Characteristics and Application of KHCOD-5G COD High Chlorine Dissolver

CODHigh chlorine digesterCODHigh chlorine digestion reflux analyzerCOD digester

KHCODThe -5 type COD high chlorine digestion reflux instrument has standardized the determination steps of water quality chemical oxygen demand COD (Cr), strictly stipulated the heating digestion time of the method, and ensured the digestion operation of reflux heating and micro boiling for 2 hours. The preparation and addition of reagent solution are consistent with the GB method, ensuring reliable and accurate analysis results.
The KHCOD-5 COD high chlorine digestion reflux analyzer mainly consists of four parts: the body, reflux tube, fan, and electric furnace plate. It uses microcomputer technology to control the heating of the electric furnace plate and fan at a fixed time, and can simultaneously heat six conical bottle reflux devices.
The chemical solution preparation, operation, and COD calculation of the instrument can be improved by diluting titrants and oxidants for COD water samples below 50mg/L, and by diluting the water sample ratio for COD water samples above 1000mg/L.

KHCOD－5GtypeCODHigh chlorineTechnical specifications for digestion reflux analyzer

1Overall requirements

1.1 No need to pour into other bottles, the triangular beaker can be heated and measured;

1.2 Energy saving and low power load;

1.3 Using high-precision flow meters to regulate nitrogen injection volume;

1.4 Using a barbed reflux tube;

1.5 Independent channels and samples do not interfere with each other.

2Main performance parameters

2.1 Flow range:5~40ml/min

2.2 Temperature range:32~399°C

2.3 Set time:0~999minAny setting

2.4 Number of Dissolved Samples:6Among them1A blank sample)

2.5 Dissolving volume:250ml

2.6 Power Supply:AC 220V 50Hz

2.7 Total gas flow rate:10L/min

2.8 Flow regulation channel:5road

2.9 Measurement range:0~1000mg/L；0~10000mg/L(Dilution of water sample)

3Implement standards

HJ/T70-2001Determination of Chemical Oxygen Demand for High Chlorine Wastewater - Chlorine Calibration Method

KHCOD-8GtypeCOD digestion reflux device for high chlorine wastewateroperation instructions

KHCOD-8GHigh chloride wastewater standardCODDissolving device, fully compliantFollowing the environmental protection industry standards of the People's Republic of China——Determination of Chemical Oxygen Demand for High Chlorine Wastewater - Chlorine Calibration Method, Chemical Solution Preparation and Operation of InstrumentsCODThe calculation is completely in accordance withHJ/T 70-2001

High chlorine wastewaterTechnical principle of COD digester:

Add a known amount of potassium dichromate solution and mercury sulfate solution to the water sample, and use silver sulfate as a catalyst in a strong acid medium2hAfter boiling and refluxing, use1，10—Using ortho phenanthroline as an indicator, titrate unreduced potassium dichromate in water samples with ferrous ammonium sulfate, and convert the amount of ferrous ammonium sulfate consumed to the mass concentration of oxygen consumed, which is the apparent concentrationCODExport the chlorine gas formed by the oxidized portion of chloride ions that have not been complexed in the water sample, absorb it with sodium hydroxide solution, add potassium iodide, and adjust it with sulfuric acidpHApproximately3～2，

Using starch as an indicator, titrate with a standard solution of sodium thiosulfate. The amount of sodium thiosulfate consumed is converted to the mass concentration of oxygen consumed, which is the chloride ion correction value. apparentCODThe difference between the correction value of chloride ions and the true value of the measured water sampleCOD.

The instrument adopts a glass burr reflux tube instead of a spherical reflux tube, and uses air cooling technology instead of tap water cooling, which can not only save water and standardize the instrument, but also improve the safety of instrument use. Simplified the later titration procedures and improved the reliability of the method.

High chlorine wastewaterTechnical indicators of COD digester:

1Anti chlorine interference:1000～20000mg/L

2Nitrogen flow rate:6～60mL/minadjustable

3Measurement range:0～1000mg/L(Greater than dilution)1000-10000mg/lMeasurement after dilution is required.

