GB2195189A - Apparatus for generating ozone - Google Patents

Abstract

Apparatus for generating ozone comprises a housing containing an anode and a cathode. A separate container encloses a d.c. generator and amplifier for generating direct current for application to the anode and cathode such that ozone is generated in proportion to an input flow of gas fed to the housing. A voltage proportional to the input flow is supplied to a comparator 86 as a reference for comparison with the output voltage measured by resistors 106, 108. The comparator output controls a transistor 90 which determines the voltage level at a saturable transformer 52 switched by an oscillator 46. The transformer output is rectified and multiplied to provide a voltage which is used to generate ozone in the required proportion. <IMAGE>

Description

SPECIFICATION Apparatus for generating ozone This invention relates to apparatus for generating ozone.

Known conventional apparatus for generating ozone use a alternating current, typically 5 Kv at 50/60 cycle a.c. voltages. One of the main problems associated with the known apparatus for generating ozone is that the very low levels of peak energy per pulse will not allow the ozone to be generated accurately. Typically, the known apparatus for generating ozone comprises a glass tube which contains neon gas under low pressure. A high potential electrode is sealed into a glass tube.

A low potential electrode in the form of a wire gauze is closely fitted around the outside of the tube. The thus formed assembly is sealed inside an aluminium jacket. Air or oxygen from which the ozone is to be generated is then passed through the assembly. A high alternating potential is applied to the inner electrode, via a connector through the bottom of the aluminium jacket, and the high alternating potential causes the gas to conduct. A discharge passes between the glass tube and the wire gauze and the ozone is generated at this location. The gauze conducts to the aluminium jacket which is earthed via a transformer. The known apparatus for generating ozone usually is such that a rotary stepping switch is employed to give a wide range of output control.

Apparatus is also known which is for generating ozone and which employs direct current.

Such known apparatus again suffers from the problem that the amount of ozone generated cannot accurately be controlled. The reason for this is that the known various types of apparatus for generating ozone are primarily manufactured for chlorination, chemical and air deodorisation and the like and such applications do not require a high degree of accuracy of control in the production of the ozone.

Ozone is currently being increasingly used in the medical industry to treat a very wide number of ailments. The ozone may be used in the treatment of deseases where it is required to kill or control bacteria, fungus infections or viruses. Circulatory disturbances, infected wounds and many other ailments may be treated with ozone. In view of this increasing use of ozone in the medical industry, it has become imperative that precise amounts of ozone can be generated in a controlled manner. The known apparatus for generating ozone does not produce the ozone in a sufficiently controlled manner.

It is an aim of the present invention to provide apparatus for generating ozone, which apparatus improves on known apparatus for generating ozone in that the apparatus of the present invention enables the ozone to be generated in a controlled manner.

Accordingly, this invention provides apparatus for generating ozone, which apparatus comprises a housing, anode and cathode means provided in the housing, and d.c. generator and amplifier means for generating direct current for application to the anode and cathode means whereby the apparatus is such that ozone is generated in proportion to an input flow of gas fed to the housing.

The gas will usually be oxygen or air and the ozone will be generated in proportion to the flow of the oxygen or air. Furthermore, the apparatus is of a relatively simple nature so that it can be cost effective to produce.

Also, the apparatus can be constructed to be portable so that it lends itself to easy use in various locations in, for example, hospitals, surgeries and clinics.

The housing may have inlet and outlet ports, the inlet port being for receiving the gas prior to the generation of the ozone, and the outlet port being for receiving the gas after the generation of the ozone.

The anode may be surrounded by the cathode. The anode may thus be an elongate member, and the cathode may be a cylinder which is provided with a plurality of apertures.

The d.c. generator and amplifier means may comprise a flyback convertor and voltage multiplier circuit.

The flyback convertor and voltage multiplier circuit may include an oscillator circuit, a driver circuit, a transformer, and rectifier means, the driver circuit being connected to the base of the primary winding of the transformer.

The d.c. generator and amplifier means may be provided in a container which is separate from the housing and which is connected to the housing by an electrical lead. If desired, the d.c. generator and amplifier means may be provided in the housing.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a circuit of first known apparatus for generating ozone; Figure 2 shows a circuit of second known apparatus for generating ozone; Figure 3 shows apparatus for generating ozone in accordance with the invention; Figure 4 shows a graph of ozone production and compares the ozone production of the apparatus of the present invention with ozone produced using known apparatus.

Figure 5 shows the electrical circuit employed in the apparatus shown in Figure 3; Figure 6 is a longitudinal section through part of the apparatus shown in Figure 3; Figure 7 is an end view looking from right to left as shown in Figure 6; Figures 8 and 9 are side and end views of a cap part employed in Figure 6; Figure 10 is an end view of a nylon insert employed in Figure 6; Figure 11 is a section on the line X-X shown in Figure 10; Figures 12,13 and 14 are various views of an anode used in Figure 6; Figures 15 and 16 are side and end views of a cathode used in Figure 6; and Figures 17 and 18 are side and end views of the housing used in Figure 6.

