SU402560A1 - ZAKALOCHNO ^ HOLIDAY UNIT - Google Patents

Description

one

The invention relates to the heat treatment of products, mainly forgings.

A quenching tempering unit containing a quenching furnace and a recirculating tempering furnace are known for using the products of the quenching furnace to heat the combustion products, but in tempering furnaces of known aggregates it is impossible to obtain a temperature above 400 ° C.

In order to eliminate this drawback and increase the productivity and efficiency of the unit, its tempering furnace is equipped with two three-section after-burning chambers with a stepped cross section along the movement of gases with guide vanes in the intervals of the sections, with secondary air supply nozzles and distribution channels for the combustion products located at the beginning of the heating zone and evenly in the exposure zone and the recirculation channels of the combustion products at the junction of the zones, while the exhaust fan is installed between the quenching furnace and the pressure chambers Ghani.

FIG. 1 shows the proposed hardening unit, a longitudinal section; in fig. 2 is a section along A-A in FIG. 1. in FIG. 3 is a section along BB in FIG. one.

The exit channel of the products of incomplete combustion / tempering furnace 2 is connected by a chimney.

3 with the suction side of the vacuum pump 4, where the recycling box of the main furnace 6 is connected 6. From the exhauster 4, two discharge boxes 7 leave, which are connected to two three-section pneumatic channels 8 in the discharge chamber 8 in the discharge channels air on the afterburning products of incomplete combustion are installed nozzle devices JO, the nozzles of which are directed

at a variable angle to the flow. One section of the three-section chambers 9 is located on the loading side, and the other on the discharge side, this allows the oven to be two-zone, consisting of a heating and holding zone. The cross section of the sections is variable, produced by steps and decreases along the movement of the gases.

In the transition x between the section m, guide vanes are installed // for disturbance

The flow, by means of a stepwise change in the section and guide vanes, promotes better mixing and more complete afterburning of products of incomplete combustion. For the ignition of the mixture, the burner J2 is installed in the chamber. The last stage of the three-section chamber 9 on the loading side is connected by the upper 13 and lower 14 channels to the working space at the beginning of the heating zone, with the lower channels 14 passing under the heated parts over the entire width of the furnace.

The last stage of the three-section chamber on the discharge side is connected by the upper 15 and lower 16 channels to the working space of the holding zone, while the channels are located on both sides of the furnace evenly along the entire length of the zone. At the junction of the heating zones and shutter speeds, the recirculation channels 17 are located at the top and bottom of the charge, connected under the load to the bottom channels of the 16 heating and shutter zones, formed from the top by the charge, as well as the sides and bottom by the lining of the tempering furnace. At the exit of the furnace, the recirculation channels 17 are connected to the recirculation box 7. A smoke exhauster 4 is installed between the chambers 9 and the quenching furnace 2.

The proposed unit operates as follows.

The products of incomplete combustion from the quenching furnace 2 through the channel / and the chimney 3, to which a certain amount of recirculated gases are mixed, from the tempering furnace 6 through the recirculation box 5 are sucked in by the exhauster 4. After the exhauster 4, the products of incomplete combustion are divided into two streams proportional to the power of the heating zones and shutter speeds and three-section chambers 9 are fed through channels 8 through the ducts 7. Air is added to the products of incomplete combustion through the nozzle device 10 o channel 8. When entering the chamber, the mixture is ignited by the burner 12. As the gases move through the chamber sections, their velocity increases, the flow turbulence increases, the gases are better stirred and burn more completely. From the last stage of the heating zone chamber, the combustion products through the channels 13 and 14 exit at the beginning of the furnace working space above the charge area and under the load area.

From the last stage of the chamber of the holding zone, the products of combustion through the channels 15 and 16 exit uniformly over the entire length of the working space of the holding zone, also under the load and above the load.

Combustion products from the exposure zone and the heating zone move towards each other above the load box, and under the load pass through channel 18 to the recirculation channels 17, and the excess combustion products through the loading and unloading windows are removed to the ventilation system.

Subject invention

Quenching and tempering unit, including a quenching furnace and a recirculating tempering furnace using products of a quenching furnace for heating, characterized in that, in order to improve the performance and operability of the unit, the latter is equipped with three sections of the secondary variable cross-section of the chambers along the movement of gases from units in the sections, with nozzles for the supply of secondary air and distribution channels for the combustion products located at the beginning of the heating zone and evenly soaking zone, recirculation channels combustion products at the junction of zones, wherein the quench exhauster is installed between the furnace and the afterburner. / 7/5

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