TECCON

BELT DRYER
2,5 to 10,0 t / H
Water evaporation RATE
 Installation of belt dryer

2 TECCON belt dryer

Belt dryer
2,5 to 10,0 t / H Water evaporation RATE

1 Zentrales Element im Pelletswerk Norica ist der PELLET.TURM

accurate and homogeneous creating excellent preconditions for the

In the production process of wood pel- production of high quality wood pellets
lets, raw materials such as saw dust or at low operating costs.
shavings with water contents of 50 % The TECCON belt dryer features a high-
and higher are typically dried to 10 %. ly efficient and flexible system for dry-
The TECCON belt dryer designed for low ing fibrous wood material. Hot water
value heat sources optimizes the dry- from boilers and waste heat from in-
ing process by a smart arrangement of dustrial processes are commonly used
components. The moisture content of for drying. The evaporation rate ranges
the dried material exiting the belt dry- from 2.5 to 10 tons of water per hour. 2
er is kept within a tight tolerance, thus

1 CAD rendering of a TECCON belt dryer, showing

air intakes at the upper section of the enclosure
and exhaust fans which blow the humid air to
the stacks
2 Rotation monitoring
3 Air blower connected to the continuous belt
cleaning device 3

TECCON belt dryer 3

 Pellet plants
Experience and Engineering EXPERTICE

With long standing in-house experience The innovative and patented PELLET. pellet plants is offered to the customer.
in operating its own pellet plant and re- TOWER has become a well-accepted TECCON installations reflect the state
nowned for its engineering excellence, key feature of pellet plants designed of art, are user friendly and carefully tai-
TECCON minimizes investment risks and installed by TECCON. With the belt lored to the needs of its customers.
and achieves a highly profitable reali- dryer and additional technologies for TECCON is entirely competent to offer
zation of wood pellet plants. pre-processing, storing and convey- comprehensive services, ranging from
ing a complete range of solutions for early consulting stages like pre-feasi-

4 TECCON belt dryer

bility studies to plant completion and
start up, augmented by plant operation
By feeding dried material with great uniformity into
assistance worldwide. TECCON also at-
the PELLET.TOWER, the belt dryer is regarded as a
taches particular importance to opti-
key element of the wood pellet plant, contributing
mizing and upgrading existing pellet
significantly to energy efficiency and operational
plant operations.
reliability.

TECCON belt dryer 5

 Function
TECCON Belt dryer

Wet raw material, most commonly fi- shavings which slowly travels on the of each zone to the de­­creasing mois-
bres from sawmills, is fed continuously permeable fabric belt. On the pressure ture release. Therefore each zone is
onto the TECCON belt dryer. The drying side, the humid air is moved on to the separately served by a variable speed
is effected by exposure to heated air. stacks and released to the atmosphere. fan. Supported by advanced instru-
A set of screw conveyors evenly dist­ In direct contact with heated air dur- mentation, the whole drying process is
ribute the material across the width of ing the first phase of the drying process, characterized by excellent controllabili-
an air permeable fabric belt. the fibres release their surface mois- ty. One or several turning devices main-
The height of the layer, adjusted by ver- ture. Subsequently, water from the in- tain a uniform air flow through the layer
tically moving the screw conveyors, is side begins to diffuse to the surface of fibres and contribute to the equaliza-
varied in order to meet specific require- of the wood particles and is again ab- tion of their moisture content.
ments of raw materials. sorbed by heated air. By regulating key process variables
On the suction side of the exhaust fans During the progressive drying process, such as height of layer, air throughput
ambient air is drawn through heat ex- zoning of the drying tunnel permits and dwell time, the moisture of the fi-
changers and through the layer of separate adjustment of the air volumes

material Flows
 Raw material
 Ambient air
 Dry hot air
 Humid exhaust air
 Hot water flow
 Cold water return

6 TECCON belt dryer

bres will precisely conform to the set
point.
To maintain the cleanliness and per-
meability high velocity air impingement
onto the returning fabric belt is con-
tinuously employed. In addition, wet
cleaning is used, when necessary. At
the outlet of the drying tunnel, the lay-
er of the dried particles falls into a dis-
charge screw supplying the next pro-
cess stage.

