Application of the hottest zero consumption consta

2022-08-11
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Industrial application of zero consumption constant flow feeder in water purification agent dosing operation in Waterworks Abstract: This paper introduces the original dosing of water purification agent in the third water plant of Changsha waterworks company and the situation after technical transformation, and emphatically demonstrates that the use of zero consumption constant flow feeder in technical transformation can not only better ensure the quality of factory water, but also reduce the drug consumption, It has certain economic practicality and popularization

key words: water purification agent dosing zero consumption constant flow liquid feeder water quality alum saving

I. preface

the dosing of water purification agent is one of the key links in the water production process of waterworks, and its dosing device plays an important role in production. How to add more reasonably and reduce the drug consumption on the basis of ensuring the water quality is an important task of the waterworks, and it is also an important content of the technological progress development plan of the urban water supply industry in 2000

Changsha Sanshui plant is a large-scale water production enterprise, with a design water production capacity of 300000 m3/day and an actual water treatment capacity of 400000 m3/day at the peak of water consumption, which has made great contributions to the water consumption of Changsha residents. Sanshui plant has been reconstructed and expanded three times in history. Due to various reasons, the original process of adding water purification agent has been adopted: alum storage and Protection Committee: ensuring professional technical operation training, door-to-door service pool - pump - alum adding pool - valve - coagulation reaction pool. There have been three major technical problems in this operation for a long time: (1) the outlet flow of the water purification agent is unstable - the water purification agent in the alum tank keeps flowing out, and the liquid level drops, and the flow is always in a reduced state; (2) Random adjustment - there is no flow meter installed, and the flow is adjusted and controlled only by subjective judgment of the naked eye: (3) sediment blockage - Sediment in the water purification agent is deposited and stuck at the control valve, often causing blockage. These problems not only increase the labor intensity of workers, resulting in unnecessary waste of reagents, but also lead to the instability of the factory water and large turbidity fluctuations, which will affect the effluent quality. Because the above process must be adjusted by people frequently, and controlled by experience, it is difficult to find problems and take measures in a scientific and reasonable manner. If we want to make a thorough change, we must carry out comprehensive technical transformation, adopt automatic filling measures, and realize the automation of detection and control. However, this transformation requires a larger scale and more funds, and the transformation period will affect the normal progress of production. Therefore, under the condition that the existing water plant process has been determined, the capital is very difficult, and it is impossible to carry out comprehensive automation transformation in the short term, Sanshui plant has been looking for and brewing an investment equipment transformation scheme that does not affect normal production, is economical and practical, practically solves the problem, and can recover the investment in the short term. Through more than a year of market research and demonstration, according to the actual situation of the water plant, the zero consumption constant flow liquid feeder developed by a scientific research unit is used in the water plant, and the effect is good

II. Flow calculation of natural outflow of alum liquor before transformation

the alum tank of Sanshui water plant is 1 meter deep, with four circular pipes horizontally installed at the bottom. After the valve is controlled, it flows out naturally by gravity, belonging to the free outflow of unsteady head of cylindrical external nozzle

set the nozzle cross-sectional area as a, and take the pipeline 0-0 as the basic surface, and set up the energy equation for the free liquid level 1-1 in front of the nozzle and the nozzle outlet cross-section 2-2, that is...

from the () formula, it can be seen that the flow of hydrostatic agent decreases with the decline of H. in order to ensure the need of water production, the hydrostatic agent needs to be adjusted every other period of time. To illustrate the problem visually, assume that the flow of hydrostatic agent is manually adjusted once every 100mm when the liquid level of hydrostatic agent decreases, regardless of the deviation of manual operation, and the manual operation is very in place. The flow at the next adjustment is just the actual hydrostatic agent consumption required for water production, which is Qo

the above analysis and demonstration show that the free outflow of water purification agent will cause the waste of water purification agent. Under the above setting conditions, the theoretical waste of agent is 7.29%

III. working principle and performance characteristics of zero consumption constant flow liquid feeder

(1) working principle when the liquid in the open container flows out naturally, the liquid level will continue to drop, and when the position of the liquid outlet is fixed, the liquid outlet pressure will decrease, thus causing the flow to decrease (formula: Q= μ 2gh)。 The zero consumption constant flow liquid feeder changes the immobility of the liquid outlet into activity, and the automatic constant drop system changes the height of the liquid outlet synchronously with the change of the liquid level. The relative drop (i.e. h remains unchanged) is constant to achieve constant flow, and the relative drop between the liquid level and the liquid outlet is changed to adjust the flow. The waste of water purification agent caused by the above non-human level change is avoided

(2) the use of more than 64 million tons of CO2 and SO2 emissions can be reduced in China. Workers generally respond well to this, which mainly has the following performance characteristics:

① no energy consumption, simple and practical, reliable performance, low operation and maintenance costs

② good flow constancy (instant flow is constant)

③ direct measurement and indication of flow, convenient and accurate adjustment

④ it is very convenient to install without civil engineering and does not affect the production of the water plant

⑤ with anti sedimentation and slag retaining device, which will not cause blockage of reagent sediment

IV. industrial test

in order to verify the application effect of zero consumption constant flow liquid feeder, the water plant has continuously measured the relevant data for 10 days before and after the technical transformation to form an atmosphere of cooperation, sharing and common improvement among industries. The measured parameters include temperature, pH value, water volume, raw water turbidity and outgoing water turbidity. According to the measured data, the water temperature, pH value and water volume of the ten day test differ very little, so the influence of these three parameters can be ignored. The relevant test data of 10 days before and after the transformation are listed in Table 2

Table 2 relevant test data of 10 days before and after the transformation

take three groups of data with similar turbidity of raw water for comparison: 17% less alum is consumed on July 22 than on June 27, 19% less alum is consumed from July 23 to June 28, 14.5% less alum is consumed on July 24 than on July 1, and the average value of the three groups is 17.3%, which is 10 percentage points higher than the theoretical value of 7.29% alum saving, which is caused by factors such as large deviation of manual operation before the transformation

the principle of mathematical statistics is applied to treat the turbidity of raw water and factory water. The results are shown in Table 2. It is not difficult to see from the standard deviation that the turbidity of raw water fluctuates greatly in the last ten days after the transformation[ δ (10) After the original =18.54 8 (x) before the original =13.71, while the factory water

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