Retread tyre specialist Vacu-Lug has installed a second coil type Babcock Wanson steam generator, complete with flue gas economiser, for its curing process.
Vacu-Lug has operated three Babcock Wanson dual-fuel VPX 2000RR steam generators since 1989, but production engineer Peter Connolly says the VPX-RR units were reaching the end of their working life.
So, with the energy saving potential from updating its steam raising equipment, Vacu-Lug went for two Babcock Wanson gas-fired vertical ESM2000 units.
ESM2000s use electronic controls to maintain the ratio between burner firing rate and water input, while variable speed drives for fan and feed water pumps enable them to tightly follow process demand.
“The ESM 2000 installation, together with an ongoing programme of process plant lagging and steam trap maintenance, has enabled us to significantly reduce our gas usage and cushion the company against rising gas prices,” confirms Connolly.
He also says that steam raising was chosen over thermal fluid heating, because of its reliability and its ability to follow demand quickly.
“Curing is a critical element of the retread process and requires three variables – heat, pressure and time… The steam generators have proven to be reliable items of plant.”
And he adds that, since Vacu-Lug processes a wide range of tyres, the curing process can lead to a highly variable steam demand. “We have found that steam generators can react to variable steam demands – they can proceed from standby to steam generation within minutes.”
And he points to Babcock Wanson’s quick Autostart facility on the ESM2000, enabling a standby generator to be brought online quickly when steam demand requires it.
Both ESM2000s at Vacu-Lug have been fitted with economisers to allow the feedwater to collect heat from the waste flue gases prior to entering the steam generator.