Binary Drying method: One solution for the preservation of large waterlogged wood

Binary drying method:One solution for the preservation of large

waterlogged wood

Cláudio MonteiroPhD student of the University of Trás-os-Montes e Alto [email protected]

Drying interleaved system that combines two drying phases.

Absolute drying: Moment where energy is induced into the system which promotes the evaporation of water and the imbalance of moisture content in the wood. Drying calibration:Time when the moisture content are calibrated through natural rebalancing of the system, where the most wetlands dry and moisten the driest areas.

Binary drying

Absolute drying Drying calibration

Bina

ry dry

ing

Clim

atic c

hamber

dehumidifier

humidi

fier

infrared sources

RPT - Resistance to penetration testing

𝑃=3121 𝑘𝑔𝑓 /𝑚²

𝐶𝑜𝑛𝑣𝑒𝑟𝑠𝑖𝑜𝑛 𝑙𝑒𝑣𝑒𝑙 𝑜𝑓 𝑑𝑒𝑔𝑟𝑎𝑑𝑎𝑡𝑖𝑜𝑛= 𝑃 𝑑h2

𝑥100

Pd = penetration depthh = Height

Ochroma pyramidale

Percentage

estimates between

Conversion level

of degradation

Condition of the

woody tissue

From the

viewpoint of

treatment

0%-10% 1 Very good No need for

consolidants11%-20% 2 Good

21%-30% 3 Reasonable Needs

assessment

31%-40% 4 Severe 1 Partial

deformation41%-50% 5 Severe 2

51%-60% 6 Severe 3

61%-70% 7 Destroyed 1 Total strain

71%-80% 8 Destroyed 2

81%-90% 9 Destroyed 3

91%-100% 10 Destroyed 4

Ref. T.H. Species Origin Degree of

deterioration of

the woody tissuePM8 98.1% Ulmus Minor

(hardwood)

Troia I 1

PM9 107.6% hardwood Ria de Aveiro F (14) 1

PM10 617.4% softwood Museu da Levada 5

PM11 118.2% hardwood Museu da levada 3

PM27 670% hardwood Ria de Aveiro F 10

PM30 360% Pinus (softwood) Ria de Aveiro A 1

PM31 684.4% hardwood Ria de Aveiro F (115) 10

The

Sample

s

Air

drying

Binary

drying

PM27

PM28

Air

drying

Binary

drying

PM9

PM6

Binary

drying

PM25

Binary

drying

Air

dryi

ng

PM24

PM30

Combin

ed

trea

tment

of

sucros

e + dr

ying

bina

ry

Impregnation with sucrose

Drying binary

A sa

carose

- And abundant natural product; - Low molecular weight (342.24 g / mol) - Good hygroscopic resistance;- Low cost and easy availability; - Ecological.

- Vulnerable to biological activity.

Advant

ages

Disadv antage s

The su

crose water solution 1

•1% formaldehyde •50% sucrose (w / w) by gradually increasing •  to saturation of the solvent by evaporation

water solution2•2% formaldehyde •50% sucrose (w / w) by gradually increasing •  to saturation of the solvent by evaporation

water solution3•4% formaldehyde •50% sucrose (w / w) by gradually increasing •  to saturation of the solvent by evaporation

Pilot water solution•10 % sucrose (w/w)

Method

ology

Impregnation by immersion sucrose• Sucrose solution by gradually increasing fractions of 5% to 40%.

• Addition of 1% formaldehyde • Immersion time: 7 weeksDrying controlled by the binary drying model• Time: 125 days

Meto

dologi

a Drying parameters

Standard Parameters Time in hours

Thermal variation ºC

Variation of RH

Duration in days

Standard 1 absolute drying

00:15 10 30% ±5 9

Drying calibration

23:45 ±2 0%

Standard 2 absolute drying

00:15 10 30% ±5 7

Drying calibration

11:45 ±2 0%

Standard3 absolute drying

00:20 20 35% ±5 55  

Drying calibration

23:40 ±2 0%

Standard 4 absolute drying

00:25 30 40% ±5 11

Drying calibration

23:35 ±2 0%

Standard 5(calibration

)

absolute drying

- - - 9

Drying calibration

24 ±2 0%

Standard 6 absolute drying

00:25 30 40% ±5 34

Drying

calibration

23:35 ±2 0%

Rate

of co

ntract

ion

Madeiras   Wet Dry Dimensional change

 ML - 1

C 22cm 22cm 0%

L 6.8cm 6.3cm 7.3%

H 7.7cm 6.5cm 15.5%

 ML- 2

C 25cm 25cm 0%

L 4.2cm 3.7cm 11.9%

H 4.1cm 4.0cm 2.4%

Result

s

ML 1

Result

s

ML 2

Conc

lusion

s

• The binary drying allows dry woods of level of degradation 1 and 2 without the addition of consolidants.

• Inhibits deformation by tension, keeping the shapes of objects without distortion or warping.

• It is an ecological method and may be combined with other methods.

• Can be easily implemented on a large scale.

In t

he f

uture • Other sources of energy, such as microwaves may

be used. • In countries with good sun exposure can be

built large chambers using the sun as a natural source of infrared radiation.

Thank you