KR100216291B1 - Rotary atomizer and method of operating it - Google Patents

Abstract

In the rotary atomizer, the disk or wheel-shaped atomizer 6 is fixed to one end of the shaft 7 which is connected to the rotor 8 of the high frequency asynchronous electric motor 2. The electric motor 2 is operated at a rotational speed substantially faster than the first continuation of the shaft 7 and the atomizer 6. The shaft 7 and the rotor 8 of the high frequency electric motor are radially supported only by the bearing 10 at either end of the portion 7a of the shaft 7 which is surrounded by the rotor 8. It consists of an integrated unit.

Description

Rotary nebulizer and its operation

The present invention secures a disk or wheel type sprayer to one end of a shaft connected to a rotor of a high frequency asynchronous motor, and adjusts its operating speed with a frequency converter to rotate substantially faster than the first critical speed of the shaft and sprayer. It relates to a disk shape or wheel atom rotary rotary atomizer that imposes velocity on the axis.

Rotary nebulizers, which typically drive spray discs or spray wheels directly with a high-speed electric motor, such as known as Keith Masters (5th edition of the Spray Drying Handbook, 1991, published in New York, 1991), include a drive motor and This has the advantage of not requiring gear shifts between denominator periods. In some of these types of nebulizers to date, a relatively short and rigid shaft supporting the spray device at the lower end has been coupled to the rotor of the high frequency motor.

According to this structure, in order to safely operate the sprayer in the speed range below the first critical speed of the shaft and the sprayer wheel, the diameter range of the sprayer wheel is limited, whereby the direct high frequency electric motor drive is required when obtaining the circumferential speed required for spraying. Can be used continuously.

U.S. Patent No. 4,713,146 incorporates a spring means between the inner shaft member and the outer shaft member to allow the shaft to move smoothly during start and stop of the sprayer, making the soccer tank more complicated and faster than the first continuity of the rotating part. It is known to operate a rotary nebulizer.

Based on this prior art, the object of the present invention can sufficiently overcome the above-mentioned problems and is easy for a rotary atomizer of a wide range of law to a small atomizer having a small wheel with a power consumption of 1 kW and a wheel diameter of 90 mm or less. In addition to providing a rotary atomizer of the type described above that can be used as well as the axis applicable to the rotary system of a simple structure.

According to the present invention, the shaft and the rotor unit are formed as an integral unit in a form in which the rotor surrounds a part of the shaft away from one end, and the shaft and the rotor unit are radially only at the other end of the shaft portion by radial bearings. By supporting the above object, the above object can be achieved.

When the nebulizer is operated at supercritical rotation speed, the nebulizer can be self-aligning during operation, and the entire system is generated due to tolerances or defects in the nebulizer wheel geometry and / or irregularities in the supply of the product to be nebulized. Less sensitive to dynamic imbalances.

Because the rotor and shaft of the high frequency motor are integral units, the structure is so compact that it is particularly suitable for small atomizers designed to handle supply volumes of up to about 50 liters per unit time. However, the present invention is not limited to this use, but can also be suitably used for a range of wheel diameters up to large atomizer wheels having a diameter of 350 mm or more and a processing capacity designed for a product of 200 tons or more per unit space.

In addition, the present invention is fixed to the disk or wheel sprayer on one end of the shaft directly connected to the rotor of the high-frequency asynchronous motor, and the operating speed is applied to impose a rotational speed faster than the first continuity of the shaft and sprayer A method of operating a rotary atomizer of the kind controlled by a frequency converter.

According to the invention, the method consists of an integral unit, in which the rotor encloses a part of the shaft away from one end, the shaft and the rotor unit being radial only by radial bearings at the other end of the shaft. And the frequency converter controls the motor to rotate the shaft at a speed in the range of 2 to 10 times the first continuation.

In normal use, the operating speed is preferably in the range of 2 to 10 times the first continuation of the rotating part, and depending on the size of the wheel, the operating speed ranges from 15,000 to 30,000 rpm, for example small. And in the case of large size 5,000 to 10,000rpm is preferred.

In view of these operating conditions, the support shaft for the spraying device, together with the other rotating parts of the sprayer, is of a dimension which can provide a first degree of continuity in the range of 500 to 6,000 rpm, preferably 1000 to 5000 rpm, being soft or It should be a shaft with elasticity.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a cross-sectional view showing one embodiment of a rotary nebulizer according to the present invention, and FIG. 2 is a nebulizer shown in FIG. 1 in which the nebulizer wheel is mounted at the lower end and the rotor winding of the high frequency motor is fixed at the top of the shaft. The drive shaft of FIG.

