Calculation and Selection of Apparatus’ Parameters for Steam Blowing the Heating Surfaces of Steam Boilers

Abstract

To determine the effectiveness of the use of apparatuses for blowing heating surfaces of boilers, a generalized characteristic of the dynamic effect of a steam jet is used: its dynamic head, which depends on the parameters of the working agent, nozzle size, and layout of the apparatus. It is shown that an acceptable efficiency of steam blowing is achieved when the dynamic pressures over the entire area of the jet action are not lower than those required for effective removal of ash deposits. A method for calculating the steam flow rate and the dynamic pressure of the jets of steam blowers is given. Experimental studies and industrial experience in the use of steam blowing have shown that additional flow deceleration is observed when a jet propagates in tube bundles, as a result of which a greater drop in dynamic head can occur than with a freely propagating jet. The degree (coefficient) of weakening of the dynamic head (in relation to the dynamic head of the free jet) in any configuration of the bundle depends mainly on the width of the transverse gap between the pipes, the number of rows of pipes cleaned from deposits along the depth of the bundle, and much less on the relative longitudinal step of the pipes. It is shown that, based on estimates of the gas-dynamic parameters and the effective range of jets of steam blowers, it is possible to set the operating parameters of the steam and form the optimal arrangement of these devices for cleaning heating surfaces. To develop steam blowing systems, it is proposed to use a specialized computer program created on the basis of research results and generalization of many years of experience in operating steam blowing devices on domestic and foreign boilers.