Composition and design of reverse osmosis cleaning device
Composition and design of reverse osmosis cleaning device RO cleaning device consists of cleaning pump, cleaning solution tank (including stirring and heater), cleaning microporous filter, pipes, valves and control instruments such as pH value, thermometer, flow meter, etc., as shown in the figure below.
(1) Cleaning solution tank
The volume of the cleaning tank can be calculated as follows: V=(V1+V2+V3)*k
In the formula, V-cleaning solution tank volume (m3);
V1 - the sum of the actual volume of the shell pressure vessel (m3);
V2-actual volume of cleaning microporous filter (m3);
V3- the sum of the actual volume of the circulation pipeline (m3);-
k-safety factor, the value is 20%~50%.
1) The pH range of the cleaning solution is usually between 2 and 12, and the material of the cleaning box can be polypropylene, glass fiber reinforced plastic, steel-lined rubber, etc.;
2) Set up a heating or cooling device to control the temperature of the cleaning solution to achieve the best cleaning effect;
3) Set up dissolving and stirring facilities, or set up a circulation return pipe from the cleaning pump to the cleaning tank instead;
4) The circulatory return pipe should extend below the cleaning liquid level, and avoid directly above the pump suction port, so as to prevent the reflux liquid from entering the pump body with air bubbles;
5) Set up a safe and fixed operating platform and upper and lower passages to facilitate the preparation and cleaning operations and observation of the liquid medicine.
(2) Clean the microporous filter
The structure is the same as the RO security filter, which is used to remove impurities and pollutants in the circulating cleaning liquid. The design flow rate should meet the requirements of the maximum cleaning flow rate of the RO unit. For small installations, it can be used with RO security filter.
(3) cleaning pump
The cleaning flow rate of the membrane element can be determined according to the RO manufacturer's regulations. The following table is the cleaning flow control value of the common diameter 20.32cm roll RO membrane element.
Cleaning pump flow calculation:Q=N1*q
In the formula, Q cleaning pump flow rate (m3/h);
N1--The total number of pressure vessels in the first section of a single set of RO equipment (pieces)
q--cleaning flow of RO membrane element with diameter of 2032cm
One stage and two sections, arranged 2:1, the total length of the concentrated water flow channel is 12m, which is a general RO device form. During normal high-pressure operation, the total pressure difference is usually 200-300kPa. Considering that the high-speed cleaning flow is similar to normal operation, it is more appropriate to determine the head of the cleaning water pump at about 400kPa. The pump material should be corrosion-resistant, not lower than 1Cr18Ni9T; the grade of stainless steel. The outlet of the pump should be equipped with a return pipeline and a valve, and the cleaning flow can be adjusted according to different cleaning methods.
(4) cleaning pipeline
Cleaning the pipeline, including cleaning the liquid inlet pipe, cleaning the produced water pipe, and cleaning the concentrated water return pipe. The operating pressure of the cleaning pipeline is low, the chemical aggressiveness of the cleaning fluid is average, and the frequency of use is low. Considering economic factors, it is recommended to use non-metallic materials for the cleaning pipeline, such as UPVC pipes. CLICK KNOW MORE