RU113083U1 - PORTABLE COOLING DEVICE USING "ION WIND" IN CROWN DISCHARGE - Google Patents

Abstract

1. A portable cooling device using "ionic wind" in a corona discharge, containing a corona electrode in the form of a needle and a non-corona electrode in the form of an annular metal plate, connected to a high voltage source, characterized in that the non-corona electrode further comprises a layer of poorly conductive material on the inner the surface of the ring installed at the end of the tubular insulator, while the corona, non-corona electrodes and the tubular insulator are located coaxially with each other, and the inner diameter of the tubular insulator and the inner diameter of the layer of poorly conductive material have the same size in the range of D = 1.5-5.0 mm , while the interelectrode distance H corresponds to the condition H = (0.4-0.6) D. ! 2. A portable cooling device using "ionic wind" in a corona discharge according to claim 1, characterized in that the radius of the needle tip of the corona electrode is equal to R = 40-50 μm.

Description

The utility model relates to technical physics, in particular to devices of electron-ion technology. The device can be used in cooling systems of microelectronic devices or other areas of technology where a gas jet is required with a small area of the working surface - an average diameter of less than 1 ÷ 3 mm and a speed of 10 ÷ 15 m / s on the axis of the jet.

It is known that a corona discharge (RS) creates an electric (“ionic”) wind due to the entrainment of gas due to collisions with the neutral component [1, 2]. This phenomenon is widely used in domestic and industrial ionizers or air purification systems using air discharge systems with a discharge gap of 10–20 mm, operating voltages of 10–20 kV and an electric (“ionic”) wind speed of up to 1 m / s.

For the purpose of cooling or treating (blowing) the surface of small-sized objects, it is necessary to create a narrow stream of gas (air), which can be provided with a compressor and an appropriate route that delivers gas to the working area. Obviously, such devices are bulky and expensive.

In the non-fiction literature there have been reports on the development of cooling systems for microelectronics based on the discharge, moreover, the type of discharge and a description of the devices are not given [3]. In connection with the implementation of Raman scattering at small discharge gaps [4], it is possible to create a portable portable discharge device generating a narrowly directed gas stream.

A device is known (US 2008197779) intended for cooling devices made in the form of an “ionic wind generator” based on the formation of a corona discharge between the electrodes.

The closest device to the claimed device is a cooling device using the "ionic wind" effect, using a configuration of needle-ring-shaped metal electrodes (JP 2008218853), in which a multi-sectional variant with this configuration of electrodes is proposed, providing (according to the authors) more high speed of "ion wind" in comparison with one section. There are no recommendations on the sizes and parameters of the proposed configuration. Therefore, such a cooling device is practically no different from domestic and industrial ionizers with the design of "needle-grid" electrodes, in which the "ionic wind" is used to pump gas through the discharge gap. The parameters of such ionizers are indicated above.

The disadvantage of these devices is the low cooling efficiency.

The technical result of the utility model: increasing the cooling rate.

To solve this problem, a portable cooling device using an “ion wind” in a corona discharge is proposed, containing a corona electrode in the form of a needle and a non-corona electrode in the form of a metal plate of a ring shape and connected to a high voltage source, according to a utility model, the non-corona electrode further comprises a layer of poorly conductive material on the inner surface of the ring mounted on the end of the tubular insulator, while the corona, non-corona electrodes and the insulator is arranged coaxially with each other, and the inner diameter of the tubular insulator and the inner diameter of the layer of poorly conducting material are the same size in the range of values D = 1.5-5.0 mm, while the interelectrode distance H corresponds to the condition H = (0.4-0 , 6) D. Moreover, the radius of the needle tip of the corona electrode is equal to R = 40-50 microns.

According to the applicant, this problem can be solved on the basis of a device using a stable corona discharge at small interelectrode gaps with a needle-ring electrode configuration and consisting of a corona electrode in the form of a needle and a non-corona electrode, which is an annular metal plate deposited on its inner surface with a layer of poorly conductive material (PPM).

The layer of poorly conductive material on the inner surface of the metal ring electrode performs the function of ensuring the stability of the corona discharge. As a high-voltage source to ensure the stable operation of the device, small-sized battery power supplies based on piezotransformers with a maximum voltage of 4.5–5 kV should be used [5]. This voltage limits the value of the discharge gap in the corona discharge to an interval of 1–3 mm.

The principle of operation of the device is based on the generation of charge carriers by a corona discharge of direct current, in which there is an effective ionization of gas molecules (atoms) near the tip of the corona electrode. During the operation of the cooling device, ions arising under the influence of a corona discharge settle on the inner surface of the tubular insulator, create a focusing effect and prevent the ions of the jet from scattering, providing an increase in the maximum longitudinal electric field strength on the axis of the device and thereby creating a narrowly directed gas stream (“ion wind”) .

The opposite end of the insulator must be open to ensure the flow of gas into the discharge zone without the occurrence of a return flow in the electric wind formation region.

The essence of the utility model is illustrated by drawings. Figure 1 shows a cross section of a device, where:

1 - cylindrical tubular insulator;

2 - an annular layer of poorly conductive material (PPM);

3 - ring metal electrode;

4 - electrode "needle";

D is the inner diameter of the insulator and the PPM ring;

H is the size of the discharge gap (from the tip of the needle to the end surface of the PPM layer);

BP - power supply (voltage up to 5 kV);

h - section of the needle with a tip parallel to the axis of the device;

l is the length of the ring;

L is the length of the cylindrical tubular electrode.

Figure 2 shows the experimental comparative characteristics of the electric wind ("ion wind").

