The fluid supply is pressurized. The nozzle delivers the fluid continuously or intermittently. There are many ways to atomize the liquid.
The choice of type of atomizing device and its design are determined by the properties of the atomized liquid, the need to obtain a homogeneous atomizing plume of a certain dispersion, the required productivity, the degree of complexity of construction and maintenance, as well as the cost. The main indicators of nozzles are atomization rate of liquid, macrostructure (angle and length of the jet; spatial distribution of droplets) and microstructure (size of droplets and their size distribution). The principle of operation of a pneumatic nozzle is based on the fact that compressed air breaks the solution into individual small particles, which is ejected from the nozzle of the nozzle at high velocity and dispersed torch. The position of the nozzle during atomization can be adjusted. Spray dryers operate on the principle of direct current, counter current and mixed current. Design design of spray drying plants is determined by technological requirements (type of product, its thermal lability, viscosity of the liquid, etc.), type of atomizing device, capacity for evaporated moisture and other parameters. Cyclones 6 are used to clean the exhaust air sucked from the tower by the fan. Pumps inject material and air into the pneumatic nozzle (atomization is made in counterflow of the drying agent).

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The process scheme is as follows: the solution or suspension to be dried is fed through a pneumatic nozzle into the drying chamber. The atomization process produces a large number of polydisperse droplets. The atomized particles have a large surface area, which results in intensive heat and mass transfer with the drying agent entering the chamber through the nozzle. They quickly lose moisture and in a few seconds spherical porous granules are formed from the suspended suspension of dewatered droplets, which fall to the bottom of the chamber and fall into a container for product collection. The granules have good friability and compressibility, so tablets produced from such granulate have high strength and compressibility at low pressures. Single-section, unidirectional (direct flow of suspension droplets relative to the coolant flow) dryers are also used in the spray granulation process, which will be discussed in the next section.
The specificity of the process determines a number of characteristic advantages of the spray drying method: high quality of the dry product; high intensity of heat and mass transfer between the dispersed material and the heat transfer gas, determined by the degree of dispersibility of the material, gas temperature and hydrodynamic features of the apparatus; possibility of process control; continuity of drying.