RU1774959C - Conveyer furnace for heating metal - Google Patents

Abstract

SUMMARY OF THE INVENTION: the furnace comprises a chamber formed by a hearth, a roof and side walls, divided into zones with gas burner devices with control systems, smoke exhaust channels connecting the working chamber to a common smoke exhaust channel. In front of the exhaust fan at the end of the common channel, a system for regulating its flow area is installed. The furnace is additionally equipped with means for regulating the flow area of each flue duct. Controls are installed in the cavity of each flue duct. 1 C.p. f-ls, 2 ill.

Description

The invention relates to furnaces for the heat treatment of metal and can be applied in the metallurgical and engineering industries, mainly for multi-zone continuous furnaces with roller hearths for the heat treatment of riots, rods, sheets, etc.

The goal is to reduce the consumption of natural gas by changing the direction of gas movement with changing temperature regimes in the zones.

On Fig, 1 shows a longitudinal section of a continuous furnace; figure 2 is a section aa in figure 1.

A passage furnace for heating metal contains a working chamber 1 formed by a vault 2, side walls 3 and a hearth 4. A common smoke exhaust channel 5 is located under the hearth 4 with a system for regulating its passage area installed at the channel outlet in front of a smoke exhaust (not shown). The working chamber 1 is divided into

temperature zones 7.8 of heating and zones of exposure 9.10 and is equipped with gas burner devices 11 with a control system (not shown). Zones 7-10 are connected to a common smoke exhaust duct 5 by means of exhaust ducts 12 located along the axis of the furnace.

In the cavity of each flue duct 12 additional control means 13 are installed (control dampers such as gate valves, throttles, etc.) to regulate the flow area. The furnace operates as follows.

The metal to be heated enters the working chamber 1. As the metal moves in the furnace, it is heated and held in zones 7-10 at specified temperatures by burning natural gas in gas burner devices 11.

The metal is heated both due to the heat of hot flue gases sent to the working volume after burning the fuel, and

cl

with

™ J

01

due to the heat radiated by the vault 2 and the side walls 3 of the furnace. Flue gases are washed and contacted with the heated metal, give it their heat, cooled and removed from the working chamber 1 through the corresponding channels 12 and devices 13.

From the point of view of providing gas flushing with metal, the distribution of flue gases in the zones of the furnace is best organized so that they are in maximum contact with the heated metal and the inner surface of the masonry of the working chamber. For this, the control flaps 13 are set so as to lengthen the path of movement of hot gases and increase their contact time with the heated metal and the inner surface of the masonry of the working chamber 1. For example, the cross section of the channels 12 in the heating zones 7 and 8 is reduced (zones with higher thermal power) and increase the cross section of the channels 12 in the holding zones 9 and 10 (zones with less heat load). At the same time, the heat load in the zones from which the flue gases are removed is reduced, since the additional heat will come to these zones with a significant amount of hot flue gases from the zones with a higher heat load. Changing the cross sections of the exhaust ducts 12 and removing the flue gases through the corresponding canals is carried out depending on the capacity, metal grade and heating conditions. Thus, it is possible to obtain a continuous, counterflow or combined movement of combustion products in the furnace (for example, in the first zones , in the latter - countercurrent, or in the first zones - countercurrent, and in the latter - flow-through, etc.

The differentiated change in the flow cross section of the wells of each zone of the working chamber creates the possibility of controlled removal of a given volume of combustion products from each zone and provides a reduction in the consumption of natural gas to the furnace in connection with a more complete (deeper) use of the heat of the combustion products (lengthening the time of hot gases with a heated metal and masonry of the working chamber)

zones of the working chamber.

Claims (2)

SUMMARY OF THE INVENTION 1. A feed-through furnace for heating a metal containing a chamber formed by a tode with a vault and side sections, divided into zones with gas burner devices and control systems and smoke exhaust channels connecting the working chamber with a common smoke exhaust channel with a system for controlling the area of its flow area installed at the outlet of the channel in front of the exhaust fan, characterized in that, in order to reduce the flow of natural gas by changing the direction of gas movement with changing temperature regimes in the zones, the furnace is equipped with additional means for regulating the flow area each flue duct. 2. Oven pop. 1. characterized in that the control means is located in the cavity of each flue duct. Umbrella ff Umbrella eleven A a FIG. 2