How an industrial setback produced a heat transfer solution
10 Dec 2018
An industrial accident caused serious damage to a plant but opened the way for a redesign of process lines with safety improvements...
British-based American Pan UK built a reputation over decade for its cleaning and recoating processes for some of the world’s largest industrial bakeries.
Equipment used by these firms receives heavy treatment from carbon and flour residue which can quickly degrade their non-stick coating.
American Pan’s process involves soaking pans for hours in heated low volatility organic solvent, followed by a series of hot and cold rinses and conditioning tanks, before a new coating is applied.
But a heating mechanism fault within a single unit in the firm’s plant line, when solvent used for cleaning process overheated and ignited, led to a fire throughout the facility.
American Pan speedily converted a warehouse facility into a process line in order to avoid customer delays.
However the firm wanted to future proof the company and improve its cleaning processes. Their objective was to remove the risk factors that had led to the fire incident and to improve overall process performance. At the same time they wanted a boiler system that did not require constant monitoring.
The system does not require 24/7 supervision says Every which means the boiler can, be left un-attended at weekends but operational for periods of time
Heat transfer expert Fulton was enlisted for the project by American Pan and its consultant RE Architects’ Richard Every.
First step was a temporary, diesel-powered boiler to provide steam with a dedicated solvent cleaning tank line featuring two, three-cell tanks containing 45,000 litres of solution each. Additional 5,000 litre tanks were used for supplementary cleaning.
Next, with space in the converted plant at a premium, the decision was taken to site Fulton’s new steam boiler system outside.
This featured horizontal, gas-fired RBC1500 boiler with NU-WAY gas burner and fully-modulating burner controls to provide a steam output of 2,393kg/h and maximum working pressure of 10.34barg. The includes automatic boiler controls, blowdown vessel, condensate return and feed tank and water treatment.
Once sited and installed, the plant room was built around it, while the temporary hire boiler was removed with its connecting pipework left in-situ should a requirement for additional steam be needed in future.
The system does not require 24/7 supervision, says Every, which means the boiler can be left un-attended at weekends but operational for periods of time: “This is vital for American Pan UK’s processes as it can take a long time from a cold start to heat the solvent and fluids in the various cleaning tanks.”
Steam from Fulton’s RBC1500 boiler system – which meets the requirements of BG01 equipment level 3 – is now being used to heat water to 50 degrees for the pre-wash facility, for heating the solvent to 106 degrees for the deep clean cycle and for heating water for one of the two final cleaning cycles.
With the process heating the solvent to 106 degrees (approximately 10% hotter than the previous system), American Pan UK has been able to reduce the acidity content of its cleaning solution to make best use of the increase in cleaning performance from the solvent.
The benefit for customers, claims the fim, is that the pans receive a deeper clean with quicker turnaround times and, when combined with the company’s proprietary coatings, a reduction in the rate at which the tins carbonise in the bakery.