Feasible methods for steam condensate recovery

Make a collection tank at a low level, and the condensed water will flow in and be transported outward by a submersible pump. It can be used as hot water or deionized water for use by other devices.

The poster said that recycling is difficult. Is it because the temperature is too high to recycle or because the process is not available? Generally, there are two types of condensate recovery: open type and closed type. 1. It is directly recycled to the condensate tank after the trap or diversion valve. If the remaining amount is not enough, it must be collected by position difference. 2. Due to the high temperature during the direct diversion recycling process, there is steam. If it is blocked or cavitated, it is recommended to install a drain trap. 3. Cavitation is likely to occur in condensate transportation. Generally, the condensate tank is higher than the pressurized pump, and cavitation is reduced through the position difference. 4. A drain pump can be used for pressurization, which can effectively prevent cavitation. Since the question asked by the poster is not clear, I can only give a general answer.

You should first find out why it is difficult to recycle, and then find ways to solve it

Our unit’s condensate water recovery method is briefly introduced below: Medium Pressure Steam Condensate Water Recovery: Because it is medium-pressure condensate and has a certain amount of sensible heat, the temperature of our condensate is around 180°C. It is recovered and flashed into low-pressure steam for semi-heat use in the installation area and large tank area. Low pressure condensate recovery: Part of the water recovered from the heat tracing is returned to the boiler room, and part is returned to the circulating pool to replenish the circulating water.

It is said that armstrong's steam-driven condensate water pump can avoid cavitation problems caused by transporting high-temperature condensate water.

I think the reason why the moderator mentioned that recycling is difficult may be because it is scattered, the return pipes are very long, and the investment is large.

Only through economic accounting, of course it is good to reuse if conditions permit, but decentralized recycling does require a lot of investment. And if you want to obtain better recycled water quality, you must invest in it, such as using non-carbon steel pipes. Otherwise, the little water that was finally recovered would turn into rust soup. These are things that engineering and technical personnel must consider when senior cadres widely publicize the significance of recycling.

If part of the water is returned to the circulating water tank and the circulating water is replenished, the temperature of the circulating water will rise. Is this economical?

