GB2106013A - A nozzle for a tank cleaning machine - Google Patents

Abstract

A nozzle suitable for a tank cleaning machine comprising a circular bore which tapers (2, 3) towards the outlet and an internal substantially parallel- sided section (1) adjacent to the outlet and parallel to the longitudinal axis of the nozzle, the length of said section (x) being 40% to 60% e.g. about 50% of the internal diameter (y) of the outlet of the nozzle. <IMAGE>

Description

SPECIFICATION A nozzle for a tank cleaning machine This invention relates to a nozzle especially suitable for tank cleaning machines.

In our UK patent application 8126949 we have described and claimed a particuarform of stream straightenerfor use in the pipe immediately upstream of the nozzle of a tank cleaning machine. This stream straightener comprises sections having tapered vanes offset to one another. We have now found that the stream emerging from the nozzle using such stream straighteners can be further improved i.e. a stream which is straighter, by the use of the nozzle of this invention.

According to this invention a nozzle suitable for a tank cleaning machine is one which has a circular bore which tapers towards the outlet and which has an internal substantially parallel-sided section adjaW cent to the outlet and parallel to the longitudinal axis of the nozzle. The width of this parallel-sided section has to be 40% to 60% of the internal diameter of the outlet of the nozzle.

In addition to the above-mentioned advantage it is found that during the construction of the nozzle the reaming of the bore is easier and more accurate by having the parallel-sided section.

The nozzle which will usually be made of bronze has a circular tapering bore. This taper need not be uniform throughout the nozzle and in generai it is preferred that the bore tapers less steeply as the outlet is approached. In particular it is preferred that the taper comprises two sections, the walls of the bores of which make a different but substantially uniform angle to the longitudinal axis of the nozzle.

Thus, in the preferred embodiment the tapered section of the bore next to the parallel-sided section has a wall which makes an angle of 33/4 to the central longitudinal axis and the adjacent tapered section of the bore has a wall which makes an angle of 63/4 to the longitudinal axis.

The width of the substantially parallel-sided section adjacent to the outlet, that is the length mea sured along the longitudinal axis of the nozzle, has to be 40% to 60% of the internal diameter of the outlet of the nozzle. Preferably the length is 45% to 55% e.g.

about 50%, of the internal diameter of the outlet.

The nozzles of this invention can be manufactured by boring or reaming, the machining commencing at the outlet end of the nozzle after an initial parallel sided bore has been drilled or cast in. Typical diameters for the nozzle are 29.0 mm, 22.0 mm and 14.3 mm.

The tank cleaning machine for which the nozzle of this invention is suitable can take various forms but it often involves a nozzle housing rotating about an axis, e.g a vertical axis, whilst a nozzle attached to the nozzle housing oscillates about an axis at an angle to the axis of rotation of the nozzle housing, e.g. at right angles thereto. With such machines the nozzle slowly rotates through 360"C usualiy about a vertical axis, thereby being directed towards the whole perimeter of the tank whilst at the same time oscillating about a horizontal axis so as to cover the depth of the wall or walls of the tank.

Two such machines are described and claimed in the specification of our UK patent 1333338 and of our Japanese utility model 24868/1980.

These nozzles can also be used in machines primarily designed for the removal of sludge from the bottom of a storage tank. One such machine is that described and claimed in our UK patent application 8029639 and comprises a central body rotatable about which is a casing provided with two substantially diametric nozzles arranged so that liquid emerging therefrom sweeps substantially only in one plane. There are means for rotating the casing about a central body, invariably a turbine, and means ensuring that when the casing is continuous- ly rotated, alternately one nozzle is closed for substantially 1800 rotation whilst the other nozzle is open. Usually such machines are suspended above the floor of the tank and the jet emerging is substantially in a horizontal plane.Usually oil is circulated through the nozzles to dislodge the sludge.

A preferred form of nozzle according to the invention is now described with reference to the drawings in which; Figures 1,2 and 3 show cross-sections of three different nozzles.

Referring to the drawings, the substantially parallel-sided sections of the nozzles are shown at 1 and the tapered portions are shown at 2 and 3. It can be seen that the walls of section 2 make an overall angle of 71/2 and that the walls of section 3 make an overall angle of 131/2". In each case the ratio ofyto xis substantially 2:1, typical Figures being Figure 1 - y = 29.0 mm, x - 14.5 mm, Figure 2 - y = 22.0 mm, x = 11.0 mm and Figure 3 - y = 14.3 mm, x = 7.1 mm.

To protect the nozzle orifice against burring in Figure 1 there is a circular stepped recess shown at 4 and in Figure 2 and 3, the outlets are bevelled as shown at 5.

CLAMS 1. A nozzle suitable for a tank cleaning machine comprising a circular bore which tapers towards the outlet and an internal substantially parallel-sided section adjacent to the outlet and parallel to the longitudinal axis of the nozzle, the width of said section being 40% to 60% of the internal diameter of the outlet of the nozzle.

2. A nozzle according to claim 1 wherein the bore of the nozzle tapers less steeply as the outlet is approached.

3. A nozzle according to either of claims 1 and 2 wherein the tapered bore comprises two sections, the walls of which sections make a different but substantially uniform angle to the longitudinal axis ofthe nozzle.

