Reduce the amount of circulating water used?
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This post was last edited by cdpulin on 2010-8-13 at 14:27. Colleagues, what measures or technologies can be used to reduce the amount of circulating water used and thus lower water consumption?
Reply to 1# gaofeng_2008: I’m not aware of the operating conditions of your circulating water system. Generally speaking, the volume of water in the circulation system cannot be changed arbitrarily; it must meet the requirements of the manufacturing process. If conditions permit, 1. the water valves of the equipment that uses circulating water can be slightly closed to reduce the amount of circulating water ； 2. Reduce the number of operating circulation water pumps and fans ； 3. Reduce the water volume fed into the tower, thereby decreasing evaporation.
What is your designed circulating water volume? If a circular water economy is to be implemented, it would be advisable to consider using variable-frequency pumps, depending on the level of water demand. Additionally, lowering the temperature of the circulating water can also reduce the amount of water required.
To reduce the amount of circulating water used, improvements to the process equipment are necessary; air cooling and other methods can be considered for heat exchangers. Improvements need to start with the process flow. For the circulating water workshop, water can only be supplied according to the water requirements of the process equipment; in other words, the amount of circulating water supplied cannot be reduced. However, the wastewater can be reused within the workshop, thereby reducing water consumption. Currently, the method of lime + ultrafiltration + reverse osmosis is commonly used, and the reuse rate for water of generally good quality can reach over 0.75. If ultrafiltration + reverse osmosis is used directly, the reuse rate can reach over 0.65. Furthermore, reducing the amount of water that drifts off and evaporates from cooling towers, upgrading old systems, and replacing water-saving collectors can also lead to significant water savings.
One is the recycling of wastewater. On the other hand, it is necessary to keep various parameters of the circulating water under control; for example, in some areas the raw water is alkaline in nature, so acid needs to be added to maintain its alkalinity and pH levels, which helps to reduce the amount of water that needs to be replenished
Who can explain it in more detail? Learning*learning*
If, without changing the overall process of the circulating water system, the amount of make-up water for the circulating water is reduced by increasing the concentration factor, thereby cutting water consumption, it should be noted that a higher concentration factor is not always better, as this has a direct impact on the treatment costs. Methods to increase the concentration ratio include: 1. The acid addition system – by using this system, temporary hardness and alkalinity can be reduced, thereby creating conditions for increasing the concentration ratio; this approach has proven effective in large industrial circulating water systems in the northern regions. 2. Addition of high-efficiency scale and corrosion inhibitors: High-efficiency scale and corrosion inhibitors developed for systems with high concentration ratios enable the achievement of the designed concentration ratio to the greatest extent possible, ensuring the reliable operation of the system. 3. Weak acid resin exchange system: Treating raw water with weak acid ion resins can reduce the carbonate hardness and corresponding alkalinity in the water. By adding a corrosion inhibitor, corrosion in the circulating water system can be prevented, thereby increasing the concentration ratio without affecting the operation of the system. 4. Sidestream weak acid treatment: Similar to the principle of the acid addition system, its main function is to reduce carbonate hardness and alkalinity, enable the circulating water system to operate at a high concentration ratio, and decrease wastewater discharge. 5. Reverse osmosis desalination technology: Using RO membranes to treat make-up water reduces its conductivity, thereby effectively increasing the concentration ratio. 6. Other technologies, such as ozone technology, etc.
What was said on floor 7 is very good. This requires adjusting the operation to a higher acid concentration based on the quality of the water used for replenishment; the concentration can be increased up to around 5, resulting in a significant water-saving effect
If conditions permit, changing the system from an open-loop to a closed-loop system and then using an air cooler can fundamentally save water. The conditions are just quite strict
Add a reuse system to recycle wastewater, treat it, and then reuse it
From a technical perspective, a closed-loop system requires the least amount of water for replenishment； In terms of operation, increasing the concentration ratio results in the lowest required water replenishment amount ； Economically speaking, by increasing the amount of recycled water, the amount of fresh water that needs to be supplied is minimized.