HOTWORK RECUPERATIVE BURNER (HRB)
In a furnace without heat recovery equipment operating on natural gas at 1200oC with 10% excess air, 63% of the energy input is lost in waste gases and not actually available to the process.
With typical air preheats in excess of 1/3 of the furnace operating temperature, the Hotwork Recuperative Burner has the ability to recover part of this energy by exhausting hot waste gases through its specially designed quarl and over an integral metallic heat exchanger which, in turn, preheats incoming combustion air.
This heat recovery significantly reduces the amount of fuel required for the process and makes the HRB Burner ideal for applications where flue gas temperatures are high and load residence time at high temperature is long, such as forging and heat-treatment furnaces or batch-type furnaces.
Exhausting/Furnace Pressure Control
Since the waste gases exhaust through the burner quarl, there is no need for a conventional flue, which speeds up design and installation of the furnace. The furnace pressure is controlled by an air-driven eductor in the burner flue arrangement.
Accurate pressure control is achieved by varying the volume of air to the eductor which in turn controls the amount of waste gases drawn out of the furnace. No separate fan is required for the air to the eductor as it is supplied by the combustion air fan.
Medium Velocity
The HRB burner has a medium velocity of 70 m/s which, combined with accurate furnace pressure control and careful burner configuration, ensures even temperature uniformity and excellent heat transfer to the load.
Extended Flue Version
In order to increase the residence time of waste gases exhausting through the burner and maximise the exchange of heat between the exhaust gases and the combustion air, the HRB Burners (HRB3.5 to HRB25) can be designed with an extended flue. Please note that these burners require higher combustion air and eductor air pressures. Figures are available from Hotwork Combustion Technology Ltd on request.
Turndown and Excess Air Capability
The turndown of the HRB on natural gas is 10/1 at furnace temperatures below 1200oC. Refer to the Combustion Data Table for turndown at higher temperatures. At maximum air flow and fuel only control, excess air levels better than 500% can be achieved.
Long Flame Design
For applications where extra radiation is required, a long flame design is available.
Fuels
The HRB5 and above are suitable for natural gas, LPG, gas oil (viscosity of 34 sec. Red. 1) or dual fuel arrangement. Smaller sizes are suitable for gas only.
Ignition, Flame Supervision and Automatic Start-up
The HRB Burner is ignited by means of a premix pilot with all fuels. The burner is fitted with a sight glass and a port is provided for a UV scanner to be installed. In order to start the burner automatically and supervise the flame permanently, Hotwork Combustion Technology can also supply flame management equipment if required.
Hotwork Compact Recuperator (HCR)
The heat exchanger inside the HRB Burner is available separately, known as the Hotwork Compact Recuperator, and can be used in conjunction with a hot air burner such as the High Velocity Burner (HV) or the E-Jet Ultra Low NOx Hot Air Burner (EJ_HA). Using the recuperator separately gives the possibility of positioning the burner and the exhaust at different locations, which may be required by certain firing patterns such as around a crucible furnace (burner at the bottom, recuperator at the top). It also enables features of certain burners such as the high velocity of the HV Burner to be used with higher fuel efficiency.
Fuel Savings
The fuel saving from air preheating depends on how much heat is transferred from the exhaust gases to the combustion air (directly related to the exhaust gas temperature). Experience from operating installations indicates that air preheat temperature will be about 35% of the furnace operating temperature.
Thermal ratings and Combustion data |
||||||||
|
Model |
HRB2 |
HRB3.5 |
HRB5 |
HRB10 |
HRB15 |
HRB20 |
HRB25 |
|
|
|
Thermal Rating - Max. (kW) |
57
|
103
|
146
|
293
|
440
|
586
|
733
|
|
|
Air Volume (Stoichiometric) |
57
|
99
|
142
|
283
|
425
|
566
|
708
|
|
|
Air pressure (Stoichiometric) |
37
|
62
|
37
|
70
|
70
|
62
|
62
|
|
|
Eductor Jet Air Volume |
102
|
241
|
241
|
481
|
765
|
991
|
1105
|
|
|
Eductor Jet Air Pressure (mb) |
45
|
70
|
18
|
37
|
43
|
80
|
50
|
|
Natural Gas |
Pressure @ Burner (mb) |
5
|
5
|
5
|
8
|
8
|
14
|
8
|
|
|
Max. Turndown (Stoichiometric) |
10/1
|
10/1
|
10/1
|
10/1
|
10/1
|
10/1
|
10/1
|
|
|
Furnace Temperature 1400oC |
2/1
|
2/1
|
2/1
|
2/1
|
2.5/1
|
3.3/1
|
3/1
|
|
|
Furnace Temperature 1300oC |
4/1
|
4/1
|
4/1
|
4/1
|
6/1
|
8/1
|
5/1
|
|
|
Furnace Temperature 1200oC |
8/1
|
8/1
|
8/1
|
8/1
|
8/1
|
8/1
|
8/1
|
|
|
Furnace Temperature <1200oC |
8/1
|
8/1
|
8/1
|
8/1
|
8/1
|
8/1
|
8/1
|
|
|
Max. Excess Air (%) |
500
|
500
|
500
|
500
|
500
|
500
|
500
|
|
Gas Oil |
Pressure @ burner (bar) |
-
|
-
|
2.2
|
2.4
|
2.4
|
2.2
|
2.2
|
|
|
Max Turndown (Stoichiometric) |
5/1
|
5/1
|
5/1
|
5/1
|
5/1
|
5/1
|
5/1
|
|
|
Max. Excess Air (%) |
500
|
500
|
500
|
500
|
500
|
500
|
500
|
|
|
Atomising Air Pressure (bar) |
2
|
2
|
2
|
2
|
2
|
2
|
2
|
|
|
Atomising Air vol. |
0.187
|
0.187
|
0.187
|
0.187
|
0.187
|
0.187
|
0.187
|
|
|
Max. Flame Length (mm) |
500
|
680
|
1000
|
1120
|
1350
|
1580
|
1650
|
|
|
Long Flame Burner Option (mm) |
800
|
980
|
1300
|
1420
|
1650
|
1880
|
1950
|
|
|
Max. Flame Diameter (mm) |
150
|
170
|
170
|
220
|
250
|
280
|
300
|
The data provided is for guidance only and could vary slightly due to manufacturing tolerances
* Required oil supply pressure: normally 5.5 to 6.8 bar
The data provided on this page is for information only and does not form part of any contract. Due to our continued commitment to research and development, we reserve the right to modify specifications or dimensions without notice. The improper use of combustion equipment can result in a condition hazardous to people and property. Users are urged to comply with national and local standards.
.: Weblog Themes By Pichak :.
