Control steam moisture content and improve the stability of feed process production

Saturated steam is often used in direct and indirect heating processes, so the quality of steam will directly affect product quality. Good steam quality should have the following requirements:

(1) Stable and sufficient steam flow.

(2) Stability and consistency of steam pressure and temperature.

(3) The steam does not contain air and other non-condensable gases.

(4) The moisture content in the steam is small and stable.

(5) There are as few impurities as possible in the steam.

Only by ensuring the above requirements can the process be safe and stable, and produce high-quality products. The steam will carry moisture, which not only causes safety risks such as water hammer, but also affects the production and heating process of the product:

1. Direct heating: In some production processes, steam needs to directly or indirectly contact the product. In the contact process, the liquid moisture carried in the steam will cause fluctuations in the moisture content of the product, such as the animal feed conditioning process and the tobacco production process.

2. Indirect heating: In the indirect heating process, the moisture carried in the steam will make the steam heating process unstable and the outlet temperature will fluctuate, which will affect the consistency of product quality.

Let's look at the impact of moisture content on the production process and product quality in the animal feed plant production process:

The moisture content of the feed is a key parameter. A low moisture content will lose the output of the feed and affect the profitability of the factory. When the moisture content is lower, the feed will be powdered and the product cannot be successfully produced; and if the moisture content of the feed is high, the equipment will have a slippery mold, and the product will also be at risk of moldy.

The moisture content depends on three parameters: the moisture content of the raw materials when they enter, the amount of water added during the production process, and the amount of water removed from the drying process (some product processes may not have this process). Among these parameters, one of the important parameters that we have not measured or controlled at present is the moisture content of steam. Steam will carry moisture and mix with the feed to gelatinize. Once the moisture content of steam fluctuates greatly and the moisture content is high, it is easy to cause The fluctuation of the moisture content of the produced product is also a problem faced by the current lean production in the feed industry.

 Not only the feed industry, but also the production processes of other industries have similar problems. To control the moisture content of steam, we first need to understand the source of moisture in the steam.

1. Moisture carried in the process of boiler steam production.

2. Moisture generated by steam heat dissipation and condensation.

From the perspective of the main source of moisture in the steam, we need to reduce the moisture carried in the boiler steam production process, and do a good job of heat preservation to reduce the heat dissipation of the steam pipe. Under the current technical conditions, the above methods can only reduce the production of moisture, but cannot control or stabilize the moisture content of the steam. Therefore, we need more technical measures/equipment to stabilize and control the moisture content of the steam:

1. Correct and reasonable steam pipeline and equipment drainage;

2. Use a steam-water separator to control steam moisture content in processes that require high moisture content;

3. In some core processes (such as the production process of cut tobacco), the overall steam moisture content control scheme is adopted to control and stabilize the steam moisture content at an extremely low level;

The moisture content of steam will fluctuate continuously with the temperature, steam load, and the operating level of workers. Therefore, we also need to accurately measure the moisture content of steam, reasonably optimize and adjust the process parameters, and achieve consistent and stable product quality.

In the process of controlling steam moisture content, technical measures/equipment are only means. We need more efficient management and maintenance of steam systems, especially technicians who have key knowledge of steam systems.