GB191323829A - Improvements in Devices for use in Regulating the Dampers of Steam Boilers. - Google Patents

Abstract

23,829. Wassmer, A. Oct. 21. Draught, regulating. - Relates to apparatus for regulating the dampers of steam-boiler furnaces according to the boiler pressure, of the type in which a diaphragm acted upon by steam from the boiler controls the movements of a pressure - actuated piston connected to the damper. Steam from the boiler passes through a spring-loaded valve into a pressure chamber, from which it escapes by a small leakage opening, the diaphragm being connected to this chamber and subjected to the pressure variations in it. Condensation is avoided owing to the constant flow of steam through the chamber, and the apparatus is rendered more sensitive than those in which the full boiler pressure acts on the diaphragm. In the apparatus shown, steam from a pipe e connected to the boiler acts on a piston f, raising a valve i and flowing by way of the passages h past it into the pressure chamber 3. From this chamber, it escapes through openings k, n and central borings in the piston l and plunger m to the atmosphere. The diaphragm is connected to the pipe 4. The valve i is loaded by a regulable spring g which presses a block s on to the plunger m, and as the boiler pressure rises or falls, the valve is raised or lowered, so that the pressure in the chamber 3 varies accordingly, the outlet for the steam remaining of constant area. In order to prevent too great throttling of the steam at low pressures, with consequent condensation in the chamber 3, the piston-rod b of the hydraulic apparatus, which moves the damper and is controlled by the diaphragm, carries a projection 2 which, in the lowest position of the piston, moves a rod y and rotates a screwed collar t on the block s. This raises the block s slightly and allows the valve i to lift to the same extent free from the pressure of the spring.