SS Pipe Cleaning Advice Needed

If you are burning the blocked coffee I can only assume you are using direct heat.

Have you considered steaming (inside) the line?

Or steam in conjunction with something similar to pigging the line?

Here is a description of line pigging: http://en.wikipedia.org/wiki/Pigging

Good luck with your pipes!

I suggested this here, I guess it didn't work.

http://cr4.globalspec.com/thread/56333/Cleaning-of-Valves

They would have had to run steam through the pipe to reach the valves.

It sounds like my arteries. What are the pipes made of? The material itself could pose a problem.

Does the product remain the same temperature from its point of origin to its destination? If it precipitates out of the solution at a certain temperature, you may need to either insulate the pipe or even install thermo wire heaters around them to keep them at a constant temperature.

Otherwise, if you simply want to clean the pipes, I would think you went the wrong way on the Ph, acetic acid (vinegar) is used in the home process and food grade too. I would venture a guess that it would work on your scale as well.

I envision a cleaning system where sections of the process are diverted by three way valves either at regular programmed intervals or on demand and flushed with a cleaning agent of some type (how about water?). This shouldn't interrupt the process too badly if done regularly. You've got to clean anyway, right? Automate the job and keep the sludge from building up in the first place. Just think of all the friends you'll make in the sanitation department.

Try these "pipe cleaners"?

:)

Just a thought regarding the root cause of your problem....the coffee is drying on the inside surface of the pipe. What is causing this? If you can keep this from happening, you will reduce your down time and increase your overall yields, right? Have you noticed if the drying is uniform about the inside perimeter of the pipe or is the coffee settling out of solution and the blockage beginning at the bottom? Have you considered increasing the flow rate in the circulation loop to keep the solution churned up inside the loop and discourage settling? Is the blockage always at the same place in the line or does it occur "randomly"? Is there a point where the blockage starts like a fitting or a necking point that could be creating an orifice and thereby an eddy current of the back side of the orifice? Could you have a pH shocking issue going on causing the coffee to precipitate out? Have you considered periodically inspecting the interior of the pipe to see just how the blockage is forming?

If you are looking for a quick/easy way to unclog the interior of the pipe with no regard for loss of the product within the line, you can try a product called "aqua mole", (roughly $170.00 US). This is a pressure washer nozzle that has a forward facing nozzle to break through a blockage, several rearward facing nozzles to help pull the nozzle through the pipe and a spinning nozzle to clean the interior of the pipe. They will make a custome unit for you if necessary. I've used one in the past to clean out drain lines in a semiconductor polishing process that used acidic and basic slurries in the same tool, the pH shock when the two slurries met within the drain line meant we were constantly battling blockage. Prior to trying this nozzle the solution was to replace the 6" drain line every year due to blockage. Our first trial completely cleaned the interior of the 50ft pipe run in less than 8 hours saving us days of down time and many man hours of labor on just the first use.

Without having ALL the facts, it is my guess that your feed pipe is too large for the required flow- and is also not well insulated- so you are getting both cooling (setting up the product plating due to cool-down) and low flow, which also contributes to plating. You used the term "circulated" but I believe that you meant "supplied" to the spray chamber without any return.

The previously suggested heat tape is one option, but you have to keep the total pipe hot (above 180F) and still run the risk of localized cooling and/or plating.

You might look into adding a recirc line very near the entrance to the spray-drying chamber with a throttling valve at the return end, just before the the connection to the mixed product heater tank upstream of the pump. Use a tee connection at the throttling valve so you can also install a shut-off valve to be opened during CIP action.

For example- if your current feed line is 1/2", you recirc line might be 1/4". You want a flow rate of at least 5 FPM in the feed line to eliminate risk of product plating on the pipe walls.

If you install the recirc line, run a heater line (adequate to hold at least 180F in pipes) "squeezed" between the two lines (use fiberglass tape to secure the pipes together) and insulate both lines (plus the heat tape) with at least 1" of fiberglass.

The constant circulation will assure that the liquid in the lines remains hot because it will be recirculated from and through the initial heating element, along with the "belts and suspenders" heat tape to cover any potential line heat losses). Depending on current unit capacity, you might have to add a second (equal size) circ pump to be sure that you are maintaining adequate volumetric flow and as a second "back-up" system in case one of the pumps fails.

A similar problem was solved by heating the outside of the pipe, and using TFE liner inside.

Wangito

have you found a solution for unclogging your pipes? if not if you can send me a sample we may have something to help you out.... email me at jstefanowicz@gotar.com and we can discuss further...