4Dissolving time:2hour30Minutes (can be set arbitrarily)

5Dissolving volume:250mL

6Measurement error:≤500mg/LThe relative standard deviation is not greater than5.0；

≤1000mg/LThe relative standard deviation is not greater than8.0%

7Heating power:1600W（220V，50HZ）

8Cooling method: dual fan cooling with water cooling

9Microcrystalline plate heating table, making8Sample (standard conical flask digestion)

10Environmental temperature:5-45℃

High chlorine wastewaterApplication scope of COD digester:

1:This method is suitable for chloride ion content less than20000mg/LChemical Oxygen Demand in High Chlorine Wastewater(COD)The measurement. The detection limit of the method is30mg/L.

2Widely used for water quality testing in industries such as oil fields, coastal refineries, oil depots, chlor alkali plants, deep-sea wastewater discharge, sewage treatment plants, monitoring stations, environmental protection bureaus, third-party testing, petrochemicals, steel mills, power plants, healthcare, universities, and production-oriented enterprises (including food mills, paper mills, printing and dyeing factories, etc.); Suitable for detecting high chlorine water quality in surface water, groundwater, industrial wastewater, domestic sewage, tap water, etc.

High chlorine wastewaterFunctional characteristics of COD digester:

1The results of nitrogen treatment on high chlorine samples were better than those without nitrogen treatment, which meets industry standards.

2Using microcomputer technology for timed control of the heating electric furnace, the microcrystalline glass plate is heated and corrosion-resistant.

3The burr reflux pipe, combined with the built-in fan, ensures good boiling cooling effect and ensures experimental accuracy.

4Users can adjust the heating power function according to the actual voltage situation to ensure the boiling effect during heating(Contract annotation)

5It has an automatic stop function when the time comes, truly achieving unmanned operation.

6Energy saving, water-saving, safe and reliable, can save thousands of yuan in water and electricity bills every year.

Instructions for using the buttons on the front panel of the instrument

feel the wind

Control the opening and closing of the fan.

at regular time

Dissolve time control setting key. The instrument's startup setting time is2hour30minute. Automatically subtract with each press of the setting key10Minutes, measured by standard reflux methodCODIt should be set as2Hour.

start

Dissolve start control button, pressAfter pressing the "Start" button, the instrument heats up, refluxes, and digests from the set value (such as2At the hour mark, the timer automatically counts down and the heating indicator light is on. When the set time is reached, the instrument automatically stops heating and the heating indicator light goes out.

4The front panel of the instrument has8Only flow meters.

Instrument usage instructions

Install all connections according to the diagram first, familiarize yourself with them before starting the experiment.

Before powering on the instrument, as much distilled water as possible should be added from the water injection port of the reflux pipe to ensure cooling effect.

Turn on the power switch on the right side panel of the instrument.

At this moment, the instrument displays“000 ”“111”“222”…“999” Finally, the maximum set value for digestion time is displayed2hour30At the same time, the fan is turned on and the fan indicator light is on.

Change the digestion time setting value

pressThe "timer" button is used to decrease the digestion time until the set value is finally2Hour. Of course, the digestion time value can also be set arbitrarily as needed.

Start reflux digestion

pressPress the "Start" button, and the instrument will start heating, digestion, and reflux. The "Start" indicator light will turn on, and the heating indicator light will flash.

Reflux digestion completed

After digestion, the instrument displays“000”And it flashes, the "start" indicator light is off, and the heating indicator light is off.

explain: 1If you want to pull out all the connecting pipes of the instrument, simply press down on the gasket at the quick connector and pull the pipeline outward.

2The nitrogen adjustment knob of the flowmeter on the instrument is precision adjustable to control the nitrogen flow rate.

Note: Sample processing and analysis methods refer to the environmental protection industry standards of the People's Republic of China——Determination of Chemical Oxygen Demand for High Chlorine Wastewater - Chlorine Calibration Method.

High chlorinePacking list of COD digester

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