In the alumina industry, the performance of evaporators plays a crucial role in production efficiency and cost control. As an important indicator for measuring the energy consumption of evaporators, the steam-water ratio has always attracted much attention. Today, we will take an in-depth look at the "true and false steam-water ratios" in the alumina industry and focus on the remarkable advantages of the seven-effect two-stage evaporator of Henan Jiuye Chemical Equipment Co., Ltd.

Ⅰ. What is the Steam-Water Ratio?

Simply put, the steam-water ratio is the ratio of steam consumed to water evaporated during the evaporation process. A lower steam-water ratio means less steam is consumed to evaporate the same amount of water, indicating higher energy efficiency. In the alumina production process, evaporation is an indispensable procedure, and the energy consumption for evaporative concentration of mother liquor accounts for more than half of the entire production process. Therefore, reducing the steam-water ratio is of great significance for energy conservation and consumption reduction in alumina production.

 Ⅱ. Reasons for Variations in Steam-Water Ratio

In actual production, the steam-water ratio is not fixed but influenced by multiple factors, with material parameters being one of the key factors. Different users have varying material parameters, necessitating the adoption of different process routes. For example, evaporators can be classified into two-stage and three-stage processes, with the three-stage process generally being more steam-efficient than the two-stage process. Additionally, evaporator processes include full countercurrent, two-stage full countercurrent, and two-stage crossflow (one-stage co-current and one-stage countercurrent). The specific process selected depends on the material's characteristics, such as raw liquid temperature, mother liquor temperature, and output requirements. 

- If the raw liquid temperature is high and there are no special requirements for mother liquor temperature (or it can be discharged at a lower temperature), using a crossflow process can achieve a very low steam-water ratio. 
- Conversely, if the raw liquid temperature is low but the mother liquor temperature requirement is high, the steam-water ratio will be relatively higher. For instance, when the raw liquid temperature is only around 60°C and the mother liquor temperature needs to reach 80°C, the steam-water ratio may reach 0.22.

 Ⅲ. Discrimination Between True and False Steam-Water Ratios

After understanding the influencing factors of the normal steam-water ratio, we must be wary of the phenomenon of "false steam-water ratios" in the industry. False steam-water ratios create the illusion of very low energy consumption in evaporators, but in reality, they do not truly reflect the equipment's energy efficiency level. There are two common scenarios of false steam-water ratios:

1. **Unaccounted Heat Sources**: Some enterprises fail to measure all heat sources entering the evaporator when calculating the steam-water ratio. For example, during the evaporation process, condensate from high-temperature digestion may be reused in the evaporation stage without being accounted for. The calculated steam-water ratio in such cases may appear very low, but it is inaccurate because an unmeasured heat source is effectively "feeding" the evaporator.

2. **Inaccurate Steam Measurement**: Another scenario involves flawed steam measurement. Some enterprises use superheated steam but fail to correctly calculate the actual steam volume after cooling and depressurization. When 1 ton of superheated steam is cooled and depressurized, its actual steam volume may increase to 1.16 tons or more. If only the initial value of superheated steam is measured instead of calculating based on the actual saturated steam volume, the steam-water ratio will appear artificially low—another form of "false" ratio.

 Ⅳ. Advantages of Jiuye's Seven-Effect Two-Stage Evaporator

In the complex landscape of steam-water ratio dynamics, the Seven-Effect Two-Stage Evaporator developed by Henan Jiuye Chemical Equipment Co., Ltd. stands out with multiple prominent advantages.

1. **Energy Efficiency and High Performance**: 
Jiuye’s Seven-Effect Two-Stage Evaporator achieves industry-leading steam-water ratios, typically controlled between **0.18–0.22 tons of steam per ton of water**—significantly more efficient than the global alumina industry’s best current performance (over **0.28 tons of steam per ton of water**). This is attributed to its advanced split-body design and optimized process routes, which maximize steam utilization and drastically reduce energy consumption.

2. **Adaptability to Diverse Materials**: 
The evaporator dynamically adjusts process routes based on varying material parameters from different users. Whether handling high or low raw liquid temperatures, or meeting specific mother liquor temperature requirements, Jiuye’s technology delivers optimal steam-water ratios through tailored工艺 selections. This flexibility provides a robust solution for diverse production needs, ensuring reliable performance across various operational scenarios.

3. **Technological Innovation**: 
Jiuye Chemical Equipment Co., Ltd. boasts robust R&D capabilities and strategic partnerships with leading institutions such as the Zhengzhou Light Metals Research Institute, Zhengzhou University's Institute of Chemical Equipment Design, and the Henan Chemical Industry Research Institute. Key innovations include: 
- **Advanced Film Distributor**: Prevents film drying or breakage on heating tube walls, ensuring consistent high heat transfer efficiency. 
- **Optimized Temperature Difference Allocation**: Enables six-stage reuse of secondary steam in the seven-effect evaporation process, further reducing steam consumption during solution concentration. 

These technologies set new benchmarks for energy efficiency in the industry.

4. **Stable and Reliable Operation**: 
In practical applications, Jiuye’s Seven-Effect Two-Stage Evaporator has demonstrated outstanding performance in major aluminum industry groups. The equipment features stable operation, simple maintenance, and reduced cleaning, repair, and overhaul frequency—significantly lowering labor intensity and improving productivity. 

**Case Study: Xinfa Group** 
In early 2016, Jiuye’s self-innovated patent product, the "Seven-Effect Two-Stage Split Evaporator," was successfully commissioned at Xinfa Group. With a design capacity of **280 tons/hour** and a targeted steam consumption of **0.18 tons steam/ton water**, the evaporator operated stably under inlet steam conditions of **0.25MPa pressure** and **140°C temperature**. Notably, its actual steam consumption reached **0.159 tons steam/ton water**—the lowest recorded in the alumina industry to date, setting a new world benchmark. 

Subsequently, Jiuye’s evaporators have been successfully deployed in enterprises such as Weiqiao Group and Guangxi Huasheng, earning wide recognition for their reliability and performance.

In the alumina industry, accurately understanding the steam-water ratio and distinguishing between true and false ratios is crucial. The Seven-Effect Two-Stage Evaporator by Henan Jiuye Chemical Equipment Co., Ltd. offers a highly efficient and reliable evaporation solution, thanks to its advantages in energy conservation, material adaptability, technological innovation, and operational stability. It stands as the preferred choice for numerous enterprises when selecting evaporator equipment. With continuous technological advancements, Jiuye Chemical Equipment Co., Ltd. is poised to continue driving innovation and contributing to the development of the alumina industry in the future.