What is a reheating furnace?
Reheating furnaces are used in hot rolling mills to heat the steel stock (Billets, blooms or slabs) to the rolling temperatures of around 1200 deg C which is suitable for plastic deformation of steel and hence for rolling in the mill.
What is the definition for reheat?
Definition of reheat transitive verb. : to heat (something) again : to make (something) hot or warm once more reheating leftovers in the microwave.
Which refractory used in the furnace roof of reheating furnace?
High Alumina Refractory Bricks, Chamotte Refractory Brick, Insulation Refractory Brick, Insulation Castable, Refractory Castable and Refractory Gunning Mortar are main refractory materials for reheating furnaces, and we supply all kind of refractories according to customer requirements.
What is soaking zone in furnace?
The soaking zone allows the heat to homogenise throughout the steel, so that when it is discharged it has a uniform temperature distribution throughout its thickness, length and width. The aim of this method is to create a tightly controlled heating trajectory as the stock travels through the furnace.
How does a recuperator work?
The recuperator transfers some of the waste heat in the exhaust to the compressed air, thus preheating it before entering the fuel burner stage. By recovering some of the energy usually lost as waste heat, the recuperator can make a heat engine or gas turbine significantly more efficient.
What is pusher type furnace?
A pusher furnace is a continuous furnace concept that allows the processing of small and large product in trays and baskets. The hearth consists of a series of steel, alloy, or ceramic skid type supports. Furnaces of this type can heat workpieces within a wide temperature range (400°–1400°C).
What is prefix of reheat?
reheat (v.) also re-heat, “to heat again or anew,” 1727, from re- “again” + heat (v.).
What is reheat factor?
Introduction. In any multistage steam turbine with continuous expansion through the stages, the cumulative heat is the sum of the heat drops in the individual stages ; the reheat factor is the ratio of the cumulative heat to the adiabatic drop from initial condition to exhaust pressure.
What is the need of refractory for all type of furnace?
The main purpose of refractory material that is used inside a marine boiler is to contain the heat generated by burning of the fuel in the furnace and to minimise heat losses from the furnace. It is therefore important that these materials have insulating properties and are able to withstand high temperatures.
Why steel is reheated?
Metal expands when heated. Length, surface area and volume will increase with temperature. The degree of thermal expansion varies with different types of metal. Thermal expansion occurs because heat increases the vibrations of the atoms in the metal.
What is the significance of optimizing furnace temperature?
What is the significance of optimizing furnace temperature? Furnaces must be operated at an optimum temperature. Too high a temperature will cause overheating of the stock leading to excess oxidation high thermal stresses on refractories and higher fuel consumption.
What is heat recuperator?
A recuperator is a special purpose counter-flow energy recovery heat exchanger positioned within the supply and exhaust air streams of an air handling system, or in the exhaust gases of an industrial process, in order to recover the waste heat.
What is the combustion system of a reheating furnace?
Combustion System of a Reheating Furnace. The main function of a reheating furnace is to raise the temperature of the semi-finished steels (billets, blooms, slabs or rounds) typically to temperatures between 1000 deg C and 1250 deg C, until it is plastic enough to be rolled to the desired section, size or shape in the hot rolling mill.
What can I do with the heat from the reheat furnace?
Waste heat from the reheat furnace can be reused for preheating billets, incoming water, etc., for which energy efficiencies can be calculated by PHAST. The heat required (kJ/h) in the reheat furnace will be reduced by 23.6% and the energy intensity (kJ/kg) will be reduced by 278.12 kJ/kg.
What factors affect the performance of a steel reheating furnace?
Air leak into the reheating furnace also influences furnace atmosphere and introduces complications for steel surface quality control. The rate and type of scale formation is an important consideration for steel reheating furnace operations regardless of the type of combustion system.
How to choose a recuperator for a continuous steel reheating furnace?
When installing a recuperator in a continuous steel reheating furnace, it is important to choose a preheated air temperature that will balance the fuel saving effect and the invested cost for the equipment.