A dual stage heat exchanger during installation

TECCON belt dryer 7

 Functional groups
FLOW OF Fibres AND PROCESS BELT

Enclosure

ce
vi
de
Wet material

ing
intake

n
Tur
g
m din
ste ui

Process belt
sy elt g
B

flow of Fibres number of turning devices and their po- gy and fulfills the twofold task of trans-
Material intake sitioning lead to considerable energy porting and passing hot air through the
Uniform height and density of a lay- savings and qualitative improvement of layer of fibres. Bronze wires woven into
er, built up from fibres, are crucial for the dried material.. the fabric in working direction prevent
an efficient drying process. In TECCON electrostatic charging.
belt dryers two counter-rotating screw Material outlet The edges of the process belt of the
conveyors are employed to evenly feed At the end of the drying tunnel the fibres TECCON dryer are bent upwards by a
wet material onto the belt, thus achiev- leave the process belt after the drive roll special design. Thereby the air flow
ing the essential uniformity. and are taken over by a screw convey- is much better sealed off and leakage
By means of a stroke spindle drive the or discharging them at the final transfer kept to a minimum. Less dust depos-
desired height of the layer is set. point, where the moisture content of the its, significant energy savings and low-
Heat tracing and thermal insulation can dried material is continuously meas- er maintenance input are achieved.
be used to prevent fibres from freezing ured as an input for control loops.
(optional). Belt assembly
process belt After passing the main drive roll, clean-
Turning devices The process belt is driven by a geared ing devices, tensioning unit and guid-
One or several turning devices mix the motor connected to the rubber covered ing system the belt runs round the main
drier upper tier of the layer with the roll. The speed of the motor is infinitely return roll and travels over the belt sup-
wetter lower tier to equalize the mois- variable according to the requirements port rolls through the drying tunnel.
ture content over the height. Turning of the process. The air-permeable belt Support rolls minimize fabric sagging
devices also loosen up the particles, made of antistatic synthetic hybrid fab- and help to keep the layer from crack-
enhancing a uniform hot air flow. The ric is a key element of the technolo- ing up.

8 TECCON belt dryer

Turning device

Tur
n

Ru
ing

b be
dev

rc
Dr
y

ov ng
ice

cle

er
ed
an
i

dr
ive
ro
ll
We

Screw
tc

conveyor
lean

discharging
ing

dried
material

Belt tensioning

Belt guiding system Wet cleaning of belt

Directional stability of the belt, permit- High pressure water nozzles clean off
ting only minute deviations, is accom- particularly resistant contaminants
plished by a fully automatic guiding whenever needed. The wet cleaning
system. In addition, contact-free sen- unit, placed in the back run, ultimately
sors are employed to monitor the belt ensures a sustainable performance of
edges to avoid any damage during op- the process belt because of its high air
eration. permeability.

Dry cleaning of belt

Best overall efficiency and full opera- 1
tional availability of the dryer can on-
ly be reached when the maximum mesh
opening of the fabric belt is maintained
at all times. An integrated self-clean-
ing unit, located directly after the drive
roll and featuring a powerful air blow-
er, supplies continuously high velocity
air. Adhering particles are removed and
recycled to the dried material discharge
conveyor.
1 Speed controlled belt
drive
2 Automatic belt guiding 2
device

