COD Constant Temperature Heater, Constant Temperature Chemical Digestion Apparatus, Digestion Unit, Rapid Digestion Furnace for Wastewater and Sewage.
why need COD digester
Chemical Oxygen Demand (COD) is one of the control parameters for environmental water quality and wastewater discharge. serving as a crucial comprehensive indicator of organic pollution in water. This instrument overcomes the drawbacks of the original COD reflux apparatus. Such as large footprint, high power consumption, water wastage. And operational inconvenience.
Main technical parameter of COD digester
Digestive capacity: 12 samples
Working temperature: 165C~180C
Temperature adjustable range: 150C~200C
Heating time: Raise to working temperature for less than 30 minutes Constant temperature accuracy: ±2C Maximum power: 1kw
Power supply: AC 220V, 50Hz
Structure theory
This device consists of an energy-saving COD constant temperature heater, heating tubes, and air condensation tubes.
The energy-saving COD constant temperature heater adopts a cast aluminum furnace body with good thermal conductivity. The furnace body is evenly distributed with 12 constant temperature heating tanks. Which can make 12 samples at the same time. The furnace temperature is transmitted from the temperature sensor to the control circuit. And the automatic constant temperature heating tube and condensing tube are made of hard glass with a small coefficient of thermal expansion. When in use, add the water sample and reagent to be digested into the heating tube, install an air condenser tube. And place it in a constant temperature bath. Ensure good boiling and sufficient reflux of the mixer inside the tube at operating temperature (165C~180C).
Note: The temperature displayed on the instrument is for reference only. And the accurate temperature should be based on the mercury temperature reading.
Usage method of the COD digester
- Connect the COD energy-saving heater power supply, turn on the original power switch, insert the thermometer into the hole, preheat for 30 seconds. And adjust the temperature to around 170-180.
- When the chloride ion content in the wastewater exceeds 30ng/L, 0.4g of mercuric sulfate should be added to the heating tube first.
- Take it. Mix 00ml of evenly mixed water sample (or dilute an appropriate amount of water sample to 20.00ml) into a heating tube. And accurately add 10.00ml of potassium dichromate standard solution and 30ml of silver sulfate solution. Add dozens of dry ceramic particles. Gently shake the heating tube to mix the solution evenly.
- Connect the condenser tube to the heating tube and place it in a constant temperature heating hole for heating. Heat for 2 hours and 5 minutes from boiling. After boiling for 2 hours, remove the heating tube and condenser tube from the heating hole, place them on the heating tube bracket. And cool them naturally or with flowing water
- Rinse the condenser tube wall and grinding area with a small amount of water. Carefully remove the condenser tube, dilute it with water to about 140ml, add 2-3 drops of ferrous indicator, add clean probe and stir. And titrate with ferrous ammonium sulfate standard solution under electromagnetic stirring until the solution color changes from yellow to blue to reddish brown. Which is the endpoint. If there is no electromagnetic stirrer. The solution in the heating tube can be quantitatively transferred to a 500ml conical flask. Diluted with water to about 140ml. And titrated to the endpoint.
- At the same time as measuring the water sample. Conduct a blank test with 20ml distilled water according to the same operating steps. And record the amount of ferrous ammonium sulfate standard solution used for titration of the blank.