A 脱水筛 和传统的有什么不同 分级筛. 的 main purpose of a 脱水筛 is to retain as much material on the screen deck as possible while removing as much water as possible.
脱水筛的尺寸
两个主要因素用于筛选脱水筛:
- 设备设计
- 排出物所需的湿度水平
设备设计
的 first factor, 脱水筛 design, deals with the screen's ability to handle the throughput. This boils down to the crossbeams and strings underneath the screen media and the media itself.
监控屏幕上的肿块
屏幕上太多的质量会导致一连串的故障. 这些失败可以出现在许多地方, but one of the easier to control and easier to observe is where the screen is isolated at the mounting point.
隔离是通过橡胶缓冲器实现的, coiled springs or other methods that are designed for the upper mass limitation of the 脱水筛's physical capacity. Each one of the isolation methods has a limited ability to recover from deformation caused by overloading.
一旦发生永久性变形或断裂, the vibration of the screen is no longer fully focused on the effort to dewater the material. This impacts the life of the 脱水筛 and the effectiveness of the 脱水 过程.
监测出料高度
监测出料高度 is another way to observe overloading, 但不适用于细碎物料的脱水. 因此, 屏幕结构设置了物理容量的上限, but many applications never approach that limit because of the other main factor, 理想的湿度是多少.
重载屏幕.
所需湿度
的 所需湿度 of the discharge is the other main factor used to determine the 脱水筛's effective capacity.
的 majority of the time, the goal is to make a “drip-free” product. That means if a person was to grab a handful of the 脱水筛 discharge and squeeze it into a ball, 不应该有水滴出来.
Several physical properties of the 脱水筛 and the material influence water removal rate, 包括:
- 筛网的排水速率
- 物料的排水速率
筛网的排液率
Every 脱水筛 has a maximum drainage related to the open area of the screen media. 开放区域越大, the higher the drainage rate or the amount of water that will pass through the screen media.
的 open area has to be balanced against the opening in the screen media. Too large of an opening will allow material to go through the screen deck along with the water. 在某些情况下，这可能是需要的.
另外, 如果开口太小, the drainage rate may not be sufficient to adequately dry the material.
脱水屏幕 generally have a much lower open area than a 分级筛. 正因为如此, it is beneficial to introduce the new material to the 脱水筛 at 50% solids by weight or higher.
的 lower amount of water in the new feed to the screen will increase the chance of retaining fines on the screen and producing a drier product.
水太多，排水速度慢.
物料的排水速率
的 material itself has a drainage rate and is a major influence in the water removal 过程. 的 different physical characteristics have to be considered for each application.
材料的级配是一个重要的因素, as coarser material generally has a higher drainage rate and allows the 脱水筛 to operate at high capacity.
A coarse material will have a thicker bed depth in terms of measurement but will have less layers of particles. This creates an easier path for the water to move through the material and report to the screen's underside.
Coarser material’s capacity on a 脱水筛 will be close to or at the screen’s physical capacity and will generally have a lower percent moisture.
In contrast, a fine gradation will reduce the capacity of the unit. Material with a finer gradation will have more layers and the material will be tightly packed. This creates a more difficult path for the water to drain through the material and report to the underside of the screen media.
使事情更加复杂, 有些材料具有联锁特性, which will further decrease the drainage rate through the material. 即使达到无滴漏的菠菜网最稳定正规平台_最全菠菜网大全, the finer particles have a tendency to retain a larger percent of moisture.
罚款随水而行
“罚款随水而行” is a comment I have repeated for numerous times, but it is still true. 的 water will carry finer particles through the screen openings. This leads to difficulty retaining the finer particles on the screen deck.
It is especially tricky to retain material that is smaller than the screen media opening. As mentioned above, the finer material will have more layers, but the bed depth will be less. Keeping the material on the screen deck longer will improve the 脱水 过程. This is especially true if the coarsest fraction is kept on longer.
带有排料堰的重型筛网介质.
最后考虑
In the end, the drainage rate of the screen and the material drive the sizing for most applications.
的re are several methods to increase each of the drainage rates. Some of them, such as weirs and dams, attempt to increase the material drainage. Other approaches, such as speed and media openings, focus on the screen drainage.
因为每个应用程序都有自己独特的属性, it takes experience and experimentation to find the right adjustment to maintain throughput and produce the driest discharge.