TECCON belt dryer 9

 Functional groups
Air system and enclosure

Exhaust stack
Enclosure
Hot water flow

Air inlet

Cold water return

Heat exchanger

Exhaust air collector

Air system ume is necessary to remove water va- Heat exchanger

Airflow por than during the last phase prior to Heat exchangers operated with a water/
Exhaust fans draw hot air through lay- discharge. For this reason, station- glycol mix, warm up the drawn-in am-
er and process belt. When dry hot air ary baffle plates are incorporated in the bient air, before the air is entering the
is passed top down through the fibres, drying tunnel to adjust the required air drying tunnel and passing through the
moisture is absorbed. Fine dust par- volumes in different drying zones. Each layer of fibres and meshes of the pro-
ticles carried along with the drying air zone is served by a separate exhaust cess belt. The number and size of heat
settle on the layer. The entire drying fan to control the air volumes required exchangers are determined by process
tunnel is kept under a slightly reduced for efficient drying of the fibres. Due to parameters. Multistage exchangers
pressure because of the induced draft the advanced air distribution the over- are used to optimize the heat efficien-
fan. Therefore air leakage and conse- all power consumption for the belt dry- cy in the temperature range from 50 to
quently dust problems are prevent- er is optimized. 120 °C for hot water.
ed. Unwanted cold air is largely inhibit- Alternatively, heat exchangers utiliz-
ed from entering the drying section via Exhaust system ing low pressure steam or hot air can
material inlet and discharge. The up- The exhaust is blown through the be offered.
wards bent edges of the process belt stacks to mix with the ambient air. In
provide additional lateral sealing. the event of very low noise levels being
stipu­lated, sound dampers can be in-
Drying tunnel with zoning stalled as an option.
During the first phase of the drying pro-
cess, when wet fibres start moving on
the process belt, a much larger air vol-

10 TECCON belt dryer

 Exhaust stack

Exhaust stack

Air system with exhaust fan

enclosure
Modular design
The modular design of the TECCON
dryer allows for flexible adaptation
to customer requirements and easy
installation. Proven components, ex-
pedient project implementation and
optimized costs will be of significant
benefit to plant operators.

Base frame and exhaust

air collector
A base frame of galvanized steel trans-
fers the loads of the plant to the foun-
dation. A stainless steel exhaust air
collector of air tight design has been
aerodynamically optimized, but is still
easy to clean.

Exhaust fan with

variable-speed drive

TECCON belt dryer 11

 Functional groups
Control, visualization, safety equipment, AUXILIARIES

Symbol image

Control, visualization flexible and dynamic. Soft start mode safety DEVICES
All functions of the belt dryer are for drives supports smooth operation Personal safety
monitored and actuated by a central and helps to control the drying process. All accesses to drying tunnel sec-
control system. Important production The operating personnel benefits from tions and screw conveyors are secured
data such as ambient air tempera- user-friendly visualization, combined by limit switches. Opening a moni-
ture, drying air temperature before and with remote control and remote main- tored access door triggers an imme-
after the layer of fibres, air pressure in tenance. Furthermore, the software is diate emergency stop. Automatic re-
the exhaust collector, inlet and outlet especially suited for optimizing and starting of the equipment is ruled out.
temperatures of the heating fluid in the fine tuning the process, for instance Unmonitored openings are bolted with
exchangers, the water content of the by trend analysis. Having numerous screws, gaining access requires tools.
dried material are measured and dis- monitoring devices relating to rota- All drives can be equipped with lock-
played. tion, current consumption of motors, able repair switches attached to each
Based on these measurements, spe- directional process belt run, differential unit.
cialized control software continuously pressure and vibration I & C Technol-
adjusts process parameters such as ogy also integrates all necessary safety General safety
belt and fan speeds, thus ensuring functions. The high degree of comput- The belt dryer has been developed, de-
constant moisture of the dried fibres erization contributes to streamlined signed and built in full compliance with
and cost efficient operation of the dryer. operation and the need for personnel is the currently applicable best engineer-
The process control system is highly kept to a minimum. ing practice. TECCON has put particular

12 TECCON belt dryer

 DIMENSION SHEET
Belt dryer with an evaporation rate of 2.5 to
10.0  t / h.
Dimensions L1, L2 and L3 will vary according to the
evaporation rate, the specification of fibres and the
type of heat available.