The device is mounted on a cylindrical tubular insulator 1 with an inner diameter of D = 1.5 ÷ 5.0 mm and a length of L≈ (4 ÷ 6) D. The maximum and minimum values of the inner diameter of the tubular insulator is determined on the one hand by a distance sufficient (necessary) for the acceleration of electrons from the ionization zone (D = 1.5 mm) and, on the other hand, by a distance (D = 5.0 mm), a restriction due to the voltage of the piezotransformer. A non-corona electrode 3 is attached to one of the end surfaces of the tubular insulator in the form of a ring-shaped metal plate (ring metal plate) on the inner surface of which there is a PPM layer with a specific electrical resistance ρ = 10 ⁴ ÷ 10 ⁵ Ohm · m with an inner diameter equal to the inner the diameter of the tubular insulator. An annular thin metal electrode 3 is installed on the outer surface of the PPM layer. The size along the axis of the composite electrode should be no more than diameter l = (0.4-1) D. The wall thickness of the PPM ring and the cylindrical (tubular) insulator can be different, but to ensure strength, stiffness and minimum dimensions, it must be within 1 ÷ 2 mm.

The corona electrode (“needle”) 4 is fixed on a cylindrical (tubular) insulator so that a section with a needle tip having a length along the device axis h = (2 ÷ 3) D is installed strictly on the axis of the tubular insulator — coaxially. The optimal distance from the tip of the tip to the plane of the PPM ring provides the maximum jet velocity and corresponds to the condition H = (0.4 ÷ 0.6) D, because with such a magnitude of the discharge gap, a maximum longitudinal electric field strength is created on the axis of the device. The diameter of the needle is the maximum longitudinal electric field strength on the axis of the device. The diameter of the needle can be different (within 0.5 ÷ 0.6 mm to ensure rigidity of the installation), but the radius of rounding of the tip of the needle should be within 30 ÷ 40 microns. If the radius of rounding of the tip is exceeded, several jets of gas may occur due to the instability of the discharge, and a decrease in the radius leads to overheating of the tip and its rapid damage by plasma-chemical processes. Therefore, the needle should be made of chemically resistant material.

The electrode 3 in the form of a metal plate and the needle 4 are connected to a high-voltage power supply unit (PSU, voltage up to 5 kV), moreover, the corona electrode (“needle”) can be connected to a terminal of any polarity. We note, however, that in the case of positive Raman scattering (on the “needle” - plus), the electric wind (“ionic wind”) is 3–4 times stronger than a negative Raman scattering (on the “needle” - minus). This difference is explained by the fact that in positive Raman scattering, the main charge carriers are oxygen and nitrogen ions, and in negative Raman scattering are electrons that have not had time to adhere to oxygen at small discharge gaps. Thus, the cross section for collisions of charged particles with neutral particles will differ in the case of Raman scattering of different polarity.

The experimental comparative characteristics of the electric wind ("ionic wind") on the axis of the device for negative and positive Raman scattering and their current-voltage characteristics (CVC) are shown in figure 2 for the diameter D = 5 mm, l = D, L = 5D, H = 2, 5 mm, h = 5 mm, rounding radius of the needle tip R = 40 μm.

The PPM layer and the cylindrical tubular insulator have a thickness of 1.5 mm. The specific resistance of the layer material is ρ = 2 · 10 ⁴ Ohm · m.

Electric wind is measured by a Pitot tube with a working diameter of d = 0.8 mm, connected to a calibrated Honeywell DCXL01DCS pressure sensor (maximum pressure 250 Pa). A pitot tube mounted on a table providing micromovement along two coordinates along and across the axis is oriented strictly along the axis of the device with a receiving hole at a distance x = 1 mm from the output section of the device. The distribution of gas velocity over the jet cross section is uneven. It smoothly decreases along the radius and is equal to zero at the radius R = D / 2.

The proposed technical solution provides, in comparison with similar cooling devices, the creation of a stable cooling jet of gas with a small diameter (narrow jet), which makes it possible to improve the quality of devices and apparatus belonging to the field of microelectronics, and thereby obtain a significant economic effect.

Literature.

1) M. Robinson, Movement of air in the electric wind of corona discharge. AIEE Trans, v. 80, pp 143-150, 1961.

2) B.A. Kozlov, V.I. Soloviev, Study of the "electric wind" in electrode systems with corona tips. ZhTF, 2007, Volume 77, Issue 7, pp. 70-76.

3) “Heat: refrigerators or wind” In the world of science, No. 3. 2010, p. 74.

4) RF patent for utility model No. 99904, issued November 27, 2010.

5) V. Klimashin, V. Nikiforov, A. Sofronov, V. Kazakov; New applications of piezotransformers. Components and Technologies, No. 1, 2004, pp. 36-40.

Claims (2)

1. A portable cooling device using an “ion wind” in a corona discharge containing a corona electrode in the form of a needle and a non-corona electrode in the form of a ring-shaped metal plate connected to a high voltage source, characterized in that the non-corona electrode further comprises a layer of poorly conducting material on the inner the surface of the ring mounted on the end of the tubular insulator, while the corona, non-corona electrodes and the tubular insulator are located coaxially moreover, the inner diameter of the tubular insulator and the inner diameter of the layer of poorly conductive material have the same size in the range of values D = 1.5-5.0 mm, while the interelectrode distance H corresponds to the condition H = (0.4-0.6) D. 2. A portable cooling device using an "ionic wind" in a corona discharge according to claim 1, characterized in that the radius of the tip of the needle of the corona electrode is R = 40-50 μm.