the Timber Drying Yard

 

Kiln Drying of Timber

 

Types of Kiln Drying Equipment

 

Benefits of Kiln Dried Timber production compared to Air Seasoning Timber

 

Using a Dehumidifier to Dry Wood

 

High Temperature Timber Drying

 

Solar Kilns for Drying Timber

 

Drying Defects in Sawn Timber

 

Case Hardening of Timber

 

Avoiding Case Hardening by Monitoring the Drying of Timber. Also Collapse & Staining of Timber