Labconco Hooded Combination Kjeldahl Systems User Manual

User’s Manual

Hooded Combination (Macro)
Kjeldahl Systems

Models
21176 Series
21177 Series
21178 Series
21179 Series

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Labconco Corporation
8811 Prospect Avenue
Kansas City, MO 64132-2696
800-821-5525, 816-333-8811
FAX [phone]
E-MAIL [e-mail]
HOME PAGE www.labconco.com

Please read the User’s Manual before operating the equipment.

Copyright © 2009 Labconco Corporation. All rights reserved.

The information contained in this manual and the accompanying products are copyrighted and all
rights reserved by Labconco Corporation. Labconco Corporation reserves the right to make periodic
design changes without obligation to notify any person or entity of such change.

Warranty

Labconco provides a warranty on all parts and factory workmanship. The warranty includes areas of
defective material and workmanship, provided such defect results from normal and proper use of the
equipment.

The warranty for all Labconco products will expire one year from date of installation or two years
from date of shipment from Labconco, whichever is sooner, except the following;

• Purifier® Logic® Biological Safety Cabinets and PuriCare® Lab Animal Research Stations
carry a three-year warranty from date of installation or four years from date of shipment from
Labconco, whichever is sooner.

• SteamScrubber® & FlaskScrubber® Glassware Washers carry a two-year warranty from date
of installation or three years from date of shipment from Labconco, whichever is sooner.

• Blood Drawing Chairs carry a ten year warranty.

• Carts carry a lifetime warranty.

• Glassware is not warranted from breakage when dropped or mishandled.

This limited warranty covers parts and labor, but not transportation and insurance charges. In the
event of a warranty claim, contact Labconco Corporation or the dealer who sold you the product. If
the cause is determined to be a manufacturing fault, the dealer or Labconco Corporation will repair or
replace all defective parts to restore the unit to operation. Under no circumstances shall Labconco
Corporation be liable for indirect, consequential, or special damages of any kind. This statement may
be altered by a specific published amendment. No individual has authorization to alter the provisions
of this warranty policy or its amendments. Lamps and filters are not covered by this warranty.
Damage due to corrosion or accidental breakage is not covered.

Returned or Damaged Goods

Do not return goods without the prior authorization from Labconco. Unauthorized returns will not be
accepted. If your shipment was damaged in transit, you must file a claim directly with the freight
carrier. Labconco Corporation and its dealers are not responsible for shipping damages.

The United States Interstate Commerce Commission rules require that claims be filed with the
delivery carrier within fifteen (15) days of delivery.

Limitation of Liability

The disposal and/or emission of substances used in connection with this equipment may be governed
by various federal, state, or local regulations. All users of this equipment are required to become
familiar with any regulations that apply in the user’s area concerning the dumping of waste materials
in or upon water, land, or air and to comply with such regulations. Labconco Corporation is held
harmless with respect to user’s compliance with such regulations.

Contacting Labconco Corporation

If you have questions that are not addressed in this manual, or if you need technical assistance, contact
Labconco’s Customer Service Department or Labconco’s Product Service Department at 1-800-821­5525 or 1-816-333-8811, between the hours of 7:00 a.m. and 6:00 p.m., Central Standard Time.

Part #2081600, Rev. T

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CHAPTER 1: INTRODUCTION 1
Components Shipped 1
General Description 2
Performance 3
Component Identification 3

CHAPTER 2: INSTALLATION 6
General Installation Notes 6
Location 6
Bonnet Assembly 6
Sash Assembly 7
Electrical Connection 7
Hood Exhaust System 7
Hood Auxiliary System 7
Electrical 8
Tap Water Supply 9
Distillation Manifold 9
Water Aspirator Exhaust System 10
Acid Fume Blower Exhaust System 12
Blower Airflow Exhaust Volume Requirement & Velocity Test 12
Digestion Rack Drip Shield 13
Sash Installation 14
Glassware Installation 15

CHAPTER 3: NORMAL OPERATION & ROUTINE

Normal Operation Start-Up 16
Clean-Up and Cosmetic Guidelines 17
Fume Removal Manifold Suction Adjustment 17
Exhaust Systems Maintenance 17
Drip Shield 18

APPENDIX A: REPLACEMENT PARTS 19

APPENDIX B: DIMENSIONS & AIRFLOW REQUIREMENTS 21

APPENDIX C: TOTAL KJELDAHL NITROGEN METHOD 22

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MAINTENANCE 16

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Components Shipped

Carefully check the contents of your Hooded Combination Kjeldahl System
for shipping damage while it is still on the shipping plate. Do not discard the
packaging material until the contents have been checked and the equipment
has been approved for installation.

