Heat treatment industry in our country mechanical industry of large energy consumption, heat treatment machinery factory factory electricity amounts to 25 ~ 30%, and the heat treatment industry has heat treatment furnace about 120000 units, of which more than 50% of the electricity, the power consumption of about 10 billion KWh each year. Our country heat treatment on average 700 KWH/t unit energy consumption, higher than the average energy consumption of the western developed countries more than doubled. Our country "15" development goals by 2010 heat treatment unit energy consumption dropped to an average of 500 KWH/t, it should be said is not easy to achieve that goal can be achieved. And reduce energy consumption and improve the quality of heat treatment products is our each heat treatment must not resign workers righteousness is not of responsibility. Adopt high efficiency and energy saving and improve heat treatment quality of the product, replace phase out old heat treatment equipment, application of new energy-saving heating equipment is a must. But there are many companies do not have conditions, some special workpiece heat treatment is not always use standard heating equipment, therefore, reform the old equipment is also an important way of energy saving.
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Over the years my factory production of lawn mower blade guard, one of the main pieces of beam is produced by a flat steel, total length of 2670 mm, need to be quenched and tempered, it is a long bar, the well type furnace quenching, and tempering USES 75 kw standard box-type furnace, and the effective heating furnace length is 1800 mm. When the furnace charging with its cross diagonal loading furnace, and that's just scrape shut the oven door, at times, but still make the furnace back wall repair, more of the main production efficiency is low, average unit energy consumption is high. Therefore put forward transformation box-type furnace, longer effective length of heating furnace, and do not increase installed capacity, as far as possible in order to improve the applicability of the furnace. Box type resistance furnace heat treatment workshop
3 technical transformation scheme
1) make the effective heating length is 1800 mm, to 2200 mm, need to be in a furnace back lengthened 400 mm.
2) due to our factory not too big of a heat treatment, using standard furnace, its height did not work, can reduce the height, and the total power of the furnace as far as possible change is not too big.
3) lining use of lightweight aluminum silicate fiber wiki not stereotypes refractories prefabricated, furnace building technology of furnace construction before forming.
4) due to changed the furnace shape and structure, rearranging heating element for this purpose.
5) change the furnace bottom structure shape.
6) temperature control point is still a little, that is, a heating zone, but the temperature measuring point location change.
4 the implementation steps and analysis
1) the first accounting, if on the structure of the original furnace back directly lengthened 400 mm unchanged, the total power increased to 90 kw to 95 kw, at least down such heat treatment energy consumption not only didn't actually increased, this plan is not desirable. Consider reduce the heating chamber height. On both sides of the distribution of the heating element from row to row 6, 8 of the wall height can reduce to 160 mm, from the original roof arch R1150mm R800mm instead, heating capacity from the original 1.71 m3 to 1.72 m3, although volume change, due to the lengthening furnace, furnace bottom heating area increased by 0.44 m2 to ensure temperature uniformity, appropriate to increase the power, especially in the bottom of the furnace power should be increased to improve the box-type resistance furnace are warm work performance.
Lengthen the heating chamber, and will highly reduce the heat treatment process to ensure the construction. If conventional arrangement, especially in the bottom of the furnace is difficult, high power electric equipment cloth balance problem is also a important problem, adjust the electric heating element for the bottom three groups by calculation, a total of 9 rows, namely 14 KW x3 = 42 KW, on both sides of the furnace for the three groups, each side 6 row, namely 13 KW * 2 + 6.5 KW * 2 = 26 KW + 13 KW = 39 KW.