Rendering Centrifuges for Beef, Poultry, and Swine
HAUS decanters and separators that split cooked animal by-products into protein solids, fat and water.
Archer Separation supplies HAUS industrial decanter centrifuges and separators to rendering plants processing beef, poultry and swine by-products. Centrifuges separate the cooked material into a protein solid for meal and a clean melted fat, continuously and with the driest possible solids.
What Is Rendering?
Rendering repurposes the inedible parts of animals separated as waste in slaughterhouses and meat processing plants, and returns them to the economy. How much of a slaughtered animal is eaten varies from country to country with cultural habits; in Western countries the waste is about 30–35 % of the animal.
Generic flowsheet for illustration. Every Archer system is designed to its own basis; ask us for one drawn for your plant.
Fast-growing animals need a lot of high-quality energy, and fats help balance the energy in high-energy mixed feeds. Fats carry far more metabolic energy than proteins or carbohydrates, on average 7,000–10,000 kcal/kg, which gives them several advantages in animal feed.
Rendering Products
Rendering benefits both the environment and the economy by turning inedible animal parts into fat and into feed ingredients for poultry, fish, cat and dog food.
Crush and grind
Animal by-products are crushed and ground.
Cook
Cooking removes moisture and kills microorganisms.
Centrifuge
The solids (protein) and melted fat (tallow) are separated by centrifuging.
Mill
The solids are ground into powder to make meat and bone meal.
New technology, strict regulations and environmental awareness have made modern rendering plants high-tech operations that need substantial investment.
Types of Rendering Products
Meat meal
Made from slaughterhouse waste and from plants producing sausages, salami and hot dogs. The fat is removed and the rest is dried and ground. It contains no feathers, horns, skin, hooves, stomach contents, blood or manure, and is rich in protein with a balanced profile of essential amino acids. In biological value it ranks second among animal-derived feeds, after fish meal.
Meat and bone meal
Made by processing whole carcasses or parts of slaughtered or dead animals: the fat is removed and the material is dried and ground. Its phosphorus and crude protein content depend on how much bone is in the raw material.
Bone meal
Made by cooking, drying and grinding animal bones after the fat and collagen tissue have been removed. It has low protein value and contributes little in essential amino acids.
Blood meal
Blood collected after slaughter is heated until it coagulates, then dewatered, dried and ground. Temperature is the critical quality factor: too much heat inactivates lysine, which then has no nutritional value for monogastric animals and lowers digestibility. Blood meal is rich in protein but low in phosphorus and calcium, and is a valuable protein source for poultry.
Poultry meal
A by-product of poultry slaughter: internal organs and other inedible parts, without feathers. Protein, calcium and phosphorus vary with the raw material. In Turkey, poultry meal is made without separating the feathers, giving high crude protein but low digestibility. In the U.S., pet food makers rate low-ash poultry meal higher, and it sells for more than high-ash product.
Feather meal
Poultry feathers are hydrolyzed, sterilized, dried and ground after slaughter; in Turkey they are usually processed with other poultry waste rather than separately. Untreated feathers are indigestible. Quality depends mainly on hydrolysis: too much pressure and temperature degrade the protein. Raw feathers are rich in the amino acid cysteine.
Rendering Processes
Three main processes
Rendering facilities use three main processes:
- Wet rendering
- Dry rendering
- Blood meal processing
Two systems for meat and bone by-products
Two primary rendering systems are used worldwide:
- Fat processing as dried material
- Fat processing as a liquid phase
Where centrifuges fit in a rendering plant
Decanter: solids out
A two- or three-phase decanter takes the cooked liquid and removes the protein fines, leaving a liquid of fat and water (or separate fat and water streams).
Separator: clean tallow
A disc-stack separator polishes the fat, taking out the last water and fine solids to give a clear, stable tallow or poultry fat.
Water phase: recover more
The separated water (stickwater) still carries protein and fat; it is typically concentrated or treated, for example with a DAF, rather than discharged as is.
These processes are used in high-value applications such as poultry fat, fish oil and edible oils, which need heat-sensitive handling.
Edible fat rendering: lard and tallow
Edible fat rendering turns clean pork or beef fat trim into lard and tallow for food use. The trim is ground and melted with steam at a moderate temperature, and a three-phase decanter splits the melt continuously into fat, a water phase and greaves. Two disk-stack separators then purify and polish the fat to a clear, low-moisture product ready for refining or packing. The greaves are cooked and pressed into cracklings, and the water phase goes to pretreatment, typically a DAF, before discharge. Archer supplies the decanter, separators and controls as one hygienic, food-grade package.
