A century-old Chicago, USA wholesale chocolate manufacturer needed a condensate recovery system for a new roaster.
The roaster uses high pressure (superheated) steam to heat air
for roasting chocolate beans in a continuous process. Condensate
at the roaster outlet is 16,000 lbs/hr at 120 psi by specification.
A competitor had already proposed a design including a (duplex)
electric condensate pump package, with no flash steam recovery.
Spirax Sarco supplied a superior solution stressing:
The maintenance and longevity advantages of steam-powered, totally mechanical condensate pumps (PPC) vs. electric pumps, particularly with high-pressure condensate.
The energy benefits of using a flash tank system to convert high-pressure condensate to low-pressure steam for improving the function of the deaerator tank.
The operational advantages of float and thermostatic (F&T) traps in process applications vs. the inverted bucket traps that the competitor proposed.
The solution incorporated the design and operational advantages of two engineered system packages for the condensate recovery system:
A flash recovery module, completely skid-mounted with a
safety valve, backpressure regulator, float traps, strainers and
other auxiliaries.
A duplex condensate recovery module, with pumps, traps,
connected piping and auxiliaries.
Spirax Sarco’s estimated payback calculation projected a total cost savings of $258,519 per year, an IRR of 365% and an ROI of 345%. Projected payback was only 3.3 months. The basis for the calculation was recovery of 16,000 lbs/hr of condensate and at least 1,800 lbs/hr of flash steam at 5 psi or 1,000 lbs/hr at 10 psi. The energy savings resulted from eliminating a separate heating source for the deaerator tank water.
The economic justification proved to be conservative; the customer obtained enough low-pressure flash steam recovery from the system that they could shut down their low-pressure boiler, resulting in considerable fuel and operational savings. These exceeded expectations led the customer to approve a proposal for two condensate pump packages, now up and running equally well.