Usually, in technical jargon, economizers are particular heat exchangers combined with boilers or gensets, built according to precise technical specifications and suitable for recovering heat from the exhaust gases. Normally they are finned tube heat exchangers built in either carbon steel or stainless steel. When the fumes come from fuels that produce dust or solid residues, a smooth tube solution is preferred to prevent clogging or reduction in efficiency.
With a DAV COIL economizer, combined with an industrial generator, the increase in efficiency is a minimum of 4% and can even reach 6% depending on the temperature of the fumes and the fluid to be heated (normally the return water from the connected system to the generator). DAV COIL is specialized to build custom economizers according to the customer's needs. Bespoke fittings or by-passes and carpentry can be made in order to have the perfect coupling with the boilers or the system.
The condensers are special heat exchangers built in 316 or 304 stainless steel. Combined with industrial boilers they are able to increase the efficiency up to 12%, thanks to the condensation of the vapour contained in the fumes. Indeed, especially in the fumes coming from the combustion of methane gas (NG), the condensers recover both sensible heat (deriving from the cooling of the fumes) and latent heat from the condensation of the vapour in the fumes.
They effectively transform a normal boiler into a condensing boiler. Also in this case, as for the economizers, when the fumes come from the combustion of fuels that produce dust or solid residues, smooth pipe solutions are preferred to prevent clogging or reductions in efficiency. DAV COIL can make condenser according to customer needs. Bespoke fittings or by-passes and carpentry can be made in order to have the perfect coupling with the boilers or the system.
Preheaters are special heat exchangers designed to preheat the combustion air before entering it into the combustion chamber of industrial boilers or generators. They can also be used in all those processes in which it is desired to recover heat from hot air / fumes by heating another aeriform in countercurrent. They are usually built with smooth tubes, (finned tubes can be used as well), with a diameter from ø42 mm up to ø76 mm in order to allow internal cleaning also.
They can be of various shapes: with either 4 or 6 passages depending on the required energy recovery target. Combined with industrial boilers they can increase the overall efficiency by 4%.
Superheaters are special smooth tube exchangers intended for superheating saturated steam to ensure “dry” steam for users requiring this type of carrier fluid. They are normally installed inside steam boilers plunged into hot fumes with medium-high temperatures (up to 950 ° C). They can be built in various bespoke shapes in order to optimize space requirements and maximize performance. They are usually built in carbon steel with pipes with a diameter ranging from 1/2 ”to 2” depending on the thermal capacity and steam flow rates. In particular conditions, they are also built in stainless steel to better resist thermal stresses.