The Hooded Combination Kjeldahl Nitrogen System has been shipped in one
complete crate to minimize damage that may occur in transit.

The Hooded Combination Kjeldahl Nitrogen System as shipped has two
components that must be assembled. The top exhaust bonnet component must
be installed on the main body and the interior light must be electrically
connected.

Make sure to inspect the product thoroughly prior to installation and report
any damage that may have occurred in transit (see Warranty page for
instructions).

Figure 1-1

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Chapter 1: Introduction

General Description

Labconco’s Hooded Combination (Macro) Kjeldahl Nitrogen System is
designed to facilitate the determination of Total Nitrogen content within
materials such as feeds, grains, soils, fertilizers, plant tissue, water, organic
wastes, and food products. The expression ‘Macro’ identifies the size of
sample vessel and the sample size that can be used with this equipment.
Other Kjeldahl systems are available, which use smaller sample vessels and
require smaller sample sizes. The apparatus can be used for the digestion
and/or distillation of all types of nitrogen containing samples. The system
consists of the Lower Digestion rack and Upper Distillation rack. Both are
used in standardized (Macro) Kjeldahl Nitrogen Determination Methods.

This Kjeldahl system is enclosed by a ventilated hood system which captures
excess heat and provides for personnel safety during the digestion and
distillation reactions. High temperature acid digestion and caustic distillation
comprise the two-step Kjeldahl Nitrogen determination method.

2117703 Twelve Place Hooded Combination Macro-Kjeldahl System

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Chapter 1: Introduction

Performance

The Hooded Combination Kjeldahl Digestion and Distillation Systems have
been designed for use in the determination of nitrogen (or ammonia)
concentrations. By calculation nitrogen can be converted to protein values for
products such as plant tissues, meats and other food substances. Nitrogen
determinations with the Hooded Combination (Macro) Kjeldahl Systems can
accommodate sample sizes up to 5 grams due to the size of the
digestion/distillation flasks. However, higher levels of organic content within
a specific sample type will require smaller sample sizes do to the vigorous
digestion reaction. Detailed procedures developed by professional laboratory
organizations such as American Association of Analytical Chemists, (AOAC)
and American Association of Cereal Chemists (AACC) should always be
consulted for step by step analytical procedures when operating this
equipment. For methodology precision and accuracy please consult the
specific published method for the type of sample or substance that will be
analyzed.

Component Identification

1. Electric Heaters. 600-watt heaters are used in both the lower digestion
and upper distillation rack of the unit. Infinite control switches regulate
each of the heaters. The curved heater elements are provided and allow
for the round base of the Kjeldahl Flasks, providing faster and more
evenly distributed heat. The heating element assembly on the digestion
rack can be moved closer to or away from the acid fume removal
manifold to accommodate different size Kjeldahl flasks. All heaters and
temperature controllers are wired to a common electrical box for
connection to a facility electrical service.

2. Lower Fume Removal Manifold. Located in back of the digestion
heater elements, this manifold is manufactured from chemical resistant
chlorinated polyvinyl chloride and fitted with heat resistant Teflon®
nipples designed to prevent leakage of the hot sulfuric acid fumes created
during the digestion process. The nipple design, extends in to the flask
opening, and efficiently removes excess acids fumes during the digestion
process. The flasks are oriented at a 45 degree angle to the fume removal
manifold to promote the condensation and refluxing of the acid fumes
back down into the digestion flask. This refluxing process prevents the
samples from boiling dry during the 45+ minute digestion process.

Component features #3 or #4 are selected by the customer when the

product is ordered. The Kjeldahl units described in this manual
feature either the blower exhaust or water ejector exhaust system to
remove the digestion fumes through the fume manifold system.