Beijing Junfa Energy Saving and Environmental Protection Technology Co., Ltd. is a high-tech enterprise integrating R&D, design and manufacturing. The company has a research and development team headed by senior technical experts from the Chinese Academy of Sciences, specializing in steam system energy optimization, waste heat, waste energy and water recovery. It has developed a number of patented technology products over the past few years. The products have been successfully used in large enterprises and institutions such as Qilu Petrochemical, Yanshan Petrochemical, Daqing Petrochemical, Lanzhou Petrochemical, Tsingtao Beer, Harbin Pharmaceutical No. 6 Plant, Brilliance Automobile, China Resources Textile, Huanghai Rubber, Guodian Shuangyashan, Tiantan Hospital, etc. It has hundreds of successful cases in more than 20 industries across the country, bringing huge economic and environmental benefits to users. 　　1. Overview of condensate recovery Steam thermal energy consists of sensible heat and latent heat. Usually thermal equipment only uses the latent heat of vaporization of steam, and the steam that releases latent heat is reduced to saturated water at the same temperature. That is, the condensate with sensible heat flows out of the thermal equipment and is recycled and reused through the steam trap and condensate pipes. 　　The temperature of condensed water (condensate water) is relatively high (generally above 100°C) and should be utilized as much as possible. At the same time, it is a good desalted water, which is most suitable for boiler water replenishment and process water with higher requirements. 　　2. Comparison of recovery methods A. Open system At present, domestic enterprises basically adopt open water tanks, water tanks, etc. to recover condensate water. In order to reduce the emission of flash secondary steam (the temperature of the condensate water is high, the pressure decreases when entering the open system, and a large amount of sensible heat turns into latent heat, forming secondary vaporization). Some companies use water to cool down, reducing water quality and utilization value. Others use a condenser to absorb the flash secondary steam with circulating water, and then discharge the heat through a cooling tower. In order to waste this energy, they also need to install equipment and spend new energy. 　　Open systems have the following problems: 　　1. A large amount of steam leakage from traps and secondary flash steam are discharged into the air. This waste accounts for about 5 to 20% of the total condensate water and 20 to 60% of the total heat. 　　2. The emission of flash steam will cause hot fog to fill the sky in winter and intense heat waves in summer, which will cause serious thermal pollution to the environment and may burn people, posing safety hazards. 　　3. The humid environment aggravates the corrosion of metal equipment and the aging of electrical equipment, causing indirect losses. 　　4. The recovery system is a dynamic two-phase flow, which often forms water hammer, causing severe vibrations in equipment and pipelines, posing safety risks. 　　5. The recovered condensate water will again dissolve oxygen, carbon dioxide and other impurities in the air, increasing post-processing costs. Using high-quality condensate water as low-grade water is itself a waste. 　　B. Closed recovery system 1. Beijing Junfa Energy Saving and Environmental Protection Technology Co., Ltd.’s closed condensate recovery complete set of equipment has been well used in hundreds of companies across the country, bringing economic and environmental benefits to the company. The principle is: It is based on the principle of dynamic two-phase flow and micro-supercooling, which eliminates the inducement of cavitation of water pumps and successfully solves the problem of cavitation of water pumps transporting high-temperature condensate water. It can increase the back pressure of the steam trap, eliminate the emission of secondary flash steam and hydrophobic steam leakage, and fully recover the heat energy contained in the steam condensed water. Eliminate cavitation of the condensate pressure pump, improve hydrophobic conditions, ensure smooth drainage, and extend the service life of the return water system. 　　2. Technical characteristics of the closed condensate recovery system: ①. After closed recovery of spent steam and condensate, the production cost of the enterprise is reduced, and the market competitiveness and net profit of the enterprise are improved. 　　②. After recovering the spent steam and condensate water, the thermal pollution caused by the discharge of condensate water and flash secondary steam is completely eliminated. There is no white steam floating in the sky of the factory, which avoids thermal pollution, beautifies the factory environment, and achieves clean production. 　　③, Completely closed recovery of spent steam and condensate under the user's normal production process conditions. 　　④, the condensed water will not be re-polluted by oxygen in the air, and can be directly used to save deaeration water. 　　⑤, The condensate water pump will not cause cavitation when transporting high-temperature condensate water, and can send the condensate water to the designated location. 　　⑥, the system is balanced and stable, and the condensate recovery device operates fully automatically and continuously. 　　3. According to the value of the condensed water itself, it is necessary to implement closed recovery of the condensed water. 　　Steam condensate water is saturated high-temperature softened water, and its thermal energy value accounts for about 20% of the steam thermal energy value. If it is directly discharged without recycling, it will be a huge waste of both water and thermal energy resources. 　　Properties of condensed water: Value of condensed water = original water value + softening value + oxygen removal value + desalination value + heat value + environmental value. The thermal energy of steam consists of sensible heat and latent heat. Usually steam equipment only uses the latent heat of steam, and the steam after releasing the latent heat is reduced to saturated water at the same temperature, that is, condensed water with sensible heat. Saturated condensed water accounts for 15.6%-26.7% of the steam heat energy at a steam pressure of 0.1-0.9MPa. The higher the steam pressure used, the higher the heat energy value of the discharged condensate water. Theoretically, condensate water is better desalinated water and has better quality than boiler feed water. 　　4. Economic and environmental benefits Practice has proven that the use of Junfa closed condensate recovery technology can produce significant economic and environmental benefits, as shown in the following: 　　First, * * The flash evaporation loss of condensed water is reduced, so that its own heat can be fully utilized. According to statistics, fully recovering the heat contained in condensate and flash steam can save 12-28% of boiler fuel compared to completely discarding it. ； Compared with cooling recovery, it can save 6%-22% of boiler fuel. Second, the water recycling rate is as high as over 90%, effectively saving water resources. At the same time, the isolation of condensate water from the air allows this part of the boiler feed water to maintain excellent quality, and accordingly reduces the cost of softening and deaeration of the boiler feed water. 　　Third, it fundamentally prevents corrosive gases from redissolving into boiler feed water, greatly alleviates corrosion of thermal equipment and pipe networks, and extends the service life of equipment and pipe networks. 　　Fourth, it greatly reduces the boiler's sewage discharge rate (generally consistent with the condensate recovery rate), increases the boiler's steam production per unit time to a certain extent, and improves the boiler output. 　　Fifth, it reduces thermal pollution and noise caused by running, escaping, dripping and leaking, and improves the working environment of workers. 　　Sixth, the total amount of harmful gas emissions such as soot, fly ash, SO2, CO2, NOx and slag emissions can be reduced by 15-30%, which can significantly reduce the pollution and damage to the surrounding environment. 　　Based on the above advantages, the technology of Beijing Junfa Company has been widely promoted and applied in more than 20 industries across the country, and the economic and social benefits generated are immeasurable. According to Beijing Junfa data, a thermal power plant in a development zone has five 35-ton steam boilers with a total capacity of 175 tons/hour, and nearly a hundred steam-using units. The thermal center adopts Beijing Junfa’s closed-circuit condensate recovery technology to achieve closed-circuit recovery of condensate throughout the region, raising the average recovery temperature of condensate water to 90°C and the condensate recovery rate to more than 85%. It saves 55,500 tons of water annually, saves about 2,000 tons of coal, and generates direct and indirect economic benefits of more than 4 million yuan. At the same time, due to the reduction in coal consumption, flue gas emissions are also reduced accordingly, and boiler blowdown and slag production are reduced. Slag emissions can be reduced by 142.57 tons per year, flue gas emissions can be reduced by 14 million cubic meters, and soot, fly ash, SO2, and NO2 emissions can be reduced by 95.3 tons, 17.11 tons, and 5.69 tons respectively. The goals of energy conservation, emission reduction and civilized production have been achieved. 　　5. Conclusion Beijing Junfa Company specializes in steam system energy optimization, waste heat, waste energy and water recovery and utilization. It has a number of patented technology products. The application of Beijing Junfa Company's closed high-temperature condensate recovery technology will bring better economic and environmental benefits to the enterprise. We have reason to believe that with * * “With the in-depth implementation of the strategy of "energy saving, emission reduction, sustainable development" and the continuous strengthening of people's awareness of environmental protection, this technology will be more widely used and developed. Its economic value and environmental significance will be increasingly obvious, and it will make greater contributions to China's sustainable development.

Our company's recycling method mainly depends on whether the conductivity of the condensate is high or low, and sometimes it also analyzes the alkalinity and PH value. If the conductivity is not high, it can be directly used in the deaerator. If the conductivity is high, it can be returned to the shallow brine tank of the desalted water station for further treatment. If it is directly put into the circulating water system as mentioned above, a small amount will not cause the temperature of the circulating water to rise too high, but it is just a pity.

The reuse of condensed water should be considered from two aspects: heat energy reuse of saturated water and water reuse. At present, for most small and medium-sized manufacturers, this issue has not attracted attention. This is not only related to the concept, but also related to the production conditions of the manufacturer. Because many small manufacturers rarely have complete public engineering systems, sometimes they want to make full use of it, but find that there is nowhere to use it, and sometimes the cost of recycling will rise.

Recycled into boiler, water softener or economizer

Our unit has a condensate tank equipped with a condensate pump, which is sent back to the decarburization system for soft water replenishment.

Deoxygenation after reflux can still be recycled