6%+ Fuel Savings with Cochran Economisers
Complete our Heat Recovery & Economiser survey so that we can determine the level of waste heat recovery for your plant.
The Cochran range of Economisers is designed to
recover heat from Boiler exhaust gases, and transfer this to the
incoming Boiler feed water, thus increasing the overall Boiler Thermal
Economisers are normally fitted to Boilers fired
with natural gas, although units of special design may be fitted to
Boilers fired with liquid fuels. However, the degree of heat recovery may be limited as a result of possible “dewpoint” corrosion.
Two standard ranges of Economisers are available,
increasing the Boiler Thermal Efficiency by a nominal 3.5, and 5.0%. The
resultant fuel saving will be in the order of 4.25, and 6.0%
For the 3.5% gain units, the Boiler Exhaust gases are cooled by a
nominal 80 °C, with an associated feed water temperature rise of around
24 °C. For the 5% gain units, the values are 115 °C, and 34 °C
Both ranges are designed to limit the gas side pressure drop to less than 0.5 ² WG, and 0.5 bar on the waterside.
The Economisers are manufactured from extended surface tubing,
within a carbon steel casing. Removable covers give access to the tubes, which can easily be removed if necessary.
They have a design pressure of 24 barg, and design temperature of 300
°C. They are CE marked in accordance with the Pressure Equipment
For dual fuel firing, when prolonged firing on oil is likely, the
Units may be supplied with an integral gas bypass. The alternative to
this is to incorporate a water bypass in the feed pipe work, thus
allowing the units to “run dry”.
The Economiser Units are ideally arranged for a vertical gas flow,
but if used with a horizontal gas flow, then additional vent and drain
connections are fitted.
Each unit is supplied with the following equipment as standard: -
Safety Valve, Vent Valve, Drain Valve, Outlet water temperature gauge,
Auto Bleed Valve.
This is supplied complete with an actuator switch, which is fitted to
the Boiler feed water-regulating valve. At low operating loads, or
whenever the regulating valve approaches its closed position, the Bleed
Valve operates to ensure a flow of water at all times through the
This prevents “steaming” within the unit, and thus possible “vapour
locking”. The outlet from the Auto Bleed valve should be piped back to
the Boiler Feed tank. External insulation and Aluminium cladding.