Buchi K-424 User manual

1
Digestion Unit K-424
Contents
Contents
Read these instructions thoroughly before you use the
Digestion Unit K-424. Store these instructions in the im-
mediate vicinity of the apparatus so that they may be consulted
at any time.
The unit must only be connected to the mains and switched
on after having completed all necessary preparations.
Chapter 2 contains important safety information. Knowledge
of this is imperative for the safe operation of the Digestion
unit.
Subject to technical change without notice. No part of these
instructions may be reproduced in any form whatsoever or
processed, reproduced or disseminated by means of
electronic or optical systems without the express written
permission of Büchi Labortechnik AG. All rights reserved.
Copyright © Büchi Labortechnik AG 2008
en, Version E Order No.
K-424 Operating instructions 96711
1 Scope of delivery 2
2 Safety 3
2.1 Symbols 3
2.2 Requirements for the operator 3
2.3 Regulation use 3
2.4 Non-regulation use 3
2.5 General hazards 4
2.6 Safety measures 4
3 Function 6
3.1 Principle of operation 6
4 Putting into operation 7
4.1 Setup location 7
4.2. Unpacking 7
4.3 Connection to the mains 7
4.4 Hose connections 8
5 Operation 9
5.1 Operating elements 9
5.2 Operating elements and their function 9
5.3 General information 9
5.4 Execution of the Kjeldahl disintegration 11
5.5 Malfunctions 11
6 Maintenance 12
6.1 General information 12
6.2 Upkeep 12
6.3 Gaskets 12
6.4 Replacing the insulation 13
6.5 Replacing the O-rings 13
6.6 Fuses 14
6.7 Customer service 14
7 Taking out of operation 15
7.1 Storage/Transport 15
7.2 Disposal 15
8 Replacement parts 16
9 Appendix 17
9.1 Technical Data 17
9.2 Materials used 17
9.3 FCC requirements 18
9.4 Declaration of conformity 19

2
Digestion Unit K-424
1 Scope of delivery
1 Scope of delivery
Fig.1: Overview K-424
Description Order No.
Versions:
K-424 standard 120 V 50 / 60 Hz 37963
K-424 standard 230 V 50 / 60 Hz 37962
Table 1: Versions
Enclosed parts:
4 Digestion tubes 37377
1 Rack 26730
1 Upper insulating plate 26736
1 Suction module complete 26842
1 Connection to suction module 26875
1 Digestion tube holder complete 38080
1 EPDM Hose 8mm 26275
1 Mains cables:
Type CH 10021
Type Schuko 10029
Type GB 17833
Type AUS 17834
Type USA 33756
1 Operating instructions in one of the
following languages
German 96710
English 96711
French 96712
Italian 96713
Spanish 96714
1 Packaging 26799
Table 2: Enclosed parts
Accessories:
Water jet pump plastic 02913
Glass cap 17396
Gasket PTFE to suction tube 22442
Collection tube for suction tube 27737
Condensation bottle complete 25100
Suction module for H2O2 digestion 37399
Büchi B-414 Scrubber 37876
Suction pipe with condensation gutter 26880
Non Kjeldahl digestion set 43677
Suction pipe with ball joint 40158
Table 3: Accessories

3
Digestion Unit K-424 2 Safety
The apparatus has been built in accordance with state-of-
the art technology and recognized safety regulations.
Nonetheless risks and dangers can arise from the
apparatus:
• If the apparatus is operated by insufficiently trained
personnel.
• If the apparatus is not used as directed.
2.1 Symbols
Stop
Information on dangers which can lead to serious damage
to property, to severe or life-threatening injuries.
Warning
Information on dangers which can lead to damage to health
or property.
Please note
Information on technical requirements. Noncompliance can
lead to faults, inefficiency and production losses.
2.2 Requirements for the operator
The unit is only to be used by laboratory and specialist
personnel and other persons, who, because of their training
or professional experience, are able to assess the dangers
which can result while operating the equipment.
2.3 Regulation use
The unit is conceived and built as a piece of laboratory
equipment. Its regulation use is the heating of concentrated
sulfuric acid used in the oxidation of organic samples.
2.4 Non-regulation use
Any other use than listed as well as any use which does
not correspond to the technical data is a misuse. The
operator bears sole risk for eventual damage related to
such use.
In particular the following uses are not allowed:
• operation in explosion-prone areas
• operation with samples that can explode or ignite due to
impact, friction, heat or sparking.
2 Safety