Referring to Figure 1, there is shown known apparatus 2 for generating ozone. The apparatus 2 comprises a plug 4, a socket 6, a H.T.

transformer 8, an ozone generator assembly 10, a rotary regavolt device 12 and a voltmeter 14. These parts are connected as shown and the transformer 8 supplies an a.c.

output along line 16 to the ozone generator assembly 10. The ozone generator assembly 10 comprises a 1m. long glass tube which is 45mm in diameter. This glass tube contains neon gas under low pressure. A high potential electrode is sealed into this tube. A low potential electrode in the form of a wire gauge is closely fitted to the outside of the tube. The formed assembly is itself sealed inside an aluminium jacket. Air or oxygen from the ozone is to be generated is then passed through the assembly.

The top end of the tube is located against a foam pad to protect the tube against damage.

A high alternating potential is applied to the inner electrode, via a connector through the bottom of the aluminium jacket. The high alternating potential causes the gas to conduct.

A discharge passes between the glass tube and the wire gauze and this is where the ozone is generated. The gauze conducts to the metal jacket which is earthed via the transformer 8. The device 12 gives a broad range of output control.

Referring to Figure 2, there is shown an electrical generator 18, a pair of tubes 20,22, the tube 20 being connected to the tube 22 and the tube 22 being connected to an outlet nozzle 24. The outlet nozzle 24 is also connected to an ozone disintegrator 26 via lead 28 as shown. The tube 20 is supplied with air or oxygen via a conduit 30 and the conduit 30 is associated with a gauge 32, a pressure control device 34, a 2/2-way solenoid valve 36 and a cylinder 38 containing oxygen or air.

The apparatus shown in Figures 1 and 2 is not able to generate the ozone in precisely controlled amounts.

Referring now to Figure 3, there is shown apparatus 40 in accordance with the invention for generating ozone. The apparatus comprises a housing 42, anode and cathode means (not shown in Figure 3) provided in the housing 42, and d.c. generator and amplifier means 44 for generating direct current for application to the anode and cathode means whereby the apparatus 40 is such that ozone is generated in proportion to an input flow of gas fed to the housing 42. The input flow of gas will usually be an input flow of oxygen or air. It will be see from Figure 3 that the apparatus 40 is of a simply constructed nature and is portable.

Referring now to Figure 4, there are shown graphs illustrating typical ozone generator yield. The graphs are plotted for 'grams of ozone per hour percentage concentration of ozone' against 'litres of air per hour'. The solid line graphs show typical output curves for an A.R. ozone discharge valve operating at 5000v 50 Hz with air dried through silica gel.

The broken line graph is that obtainable from using the apparatus shown in Figure 3. When dry oxygen is used, the ozone yield may be approximately doubled.

Referring now to Figure 5, there is shown a circuit for the d.c. generator and amplifier means 44. The d.c. generator and amplifier means 44 is basically a flyback convertor and voltage amplifier circuit. More specifically, the flyback convertor and voltage amplifies circuit comprises an oscillator circuit 46, a driver circuit 48, an input protection circuit 50, a transformer 52 having a primary winding 54 and a secondary winding 56, and a voltage multiplier 58 which includes rectification means (not shown).

The oscillator circuit 46 comprises four NAND gates 60,62,64,66, resistances 68,70 and 72 and a pair of transistors 74,76.

The driver circuit 48 comprises a resistance 78, capacitors 80,82, a variable resistance 84, an integrated circuit 86, a resistance 88, a transistor 90, and a capacitor 92.

The input protection circuit 50 comprises a Zener diode 94 and a capacitor 96.

In operation of the circuit shown in Figure 5, a mains voltage input may be applied at input terminals 98, 100. The variable resistance 84 may be used to enable operator fine tuning if this is required. The tuning will however normally be effected by a flow sensor input, this being achieved by connecting sensor inputs between terminal 102 on the integrated circuit 86 and zero volts.

A high d.c. voltage is generated by the circuit and this voltage can be set at any desired level between zero and 10 KV. The high d.c.

voltage is fed to the housing 42 via a lead 104 (see Figure 3). Varying levels of ozone are then produced, depending upon the set voltage level as will be described hereinbelow.

The oscillator circuit 46 is configured as an astable multivibrator which produces a continuous square wave signal of approximately 20 KHz. This signal is fed to the base of the Darlington transistor pair of transistors 74,76.

The current to the base of the transistor 74 is restricted by the resistor 70, thus preventing saturation of the transistors 74,76 and ensuring a fast turn off. The collector of transistor 76 drives the primary winding 54 of the transformer 52. When the transistor 76 is switched on, the transformer 52 is saturated.

