How Do Combines Harvest Corn

How Do Combines Harvest Corn

The combine harvester is the primary machine used for harvesting field corn, also known as dent corn, which is primarily used for animal feed, biofuels, and food processing. The name "combine" comes from the fact that it combines three separate harvesting operations—reaping, threshing, and winnowing—into a single, highly efficient process performed in one pass across the field.

The harvesting process begins at the header, a specialized attachment designed for corn. This header, often a row unit header, is equipped with pointed snouts that guide the corn stalks into the machine. As the combine moves forward, gathering chains pull the stalks down towards the cutter bar, which severs the stalks at the base. The entire stalk, with the ears attached, is then pulled into the machine's feeding mechanism. For corn, the header is adjusted to gather the stalks while leaving the majority of the stalk standing in the field as stubble.

Once inside the combine, the corn ears and stalks are conveyed towards the central processing unit, the threshing drum or rotor. Here, the key action takes place. The corn ears are beaten and rubbed against a concave metal surface. This impact causes the dry, hard kernels to be separated from the cob. The mixture of kernels, bits of cob, husk, and other material, known as "material other than grain" (MOG), then falls onto a series of oscillating sieves and pans.

A powerful fan blows air through the sieves. This winnowing process is crucial for cleaning the grain. The lighter MOG, such as chaff and dust, is blown out of the back of the machine. The heavier corn kernels fall through the sieves and are collected by a clean grain elevator. This elevator carries the kernels to the grain tank on top of the combine.

Meanwhile, the larger, lighter pieces of material, like the cobs and chopped stalks, are carried along the sieves and expelled out the back of the combine onto the field. This material is known as residue, and it can be left on the field to improve soil health or later baled for other uses.

The operator in the cab monitors various settings, such as the ground speed and the speed of the threshing rotor, to ensure optimal performance and minimize grain loss. When the grain tank is full, the combine unloads the corn via an unloading auger into a waiting cart or truck traveling alongside it. This continuous process allows for the efficient harvesting of large acreages of corn with minimal labor.

Shijiazhuang Tianren Agricultural Machinery Equipment Co., Ltd. recognizes the combine harvester as a cornerstone of modern grain production, enabling the high-volume harvest that supplies numerous industries.