US 5,423,917 A · Method for cleaning heat exchanger tubes by creating shock wave and mixing the liquid with injected air

Abstract

A method for cleaning tubes and heat exchangers as set forth. The method and apparatus involve an elongate lance which is mounted to move in an X and Y pattern to align with a set of tubes. Each tube is cleaned by positioning the lance at the end of each tube to be cleaned. A plug is placed in the tube to be cleaned to form a standing column for water. By means of a valve control system, the standing column of water is cycled from low to high pressure by switching the flow of water. In this switched mode, water is delivered under pressure into the column. The lance tip functions in conjunction with an orifice upstream of the lance tip to form a shock wave of energy radiating along the standing column of water from the orifice into the tube to be cleaned. The addition of water to the tube ultimately moves the plug along the length of the tube. It is one theory of operation of the present disclosure that the column of water exposed to shock waves is used in cleaning, i.e., shock waves do the cleaning while the addition of water merely provides sufficient water to form the standing column of water in the tube.

Claims14

Dependent claims

A method of cleaning a tube comprising the steps of:

(a) introducing a liquid to the inner surfaces of a tube to be cleaned;
(b) forming a column of liquid defined by a valve at one end of the column and a plug inserted into said tube on the other end of the column wherein the said column of liquid is introduced by a pump operatedd by a motor and wherein said pump is connected to an orifice;
(c) restricting flow volume so a high flow volume downstream of the orifice is accompanied by a low downstream pressure while a low flow volume downstream is accompanied by a high downstream pressure;
(d) introducing a controlled pressure surge to the column of liquid through said valve;
(e) cycling the pressure in the tube between high pressure and low pressure;
(f) thus creating a shock wave along the length of the tube to the plug wherein said shock wave is enhanced by mixing the liquid with injected air.

3 more elements

Dependencies are inferred from the claim text.

Method for cleaning heat exchanger tubes by creating shock wave and mixing the liquid with injected air

Life of this patent

Method for cleaning heat exchanger tubes by creating shock wave and mixing the liquid with injected air

Life of this patent

Abstract

Claims14