4. A nozzle according to any one of the preceding claims wherein the width of the substantially para llel-sided section is 45% to 55% of the internal diameter of the outlet.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A nozzle for a tank cleaning machine This invention relates to a nozzle especially suitable for tank cleaning machines. In our UK patent application 8126949 we have described and claimed a particuarform of stream straightenerfor use in the pipe immediately upstream of the nozzle of a tank cleaning machine. This stream straightener comprises sections having tapered vanes offset to one another. We have now found that the stream emerging from the nozzle using such stream straighteners can be further improved i.e. a stream which is straighter, by the use of the nozzle of this invention. According to this invention a nozzle suitable for a tank cleaning machine is one which has a circular bore which tapers towards the outlet and which has an internal substantially parallel-sided section adjaW cent to the outlet and parallel to the longitudinal axis of the nozzle. The width of this parallel-sided section has to be 40% to 60% of the internal diameter of the outlet of the nozzle. In addition to the above-mentioned advantage it is found that during the construction of the nozzle the reaming of the bore is easier and more accurate by having the parallel-sided section. The nozzle which will usually be made of bronze has a circular tapering bore. This taper need not be uniform throughout the nozzle and in generai it is preferred that the bore tapers less steeply as the outlet is approached. In particular it is preferred that the taper comprises two sections, the walls of the bores of which make a different but substantially uniform angle to the longitudinal axis of the nozzle. Thus, in the preferred embodiment the tapered section of the bore next to the parallel-sided section has a wall which makes an angle of 33/4 to the central longitudinal axis and the adjacent tapered section of the bore has a wall which makes an angle of 63/4 to the longitudinal axis. The width of the substantially parallel-sided section adjacent to the outlet, that is the length mea sured along the longitudinal axis of the nozzle, has to be 40% to 60% of the internal diameter of the outlet of the nozzle. Preferably the length is 45% to 55% e.g. about 50%, of the internal diameter of the outlet. The nozzles of this invention can be manufactured by boring or reaming, the machining commencing at the outlet end of the nozzle after an initial parallel sided bore has been drilled or cast in. Typical diameters for the nozzle are 29.0 mm, 22.0 mm and 14.3 mm. The tank cleaning machine for which the nozzle of this invention is suitable can take various forms but it often involves a nozzle housing rotating about an axis, e.g a vertical axis, whilst a nozzle attached to the nozzle housing oscillates about an axis at an angle to the axis of rotation of the nozzle housing, e.g. at right angles thereto. With such machines the nozzle slowly rotates through 360"C usualiy about a vertical axis, thereby being directed towards the whole perimeter of the tank whilst at the same time oscillating about a horizontal axis so as to cover the depth of the wall or walls of the tank. Two such machines are described and claimed in the specification of our UK patent 1333338 and of our Japanese utility model 24868/1980. These nozzles can also be used in machines primarily designed for the removal of sludge from the bottom of a storage tank. One such machine is that described and claimed in our UK patent application 8029639 and comprises a central body rotatable about which is a casing provided with two substantially diametric nozzles arranged so that liquid emerging therefrom sweeps substantially only in one plane. There are means for rotating the casing about a central body, invariably a turbine, and means ensuring that when the casing is continuous- ly rotated, alternately one nozzle is closed for substantially 1800 rotation whilst the other nozzle is open. Usually such machines are suspended above the floor of the tank and the jet emerging is substantially in a horizontal plane.Usually oil is circulated through the nozzles to dislodge the sludge. A preferred form of nozzle according to the invention is now described with reference to the drawings in which; Figures 1,2 and 3 show cross-sections of three different nozzles. Referring to the drawings, the substantially parallel-sided sections of the nozzles are shown at 1 and the tapered portions are shown at 2 and 3. It can be seen that the walls of section 2 make an overall angle of 71/2 and that the walls of section 3 make an overall angle of 131/2". In each case the ratio ofyto xis substantially 2:1, typical Figures being Figure 1 - y = 29.0 mm, x - 14.5 mm, Figure 2 - y = 22.0 mm, x = 11.0 mm and Figure 3 - y = 14.3 mm, x = 7.1 mm. To protect the nozzle orifice against burring in Figure 1 there is a circular stepped recess shown at 4 and in Figure 2 and 3, the outlets are bevelled as shown at 5. CLAMS

1. A nozzle suitable for a tank cleaning machine comprising a circular bore which tapers towards the outlet and an internal substantially parallel-sided section adjacent to the outlet and parallel to the longitudinal axis of the nozzle, the width of said section being 40% to 60% of the internal diameter of the outlet of the nozzle.

2. A nozzle according to claim 1 wherein the bore of the nozzle tapers less steeply as the outlet is approached.

3. A nozzle according to either of claims 1 and 2 wherein the tapered bore comprises two sections, the walls of which sections make a different but substantially uniform angle to the longitudinal axis ofthe nozzle.

4. A nozzle according to any one of the preceding claims wherein the width of the substantially para llel-sided section is 45% to 55% of the internal diameter of the outlet.

5. A nozzle according to claim 1 substantially as hereinbefore described with reference to the drawings.