As the transistor 76 switches off, the magnetic flux in the transformer 52 collapses rapidly, producing a high voltage pulse in the secondary winding 56 of the transformer 52.

Because the transistors 90,74 are being switched on and off at the rate of 20 KHz, a high frequency high voltage alternating current is generated. This is then rectified and amplified in the voltage multiplier 58, using a capacitor diode chain, to produce a variable d.c.

voltage of up to 10 Kv.

The current available to drive the transformer 52 is governed by the power transistor 90. When the transistor 90 is switched fully on, the maximum convertor output voltage is generated. As it is progressively turned off, so that output voltage is decreased.

The current through the transistor 90 is controlled by the voltage comparator integrated circuit 86. The voltage comparator integrated circuit 86 compares the voltage set by the variable resistance 84 with that fed back from the output via the potential divider chain afforded by resistance 106 and resistance 108. The integrated circuit 86 then adjusts the current through the transistor 90 to maintain the output voltage set by the variable resistance 84. Ozone is thus generated in an accurate manner proportional to flow by voltage reference variation between terminal 102 on the integrated circuit 86 and zero volts.

The flow sensors must be infra red or chopper vane type sensors. A pair of thermistors may also be used if desired.

Referring now to Figures 6 and 7, there is shown the housing 42. As can be seen, the housing 42 has a fixed end 110 and an end cap 112. The fixed end 110 has an inlet pipe 114 through which air or oxygen initially flows. The end cap 112 has an outlet pipe 116 through which the air or oxygen, supplemented with the generated ozone, will flow.

Positioned inside the housing 42 are four nylon inserts 118, 120, 122, 124. Positioned between each pair of nylon inserts as shown is an anode 126 which is an elongate member which is best shown in Figures 12,13 and 14.

As can be seen most clearly from Figures 12,13 and 14, the anode 126 has a central threaded portion 128 and plain ends 130,132.

A cathode 134 in the form of a cylindrical gauze 136 is provided around each of the anodes 126. The gauze 136 is provided with a plurality of apertures 138. The cathode 134 can be formed from flat gauze and the folded ends of the gauze need not be joined and they can leave a longitudinal slit 140 as shown in Figures 15 and 16.

The nylon inserts 118,120,122,124 are best illustrated in Figures 10 and 11 which shows one of the nylon inserts 118. As can be seen, the nylon insert 118 is provided with a plurality of apertures 142, a plurality of apertures 144 and a central aperture 146. The apertures 142 are larger than the apertures 144, and the apertures 144 are larger than the aperture 146. The air or oxygen can thus flow easily through the housing 42 from the inlet pipe 114 to the outlet pipe 116. The ozone is generated in the discharge areas between the anodes 126 and the cathodes 134.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example two anodes 126 and two cathodes 134 have been shown employed in Figure 6 since this arrangement gives a high ozone yield for a relatively small size of housing 42.

If desired, however, only one anode 126 and one cathode 134 need be employed. The gas fed to the inlet pipe 114 can be oxygen or air. The apparatus 2 can operate from saw tooth or square wave direct current. Medical ailments including aids can be treated with the generated ozone. The inserts 118,120,122, 124 can be made of plastics materials other than nylon. The housing 44 may be provided with operational indicator light 148 and on ON/OFF switch 150 as shown in Figure 3.

Claims (9)

1. Apparatus for generating ozone, which apparatus comprises a housing, anode and cathode means provided in the housing, and d.c. generator and amplifier means for generating direct current for application to the anode and cathode means whereby the apparatus is such that ozone is generated in proportion to an input flow of gas fed to the housing.

2. Apparatus according to claim 1 in which the housing has inlet and outlet ports, the inlet port being for receiving the gas prior to the generation of the ozone, and the outlet port being for receiving the gas after generation of the ozone.

3. Apparatus according to claim 1 or claim 2 in which the anode is surrounded by the cathode.

4. Apparatus according to any one of the preceding claims in which the anode is an elongate member, and the cathode is a cylinder which is provided with a plurality of apertures.

5. Apparatus according to any one of the preceding claims in which the d.c. generator and amplifier means comprises a flyback convertor and voltage multiplier circuit.

6. Apparatus according to claim 5 in which the flyback convertor and voltage multiplier circuit includes an oscillator circuit, a driver circuit, a transformer, and rectifier means, the driver circuit being connected to the base of a primary winding of the transformer.

7. Apparatus according to claim 5 or claim 6 in which the d.c. generator and amplifier means is provided in a container which is se parate from the housing and which is connected to the housing by an electrical lead.

8. Apparatus according to claim 5 or claim 6 in which the d.c. generator and amplifier means is provided in the housing.

9. Apparatus for generating ozone, substantially as herein described with reference to the accompanying drawings.