Falling Film Evaporator

Almost sounds like a distilling tower.

In a way, it is.

Falling film evaporator (of dreams), or WFE not needed when married. WIFE - uses laser eyes to totally evaporate all dreams from taking place. Some days she is actually quite nasty, others she is intolerably mean as hell.

I think she has a tumor the size of herself. She keeps trying to have me removed.

At least I am listening to Big Band music at work, she can't kill my dreams entirely.

I can talk to her if you like...... maybe, you not really a tumor,... but a wart.......I can give her some home remedy's....... like, ahhhh, lets see,.......... the milk from the milkweed plant removes warts.......

Well, if one needed to concentrate sugar syrup, strawberry jam or spicy brown sauce, then a wiped film evaporator would be a way of doing it without thermal degradation at the heat exchange surface.

How did that Google search go, then?

Or for producing liquid smoke, a lot of nasties gets removed on a WFE. Such as Benzene

And if there are heat sensitive components, put it under vacumn to lower the evaporation temperature.

You missed out one of life's eternal pleasures.

Tate & Lyle Golden Syrup is concentrated up in a Falling Film Exchanger.

Its too long since I worked at T & L and I was in treacle and ordinary syrup (setting up a pigged line for the loading) but as far as I recall

They used this format because of the extreme temperature sensitivity - it can go off colour if over heated; too thick etc

Steam ran in the tubes and falling film ran down the outside under some vacuum

In terms of control its really no different to any exchanger. You need tight control of the heating fluid. In this case it was steam so you control the pressure of the steam to control the condensing temperature and thereby the temperature on the hot side.

You need to control the heat input. This can be achieved by

i) Control the flow of heating medium

ii) Control the heat transfer area. With a steam system condensate flows out. If you control the liquid level you can flood liquid back into the exchanger and reduce the heat transfer area that the live steam sees

Then you need to do the same for the cold fluid. Usually for the cold fluid the outlet temperature is critical. In the example I gave the vacuum is also critical as this impacts the temperature required to achieve the water removal.

In short there isn't an easy answer but Film Exchangers are usually very big for the duty and very expensive so you need to over egg the measurement but do NOT put too many controllers in place otherwise it will never work. The usual suspects of Temp, Pressure and flow for both sides in and out are required. In addition if there is some way of measuring the film thickness (radar / nucleonic) at various points that would be a boon.

See also Chester-Jensen, Paul Mueller, and Baudelot cooler.

Somehow this discussion has diverged into scraped-surface heat exchangers, such as are used for making ice cream, for instance.

Scraped surface cookers you mean...btw, you also make cheese with those. The biggest differences between a scraped surface cooker and evaporator is that the evaporator is mounted verticallly, the cooks one can install vacuum, I know some batch cheese cookers has vacuum.

A lot of processes is related between the different industries, with certain tweeks, an example, a lot of processes for food production actually derived from the sanitation industry.

One doesn't exactly cook ice cream....

As I said,..... "A lot of processes is related between the different industries, with certain tweeks, an example,"

The one that can realize the similarities.....can name his price. And yes, you can cook ice cream.

It's still a heat exchanger. The flow is the other way, that's all.

Ice cream. Anyone want a Belgian choc-chip or a raspberry ripple? Del's buying...

I agree. Wiped Film Evaporators (WFEs) and Falling Film Evaporators (FFEs) are two different animals with different applications. From Wiki article, I read that the primary application is concentration, while the primary application for WFEs is separation.

I have experience with a WFE and it was a headache to keep running. It was operated under a vacuum which was effected by a series of steam eductors. Our biggest problem was finding and fixing leaks.

At any rate, I doubt OP will be back.

Your correct in all aspects between the WFE and falling film, control can be a beast in a WFE. I would think that a falling film evaporator, one can pull a vacuum also.

It's too bad that the OP didn't at least acknowledge. Maybe he's just doing research, or more than likely homework.

I just missed my editing time....

They are similar.

http://www.sulzer.com/en/Products-and-Services/Separation-Technology/Evaporation/Thin-or-Wiped-Film-Evaporator

Nit picking, if one doesn't know what really is required, a the proper process...WFE or Falling Film, then it's irrelevent.

Of course there can be overlap in application between the two. So frustrating when the OP drops a indeterminate bomb and leaves!

At times, what offsets it, is I enjoy feed back from others experiences..... I myself, see falling film Evaporators (FFE) and WFE as very similar. its just at different levels or requirements at which they are applied. And I really shouldn't do that..... And treat them as different beasts.

But you nailed it about control on the WFE's.

Whilst the Danish numbers are good and wind has a future as part of the basket the numbers are for a few hours on Saturday morning. I am not sure how the power demand for danish industry is figured into the numbers if they generate their own power and export the excess.

And at least that story is accurately headlined that its a %of the electricity demand. I am not sure how that compares with the overall energy usage in Denmark once all teh transport energy is factoredin

To the OP: Please clarify your application. Two different, though somewhat related, concepts are being presented, and we don't really know which one you need.

The instrumentation that is needed is determined by process requirements and may well vary from installation to installation; it is not something that is equipment-type-specific. A unit that is used to make orange juice concentrate might need something completely different to the same piece of kit on, oh, say, tomato puree.

Recommendation: grab a copy of a P&ID from the facility, showing one, and discuss it with a Mentor locally.

excellent suggestions..... the OP has to do some thinking just to set a reference point of requirements.

And if the OP is a lazy but smart..... he/she may wait it out until we have the process all figured out for him/her.

thank u for the answer, well it is for cane juice.if anyone have pid for ffe for cane juice then please help me.

What are you trying to do with the cane juice? Heat it up or cool it down? What is the medium on the other side of the exchanger? What temperatures are involved? Please explain your process.

He trying to make it concentrated into syrup. Then he is probably going to crystallize it to sugar (cane sugar) for sale (somewhere), and make money.

Here this fellow is out there trying to earn a living while the rest of us are sitting on our laurels (that is what we call that these days).

On the other hand, he could be going to smuggle the sugar into England, make rum, and get them all drunk.