Time and temperature are closely connected, in just the same way as when cooking food. When the cooking temperature is lowered, the cooking time is adjusted to make it longer.
The cooking time is adjusted to the character of the raw material and the pulp grade. The goal is to obtain a desired Kappa number, that is to say, reducing as much lignin as possible without weakening or losing too much cellulose. For bleached end products, low chemical consumption in the subsequent bleaching process is enabled, which is positive for both the production cost and the environment.
For sulfate cooking, there is a mathematical relationship that combines time and temperature into one parameter: The H-factor. By controlling the composition of the cooking liquor in the cooking process and the H-factor, the desired result of the cooking is achieved.
How long does the raw material cook?
The cooking time in Valmet’s CompactCooking™ is adjusted to the type of raw material and the desired result, in just the same way as the cooking time for food.
Time your cooking
Proper cooking takes time but sometimes you need fast food. How do you make both ends meet?
When you are in a hurry, it is best to serve food that can be prepared on the run. A fresh salad, perhaps? Hurrying up a beef steak in the oven, frying pan or on the grill is not the correct way. You destroy the delicate raw ingredient. It turns out dry and boring or in the worst case, burnt. Grill instead at a low temperature, or barbecue in a smoker.
Time and patience can be important skills for a chef. The payback comes when you sit down at the dinner table and enjoy a wonderful tender steak that is tastier than ever before. Proper cooking take it’s time.