SU43017A1 - Furnace plant for heat treatment of pipes and tubular products - Google Patents

Description

The proposed furnace is intended for the heat treatment of pipes and welded tubular structures from chromium-molybdenum and other special steels used in aircraft building and other similar industries, and consists of several electrically heated shaft furnaces arranged in such a way that the main heating shaft is located on a turntable additional devices, such as: a holiday mine, quenching baths (oil and saltpeter), etc.

In FIG. 1 shows a general view of a furnace installation, and FIG. 2 is a section along line AB in FIG. one.

The inner working chamber is a circular shaft with a diameter of 1 M and a height of 6 M, which makes it possible to workpieces in the furnace up to 0.5 M in diameter and in length up to 5 m.

The unit consists of a main shaft 7 with a temperature of up to 920 °, a second shaft 2 for tempering or heating parts up to 600 ° and quenching oil bath 4 with a cooler and saltpeter 3 up to a temperature of 250 °. In addition, the furnace normalizes the parts with their cooling in the well or in the open air and has a special bath 5 with an alkaline or soda solution heated to 70-90 ° to wash the oil-hardened parts.

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The main shaft stands vertically on the three supporting columns, being raised from the workshop floor, and all the other furnaces and baths are located on the turntable rotating around the central supporting column in the ring well located below the floor level and serve the main furnace as needed. All operations are mechanized and also have the ability to be actuated by hand.

The main materials for building the furnace are varietal, boiler and sheet iron, pipes, fireclay bricks, a small amount of shaped ceramics, infusor earth and, as resistance, nichrome, which can be partially replaced with stainless steel tapes for auxiliary units.

The furnace has a loading device consisting of an iron chain passing through the center of the vault with a sand gate, which creates an airtight vault; the weight of the workpieces is balanced by counterweights at the cold end of the chain, which makes it possible to operate with loading by hand. The chain does not suffer from heating, since it only works in the furnace for a few seconds while lowering the charge into the quenching medium, and the rest of the time the chain is outside the furnace. For longer life, the chain is alitized, as well as all iron parts operating under conditions of high

temperature The loading hook or ring and sandbag box are made of nichrome or stainless steel.

For installation and repair of the furnace, a derrick rotary crane is installed on the central support column, which also serves for loading operations on the turntable driven by a hand winch with a chain hoist in the first case and with light blocks in the second.

The bridge is rotated by means of an electric motor through a worm gear with pneumatic brake and, in addition, in case of a failure of the mechanisms, it can be made by hand through a crane winch and a system of blocks.

All the moving parts of the furnace are somehow: the bridge, gate, crane and lift are mounted on ball bearings, which makes it possible to work with a low expenditure of power energy.

The subject matter of the invention.

A furnace for heat treatment of pipes and tubular products consisting of several electrically heated shaft furnaces, characterized in that the main working shaft is raised above the floor of the workshop, while the auxiliary shaft furnaces and baths are located below, on the turntable, for the possibility of alternating bring them under the main working mine.

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