Description:
BACKGROUND OF THE INVENTION
The present invention resides in an arrangement for producing unipolar air ions in an air stream having arranged in its path a needle electrode isolated from ground potential. A high DC potential is applied to the needle electrode. Whereas one terminal of the high DC voltage is applied to the needle electrode, the other terminal of this DC voltage supply is connected to ground. The arrangement is adapted principally for producing air ions of a predetermined polarity in any desired space, and preferably in motor vehicles. In a conventional arrangement producing unipolar air ions, a group of a number of electrically isolated needle electrodes are arranged in the path of an air stream, and have applied to them a high DC potential. As a result of this arrangement, a very nonhomogeneous field prevails between the needle points of the electrodes and the surrounding wall surfaces of the space or enclosure in which they reside. At the same time such highly nonhomogeneous fields also prevail between these needle points of the electrodes and any neighboring electrode of opposite polarity. With the establishment of such a nonhomogeneous field, corona discharges result within the region of the needle points.
It has been found that with such a needle electrode arrangement, it is possible to realize ions in sufficient quantity through the application of an adequately high voltage. Under such conditions, however, a considerable amount of ozone and nitrous oxide are produced at the same time, and this is particularly undesirable from the biological and physiological viewpoint.
Accordingly, it is an object of the present invention to produce an arrangement from which a sufficient quantity of ions may be realized without obtaining significant amounts of ozone and nitrous oxide.
The object of the present invention is achieved, in a novel manner, by providing an ionization arrangement in which only a single metallic needle electrode is used. The DC voltage applied to the electrode is adjusted to have a potential which is just equal to the ionization field strength, or slightly in excess thereof.
An arrangement which uses only a single needle electrode, the maximum possible nonhomogeneity of the field is realized. In such a configuration, the field lines in the region of the needle point are of substantially greater density than when a number of neighboring needle points are applied. Thus, when a plurality of such neighboring needle points are situated next to each other, the field lines become divided or distributed among the plurality of needle points. As a result, the ionization field strength is attained with a lower voltage, when using only a single needle point, than when using a number or a plurality of needle points. If, now, care is taken to assure that the applied voltage is maintained so low that the ionization field strength may become only slightly exceeded, then only a relative small amount of energy becomes released so that the ozone and nitrous oxide production is substantially small or even negligible.
Further reduction in the applied voltage may be realized by providing a metallic needle point which is substantially as fine as hair by having a diameter less than 0.1 millimeter. Measurements have shown that the natural ion concentration may be unipolarly increased by a factor well over 1,000 through such an arrangement, in accordance with the present invention. This situation applies to air set in motion through ventilating fans, rotary air circulators, or through the fresh air streams emerging from air ducts in air conditioning systems. This situation, furthermore, applies to either stationary or movable enclosures or spaces.
The amount of ion concentration which may be realized through the application of the present invention, has been found to be adequate through experience for all climatic and therapeutic purposes. Thus, through the application of a relatively low voltage, an amazingly high ion concentration is realized in the passing air stream. For example, if an electrostatic volt meter is located 50 centimeters from the ion source, and the volt meter has a measuring range of 250 volts, full discharge is achieved in ten seconds through the use of a spherical electrode having a diameter of 15 millimeters. With natural air ion concentration approximately 6 hours are required, in contrast with the present invention. Furthermore, in spite of the high ion generation, the ozone and nitrous oxide concentration is negligibly small.
In a further embodiment, the present invention, a regulator arrangement is provided for varying the velocity of the air stream. As a result of such an arrangement, the ion concentration in the air stream, as well as in the space supplied by the air stream, may be varied.
It is also of advantage to deflect the ions out of their main path of motion. An arrangement for producing this effect may, for example, include electrodes which are charged oppositely to the unipolar air ions. As a result of such an arrangement, the ions can be deflected in a sidewise manner, and the ion density in the air stream may thereby be varied as desired.
In the event that a still larger number of ions is required, several air ducts may be associated with only one air stream and only a single ionization needle point.