®

Teflon is a registered trademark of E. I. du Pont de Nemours and Company or its affiliates.

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Chapter 1: Introduction

3. Acid Fume Blower Exhaust System. Located on the left side of the
unit, this blower removes excess sulfuric acid fumes from the digestion
flasks. The blower is direct-drive with corrosion resistant impeller wheel.
The blower draws the sulfuric acid fumes through the CPVC digestion
manifold and discharges the fumes under positive pressure out through a
duct work system connected to the buildings exterior. The 6" exhaust
stack of the blower must be connected to a leak-tight PVC duct work
system that vents 10 ft (3 meters) above the building roof.

4. Acid Fume Water Aspirator Exhaust System. A water aspirator fume
removal system located on the left side of the digestion fume manifold is
alternatively available on Kjeldahl systems. The water aspirator draws
excess acid fumes by producing a vacuum in the digestion manifold and
the flask nipples. The acid fumes are dissolved in the water and flushed to
a 3-inch drain connection. The water ejector includes an air-vent pipe
connection, which must to ducted to the roof of the building. The vent
pipe prevents an air-lock from occurring within the water aspirator. The
water aspirator requires a 3/4" NPT water connection with 60 psig and 6­8 gallons per minute flow rate in order to operate.

5. Temperature Gauge The condensation rack behind the upper distillation
heating elements requires cooling water. The temperature of the
distillation cooling water can be adjusted to promote condensation and
suit individual requirements with the flow control valve handle, located
below the distillation heaters. Water temperature is indicated on the
thermometer, which is located at the water outlet of the distillation
manifold. The water connections are 3/4" NPT and the supply line should
be 1/2" minimum for proper water flow through the unit. For facilities
where the ground water temperature exceeds 80°F (27°C), a recirculation
water chiller system will be required to achieve sufficient condensation
results.

6. Distillation Condensation Manifold Epoxy coated steel outer columns
with stainless steel inner condensation columns provide long life. Each of
the six column manifold features 3/4" NPT tap water inlet and outlets for
easy plumbing connections.

7. Hood Exhaust Connection At the top of each Hooded Combination
Kjeldahl System are two duct work connection collars. The exhaust collar
is positioned to the right of the make-up air collar. The exhaust collar
must be connected to a dedicated duct work system with a roof mounted
blower. This exhaust connection will vent hot air and small amounts of
acid fumes. If the Hooded Combination Kjeldahl System is furnished
with an Acid Fume Blower Exhaust the two duct work system must not
be connected together. Each duct work system must be routed to the
building exterior independently. The make-up air collar can be connected
to a duct work system which can supply up to 75% of the total exhaust air
volume.

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Chapter 1: Introduction

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Figure 1-2

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General Installation Notes

The Hooded Combination Macro-Kjeldahl System is shipped in two sections. The
top exhaust bonnet and glass sashes will need to be installed after the main body
has been installed in its final location. Exhaust duct work, electrical service,
water supply and drain connections should be completed by a licensed contractor.

The customer will need to purchase their preferred size of Kjeldahl Flasks, with
one-hole-rubber-stoppers and distillate receiving flasks. The glass Connecting
Bulbs and Delivery Tubes are provided with each Kjeldahl System.

Connecting Bulbs and Delivery Tubes
are included with Macro Kjeldahl Systems.
For installation of the Connecting Bulbs
and Delivery Tubes see section on Glassware
Installation and Figure 2-9.

Use caution when you remove the protective packaging material taped to the
heater runways as fragile components are involved. Levelers are shipped
installed, as are the distillation cooling water thermometers.

Location

If possible, the apparatus should be uncrated in the room in which it is to be
placed. Hooded Combination Macro-Kjeldahl Systems are heavy and can not be
disassembled to reduce their overall size. Special arrangements should be made in
advance for moving the systems to their final location within a facility. Special
instruction tags are attached to the apparatus; they must not be removed until the
installation has been completed.

Bonnet Assembly

The hood bonnet must be installed on top of the substructure of the hood. This is
accomplished by elevating the bonnet up onto the top of the substructure. It is not
required to bolt the bonnet in place, as its weight on the foam gasket seal will hold
it in its proper place.

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