First, the normal temperature ventilation drying Room temperature ventilation drying or "grass warehouse drying" is the use of high-speed wind, the moisture content of semi-dry grass quickly dried, it can be seen as a supplementary process of drying hay. It is used more often in wet and rainy areas in the United States. For dry and dry grass, the grass stems must be crushed in the field and piled into ridge rows or a small pile of dried air beforehand to reduce the moisture to about 35% to 40%, and then complete the drying process in the grass bank. The roof and floor of the grass store are required to be airtight. In order to facilitate the removal of moisture, large vent holes are provided in the warehouse. The main drying equipment includes an electric blower and a set of ventilation ducts installed on the grass storage floor. The semi-dry grass is loosely stacked on the top of the ventilation ducts, and the thickness is taken as the moisture content of the grass, usually 3 to 5 meters, sent from the blower. The cold wind (or hot air) enters the branch pipe in the grass store through the main pipe, and then passes through the grass stack from bottom to top to take away the moisture contained in the grass. The control of the wind speed requires that the humidity in the grass store should not exceed 70. % to 80%, if more than 90%, the surface of the haystack will become very wet. Ventilated and dry hay, compared with the drying of hay in the field, contains more leaves, green color, and carotene about 3 to 4 times higher.
Second, the low-temperature drying method of low-temperature drying method This method uses heated air, the grass drying water, drying temperature, such as 50 °C ~ 70 °C, takes about 5 to 6 hours, such as 120 °C ~ 150 °C, about the Drying is completed within 5 to 30 minutes. The uncut grass is placed in a shallow box or a conveyor belt and sent to a drying room (furnace) for drying. Most of the heat sources used are solid fuels. Shallow box dryers produce 2,000 to 3,000 kilograms of hay a day. Conveyor belt dryers produce 200 to 1,000 kilograms per hour. This method is commonly used in small ranches.
Second, the low-temperature drying method of low-temperature drying method This method uses heated air, the grass drying water, drying temperature, such as 50 °C ~ 70 °C, takes about 5 to 6 hours, such as 120 °C ~ 150 °C, about the Drying is completed within 5 to 30 minutes. The uncut grass is placed in a shallow box or a conveyor belt and sent to a drying room (furnace) for drying. Most of the heat sources used are solid fuels. Shallow box dryers produce 2,000 to 3,000 kilograms of hay a day. Conveyor belt dryers produce 200 to 1,000 kilograms per hour. This method is commonly used in small ranches.