How is the condensate water returned?

Our steam condensate is collected for internal use, with any excess being fed into the pipeline network.

To this day, many facilities still waste the condensed water discharged by heat exchange equipment, resulting in steam filling the areas inside and outside the workshops. This not only wastes thermal energy but also precious water resources, while causing environmental thermal pollution. In an era of fierce market competition, growing shortages of water resources, and increasing emphasis on environmental protection, it is simply unacceptable to continue wasting and polluting the environment in this way. There are three methods for recovering condensate water: 1. Gravity recovery: This method relies on the principle that water flows downward, and it requires specific terrain conditions; it is difficult for ordinary enterprises to implement. 2. Pressurized recovery: It requires a hot water pump system and related control equipment; it involves high investment, takes up space, consumes electricity, is prone to damage, causes thermal pollution, and has high operating costs. 3. Pump-free backpressure automatic recovery: Without the need for any external power source or electricity consumption, this method makes use of the high backpressure behind the valve along with a scientifically designed piping system to achieve pump-free automatic recovery of condensate water. It requires minimal investment, yields quick results, and offers high returns. The most common method for recovering high-temperature water is the well-known tank-pump system. It requires electricity, the hot water pump is prone to cavitation damage, and it also causes environmental thermal pollution. A better hermetically sealed automatic pump system can eliminate thermal pollution. However, its investment is high, it continues to consume electricity during operation, and its service life is not ideal. Mr. Li Jiagui from Hangzhou West Lake Valve Factory strongly advocates for a cost-effective condensate recovery system – an automatic pumpless backpressure elevation system for high-temperature condensate. 1. System composition: automatic lift steam trap assembly, scientific and rational management design. 2. Operating principle: By utilizing the high back pressure behind the steam trap, the variation in density of high-temperature condensate as it flows through the pipes (in a two-phase fluid state of water and vapor), and a well-designed piping system, the high-temperature condensate is automatically lifted to a certain height before being reused. 3. Features: Multiple lifting points with centralized pipe recovery; no external power required, zero electricity consumption ； Low investment, easy installation, stable operation ； Long service life, no thermal pollution, and a condensate recovery rate of >95%. 0.2 MPa can automatically lift the condensate water by a head of up to 10 m. 4. Theoretical basis: There are mainly three theoretical reasons why we strongly advocate the use of pumpless backpressure recovery systems for the recovery of condensate water: a. The \"Li’s\" brand steam traps produced by Hangzhou West Lake Valve Factory exhibit excellent performance. In a pumpless backpressure recovery system, there is inevitably a certain amount of backpressure at the outlet of the \"Lee\" valve (such as 0.1 MPa), which reduces the pressure difference between the inlet and outlet of the steam trap. Nevertheless, the steam traps we use still possess reliable drainage capabilities (including compliance with the spare factor requirements), enabling them to promptly remove the condensate generated within the equipment. As a result, no water accumulates inside the equipment, which prevents any impact on the production process requirements and also eliminates the risk of water hammer. And these are precisely the issues that users are very concerned about, as well as the things we pay attention to first when conducting engineering design. b. As the high-temperature condensate flows through the pipes, its density changes due to variations in the pressure along the flow path. At 0.1 MPa, the density of saturated water is 942 kg/m3. In the rising section of the return pipe, its density changes according to an exponential law. Based on our years of research into the variation pattern of the density ρ of condensate water at increasing heights, the phenomenological formula is ρ = ρ0e^−a√h, where a is a constant, h is in meters, and ρ0 is the density of the condensate water at the bottom of the height increment. Therefore, the pressure loss when climbing the higher elevation sections will no longer be the traditionally ideal value, but will be much lower. Multiple measurements of the pressure loss in the return water pipeline have confirmed this variation law. It can be inferred from this that for most low-pressure steam-using equipment, as long as there is condensate with some recovery value, a pumpless backpressure recovery system, which requires the least investment, can be considered for recovering the condensate. c. Conduct conservative and reliable hydraulic calculations in accordance with fluid mechanics principles, leaving a certain margin of safety. When performing hydraulic calculations in engineering design, we follow the square of resistance rule and control the flow rate of the condensate water. It not only meets the water delivery requirements of the return water pipeline network and ensures its safe operation, but also leaves a certain margin in the pipeline network’s water delivery capacity. The energy-saving benefits of the pump-free backpressure automatic boosting and recovery system for high-temperature condensate come from three aspects: 1. Energy savings resulting from steam reduction: Currently, there are a variety of drain valves used in industrial equipment, which can be classified into two main categories – thermodynamic type and mechanical type – and their performance is generally unsatisfactory. Thermodynamic steam traps, due to their structural and operational principles, discharge both water and steam together; they suffer from frequent malfunctions and will release steam even in the absence of water, resulting in significant waste of steam. Their leakage rate ranges from 6% to 10%, they are prone to damage, and have a short service life. Mechanical steam traps (such as lever-type full-ball and inverted bucket types) are also prone to wear due to their structural design, which leads to steam leakage, typically in the range of 3% to 6%. The \"Li’s\" brand free-floating ball type steam trap, as tested by the Steam Trap Testing Center, has a leakage rate of ≤0.1%. Even if this value is assumed to be 1%, it still results in a steam savings of over 5% compared to other types of steam traps. 2. Energy-saving benefits of pumpless backpressure recovery for high-temperature condensate: Generally speaking, the amount of condensate generated is equal to the amount of steam consumed by the equipment. The recovery rate of high-temperature condensate water using pump-free backpressure recovery is over 95%, and its temperature can reach above 85°C. If this high-temperature condensate water at 85°C is reused in the soft water tanks of boiler rooms or in places that require hot water, the energy-saving benefits can be determined through thermal calculations: namely, the amount of saturated steam at 0.2 MPa required to heat 1 ton of cold water at 20°C to 85°C. Q_absorbed = Q_released (Q_released = Qlatent + Q_sensible, where Qlatent is the heat released when saturated steam at 0.2 MPa condenses into saturated water at that temperature) ； Q sensible heat is the heat released when 0.2 MPa saturated water is converted to water at 85°C at that temperature). m1×c×〔(273+85)–(273+20)]×4.187 = m2×c′ + m2×c×〔(273+120)–(273+85)]×4.187. In other words, 1000×1×(358–293)×4.187 = m2×[2202 + 1×(393–358)×4.187]. This means that it takes 116 kilograms of saturated steam at 0.2 MPa to heat 1 ton of cold water at 20°C to 85°C; conversely, recovering 1 ton of hot condensate water at 85°C allows for the savings of 116 kilograms of saturated steam at 0.2 MPa. 3. Water-saving benefits: The recovered high-temperature condensate water is valuable soft water, with a recovery rate of over 95%. It not only contains a large amount of usable \"sensible heat\" but also helps to significantly reduce the amount of water used in boilers and production processes, while simultaneously decreasing wastewater discharge. Over the past two decades, the Technology Development Department of Hangzhou West Lake Valve Factory has designed pump-free backpressure recovery systems for thousands of enterprises (many of which are large-scale printing and dyeing, beer, and chemical industries). These systems have achieved the desired results, and their overall performance, investment cost, and service life are all superior to those of the current advanced closed-loop pump-driven recovery systems. Some manufacturers believe that the system we designed is relatively simple. We believe that in order to ensure the production process and to recover all high-temperature condensate water, what matters for a system is not who invests the most or who equips the factory with more expensive fixed assets; rather, it is about which approach requires less investment to achieve the same goal, and which system is more reliable and has a longer service life. That is, if it generates greater benefits for the enterprise, then that person’s level is higher. http://www.hzxhfmc.com