KjelDigester K-446 / K-449

Technical data sheet

The KjelDigester offers fast and safe digestion of up to 20 samples simultaneously. The fully auto-
mated model K-449 offers a convenient automatic lift for raising and lowering the sample tube
rack and a programming mode so that all digestion methods can be saved. The manual K-446 is
an entry level block digester with effortless manual control and manual rack handling. The sample
tube rack of both digesters can be placed directly into the KjelSampler K-376 and K-377 for fully
automated, high throughput nitrogen and protein determination according to Kjeldahl.
Scope of delivery
The KjelDigester models are delivered ready to use with the standard package comprising of:

Components Qty

Sample tubes 300 mL 20

Rack 20 position 1

Suction module * 1

Hose to Scrubber 1.5 m 1

Hose connecter S19 (ball joint) 1

Clamp for hose connecter S19 1

Drip tray 1

Drip tray holder 1

* standard or with condensate trap

Order code
Choose the configuration according to your needs:

1 1 5 4 4 0 0 0

KjelDigester model
6 K-446 (manual)
9 K-449 (fully automated)

Suction module
1 Suction module standard
2 Suction module with condensate trap

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Dimensions and weight
K-446 K-449

Dimensions (W×H×D) 472 × 764 × 524 mm 472 × 764 × 558 mm

Weight (without accessories) 18.5 kg 25.8 kg

Total weight (incl. all accessories) 30.3 kg 37.3 kg

454 mm 454 mm 454 mm

764 mm

764 mm

764 mm
37 mm
37 mm 37 mm

435 mm 435 mm 435 mm

524 mm
558 mm 558 mm
472 mm 472 mm 472 mm

KjelDigester K-446 KjelDigester K-449

Technical data

Operating voltage 220 – 240 V ±10 %

Frequency 50/60 Hz

Power consumption max. 2300 W

Display LCD (2 lines)

Temperature control range 30 – 450 °C

Resolution temperature display ±1 °C

Average temperature stability ±1 °C

Temperature accuracy absolute ±7 °C at 420 °C

Approval UL/CSA, CE

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Accessories
General accessories Qty Order number Picture

Suction tube standard 1 11058651 1

Suitable for most applications

Suction tube with condensate trap 1 11058827 2

For aqueous samples, prevents backflow of condensate into the sample tube

Fume collection tube with ball joint 1 11058825 3

Collects the digestion fumes from the four suction modules

Sample tubes 300 mL 4 037377 4

For sample volumes up to 200 mL in volume or 5 g in weight

Sample tubes 300 mL 20 11059690 4

Glass caps 4 040049 5

For occupying empty sample positions, to close the suction circuit

Rack 1 11059831 6

For holding up to 20 sample tubes in position

Stand for rack 1 11058659 7

Protects the sample tubes from smashing, as well as other damage

Retaining plate 1 038559 8

Holds the tubes firmLy in the rack when it is placed into the dishwasher for
cleaning

Air supply for internal fan 1 040079

Supplies clean air to the display, as well as the built-in fan

Brush for cleaning troughs in the block 1 043929 9

Is used in conjugation with an electric drill to remove heavy soiling’s, it exactly

matches the throughs in the block

Application related accessories Qty Order number Picture

Digestion rods 10 043087

To prevent boiling delays

User protection shield (for H2O2 and TKN applications) 1 11057889 10

Protects the user from any possible splashes, which may occur from H2O2
usage or boiling delays

Heat shield for rack 1 040052 11

Provides heat insulation for sample tubes during digestion

Weighing Boats 100 11060522

Nitrogen-free paper, 58 x 10 x 10 mm

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Documentation Qty Order number

Kjeldahl Guide (EN) 1 11055033

Comprehensive guide covering all aspects of the theoretical and practical
know-how

Kjeldahl Practice Guide (EN) 1 11592548

Provides theoretical background information, useful hints and calculation
tables for daily routine work

Kjeldahl Practice Guide (DE) 1 11592547

Kjeldahl Practice Guide (CN) 1 11592549

IQ/OQ set (EN) 1 11059762

Complete set for Installation and Operational Qualification of the instrument

Repeating OQ (EN) 1 11059763

Fume removal Qty Order number Picture

Condensate bottle 1 025100 12

Is used between the Scrubber and the digester to precondense fumes

Connection cable to Scrubber 1 030973

The Scrubber is controlled by the digester by the cable connection (already
incl. at Scrubber ECO models)

Scrubber K-415 (TripleScrubECO ) 1 114152331

Ideal Scrubber model for Kjeldahl digestions at maximum automation

Kjeldahl Tablets* Order number

Titanium 3.71 g (3.500 g K2SO4, 0.105 g CuSO4 • 5 H2O, 0.105 g TiO2) 11057980

Missouri 5.00 g (4.980 g K2SO4, 0.020 g CuSO4 • 5 H2O) 11057982

ECO 4.00 g (3.998 g K2SO4, 0.002 g CuSO4 • 5 H2O) 11057983

Titanium Micro 1.59 g (1.500 g K2SO4, 0.045 g CuSO4 • 5 H2O, 0.045 g TiO2) 11057981

Copper Micro 1.65 g (1.500 g K2SO4, 0.150 g CuSO4 • 5 H2O) 11057985

Antifoam 1.00 g (0.970 g Na2SO4, 0.030 g Silicone Antifoam) 11057984

* Box of 1000 tablets

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Accessories pictures

1
12 9

11

10

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Functional principle
The KjelDigester is used to convert organic bound nitrogen (e.g. in proteins) in a sample into ammonium
sulfate. During the digestion process, acid fumes and reaction gases may emerge and are handled by the
Scrubber K-415. The K-415 is connected to digester system for neutralizing acid fumes and adsorbing unple-
asant odors.

∙∙ The aluminum block 1 generates high temperatures in the samples 2

∙∙ The sample is digested in constantly boiling sulfuric acid
∙∙ Hot acid fumes rise into the condensation zone 3 , and condense and rinse back down to the sample crea-
ting a constant reflux
∙∙ Residual fumes 4 which escape the condensation zone are highly corrosive and must be withdrawn and
efficiently neutralized (e.g. with the Scrubber K-415)

Acid vapor outlet

to suction unit
(e.g. Scrubber)
4

Safety
(≈ 5 cm) zone

Condensation 3
zone

block heating
1
Boiling / digesting 2
sample

K-446 K-449 Data Sheet en 1408 B / Technical data are subject to change without
notice / Quality Systems ISO 9001 The English version is the original language
version and serves as basis for all translations into other languages.

www.buchi.com/kjeldahl Quality in your hands