你应该知道喷雾干燥机的要领
它包括三个阶段，使用的精细喷雾或滴在雾化过程中的任何液体进料，喷雾接触和悬浮的热气体通过一个流，允许液体的蒸发和除去干燥的固体，在类似的形状和尺寸的雾化液滴。^后，通过的气体流中，被划分干粉物质并收集。略去干燥气体现在被视为满足环境要求，之后将被空气内发射，或它可以被重新分发系统内。
重点选项雾化的
可以使用各种类型的喷涂，包括离心式，声波雾化喷嘴和空气。
的颗粒尺寸分布在介质上几乎是恒定的，在任何给定的方法，该方法被用于雾化。屋面介质本身可能从尽可能小为15微米至250微米的范围内变化，但是，它是极大地依赖于已经被发送到的液体的能量的数量。此外，质量液流，固体含量，粘度和表面张力，对粒径有直接的影响，但不车轮的圆周速度的程度。因此增加的进料速率内也可能增加的粒子的大小，但使用一个可变速度的离心雾化器，可以方便的大小已被指定的校正。
喷射雾化喷嘴的另一个常见的类型是液压的压力。在这里，流体是通过泵加压，然后被迫穿过的孔，以划分该液体内细滴。的孔的大小的范围内大约0.5至3毫米的范围内。其结果是，一个简单的喷嘴定义为约700 kg / h的整个进料，这也是依赖于粘度，压力，尺寸的孔的固体含量以及有限的顺序。
丢弃所有通过该节流孔的查询结果在更小的液滴，并减少对于任何给定的进料流的粒子的大小的增加的压力，喷嘴需要将替换的一个更小的孔。这也需要更大的压力从泵，以便获得正确的数量，通过喷射器的流量。一些大型系统中可以有多达50喷嘴，从而，使得难以控制粒子的大小。
主要用于小型喷雾干燥器系统的第三个方法是在双流体气动雾化。凡雾化来实现，通过第^体与第二流体是常压缩空气内创建一个环境的相互作用。在这种情况下，无论是空气的压力，也没有液体的要求是非常高的。也许，一个典型的200至350千帕范围内，可以完成这项工作。的粒子的大小来控制，通过改变液体流动的压缩空气流的整体比例。
这种类型的雾化甲大有裨益可以归因于降低的速度水平的液体在离开喷嘴，这也导致的飞行路径，需要较短的干燥时间。与此相关，双流体喷嘴的过程变得适合于使用在实验室和中试规模的设备。
essentials that you should know for your spray dryer
posted on september 12, 2012 by admin
comprising of three stages, spray dryer is used with the atomization process of any liquid feed in a fine spray or drops, the spray contacts and is suspended through a stream of hot gas, allowing the evaporation of the liquid and removing the dry solid, in the similar shape and size that of the atomized droplets. finally, through the gas stream, the dry powder substance is divided and collected. the spent out drying gas is now treated for meeting environmental requirements after which they are emitted within air or it may either be re-circulated within the system.
the key option atomization
various types of spraying can be used, including centrifugal, sonic atomization nozzle and air.
the particle size distribution on the medium is almost constant in any given method that is used for atomization. roofing medium itself may vary from as small as 15 microns to a range of 250 microns; however, it is greatly dependant on the quantity of energy that has been transmitted into the liquid. moreover, the mass liquid flow, the solid contents, its viscosity as well as the surface tension, have a direct influence on the particle size but, not to the extent of the peripheral speed of the wheel. thus an increase within the rate of the feed might also increase the size of the particle, but using a centrifugal atomizer of a variable speed can facilitate the correction of the size that has been specified.
another common type of spray atomizing nozzle is the hydraulic pressure. here the fluid is pressurized by means of a pump and then forced to pass through a hole in order to divide that liquid within fine droplets. the size of the holes lies within the range of approx 0.5 to 3 mm. the result is that a simple nozzle is defined to a limited order of about 700 kg / h of the entire feed, which is also dependant on the viscosity, pressure, size as well as the solid contents of the orifice.
an increased pressure of the drop all over that orifice results in smaller droplets and to reduce the size of the particle for any given flow of the feed, the nozzle requires to be replaced by a much smaller orifice. this also requires greater pressure from the pump so as to obtain the right quantity of the flow that passes through the injector. some large systems can have as much as 50 nozzles, thereby, making it difficult to control the particle size.
the third method being used mainly in small spray dryer systems is the two-fluid pneumatic atomization. where atomization is achieved through creating an environment of interaction within the first fluid with the second fluid that is normally compressed air. under this situation, neither the air pressure nor the liquid requires to be really high. perhaps, a typical range between 200 and 350 kpa can get the job done. the size of the particles is controlled through changing the overall ratio of the liquid flow to that of the compressed air flow.
a great benefit of this type of atomization can be attributed to the reduced velocity levels of the liquid at the time of exiting the nozzle, which also results in a flight path requiring shorter drying. with this, the two-fluid nozzle process becomes suitable for using in equipment of laboratory and pilot scale.