Generic flowsheet for illustration. Every Archer system is designed to its own basis; ask us for one drawn for your plant.
Rendering Process Overview
| Decanter inlet | 6–7 % solids |
|---|---|
| Decanter outlet | Less than 1 % solids |
| Fat content in solids | 20–30 % |
| Product temperature | 80–90 °C |
| G-force | 3,000 g |
| Centrifugation time | 5 minutes |
Two-Phase Output Products
| Oil output | 0.5–1.0 % dry matter |
|---|---|
| Solid output | The product leaving the disc dryer is fed to presses. The residual oil sludge from pressing is purified further in a decanter centrifuge; about one tenth of the rendering product leaving the disc dryer goes through the decanter. |
Average values (%) of solid products from decanter and press
| Meat and Bone Meal (Processed Animal Protein) | Poultry By-Products | Feather Meal | Blood Meal | |
|---|---|---|---|---|
| Protein | 45-65 | 60-68 | 80-85 | 90-95 |
| Fat | 12-16 | 12-16 | 7-11 | 1 |
| Ash | 22-35 | 10-20 | 4-10 | 2-3 |
| Phosphorus | 3-7 | 2-3 | 0.5 | 0.2-1.0 |
| Water | 5-7 | 4-7 | 6-8 | 4-7 |
Typical composition of solid by-products from animal processing, which are often used in animal feed.
Amino acid values (%) in solid products from decanter and press
| Amino Acid | Meat and Bone Meal (Processed Animal Protein) | Poultry By-Products | Feather Meal | Blood Meal |
|---|---|---|---|---|
| Methionine | 0.7 | 1.0 | 0.6 | 0.6 |
| Cystine | 0.7 | 1.0 | 4.3 | 0.5 |
| Lysine | 2.6 | 3.1 | 2.3 | 7.1 |
| Threonine | 1.7 | 2.2 | 3.8 | 3.2 |
| Isoleucine | 1.5 | 2.2 | 3.9 | 1.0 |
| Valine | 2.4 | 2.9 | 5.9 | 7.3 |
| Tryptophan | 0.3 | 0.4 | 0.6 | 1.3 |
| Arginine | 3.3 | 3.9 | 5.6 | 3.6 |
| Histidine | 1.0 | 1.1 | 0.9 | 3.5 |
| Leucine | 3.3 | 4.0 | 6.9 | 10.5 |
| Phenylalanine | 1.8 | 2.3 | 3.9 | 5.7 |
| Tyrosine | 1.2 | 1.7 | 2.5 | 2.1 |
| Glycine | 6.7 | 6.2 | 6.1 | 4.6 |
| Serine | 2.2 | 2.7 | 8.5 | 4.3 |
Reading the tables
- Values: percentage (%) of each component or amino acid in the by-product
- Decanter and press: the industrial steps that separate solids from liquids and produce these solid products
- By-products: meat and bone meal (processed animal protein), poultry by-products, feather meal and blood meal, all common animal feed ingredients
- Use: a guide to the nutritional composition of these by-products for animal feed formulation
More About HAUS
I Series industrial decanters
The HAUS DDI Series decanter centrifuge has a horizontal rotating bowl, a scroll conveyor that discharges the separated solids continuously, and a dual-motor drive that controls the differential speed between bowl and scroll.
It is built for industries that need durability: rendering, chemical, pharmaceutical, solid and liquid fat extraction, protein recovery, mining, lubricants and fuel processing. Its job is to separate solids from liquid mixtures into one or two purified liquid phases with the driest possible solids, which makes it very effective at processing by-products and recovering valuable materials for recycling.
I Series industrial separators
HAUS I Series separators use strong centrifugal force for high separation efficiency in industrial duties. They are developed for vegetable oils such as coconut and palm oil, waste oils, oil refining and animal fats such as fish oil, and are used in many sectors worldwide.
- Bowl in selected duplex stainless steel for corrosion resistance
- Seals designed for high-temperature service
- Replaceable wear protection on the high-speed bowl and piston
- Built for continuous operation and consistent product quality
- Rapid discharge systems that cut power use and save time
Related pages
Decanter centrifuges
Two- and three-phase decanters and how they work.
Disk stack centrifuges
Separators for polishing tallow and oils.
HAUS Centrifuge Technologies
Our decanter and separator manufacturing partner.
Meat processing
Separation and water clarification for meat plants.
DAF systems
Recovering fat and solids from plant wastewater.
Remote monitoring
Our engineers watch your centrifuges and step in early.
Fish Meal and Fish Oil
Press liquor, fish oil and stickwater separation.