JPS5834002A - Ultrasonic spray drying method - Google Patents

Abstract

PURPOSE:To instantaneously dry a liquid sample, by atomizing said liquid sample into a high temp. air stream by utilizing ultrasonic waves. CONSTITUTION:When a liquid supplying pump 2 is rotated and a heater 7 is switched on as well as a suction fan 14 is rotated, a liquid containing fine particles is atomized by an ultrasonic sprayer 3 and introduced into a drying cylinder 8. On the other hand, air accelerated by the heater 7 is flowed into the upper part of the drying cylinder 8 tangentially at a high velocity to dry the atomized liquid herein. The dried coarse particles are fallen into a container 9 and the remainder of dried particles are flowed into a first cyclone 10 along with hot air to be classified into small particles and fine particles and the former is dropped into a small particle container. The fine particles are sent to a second cyclone 12 to be collected by a container 13. In addition, because the particle size of atomized particles can be controlled by the flow amount of the liquid sample and the speed adjustment of the liquid sending pump, the adjustment of the particle size of the powder becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves turning a substance or suspension that becomes a fine powder when dried into fine particles, significantly increasing the specific surface area, and exposing the fine particles to hot air.
This invention relates to improvements in the so-called spray drying method for drying droplets. Specifically, the present invention relates to a method of atomizing the above-mentioned liquid sample using ultrasonic waves in a high-temperature air stream and instantaneously drying it.

Conventional spray drying methods include a method that requires a compressor and generates mist by adjusting the liquid and air, and a method that uses a high-speed motor to turn blades and pour the liquid into the blades to generate mist using centrifugal force. The present invention is a drying apparatus using a spray generation method fundamentally different from these methods, and will be explained below with reference to the drawings.

1 is a sample liquid, and 2 is a liquid sending pump with a flow rate regulator.

3 is an ultrasonic spray generator, and a liquid feeding pipe P passes through the center thereof. 4 is an amplifier for the ultrasonic spray generator, and by operating this, it is possible to adjust the vibration frequency, etc. Reference numeral 7 denotes a heater whose temperature is controlled by a heater temperature controller 5.

This is an amplifier for the 6I/i temperature controller. Reference numeral 8 denotes a drying cylinder, on the top of which there is an ultrasonic nozzle 3a generated by the ultrasonic spray generator 3, and in the center of the nozzle 3a a liquid feeding pipe P is located. A coarse particle container 9 is attached to the lower end of the drying cylinder 8. A heated air supply pipe 7a heated by the heater 7 is tangentially connected to the upper part of the drying cylinder 8 via a connecting flange 17. 10 is a first cyclone, whose inlet pipe 10a is connected to the lower part of the drying cylinder 8, and whose outlet pipe 10b is connected to the lower part of the drying cylinder 8.
is connected to the inlet pipe 12a of the second cyclone 12. 14 is a suction fan, and 15 is an air volume regulator. A dry air flowmeter 16 is installed between the inlet pipe 10a and the outlet pipe 10b of the first cyclone. 11 is a fine grain container of the first cyclone, and 13 is a fine grain container of the second cyclone.

With the above configuration, when the liquid feed pump 2 is turned, the heater 7 is turned on, and the suction fan 14 is rotated, the liquid containing fine particles is atomized by the ultrasonic spray generator 3 and placed inside the drying cylinder. to go into. On the other hand, the air heated by the heater 7 flows tangentially into the upper part of the drying tube 8 at high speed and dries the atomized liquid there. In this case, the size of the mist particles can be adjusted by adjusting the flow rate of the sample liquid and the speed of the liquid pump.

Coarse particles of the dried particles fall into a container 9, and the rest flow into a first cyclone 10 together with hot air, where they are classified into fine particles and fine particles, and the fine particles fall into a fine particle container 11. The fines are sent to a second cyclone where they are collected in a container 13.

The present invention does not use compressed air like conventional spray dryers and therefore does not require a compressor.

Therefore, there is no need to heat the air in the compressor, which saves electricity.

Since the amount of mist particles can be adjusted by adjusting the flow rate of the sample liquid and the speed of the liquid feed pump, it is possible to adjust the particle size of the powder. Therefore, there is no need to replace the spray nozzle when the particle size changes, as was the case in the past.

[Brief explanation of drawings]

The figure shows an apparatus for carrying out the method. In the figure: - 1 Sample liquid 2 Liquid sending pump (with flow rate regulator)
3 Ultrasonic spray generator 4 Amplifier for ultrasonic spray generator 5
Heater - Temperature regulator 6 Heater - Temperature regulator amplifier 7 Heater 8 Drying tube 9 Coarse grain container 10 First cyclone 11 Fine grain container 12 Second cyclone 13 Fine grain container
14 Suction fan 15 Air volume regulator for suction fan 16 Dry air flow meter 17 Connecting glass flange and above Applicant Tsutsui -be representative Patent attorney Isamu Ohashi

Claims (1)

[Claims] An ultrasonic spray drying method that is characterized by dropping a solution or suspension of a sample in the form of a mist using ultrasonic waves into a high-temperature air stream from the top of a drying cylinder, and instantaneously drying it.