回转式烘干机：直接干燥法与间接干燥

在确定什么类型的旋转干燥器的重要因素之一是正确的一定的过程是直接或间接热的用法。旋转式干燥机是利用无论是直接对流式传热或间接传热，热表面干燥设备内提供的热量通过传导和辐射能力。直接或间接干燥的测定是或然以被干燥的材料，在工艺条件和所需的^终产物的性质。

Heyl & Patterson的Renneburg的司可以生产两种类型的机，并提供了一个试验工厂的测试实验室，以确定较佳的技术和设备，为客户的业务。

对于直接干燥的目的，热空气进入所述旋转的缸体的一端，在其另一端穿过它并退出。机票焊接到气缸升降机的内部壁和淋浴的湿物料，将它与热空气直接接触。航班的配置取决于被加工的材料的特性。这种配置被定制，以有效地处理的产品，因为它流经干燥器。也根据客户的干衣机的容量和特性的产品的长度和直径的气缸。

通常情况下，转筒干燥器充满气缸容积的10％-15％。气缸的长度通常是至少4倍的直径，以实现产品和空气流之间的有效的热传递和温度平衡。

直接热旋转干燥器中的气流可以是计数器或平行于干燥器内的材料的搬送。并联均流机暴露在潮湿的饲料原料，以热门的空气温度。他们是非常有效的处理含水量高的污泥滤饼。由于快速的热交换，有显着的蒸发冷却的产品。这种冷却效应使干燥的宽范围的材料没有热降解的材料具有不同的热敏感性。

逆流烘干机暴露在干燥的材料的^高气温。这种配置通常是好的过程，需要一个特定的升高放电产物的温度或水分含量非常低。

间接加热型回转干燥机是常用的产品粒径小，可能会导致产生过多的灰尘。它们也可以用来为需要极端控制干燥器排气的进程。间接热干燥器取决于传导和辐射的热传递，从气缸壁的湿料。一个静止炉周围的旋转滚筒和加热汽缸壁。需要很少或根本没有气流通过烘干机。间接旋转干燥器，可以只提供一个有限的量的传热面积。他们不能有效地处理，往往坚持的加热气缸壁的材料。

Heyl & Patterson转筒干燥器的设计和建造，以客户的要求。因为我们自定义的工程师，回转烘干机，并保持原来的图纸，我们可以根据原来的规格，升级或维修服务的任何机。 Heyl & Patterson提供卓越的客户支持之前，期间和之后，我们提供的每一个产品的购买。

Rotary Dryers: Direct Drying vs. Indirect Drying

One of the most important factors in determining what type of Rotary Dryer is right for a certain process is the usage of direct or indirect heat. Rotary Dryers are capable of utilizing either direct convection style heat transfer or indirect heat transfer, in which hot surfaces within the dryer provide heat by conduction and radiation. The determination of direct or indirect drying is contingent on the properties of the material to be dried, the process conditions and the desired end product.

Heyl & Patterson's Renneburg Division can manufacture either type of dryer, and offers a pilot plant testing lab to determine the best technology and equipment for a customer's operations.

For direct drying purposes, hot air enters the rotating cylinder at one end, passes through it and exits at the other end. Flights welded to the internal walls of the cylinder lift and shower the wet material, bringing it into direct contact with the hot air. The configuration of the flights depends on the characteristics of the material being processed. This configuration is customized to efficiently handle the product as it flows through the dryer. The length and diameter of the cylinder are also customized according to the capacity of the dryer and the characteristics of the product.

Typically, Rotary Dryers are filled to 10-15% of cylinder volume. The length of the cylinder is usually at least four times the diameter in order to achieve efficient heat transfer and temperature equilibrium between the product and the air stream.

The airflow in direct heat rotary dryers can be either counter or parallel to the conveyance of the material inside the dryer. Parallel flow dryers expose the wet feed material to the hottest air temperature. They are very efficient for handling high moisture content sludge and filter cakes. Because of the rapid heat exchange, there is significant evaporative cooling of the product. This cooling effect allows for drying a wide range of materials with varying heat sensitivities without thermally degrading the materials.

Counter flow dryers expose the driest material to the highest air temperature. This configuration is usually best for processes that require a specific elevated discharge product temperature or very low moisture content.

Indirect heat Rotary Dryers are most frequently used for products with small particle sizes that could result in excessive dust generation. They are also used for processes that require extreme control of the dryer exhaust. Indirect heat dryers depend on conduction and radiation to transfer the heat from the cylinder walls to the wet feed. A stationary furnace surrounds the rotary cylinder and heats the cylinder walls. Little or no airflow is required to pass through the dryer. Indirect rotary dryers can provide only a limited amount of heat transfer area. They cannot efficiently handle materials that tend to stick to the heated walls of the cylinder.

Heyl & Patterson Rotary Dryers are designed and built to the customer's requirements. Because we custom engineer each Rotary Dryer and maintain the original drawings, we can service any dryer with upgrades or repairs according to its original specifications. Heyl & Patterson provides superior customer support before, during and after the purchase of every product we supply.