US2101603A - Humidifier - Google Patents

Description

5. C STIMSON Dec. 7, 1937.

HUMIDIFIER glwgcntm:

Filed ,Nov. 13, 1955 Stream/g6.

Patented Dec. 7, 1937 PATEN HUMIDIFIER Samuel Carl Stimson, Winston Salem, C., ,as-, signorto The Bahnson Company, Winston- Salem, N. 0., a corporation of North Carolina Application November 1 3, 1935, Serial No'. 49,611

This invention relates to humidifiers of the type including a fan for creating an air current and a rotating disk for projecting water'ag'ain'st abutments or teeth,"'t11e water being thereby disintegrated into afine mist which evaporates rapidly in the air current. I

. Humidifiers of-this type have been in use for many years "and," in general, include an electric motorhaving a shaft'which extends beyond opposite sides of the motor casing, the fan and disk being secured to oppositeends of the motor shaft. Typical constructions are shown in the patents to Fries, 947,300, dated Jan. 25, 1 910, Bahnson, 1,267,166; dated May 21,-1913', and impson, 1,=966;8'72,dated July 173 1934; The efii'ciency of such devices is not primarily dependent uponthe quantity of water'which can be discharged into the air current, but uponthemaxim-um quantity which can beevaporated without an accompany .ing entrainment i of' unevaporated particles. Such "unevaporatedparticlesmay cause serious damagewhen deposited upon machinery-or the goods, such as paper, thread or cloth, which are employed in the manufacturing processes. The effective evaporative" capacity of a" humidifier therefore depends upon th-quantityand velocity of the air in-inotion, andupon the velocity at which thewater is projected from therotating disk. It is obviousthat such factors as excessive wear, vibration and noise, and power consumption have placed ratherdefinite structural limits upon the speed and diameter of the water-im pelling disks of the prior devices, and have thus set rather definite limits for the maximum capacitybfthe prior humidifiers. J; Objects of the present invention'are to provide humidifiers of the fan and rotating disk type which are characterized by an increased evapora- 'tive efficiency and by quiet operation. An object is to provide a humidifier including a fan, a water-impelling disk and power mechanism for rotating the fan at 'one speed and the disk at a much higher speed. More particularly, an object is toprovide a humidifier including a low speed motor for directly driving 'a low speed fan, and a step-up drive between the motor and disk for driving the latter at high speed. A further object is to provide a humidifier of the type state'd, in which the high speed disk andlits, associated casing are of less diameter than the fan blades, thus facilitating the formation of a small diamet-er air stream into which the water mist is discharged.

These and other objects and advantages of the invention will be apparent fromthe following specification when taken with theaccompanying drawing; in which:

T OFFICE i Fig. 'l is a fragmentary schematic" view or an embodiment of the invention which includes sep aratemotorelement'sfor the fan andwater disk; Fig. 2 is a side elevation, with'parts in section,

. of a construction in-which the motor drives the water disk througha gear train; and Fig. 3 is a fragmentary front elevation of the gearbox. I i' In Fig. l of the drawing, the reference numeral l identifies the casing" of'ian induction motor which has a low' speed field 2 and'associated armature 3 for rotating the fan F and a high speed field 4 and armature 5 for rotating the disk D. The fan and disk are secured to the respective shafts 3', 5' that are in axial alin-ement' and supported in independent sets of bearings. Power is supplied to the motor from an alternat ing current line L'ffwhich may befthe usualGO cycle system customarily employed for light and power. The low speed section is connected directly across the line L, and the high speed sec tion of the motor is fed through a frequency mul tiplier 6 and high frequency lin'eL'. As indicated by the legends; the speed of the fan may be'1750 R. P. M.;and that of the disk approximately 7000 R. P. Ml in a typical case! The fan speed of 1750 R. PL M. will be recognized as a standard speed for induction motors operating on a 60 cycle power line and, while'other speeds maybe employed, this speed has been found to be quite satisfactory for quiet operation and high air displacement at low power consumption. The higher speed of the water-impelling disk D will be selected in accordance with other design require; inents toprovide the mostsatisfactor'yconstruction for the particular conditions which are to be met. The frequency multiplier may be of the frequency changer or the motor-generator type and may be designed to provide any desired speed for the disk D.

