CASE STUDY
Biomass | Thermal Oil Waste Heat Recovery Plant
| PLANT LOCATION | Asia |
| FACILITY DESCRIPTION | Wood Processing / Saw Milling |
| BOILER TYPE | Forced Circulation |
| BOILER CAPACITY | 2 [MW] |
Conditions:
A medium sized timber processing plant was looking to expand its operation by introducing a new product. The production expansion was going to impose a significant additional burden on the site heat plant capacity. The site was remote with no reticulated gas supply available and the cheapest alternative fuel source was a bulk LPG which would have to be trucked in. A cost benefit analysis indicated that the cost of providing LPG as a substitute fuel source would render the proposed production expansion unviable.
The existing heat plant had been deliberately designed to operate inefficiently with very high exhaust gas temperatures (600 -700 °C) to maximize its capacity to dispose of waste wood streams. One possible source of the additional heat needed for the new project was to expand the output of the heat plant by improving its efficiency. This could be achieved by designing and installing additional heating surface onto the existing waste wood heat plant in the form of a backend heat recovery system.
A complicating factor was that the supplier of the original thermal oil heater was no longer in business and as such no OEM support was available to provide possible options for replacing or upgrading the existing thermal oil plant.
Design Boiler was engaged to investigate the problem and determine if a more cost-effective option could be found. After conducting a series of tests on the existing wood waste fired thermal oil heater it became apparent that a new economizer fitted to the back end of the unit would recover sufficient additional heat to meet the anticipated shortfall.
Design boiler provided a design for a plain tube economizer complete with fabrication drawings. The new unit was specifically designed to fit into the existing ductwork as a single module. This enabled the installation to be completed within the annual 1 week plant shut down. The new thermal oil heater plant complete with new economizer was commissioned successfully.
