MANUAL DE INSTRUCCIONES
CÓDIGO 80158 REV E
02/2021
Pag.: 20
J
.P. SELECTA s.a.u.
Autovía A2 Km 585.1 Abrera 08630 (Barcelona) España
Tel 34 93 770 08 77 Fax 34 93 770 23 62
e-mail: [email protected] - website: http://www.grupo-selecta.com
3. Equipment description
Digestion unit BLOC-DIGEST is used for digestion in Kjeldahl nitrogen
determination and measurement of the COD. Other possible application is
hydrolysis of samples in determining fat.
The digestion equipment usually uses a heating block, a control unit, a rack for
sample tubes manipulation and a fumes removal system.
For smokes neutralization some other equipments are needed:
4001611
Scrubbing unit
4001610
Water circulation pump
The heater block houses the digestion tubes, in order to get an optimal heating
transfer to samples. It only uses tubes with suitable diameter according to the
heater.
The heater is protected agains overtemperature with a device that cuts the power
supply if temperature exceeds 550ºC.
The temperature of the heating block is regulated by the control unit that is
separated from the heating block to prevent spoilage splashes, spills, fumes, etc.
This unit (RAT 2) allows up to 20 programs of 4 steps for temperature and time.
In the Kjeldahl digestion or hydrolysis our for heating in several steps allows
optimal control of the foams produced, to be able to evaporate water from the
sample before digestion at 400 ° C
For extracting the fumes produced by the digestion, fume collector may be used
with a jet pump, a sucker or scrubber.
Binding of steam hood with the sample tube is not airtight. This allows absorbing
small explosions without damaging the glassware. The extractor fan leads to the
drain due to the vacuum or suction produced at the end of the collector outlet
tube. Therefore it is essential to the proper functioning of the jet pump must
produce a negative pressure of 0.6 bar.
For D.Q.O. digestion fumes that are not removed no fumes are extracted but
few glasses condense the steam produced is used and return the liquid to the
tube sample. (Reflux condenser).
The Kjeldhal digestion
systems evolve irritating
acid fumes.
They need a proper insta
-
llation for treating released
fumes.
