User’s Manual Two and Six Place (Macro) Kjeldahl Digestion Systems Models 2128401 2125601 2125602 2125603 To receive important product updates, complete your product registration card online at register.labconco.com Labconco Corporation 8811 Prospect Avenue Kansas City, MO 64132-2696 800-821-5525, 816-333-8811 FAX 816-363-0130 E-MAIL labconco@labconco.com HOME PAGE www.labconco.com Please read the User’s Manual before operating the equipment.
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TABLE OF CONTENTS CHAPTER 1: INTRODUCTION Components Shipped General Description Performance Component Identification 1 1 2 3 3 CHAPTER 2: INSTALLATION General Installation Notes Location Electrical Acid Fume Blower Exhaust System Blower Airflow Exhaust Volume Requirement & Velocity Test Digestion Rack Drip Shield 6 6 6 7 8 8 9 CHAPTER 3: NORMAL OPERATION & ROUTINE MAINTENANCE Normal Operation Start-Up Clean-Up and Cosmetic Guidelines Fume Removal Manifold Suction Adjustment Exhaust Systems Maintenance
Chapter 1: Introduction Components Shipped Carefully check the contents of your Two-Place or Six-Place Kjeldahl Digestion System for shipping damage while it is still on the shipping pallet. Do not discard the packaging material until the contents have been checked and the equipment has been approved for installation. The Two-Place or Six-Place Kjeldahl Nitrogen Digestion System has been shipped in one complete crate to minimize damage that may occur in transit.
Chapter 1: Introduction General Description Labconco’s Two and Six-Place (Macro) Kjeldahl Digestion Systems are 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.
Chapter 1: Introduction Performance The Two and Six-Place Kjeldahl Digestion 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 (Macro) Digestion Systems can accommodate sample sizes up to 5 grams, due to the size of the digestion flasks.
Chapter 1: Introduction Six-Place Digestion System Fume Removal Options 3. Acid Fume Piping Exhaust System. Located on the left side of the unit, this exhaust piping removes excess Sulfuric Acid fumes from the digestion flasks. Attention - The Exhaust Piping must be connected to a remote blower to remove acid fumes. The unit does NOT have an integral blower.
Chapter 1: Introduction Six Place Kjeldahl Digestion System 3 2 1 Product Service 1-800-522-7658 5
Chapter 2: Installation General Installation Notes The Two and Six-Place Kjeldahl Digestion Systems are shipped fully assembled. The Six-Place Kjeldahl Digestion System will require exhaust duct work which should be made by a licensed contractor. The Two-Place Kjeldahl Digestions System can be installed by the customer inside a fume hood and the fume removal manifold connected to a common laboratory faucet water aspirator.
Chapter 2: Installation Electrical The Two-Place Kjeldahl Digestion System comes with an 8-foot, 3 wire cord and plug and can be connected to a 115 volt 60Hz 11 Amp circuit. The Six-Place Digestion Kjeldahl System has been wired at the factory per the product model number ordered by the customer. Labconco model numbers ending in -11 are 115 volts. Model numbers ending in -12 are 230 volts. Models ending in -13 are 230 volt, three phase.
Chapter 2: Installation Acid Fume Blower Exhaust System The exhaust duct connection on top of the damper is sized for use with 6" nominal (6-5/8" O.D.) vent duct. The exhaust piping assembly is supplied with a short piece of 6" PVC pipe and a flexible coupling with clamps to connect the dedicated duct work exhaust. The flexible coupling must be sealed air-tight to the exhaust duct work. All exhaust duct work must be acid-resistant and sealed air-tight. Use only acidresistant sealant on duct work joints.
Chapter 2: Installation (Duct Area in Square Feet) x (Average Airflow Velocity in feet per minute) = (Air Volume CFM) (Pi) x (radius²) x (117 FPM) = 25 CFM The exhaust stack rising from the piping assembly must be vented to the outside atmosphere via acid-resistant, sealed duct work and a remote blower (not included). If the remote blower pulls more than 25 CFM at the measurement point (48” above flexible coupling), close the damper shown in Fig. 2-6 to reduce airflow to the recommended 25 CFM.
