BATCH COOKER

A & S THAI WORKS CO., LTD

The batch cooker has been used in the rendering industry since the 1940s.
It is a simple steam heated machine with a jacketed cylinder and a mixing rotor that can process, cook and dry materials in “one batch”

  • Mixed meat and meat, bone and intestines (high temp drying) fry and dry the material in oil bath at 135 deg C, to be used with high pressure press
  • Mixed poultry offal = offal and feathers mixed together (hydrolyzing and drying) => meal for animal feed and tallow/chicken oil, with high pressure press
  • Feathers (hydrolyzing and drying) => feather meal for animal feed
  • Blood (cooking and drying of decanter cake) => blood meal for animal feed
  • Wool and hair from processing of sheep, hog (swine) (hydrolyzing and drying) => feed back into the rendering process

Today batch cookers are used mainly for small, low cost rendering capacities, while continuous systems are being used for larger capacities.   For feathers, the batch cooker is sometimes used together with a more efficient disc dryer and increase capacity about 30%.

Batch process includes the following steps:  Feathers, wool and hog hair:

  • HYDROLYZING and drying in a batch cooker at internal pressure about 3 bar for 20 minutes to make the feathers digestible – (pressure and time can vary)
  • Hydrolyzing and then drying in a disc dryer
  • Cooling of meal and hammer milling

For Mixed meat, bone and intestines the batch cooker will act as a HIGH TEMP frying pan where the material is cooked and dried in a high temperature oil bath, up to 135 deg C. Then the hot material is pressed in a high pressure press where the tallow/fat/oil is separated.

The batch cooker design has a heated shell with a steam jacket and a heated mixer rotor. There is an inlet chute and
a bottom outlet, both with knife gate valves. The body is designed to withstand internal pressure up to 5 bar (operation 3 bar)

ASTW make three most common sizes;

  • 5,000 liters, popular name 5 x 12 foot batch cooker
  • 10,000 liters, popular name 5.5 x 18.5 foot batch cooker
  • 1,700 liters, popular name 3 x 9 foot batch cooker,
    2 options! a) normal batch cooker. b) no jacket, injection of live steam for hydrolysis of wool and direct injection into dryer

Technical Specification: ASTW HTR - High Temperature Rendering using batch cooker

This process consist of the basic components: raw material pre treatment – batch cooker – high pressure screw press (when fat and oil is present)- decanter/separator oil/tallow clarification – meal handling/cooling/hammermill – condenser/odor control – storage

Plant Process Capacity tons input per hr (feather & mix), (meat & bone) Total Steam Consumption ton/hr Electric total KW installed
2
135
4
235
4
280
8
375

Material to be processed in kg: (filling values may vary)

Mixed meat and bone
and intestines
(cooking and drying
only)

• BC 1,700 = 900 kg
• BC 5,000 = 2,800 kg
• BC 10,000 = 5,200kg

Mixed poultry offal
(offal and feathers
mixed together)
(hydrolyzing and
drying)

• BC 1,700 = 900 kg
• BC 5,000 = 2,600 kg
• BC 10,000 = 5,200kg

Feathers (hydrolyzing
and drying)

• BC 1,700 = 850 kg
• BC 5,000 = 2,400 kg
• BC 10,000 = 4,000kg

(*Note that with a disc
dryer the total capacity
will increase about 30%)

Blood (cooking and
drying only)

• BC 1,700 = 700 kg
• BC 5,000 = 2,000 kg
• BC 10,000 = 4,000kg

Wool and hair from
processing of sheep,
hog (swine)
(hydrolyzing and
drying)

• BC 1,700 = 780 kg
• BC 5,000 = 2,300 kg
• BC 10,000 = 4,600kg