The rotary nebulizer of the illustrated embodiment according to the invention is configured to be installed on top of a chamber, such as a spray drying chamber, and has a support bracket 1 for connection with the ceiling wall of the chamber.

The support bracket 1 supports a frame or motor casing 2 of a drive motor, which is a high frequency asynchronous motor controlled by a frequency converter (not shown) known in the art.

The motor casing 2 is covered with an outer sheath 3 protruding above the ceiling of the chamber, through which the feeding pipe 4 for supplying the product, for example the liquid to be sprayed, is shown. In the embodiment it extends downwardly through the lower part casing 5 so as to end against the atomizer, which is the atomizer wheel 6 of conventional construction.

The nebulizer wheel 6 is fixed to the lower end of a drive shaft 7 consisting of an integral single piece spindle extending vertically upwards towards the motor casing 2 according to the invention, as shown in FIG. The rotor winding 8 is fixed directly to the upper portion 7a of the shaft.

As shown, the shaft consists of a relatively thin and rigid spindle which is radially supported only by bearings 9 and 10 mounted on either side of the upper portion 7a of the shaft in the motor casing 2, Among the bearings, the lower support bearing 10 supports the shaft 7 in the axial direction.

Since the relatively long free portion 7b of the shaft extends downwardly from the lower support bearing 10 towards the atomizer wheel 6, the rotating part of the atomizer when passing the first continuation at the start or stop of the atomizer operation. Radially deflection occurs.

In a typical case, the shaft and atomizer are sized to have a first degree of continuity in the range of 500 to 6,000 rpm, and preferably the rotating portion is sized to have the first degree of continuity in the range of 1000 to 5000 rpm. Lose.

System rotational design and dimensioning to have specific critical speed values by computer aided engineering is known in the art. Usually, the 2nd continuous continuation of a rotating part is set several times, for example, about 10 times higher than the 1st continuous continuation.

The motor controlled via the non-shown frequency converter is operated to impose a cone rotational speed on the shaft rather than the first continuity of the rotating portion.

As described above, the preferred speed range is two to ten times the first duration of rotation.

In order to limit the radial deflection of the rotating part at the start and stop of the sprayer, the lower sprayer, in which the guide bearing 11 with radial tolerance with respect to the axis 7 is relatively close on the sprayer wheel 6. You may install in the casing 5.

Claims (7)

A disk or wheeled sprayer 6 is connected to one end of the shaft 7 connected to the rotor 8 of the high frequency asynchronous motor 2, and the shaft 7 and the sprayer 6 of the sprayer 6 are connected. In a rotary atomizer of the type which adjusts the operating speed of the electric motor with a frequency converter tube so as to impart a rotational speed substantially faster than 1 continuous continuity, the shaft 7 and the rotor 8 are connected to the rotor. (8) consists of an integral unit which encloses a portion 7a of the shaft 7 spaced apart from the one end, the shaft and the rotor having a lady at either end of the portion 7a of the shaft 7. Rotary atomizer, characterized in that it is supported radially only by the bearings (9, 10). The rotary atomizer of claim 1, wherein said operating speed is within a range of 2 to 10 times said first continuity. The rotary atomizer of claim 1, wherein the shaft and atomizer are dimensioned to have a first impurity in the range of 500 to 6,000 rpm. 4. The rotary atomizer of claim 3, wherein the shaft and atomizer are dimensioned to have a first degree of continuity in the range of 1,000 to 5,000 rpm. Rotary atomizer according to one of the preceding claims, characterized in that the atomizer (6) is configured to provide a circumferential speed in the range of 50 to 350 kPa. 3. A separate guide bearing (11) with radial tolerances with respect to the shaft (7) is installed in relatively close proximity to the spraying device (6), so that the shaft (7) A rotary atomizer, characterized by limiting radial deflection. A disk or wheeled sprayer 6 is connected to one end of the shaft 7 which is directly connected to the rotor 8 of the high frequency asynchronous motor 2. In the method of operating a rotary atomizer of the kind that adjusts the operating speed of the electric motor with a frequency converter tube to impart a rotational speed substantially faster than the first continuation, the shaft (7) and the rotor (8). ) Consists of a unitary unit which encloses a portion 7a of the shaft 7 in which the rotor 8 is spaced from the one end, the shaft and the rotor of the portion 7a of the shaft 7 being In a state in which the bearing is radially supported only by the radial bearings 9 and 10 at one end, the frequency converter tube rotates the shaft at a speed within a range of 2 to 10 times the first continuity. To control the Operation of the rotary atomizer.