SUMMARY OF THE INVENTION
An arrangement for producing a high concentration of unipolar air ions. A moving stream of air is generated in an air duct or air tunnel, through, for example, a fan arrangement. Mounted along the wall of the air duct is a needle electrode which is electrically insulated from the walls of the duct. A DC voltage source applies a DC potential to the needle electrode through one of its terminals. The other terminal of the DC voltage supply is connected to both the wall of the air duct and to ground. As a result of the high concentration and density of field lines at the point of the needle electrode, air ions are generated. Ions of one polarity are attracted to the walls of the air duct, whereas the ions of opposite polarity are conveyed along and taken from the duct. A trapping grate mounted within the air duct and also at ground potential, serves to further trap ions of that polarity which is desired to be removed from the air stream and which have not been caught by the walls of the air duct. At the exit of the duct, an electrically isolated deflection duct is provided, to which a DC potential is applied for the purpose of deflecting the emerging ions and thereby varying the density of the ions stream.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a functional schematic diagram and shows the ionization arrangement in accordance with the present invention; and
FIG. 2 is a functional schematic diagram and shows another embodiment of the arrangement of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, a ventilating fan 2 is located within an air tunnel or air duct 1. The ventilating fan 2 is driven by an operating motor 3 energized from an alternating current source having the terminal 5. A variable resistor 4 is connected in the motor circuit for the motor 3, for the purpose of regulating the operation of this motor. A rod-shaped electrode 6 is mounted and inserted into the duct 1 by means of an insulating member 8. Thus, the dielectric member 8 isolates the electrode electrically from the walls of the duct 1. The electrode 6 terminates in a needle point 7 which is hair-fine. The electrode 6 with this needle point, is made of duct resisting material such as stainless steel, for example.
A metallic grate or screen 9 is situated in the flow path of the air beyond the needle point 7. This metallic grate or screen 9 is electrically connected to the wall of the duct or air passage 1. The electrodes 10 are provided beyond this grate 9 and along the sides of the duct and in proximity of the duct.
A DC voltage may be applied to the terminals 11. This voltage may be applied through, for example, a battery. The adjustable resistor 12 connected across the terminals 11 functions in conjunction with the DC source applied to these terminals 11, so as to produce a source of high DC voltage. The winding of the adjustable resistor 12 is connected across the terminals 11, of which one terminal 13 is connected to the wall of the air duct 1. The movable contact 14 of the adjustable resistor 12 is connected to the electrode 6. Thus, the potential of the movable contact establishes the potential of the needle point 7. An additional adjustable resistor 15 has its winding connected across the terminals 11 and hence across the DC source applied to these terminals. The movable contact 16 of this adjustable resistor 15 is connected to the electrodes 10.
In operation, air is set into motion through the duct or tunnel 1, by means of the ventilating fan 2. An electrical field prevails between the needle point 7 and the walls of the duct or tunnel 1, with the condition that a high concentration of field lines exists at the point 7. The adjustable resistor is set through the movable contact 14 such that the potential applied to the electrode 6 attains the ionization field strength. As a result, both positive and negative air ions are produced in the region or proximity of the needle point 7. The positive air ions become caught or trapped by the wall of the duct 1 which is charged to opposite polarity, or by the metallic grate 9. The negative air ions, on the other hand, stream out of the duct and become deflected through the action of the electrodes 10 which have a positive charge.
By varying the variable resistor 4, the speed of the motor 3 may be correspondingly varied in an increasing or decreasing manner. Any such change in the speed of the motor 3 is reflected in the speed of the fan 2 which thereby changes or varies the speed of an air flow to the tunnel or duct 1. Thus, the mass flow of air through the duct 1 may be increased or decreased by correspondingly increasing or decreasing rotational speed of the fan. With such variation in the speed of the air through the duct or tunnel 1, the ion concentration may be regulated.
By adjusting or setting the movable contact 14 of the variable resistor 12, the potential applied to the needle point 7 may be selectively varied. By setting or adjusting the movable contact 16 of the variable resistor 15, at the same time, the deflection of the negative ions may be selectively established, in a predetermined manner, and as a result a desired distribution or separation of ions in the air stream may be realized.
In FIG. 2 three air ducts 17, 18 and 19 are associated with the ventilating fan 2. Each of these air ducts contain an insulated needle electrode 20, 21 and 22, respectively. Each of the air ducts, for example, is provided with a grate 23, 24 and 25. Deflecting electrodes 26 are, moreover, also installed as part of the embodiment of FIG. 2. This arrangement of FIG. 2 has the particular advantage of increasing the ion yield through the present invention.
In the event that positive air ions are needed or required, it is possible to obtain such positive ions by interchanging the electrical terminals of the needle electrode and the wall of the air duct. It is also quite possible to omit or avoid the ventilating fan 2 when an air stream may be realized through other means. This is the case, for example, with a moving motor vehicle, the relative movement between the latter and the surrounding air causing air to flow through the inlet ducts, and into the interior, such as the cab or passenger compartment, of the vehicle.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in an arrangement for producing unipolar air ions, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.