4
Digestion Unit K-424
2.5 General hazards
General hazards arise from:
• Hot sulfuric acid
• Combustible gases or vapors in the immediate vicinity
of the apparatus
• Damaged glassware
• Location of the apparatus to close to the wall (see
section 4.1 Set up location)
• Hot surfaces
Except for authorized repair personnel it is forbidden to remove
covers using commercially available tools.
The device must not be put into operation with damaged
glass parts.
Contact with electrically live parts presents a danger to life
and limb!
2.6 Safety measures
It is recommended that the apparatus be operated
exclusively under an exhaust hood.
The wearing of personal safety equipment such as safety
glasses, gloves and lllllaboratory coats is necessary.
As a necessary part of the digestion unit K-424, this instruction
manual must at all times be available to the operating
personnel at the location where the apparatus is being
used. This also applies to the further editions in other
languages which may be ordered seperately.
Modifications
Any modifications on the apparatus itself or on replacement
or accessory parts, and any use of replacement or
accessory parts other than those listed in these operating
instructions is permissible only with the express written
approval of Büchi Labortechnik AG.
Responsibilities of the operator
The operator is responsible for providing proper instruction
for his staff. For that purpose, these operating instructions
may also be ordered in other languages.
The operator must inform the manufacturer immediately of
any and all events relevant to product safety that arise
during his operation of the apparatus.
If assuming that a safe operation is not possible any more
the unit must be put out of operation and secured against
unintended further operation.
2 Safety

5
Digestion Unit K-424
2 Safety
It is to be assumed that a safe operation is not possible
any more
sif the unit is visibly damaged,
sIf the unit is not functioning any more
safter long storage under anfavourable conditions,
safter being transported under difficult conditions.
The unit must not be operated with combustible substances.
If you need the assistance of Büchi Service, it is required
to indicate and declare eventually remaining dangerous
substances (e.g., as defined in EC guidelines L 360, 1976/
79 or VBG 16) in or on the apparatus for reason of on-the-
job safety or pollution control.

6
Digestion Unit K-424 3 Function
3 Function
The digestion unit K-424 is suitable for digestions involving
concentrated boiling sulfuric acid at a temperature of
approximately 370° C.
3.1 Principle of operation
Sample tubes
Heating
Suction module
Hose to water jet pump or to Scrubber B-414.




Fig. 2: Principle of operation K-424

7
Digestion Unit K-424 4 Putting into operation
4 Putting into operation
4.1 Setup location
The digestion unit must be installed on a stable, clean and
flat base.
For reasons of safety, a gap of at least 30 cm must be left
open between the back of the machine and the wall or
other objects. Never place any containers, chemical
products or other equipment behind the digestion unit.
4.2 Unpacking
The original package must be kept for possible later
transport.
If the package has been damaged, check the machine
carefully for broken glass or damage to the housing.
Make certain that the socket voltage is the same as that
shown on the machine nameplate. Always connect the
machine to an earthed (grounded) socket. This avoids risks
due to an internal defect.
4.3 Connection to the mains
Before switching on the K-424 for the first time check that
the voltage on the socket corrsponds to the voltage
indicated on the apparatus identification plate.
Always connect the apparatus to a grounded (earthed)
socket.
External couplings and extension cords must contain a
protective conductor ( 3-pole couplings, cables, and plug-
in devices). Any and all interruptions in the protective
conductor are forbidden. This avoids risks due to an internal
defect.

8
Digestion Unit K-424 4 Putting into operation
4.4 Hose connections
Mount the safety shield (A) with the fitted hoses on the unit
(see photograph).
Assemble the connection to the suction module (B) and install
on the hose (C) and on the suction modules (D).
Connect the EPDM hose to the scrubber B-414 or to the
water jet pump (e.g. made from plastic) Art. No. 02913.
When working with a water jet pump unpleasant odours
may escape into the environment if the suction is not power-
ful enough.
Fig. 3: Hose connections enlarged section
Fig. 4: Connection to fume exhaust
A
026757 002073
026240 003577
B
D
B
Scrubber E
C