GB2440948A - A method of removing blockages from the internal surfaces of pipes - Google Patents

Abstract

A method of removing blockages in pipework by attaching an arbitrary number of ultrasonic transducers, clamped and/or wrapped around the outside of said pipework, producing multi-frequency ultrasonic vibrations in the pipe wall and consequently the pipework internal liquid/solid medium, serving to produce cavitation in the pipe internal medium causing loosening, liquidation and/or deconsolidation of solid particles in said medium. Multi-frequency vibrations from 20-100KHz induce cavitation bubbles of varying size which cause de-flocculation of solid particles inside the pipework which may hinder the pipe's potential flow capacity. This involves an arbitrary number of ultrasonic transducers of suitable power capacity being arranged and clamped very firmly around the pipe in a radial fashion which transmit ultrasonic vibration to the solid blockage and break up the material in a similar manner to "ultrasonic bath parts washers" and "ultrasonic jewellery cleaners." The power levels required for effective operation will vary according to solids composition, pipe diameter and pipe wall thickness. Frequencies of operation will depend on solids composition, generally more dense solids will require a higher frequency to create smaller cavitation bubbles to destroy the more compacted structure of the material.

Description

<p>Patent Soecification Title: Non-Intrusive ultrasonic cleaning and

unbtocking of pipework</p>

<p>Background:</p>

<p>This concept was originally developed after considering the extensive problems found In the oil and gas production and processing Industries with regard to calcium carbonate deposits on pipe internals, leading to. considerable deferment of all and gas production and the consequent large revenue losses for the companies involved. The technique as described however, I. also equally applicable to a large number of Industries and many types of pipework blocked by deposited solids.</p>

<p>Description:</p>

<p>A method of removing scale, debris end stubborn but friable material from the Inside of liquid-filled pipework by applying high power ultrasonic vibration external to said plpework by means of non-permanent ultrasonic transducer(s).</p>

<p>Drawings: The drawing shows an axial cross-section of a pipe with a solid deposition problem (cross-hatched). There are four ultrasonic transducers clamped around the pipe wail, by means of a chain or strap, which transmit their produced vibrations to the pipe wail by solid moulded "vibration transfer blocks'. The transducers are clamped in place by means of a radiafly-mounted tensioning device (tensioning screw, cam clamp or similar). The array of transducers Is supplied power from a proprietary ultrasonic power supply, which may have variable and sweeping frequency, variable amplitude, and variable waveform characteristics.</p>

<p>Pipe thickness is not shown to scale, however the ability to transfer the ultrasonic vibration to the affected area directly will decline as pipe wall thickness Increases, I Ct! 1IJ,I*cn........</p>

Claims (1)

1. <p>Claims To partially or totally remove blockages from liquid-filled pipe

   internals whilst obliviatirig the need for breaching said pipe.</p>

   <p>To restore flow capacity to pipework systems fouled with solids or contamination.</p>

   <p>To provide a non-intrusive method of pipe bore cleaning.</p>

   <p>To decrease the exposure of personnel to hazardous chemicals and work practices.</p>

   <p>To decrease the financial impact associated with the unblocking of pipework.</p>