Chapter 3: Normal Operation & Routine Maintenance Normal Operation Start-Up 1. The KNA apparatus is designed for use with either 500 or 800-ml Kjeldahl Flasks. The distillation heaters are free to move forward or backward on the runway to accommodate either size flask. 2. Turn the heat controllers to the high setting on both the Digester and Distillation racks if both racks will be used simultaneously. Wait approximately 5 to 10 minutes to insure proper preheating. 3.
Chapter 3: Normal Operation & Routine Maintenance Clean-Up and Cosmetic Guidelines • • • Keeping the Kjeldahl Digestion System clean will preserve the appearance and improve life of the equipment. The equipment can be kept clean by washing with a weak solution of sodium hydroxide and rinsing with clear water. Sulphate, a salt of Sulfuric Acid, may build up between the channel support and the fume removal manifold.
Appendix A: Replacement Parts Electrical Heaters and Motor/Blower Parts Part Number Description 1315400 1315500 2011500 2023200 2033100 2033200 2023100 2031800 1870200 1317100 2056600 2053000 1967000 2144600 1662200 2165800 1880128 Heater Control, Infinite (115Volts) Heater Control, Infinite (230Volts) Core Plate Casting, (package of 6) Heater Base Casting (electric or gas) Heater element, 115V, 600 W, (package of 6) Heater element, 230V, 600 W, (package of 6) Heater Top ceramic casting (electric or gas)
Appendix B: Dimensions & Airflow Requirements B-1 Product Service 1-800-522-7658 13
Chapter 3: Normal Operation & Routine Maintenance B-2 14 Product Service 1-800-522-7658
Appendix C: Total Kjeldahl Nitrogen Method Titrimetric Determination Various scientific associations offer approved Kjeldahl methods. These methods are available at their websites.
Appendix C: Total Kjeldahl Nitrogen Method distillate receiving vessels, such as 250 ml Erlenmeyer flasks. The equipment is available as a combined system, featuring both digestion and distillation apparatus. The preheated burners should bring 250 ml of water at 25° C to a rolling boil with in 5 minutes. Condensation columns should cool distillate to 75° F (23.8°C). 3.3. Titration Class A Burets, 25-50 ml. for dispensing Standardized Acid solution. 3.4. Analytical balance, sensitive to 0.0001grams. 4.
Appendix C: Total Kjeldahl Nitrogen Method the flask neck on the fume removal system. If necessary lower the burner heat setting to prevent sample from foaming up into neck of flask. Once, the sample comes to a smooth rolling boil return heat setting to maximum. When digestion sample clears (no black specs with pale green tint color), continue to boil for an equal length of time as required to reach the clear point, (total time approx. 1 hr).
Appendix C: Total Kjeldahl Nitrogen Method 7. Titration 7.1. Depending on the samples expected nitrogen level and the sensitivity of the titration desired, select the appropriate standardized H2SO4 solution (0.02 or 0.10 normal). High or low nitrogen concentrations will require standardized H2SO4 solutions with stronger or weaker normalitys. Titrations should require at least 15 ml of titrant to be accurate. Fill a class A. buret to the zero line with the standardized H2SO4 solution.
Appendix C: Total Kjeldahl Nitrogen Method Distillation: Excess base is added to the digestion product to convert NH4 to NH3 as indicated in the following equation. The NH3 is recovered by distilling the reaction product. ammonium ammonia heat sulfate gas (NH4)2SO4 + 2NaOH → 2NH3 + Na2SO4 + 2H2O Titration quantifies the amount of ammonia in the receiving solution. The amount of nitrogen in a sample can be calculated from the quantified amount of ammonia ion in the receiving solution.
