low-temperature humidification method

Typical process flow for the continuous low-temperature humidification method:

1.Raw material pre-treatment: Livestock, poultry, or slaughter by-products are transported to the processing center in sealed vehicles;they are crushed into fragments with a particle size of 30–50 mm (though some equipment can process whole animals directly);he material is then conveyed into a buffer hopper via a sealed screw conveyor.

2.Low-temperature heating (core process): Material is fed into the raw material heater via a variable-speed conveyor;live steam is injected directly through specially optimized nozzles to rapidly heat the material to the target temperature (determined by the raw material type and desired product).Dual-temperature and dual-speed control is employed: the material is first rapidly heated to a specific temperature to inactivate enzymes,followed by a further temperature increase to complete fat release. The entire process takes place under sealed, oxygen-free conditions, with precise control over residence time.

3.Multi-stage separation: The heated material enters a decanter centrifuge system for solid-liquid-liquid three-phase separation.The separated fat phase proceeds to a high-speed centrifuge for further purification (achieving a purity of over 99.5%),while the solid phase (bone or protein residue) moves to a downstream drying system, and the process water (stick water) is sent to an evaporation system for concentration.

4.Drying and pulverization: Solid materials enter the dryer for final drying (utilizing waste heat from the evaporation system);after drying, the material undergoes pulverization, cooling (with humidity control to prevent bacterial contamination), screening, and packaging.

5.In the oil refining process, crude oil is heated, agitated, and purified using a horizontal centrifuge before entering storage tanks;the resulting product can be used for biodiesel production or as an industrial raw material.

Compared to the traditional high-temperature, high-pressure (≥135°C, ≥0.3 MPa) humidification method,the low-temperature humidification method offers the following significant technical advantages:

In the low-temperature humidification process, the settings for temperature, pressure, and time must take into account the following material characteristics:

Impact of moisture content and setting principles:

1.Materials with high moisture content—such as slaughterhouse waste and livestock/poultry by-products—actually offer greater economic advantages when processed via low-temperature wet rendering;the higher the moisture content, the more significant the energy savings achieved through mechanical dewatering via centrifuge.

2.For materials with high moisture content, the steam injection time can be appropriately reduced,though the separation time must be extended accordingly.

3.Process water (stick water) can be concentrated in an evaporation system and either added back to the solid fraction or used as a flavor additive.

Impact of material particle size and setting principles:

1.The smaller the particle size, the larger the heat transfer area, allowing for a shorter heating time;

2.Coarsely crushed material (30–50 mm) requires a higher steam injection rate and a longer holding time to ensure the core temperature meets the required standard;

3.Finely comminuted material (e.g., minced meat) offers good heating uniformity, but care must be taken to prevent excessive gelatinization, which could impair solid-liquid separation efficiency.

Low-temperature hydrolysis technology is elevating the resource utilization of livestock and poultry processing by-products to a new level;Chengzhu empowers the industry to achieve green, sustainable production through specialized equipment and technology.