It is a common practice in the electric utility industry to utilize multiple stages of shell and tube heaters to preheat feedwater going to the boiler. The challenge has always been transferring as much heat as possible from the steam inside the shell to the water in the tubes. The mechanical design of the heaters helps this by providing baffles to prevent steam from exiting the heater rather than condensing. Heaters cascade from the highest shell pressure being the last in the train to the lowest being the first. There is also one heater called a deaerator that is an open heater between the low-pressure and high-pressure closed heaters where steam mixes with feedwater and any entrained air is removed. The steam for heating feedwater comes from extraction stages of the turbine and from the drain of the next higher-pressure heater.At first blush, this ... Continue ReadingContinue ReadingView Comments (1)
In this last installment on this topic I said that the main purpose of automation is no longer to eliminate labor. That may have been the purpose some decades ago, but it is no longer the purpose of automation. I spent some time explaining that fundamentally that was the case because if some type of machine or automated equipment could be used to replace manual labor, it would have already been installed a long time ago. So... Continue ReadingContinue ReadingView Comments (1)
This is a continuation of an earlier article which discussed the importance of specifications in engineering services projects. That article described the importance of good specifications to define a project’s scope of work. This posting continues from there, with advice intended to help developers continue the good work that began with specifications. This post is not intended to give advice to project managers on how to run a project. We are not project managers – we are engineers who have worked with many clients on many project teams, with some experiences to share on the benefits of providing early-stage review of project development with your client. Once project specifications are written or received and development is underway, it is wise to keep the client involved in the initial stages of development. That may seem obvious to some readers and completely unnecessa... Continue ReadingContinue ReadingLeave a Comment
Regardless of your plant’s age, your control system is now one of its most critical components. You cannot operate effectively in the 21st century without a modern control system designed for the way your plant works now—and for the way it will work in the future. Upgrading your control system is much more than a “rip and replace” exercise.