CN1047224A - Ultrasonic probe - Google Patents

Abstract

A kind of tip end surface with minor diameter probe, probe has the piezoelectric sender of a concave surface, can be in order to improve cavitation.

Description

Ultrasonic probe

As everyone knows, the piezoelectric sender of band probe can be used in the ultrasonic wave processing.Chemist and microbiologist are adopting this converter to produce high-intensity cavitation always, supply homogenizing to be difficult to combination reaction, broken cells, extraction, sized particles, purification, the acceleration chemical reaction that carries out, and also have other many purposes.

This quasi-converter with needle probe also is well-known, and it is mainly in order to clean aperture.

Sometimes need probe with an energy fast processing small sample.This probe can use with the calibrating chemical bond, in order in the production of oil and natural gas and cooling procedure and analyze the bacterium that has or not sulphate reducing exist in Waste Water Treatment and in paper pulp and paper production process.

When adopting diameter, find that the cavitation that they produce is difficult to bring about the desired effect in the application of many small size scopes less than the general probe of about 0.08 inch (0.2 centimetre).Thereby this is owing to disperseed the edge effect of probe tip place sound field to play dominating role the sound intensity to be surpassed due to the needed threshold value of generation cavitation.

The inventor finds that diameter just can strengthen the cavitation that it produced less than the ultrasonic probe of 0.08 inch (0.2 centimetre) greatly if its tip end surface has the concave surface that can make sound field focusing, thereby has solved the problem of edge effect dispersion sound field.So-called concave surface is meant depression simple on the probe tip surface.This concave surface can be the concave surface of radial symmetric, and for example sphere, parabola, ellipsoid or taper surface etc. also can be the concave surface of single shaft to symmetry, for example wedge shape or arc-shaped concave.

Other also can adopt the concave surface that sound field can play the symmetric figure of focussing force and the desired cavitation of generation, but these concave surfaces more are difficult to making, so had better be without them.Comparatively ideal concave surface is the concave surface of radial symmetric, because the easiest processing of this concave surface, as long as carry out simple turning, and in the end (promptly improving the coating processing of wearability) in the treatment process, they also are easy to most process.

Simple concave surface can produce quite wide stable high-intensity cavitation district on the minor diameter probe tip, makes it satisfy the sonochemical process requirement that resembles quick lysis and so on easily.It is very little that this advantage is added probe diameter, make device of the present invention can be used for the processing of small samples, and can with ferment and other temperature-sensitive material adapted, because it does not cause sample overheated, sample is effectively circulated so that uniform treatment, and the needed drive current of the probe that diameter group is bigger is little, thereby can make its work with battery, so device of the present invention is not difficult to pack in the power autonomous portable small-sized on-the-spot instrument that uses.

Fig. 1 is piezoelectric sender and probe incorporated side view together.

Fig. 2 is the profile of probe tip, the concave surface of radial symmetric is shown, i.e. sphere.

Fig. 3 and 4 is another profiles of the tapered concave surface of probe tip.

Referring now to description of drawings device of the present invention.

Fig. 1 illustrates the probe 1 of general piezoelectric sender.This probe can be contained in (not shown) in the suitable shell.

In the present embodiment, probe and converter are combined into an element, and therefore it be sometimes referred to as Contiuum type probe converter with the mode resonance of single half-wavelength.In other embodiments, they can be made up of two elements: a half-wavelength controlled resonant converter and a half-wavelength resonance probe (not shown).So just can adopt the probe tip of different-diameter.In case of necessity, converter can connect the probe greater than half-wavelength, for example the long probe of all-wave.

The converter of device shown in Figure 1 partly comprises pedestal 2, electrode 3, piezo-electric crystal 4 and is screwed into the end face of probe 1 so that crystal/electrode interlayer spare is clamped in bolt (not shown) between probe and the pedestal by pedestal, electrode and crystal.Electrode 3 couples together power supply (not shown) and piezo-electric crystal 4.Electrode can be made with general material, for example Be-Cu or nickel, and crystal can adopt general crystal, for example barium titanate or lead zirconate titanate crystal.

Probe 1 can be made with general material, for example aluminium or titanium alloy, and in certain embodiments, tip end surface 5 is handled or applied to the most handy such as chromium oxide, aluminium oxide, aluminium oxide/titanium dioxide alloy or similarly high-abrasive material.

In device of the present invention, the diameter of probe tip 6 is less than 0.08 inch (0.2 centimetre).If diameter is worth greater than this, produces required cavitation and just needn't on tip end surface 5, establish concave surface.

Fig. 2,3 and 4 illustrates the different embodiment of scrobicula face on the probe tip surface.Concave surface among Fig. 2 is a sphere, and among Fig. 3 and Fig. 4 is taper surface.

Produce best cavitation effect, only need have simple concave surface just much of that on the probe tip; In fact, during concave surface dark (being that it is a hole or flat-bottom hole), the cavitation that is produced is relatively poor on the contrary, and can corrode prematurely because of the hole and damage.Comparatively ideal cavitation requires to design to such an extent that make concave sidewalls and probe axis form the angle that is not less than 45 degree, so that the oscillating component that makes tip end surface be parallel to probe axis strengthens as far as possible.The diameter of concave surface openend or size preferably only than tip diameter or undersized some so that the area that acoustic irradiation is focused on increases as far as possible.

Illustrate below the size of concave surface.

Among Fig. 2, probe tip diameter D is 0.050 inch, and the concave surface depth d is 0.010 inch, and spherical radius R is 0.020 inch.

Among Fig. 3, diameter D remains unchanged, and depth d is 0.008 inch, and angle a is 60 degree. Among Fig. 4, D is still constant, and d is 0.012 inch, and a is 45 degree.

It should be understood that these sizes only are for example, can also enumerate other many examples, this is decided by the method that forms concave surface usually.

Concave surface on the detecting head surface can form for example turning, grinding, bore hole or spark machined etc. with the general machining method.

Device of the present invention can be operated by general fashion, promptly adopts 20 to 120 kilo hertzs frequency, depends on size of devices and required power.The comparatively ideal frequency range of small sample sonochemical process is 40 to 70 hertz.

Device of the present invention is applicable to the occasion that any employing ultrasonic wave is handled.From the characteristics of this device, it is specially adapted to fast processing thermal sensitivity small sample.Therefore it can be used for dissolving the bacterium of energy sulphate reducing when detecting with the immunoassays method.In this use, it can be contained in the small-sized field test instrument of power autonomous and calibrating chemical system, in order to analyze the biological corrosion problem in the oil and natural gas production.

Claims (4)

1, a kind of in order to produce the piezoelectric sender with a probe of cavitation, it is characterized in that its improved content comprises that the diameter of described probe tip is less than 0.08 inch (0.2 centimetre), and this tip end surface has a concave surface.

2, probe as claimed in claim 1 is characterized in that, described concave surface is a radial symmetric.

3, probe as claimed in claim 1 is characterized in that, described concave surface is that single shaft is to symmetry.

4, probe as claimed in claim 1 is characterized in that, the frequency range of described converter is 20 to 120 kilo hertzs.