Closed cycle spray dryer

The closed cycle spray dryer is an efficient, safe and environmentally friendly drying equipment. It uses inert gas to circulate in a closed system, and is specially used to deal with materials containing organic solvents, flammable, explosive, oxidizing or toxic and harmful materials, and can recover valuable solvents at the same time.

Main working principles of closed cycle spray dryer:

Establish an inert environment: The system first replaces the internal air with an inert gas (such as nitrogen) to create an oxygen free, non flammable environment.

Circulation and Heating: Inert gas is driven by a fan and circulates within the system. It is first heated to the set temperature by a heater.

Atomization and drying: The material is transported by a material pump to the atomizer at the top of the drying tower, where it is dispersed into extremely fine droplets. These droplets come into full contact with the hot inert gas, and the organic solvent (or water) inside is instantly evaporated.

Gas solid separation: The dried powder is collected at the bottom of the tower. The wet inert gas carrying solvent vapor enters the subsequent processing unit.

Solvent condensation recovery: Wet inert gas passes through a condenser, where solvent vapor is condensed into liquid and recovered. The recycled solvent can be purified and reused, which saves costs and is environmentally friendly.

Medium reheating: The inert gas removed from the solvent becomes dry and clean, and is then sent back to the heater for heating, starting the next cycle.

The entire process is carried out in a closed system, where inert gas is circulated and only a very small amount of gas is discharged due to system pressure, and is treated by specialized equipment.

Main uses of closed cycle spray dryer:

It is specifically designed to handle materials that cannot be processed by ordinary dryers or are very dangerous to handle:

Materials containing organic solvents:

For example, systems using ethanol, acetone, dichloromethane, DMF, THF, and other solvents.

Application areas: pharmaceutical, chemical, and fine chemical intermediates.

Flammable and explosive materials:

The material itself or its dust poses a risk of explosion in the air. Inert gas was used to eliminate explosive conditions.

Application areas: dyes, pigments, certain polymers, coal derivatives.

Easily oxidizable materials:

Materials will decompose, denature, or lose their activity when exposed to oxygen at high temperatures.

Application fields:

Food industry: vitamins, polyunsaturated fatty acids (DHA, ARA), probiotics, enzyme preparations.

Pharmaceutical industry: antibiotics, cell extracts, and some active pharmaceutical ingredients (APIs).

Toxic and harmful materials:

The entire system is enclosed to prevent toxic solvents or material vapors from leaking into the working environment, protecting operators and the environment.

Application areas: pesticides, insecticides, certain pharmaceutical intermediates.

Process for solvent recycling:

When the solvent cost is high or recycling is required by environmental regulations, a closed-loop system is the ideal choice.

Structure of closed cycle spray dryer

The material of the part of the host that comes into contact with the material is SUS 304. The host is divided into four parts: the base, the raw material container, the diffusion chamber, and the passage

The top ring of the filter chamber base is sealed with silicone airbag inflation; Equipment host cylinder lifting silicone seal; The raw material container is placed on a four-wheel drive

On a movable small car; Sealed product sampler, equipped with observation spotlight; Install 4 anti high voltage lenses on the main tower for

Observe the materials, two on the raw material container; The interior of the host is mirror polished, and the exterior is 600 mesh brushed polished; Top of the middle tube

Spray grab 3 pieces, equipped with secondary air intake, top explosion relief plate for pressure relief, pressure relief pipeline designed for 2 bar explosion-proof (with maintenance manhole), convenient for

Automatic cleaning.

Filtration system: using dual filtration chambers; Anti static electricity; Controlled by PLC, the cylinder alternately shakes the bag, and the shaking bag system has a device to prevent rotation; Manual control of bag shaking rack lifting and automatic control of locking; The filter bag is sealed with airbags.

Exhaust system: Exhaust gas filter, made of 304 stainless steel, with no reinforcing ribs on the inner wall, using pulse back blowing, washable, and good filtering effect; Reasonably matched centrifugal fans; Take necessary noise reduction measures. The exhaust duct is made of SUS304 material.

The intake air treatment system adopts steam regulating valves, intake valves, and main air volume control locators, equipped with primary efficiency, medium efficiency, high temperature resistant and high-efficiency filters, and steam heaters; Stainless steel fully welded cabinet with double-layer insulation. Comprehensive performance of equipment operation: The equipment is equipped with good vibration reduction, transmission, speed change, cooling, and lubrication devices. During the maintenance cycle, under continuous full load production conditions, there is no oil leakage or obvious temperature rise, no obvious vibration and noise deterioration, and it always meets the factory acceptance standards. Modules that require disassembly and calibration should have positioning rods.