standardDetailed description and improvement of COD digester

(Nanjing Kehuan Analytical Instrument Co., Ltd.)

The standard COD digester was initially improved on the basis of electric furnaces, iron racks, and condensed circulating water. The circulating water cooling was changed to burr condensation tube air cooling, and 6 electric furnaces were made on one electric furnace plate for 6 samples. The operation is simple and convenient, and it is energy-saving and labor-saving.

After more than 10 years of user experience, several aspects have been improved:

1Electric furnace plate: Silicon carbide electric furnace plate has uneven surface, uneven heating, and is extremely difficult to cool; Now we have chosen new energy-saving and environmentally friendly template materials, thick diameter low function heating wires, and microcrystalline glass heating countertops to solve the problems that customers need to solve.

2control panel; There are three buttons on the control panel: start, timer, and air cooling. The display window only shows the heating time numerically, which has now been changed to LCD display. The menu is operated in Chinese and displays real-time temperature changes and digestion time.

3Cooling; The single fan cooling small condenser tube has been changed to dual fan cooling, with a large and high 3-bubble burr condenser tube.

There are many situations that have been reported by users, and we have made improvements one by one. The new model KHCOD-8K has added a new function of controllable silicon to adjust the heating power in the heating part. During the heating process, the instrument directly displays the change in heating temperature. Without the need to reset, the potentiometer can be adjusted freely to change the heating power, thereby controlling the heating temperature. Regardless of spring, summer, autumn, winter, the boiling condition of the reaction liquid can be controlled at any time. At the same time, the condenser tube is lengthened and the water cooling area is changed to 3 bubbles to increase the diameter, improve the condensation effect, prevent atomization and gasification, ensure that the reaction liquid does not escape during digestion reflux, and ensure the accuracy of measurement data. Microcrystalline heating plate is used for isolated heating, with a fast cooling rate. Under the guidance of the teacher, the next step is to apply for the national filling list, which can automatically titrate and add the function of automatic mixing and stirring of reaction solution.

Compliant with national standards: The new standard HJ828-2017 replaces the original GB 11914-89

LCD display: displays standby, digestion, temperature control, air cooling, heating temperature, and digestion time,

Measurement range: 5-700mg/L, 700mg/L-10000mg/L, measured after dilution of water sample

Dissolving time: 1 minute to 9 hours and 60 minutes (user set heating time, normal 2 hours and 30 minutes)

Temperature control: Room temperature 400 ℃, automatic heating, pressure regulation and temperature control, usingsatisfactionBoiling effect.

Measurement error: The relative standard deviation of potassium hydrogen phthalate standard solution (500mg/L) shall not exceed 5.0%;

The relative standard deviation of industrial organic wastewater (500mg/L) is not more than 8.0%.

Environmental temperature: ≤ 40 ℃

Cooling method: DualFan air coolingAdd 3 bubblesCondenser tube water coolingDouble cooling effect.

Sample size for digestion: 8 250ml conical flasks,Simultaneously heat and digest in two rows Ensure easy sampling.

Heating table: Microcrystalline glass heating table, overall structure of heating plate, overhead heating, easy to remove for replacement and maintenance,Easy for users to operate.

Heating power: ≤ 1600W (AC 220V, 50HZ)

Instrument size: 490 * 290 * 605mm (H)