emphasis on standards for safe opera- • Pressure, temperature, rotation, po- • Two-stage heat exchangers for
tion, also drawing from extensive own sition and motor current monitoring usage of low temperature heat
experience. • Automatic fire extinguishing system • Super Premium Efficiency
The safety of the machines is subject to with dry extinguishing lines drives and fans
the following EC directives:
• Machinery directive 2006 / 42 / EG accessories Weather ability
• EMV directive 2004 / 108 / EG Optional packages for customizing the • Enclosure for outdoor installation
• Low-voltage-directive 2006 / 95 / EG dryers are available. • Insulation of exhaust air collector
and applied harmonized standards. • Heat tracing of water-carrying pipes
Operating comfort • Container for housing of elec-
Compliance with the guidelines is con- • Feeding bin with metering de- tric and I & C equipment
firmed by the declaration of conform- vice at the discharge
ity according to Machinery Directive • Sound dampers for exhaust air
2006 /  42 / EG certified by CE marking. • Continuous In-line moisture
Further safety features are measurement at raw material inlet
• Comprehensive explosion
and fire protection concept Plant performance
• Suitability for installa- • Additional turning devices
tion in ATEX Zone 22

TECCON belt dryer 13

 Optimized for wood pelleting plants

The TECCON belt dryer is tailored to Zoning of the drying tunnel • Quality improvement of dried
meet all the parameters of a drying • More precise control of fibres because of gentle drying
process which help to upgrade the drying process
production and quality of wood pel- • Increased flexibility Comprehensive I & C technology
lets. Therefore, the dryer is uniquely • Uniform moisture content • Easy to operate
suited for wood pellet plants. • Lower energy consumption • Automatic operation
Among the most important features • Excellent response to par- • Low maintenance costs
are: tial load operation • High availability
• Low electric power consumption
Process belt-lateral sealing Additional turning devices • High quality dried fibres
The edges of the belt are bent up- • Greatly improved homogene-
wards with a difference in height of ity of moisture in dried fibres Quality components
about 100 mm. The trough shaped • Tangible energy savings • High reliability
belt makes it difficult for the drying air • High expected technical lifetime
to bypass the fiber layer. By introduc- Speed controlled fan drives • Low expenditures for maintenance
ing this barrier, undesirable airflows • Cost effectiveness • Low energy losses
are remarkably diminished with fol- • Exact control of the drying process
lowing operational advantages: • Excellent performance un- Operational safety
• Higher energy efficiency der partial load operations • Sophisticated fire and dust ex-
• Improved dust containment plosion protection concept
• Less effort for cleaning, espe- Optimized heat exchangers • Advanced air pollution control
cially in exhaust collectors • Energy efficiency • Optimal quality of dried ma-
• Lower maintenance costs • Economical use of low tem- terial for wood pellets
• Lower dust emissions perature energy sources

14 TECCON belt dryer

Highlights

HOMOGENEOUS DRIED FIBROUS MATERIAL ACCURATELY MEETING SPECIFICATIONS

USER FRIENDLY, LOW MAINTENANCE

EXCELLENT AVAILIBILITY AND TECHNICAL LIFETIME

LOW DUST EMISSIONS

LOW THERMAL AND ELECTRIC ENERGY CONSUMPTION

The air-permeable process belt of antistatic

synthetic-metal-hybrid material is particularly
suited for the dual function: Transport of and airflow
through the layer of fibres. The edges of the process
belt in TECCON’s dryer design are bent upwards.
This approach minimizes bypass air leakages,
leading to reduced energy losses and less dust
deposits.

TECCON belt dryer 15

 CAD image of a TECCON belt dryer

Teccon Konstruktionen GMBH

Katschbergstrasse 78 – 80
9851 Lieserbrücke, Austria © Intellectual property of TECCON Konstruktionen
Phone: +43 4762-44 820 GmbH
Fax: +43 4762-44 820 29 Subject to technical modifications – not binding.
office@teccon.at For General Terms and Conditions see
http://www.teccon.at/teccon/home_e/infos_
www.teccon.at impressum_e.html