Kettle boil always weaker for 2nd batch of the day-- why??

[Jules]

I really hope someone knows how to fix this!

Our brew kettle is steam heated. We do 2nd batches a day. The first batch always has a very strong boil and we need to restrict the steam to the kettle to prevent a boil over. However, the 2nd batch of the day is always weak to the point that we can't achieve a rolling boil.

We have tried replacing the steam trap 2 times with newer models added a release valve before the trap to dump condensate (usually it's less than 100ml -- the kettle is 10 BBL), added a condensate release valve before the steam input to the kettle, and recently we tried removing the solenoid to the kettle to let the steam go in direct.

Other information:
1. We have 2 HLTs that we heat before and between batches.
2. We never heat any other tanks during the kettle boil.
3. Steam pressure is always stable at 2bar.
4. We rearranged the brewery layout 5 months ago and the condensate exhaust pipe from the kettle is longer than before. Previously we had no issue. This gradually appeared over the past 2 months.
5. Contacting the manufacturer was unhelpful.
6. My brewery is in Japan.

We're really running out of ideas on what the problem may be. I hope someone else has had the same problem and knows what to do!

Thanks!

[dick murton]

Are you sure the condensate line is fully self draining an there are no "goalposts" in the line? I was going to suggest the heating surfaces were fouling badly, but since you say this problem has only arisen since the move around, it suggests the condensate pipe is the blocking up. Is there a joint local to the kettle you could break for a trial or two?

If the water treatment for the steam is not adequate, you could be getting sedimentation of precipitates, or even rust (obviously depends on what the rest of pipework etc is made from)

[lhall]

I agree with Dick, sounds like a condensate line problem. There might be a section of condensate pipe that isn't sloped downhill? Can you put a drain valve right near the kettle and see if manually draining the condensate helps? Also, some steam traps need to get hot before they will start passing water properly. Draining the condensate by hand at the beginning, until it heats up, sometimes helps.

[13356690973]

Do you have your system steam inlet and outlet place picture? sometimes the kettle tun has a not suitable steam inlet and outlet design( the correct steam inlet port should be overtop the outlet port)

[Jules]

Here is are photos of the inlet and outlet with the 2 valve condensate additions. The additions were made because we believed condensate was over accumulating in the steam jackets. Water does drain out of the release valves when opened but I have no experience about how much is normal.

Yesterday we added a 2nd trap to our pipe system as we believed condensate was accumulating between the 2 HLTs and therefore not providing adequate steam to the kettle. But unfortunately today's 1st batch of the day is now just as weak as the 2nd batch is!

[Jules]

I agree with Dick, sounds like a condensate line problem. There might be a section of condensate pipe that isn't sloped downhill? Can you put a drain valve right near the kettle and see if manually draining the condensate helps? Also, some steam traps need to get hot before they will start passing water properly. Draining the condensate by hand at the beginning, until it heats up, sometimes helps.

Yeah, I took a look at the angle of the outlet. It's perfectly level until the joint before the elbow going down to the floor pipe. After the joint, it does angle up.

[Jules]

Are you sure the condensate line is fully self draining an there are no "goalposts" in the line? I was going to suggest the heating surfaces were fouling badly, but since you say this problem has only arisen since the move around, it suggests the condensate pipe is the blocking up. Is there a joint local to the kettle you could break for a trial or two?

If the water treatment for the steam is not adequate, you could be getting sedimentation of precipitates, or even rust (obviously depends on what the rest of pipework etc is made from)

Yeah we have tried breaking the pipe. Everything appears normal. No buildup or blockage. The rest of the line outside is obstruction free as well.

We treat our water and according to what I've been told, everything is in spec and all the pipework material is correct.

[Jules]

Do steam jackets ever fail? And what would be the causes? This kettle is 3 years old now.

[13356690973]

take down this part to try

[13356690973]

maybe it is blocked by scale

[13356690973]

the cap thread on it, take it down and check if there are water or scale incrustation

[Derrick]

I really hope someone knows how to fix this!

Our brew kettle is steam heated. We do 2nd batches a day. The first batch always has a very strong boil and we need to restrict the steam to the kettle to prevent a boil over. However, the 2nd batch of the day is always weak to the point that we can't achieve a rolling boil.

We have tried replacing the steam trap 2 times with newer models added a release valve before the trap to dump condensate (usually it's less than 100ml -- the kettle is 10 BBL), added a condensate release valve before the steam input to the kettle, and recently we tried removing the solenoid to the kettle to let the steam go in direct.

Other information:
1. We have 2 HLTs that we heat before and between batches.
2. We never heat any other tanks during the kettle boil.
3. Steam pressure is always stable at 2bar.
4. We rearranged the brewery layout 5 months ago and the condensate exhaust pipe from the kettle is longer than before. Previously we had no issue. This gradually appeared over the past 2 months.
5. Contacting the manufacturer was unhelpful.
6. My brewery is in Japan.

We're really running out of ideas on what the problem may be. I hope someone else has had the same problem and knows what to do!

Thanks!

I think the main issue is trap valve for condensating. The condensated water can not flow through trap valve frequently, which results in steam can not flow in smoothly. So you can open trap valve manually and see if it works. If you need more information,contact me. I will try to help you solve it.