As shown in Figs. 2 and 3, the invention may be embodied in a single motor construction by mounting one rotating element, such as the fan F, directly upon the shaft 1 of motor M, and driving the other rotating element through a changespeed transmission. A bracket 8 supports the motor M, a fan guard 9, and a drain pan IE which is positioned below the disk D to carry away any water which drains from the casing l l. The casing l l and the ring member l2 which supports a row of teeth l3 at the periphery of the disk D preferably take the form of dished or concave annular members which may be spun from copper or other appropriate materials. Water is delivered to the inner face of the disk, adjacent its center, through a pipe I4, and the flow may be controlled by any appropriate mechanism.

As distinguished from prior devices of this general type in which the disk D is mounted directly upon the shaft 1 of motor M, the disk is secured to a shaft I5 which is supported in roller bearings I6, I! that are in axial alinement with the outer bearing I8 of the motor shaft I. The gear box or casing I9 has a partition wall in which the bearing I 6 is mounted and a main cover plate 20 which carries the bearing IT. A stub shaft 2I is journalled in bearings 22, 23 that are mounted on the gear box I9 and a small cover plate 24, respectively. The gear box is preferably apertured to receive bolts 25 that engage in the threaded openings by which the front frame member of the conventional motor design was secured to the main casing to enclose the shaft bearing I8. The gear train includes a large gear 26 on shaft I and meshing with the small gear 21 on the stub shaft, and the large gear 28 on the stub shaft meshing with a smaller gear 29 on the disk shaft I5. Quiet operation and a balancing of end thrust is obtained by using helical gears of opposite slope for'the two sections of the gear train. When the bolt holes of the gear box are so located as to match with the threaded bores of the motor casings of humidifiers of prior design, the gear box, disk and casings may be used as a replacement unit to modernize the old style machines. This change involves only the removal of the old large size disk and casing, and the shortening of the motor shaft to receive gear 26.

In one embodiment of the invention which had a high evaporative efficiency, the gear train sections each had a, 2 to 1 ratio and the disk was therefore rotated at four times the speed of the fan. Particular attention is directed to the fact that disk D and easing II of the Fig. 2 construction are of substantially smaller diameter than the fan F. 'Prior attempts to obtain high evaporative capacity had led to the use of disks of increasing sizes and some commercial designs have included 16 inch disks. Humidifiers constructed in accordance with this invention have developed a greater evaporative capacity with 9 inch disks than can be obtained with the 16 inch disks of the prior designs. The reduction in disk diameter is explained by the much higher peripheral speed obtained when the disk is rotated at a higher speed than can be employed for the fan.

The smaller diameter of the disk is accompanied by a reduction in the size of the disk casing II, and this results in further improvement in the operating characteristics. The air stream created by the fan F is not greatly diverted or expanded as it passes around the casing of motor M and the small diameter and smoothly curved disk casing II. The air current which passes over the edge of the casing I I is therefore a relativly high velocity stream or hollow column of air which is well adapted to evaporate the mist of water which is created by the disk;D and teeth I3.

. The invention therefore provides both a more efficient atomization of the Water and an air stream of higher velocity and more compact shape for evaporating the atomized water. Both results are obtained without materially increasing the power consumption and without increasing the noise of operation or the wear on the moving parts.

Although it would be possible to secure the disk to the shaft of a high speed motor, and to use a speed reduction drive to the fan, the illustrated arrangement of a direct fan drive from a low speed motor is to be preferred as it is characterized by minimum noise and wear.

It isto be understood that there is some latitude in the design and construction of the mechanism, whether mechanical or. electrical, which is employed to drive the axially alined fan and disk at different speeds. -Various changes which may be made in the several parts and their relative arrangement fall within the spirit of my invention as set forth in the following claims.

I claim:

1. A unit adapted to be used with a humidifier of the type including a motor having a casing and a shaft, and a fan and a disk mounted upon opposite ends of said motor shaft; said unit comprising a gear box adapted to be secured to said motor casing, a shaft in said gear box, a disk mounted on said gear box shaft, a gear adapted to be'secured to the shaft of the motor, a transmission train connecting'said gear and said disk shaft for rotating the latter at higher speed than said gear, an atomizer ring at the periphery of said disk, and a casing enclosing said atomizer ring and disk, said second casing being adapted to be attached to said motor casing.

2. A unit as claimed in claim 1, wherein said gear is a helical gear and said transmission train includes a stub shaft in said gear box, a helical gear on said stub shaft and meshing with said first gear, and a pair of meshing gears on said stub shaft and said disk shaft, respectively, said second pair of gears being helical gears of an inclination opposite to that-0f said first pair of meshing gears.

' SAMUEL CARL STIMSON.

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