MIZUNO REPLICATION AND MATERIALS ONLY

Quote from Alan Smith

We just bought a mass-spec and all the vacuum gear. I think I need a lie down in the dark now.

What do you think of my obtaining the Extorr XT100 Residual Gas Analyzer which would provide me with a Pirani vacuum gauge for lower vacuum values and a Bayard-Alpert gauge for the higher vacuum levels. In addition, I get a spectrum analyzer that goes from 1 to 100 amu. That would allow me to see the H2O peak at 18 and the He peak for detecting leaks and also later on, detecting He if the reactor produces any.

Quote from Alan Smith

Is it complete with all the required pumps and valves? And a calibration certificate? (assuming it isn't new)

I did not find a used one so I thought that I would buy it new.

My first question is why normal vacuum design has been ignored in this case. For example, typically the path from the system to the turbo molecular pump is typically much larger and the reason for this is discussed in detail in books on this subject such as Karl Jousten's Handbook of Vacuum Technology. I am attaching two pictures showing the typical large pipes that the textbooks recommend and experts usually use between the system and the turbo molecular pump. The reason that this is not being used in this particular system is presumably because of heat conduction. The result of using a smaller pipe is a longer waiting time to perform thorough evacuation.

Ideally the RGA should be mounted to monitor the gas inside the reactor itself, not a remote location. Given that the RGA is going to be remote, can we say that it is in second compartment, and that it is the second compartment that is connected to the vacuum pumps and vacuum monitoring? If so, what is the size of that compartment and what is the largest pipe that can be used to connect the reactor and the second compartment?

I would certainly want to discuss the design of this experiment. In fact, the concept of DOE or Design of Experiments should be discussed in any project of this type. We need to identify the critical factors and be prepared to vary them.

Earlier experiments showed that using water cooling didn't work because it took away too much heat or took it away too quickly. Given that, If one of the main goals is to obtain a maximum COP, shouldn't we be varying both the air flow and the radiation paths as critical factors as we head towards the optimization of COP?

Quote from Alan Smith

There is a kind of layman explanation for the large pipe that I like. When you get down to 10-8 or so there are so few gas molecules left in the system that there is no 'suck', no flow. Only gas molecules that wander down the pipe by accident get pumped out. So tyhe bigger the pipe diameter the more chance that a confused molecule will walk down it.

Precisely. It is comments like "When a cell is left with no nickel reactant for several weeks, pressure does not change significantly." This project is going to take a lot of patience.

Stainless steel can under certain conditions outgas sulfur compounds, which can often be powerful catalyst poisoners. What are possible mitigations against this problem or what sort of getters are generally used in vacuum systems for this?

Quote from can

Stainless steel can under certain conditions outgas sulfur compounds, which can often be powerful catalyst poisoners. What are possible mitigations against this problem or what sort of getters are generally used in vacuum systems for this?

yes, that is why you should vacuum and bake out all your parts before you just start something like this.

Even fingerprints (oil) inside can mess you up.

Quote from oldguy

yes, that is why you should vacuum and bake out all your parts before you just start something like this.

Even fingerprints (oil) inside can mess you up.

Fingerprints sure can mess you up. Cleaning is essential, and you have to check with a mass spectrometer to make sure the gas coming out is clean.

Quote from Desireless

I am new here and cant post outside the Guest forum.

My intention is to replicate Mizuno R20 reactor.

I already have everything. Except I am welding reactor shell during these days.

Then checking vacuum tightness will take several days.

Photos will come soon.

Question - do you think it will play any role if the sheath heater will be placed inside another stainless steel tube?

What if the heater is still at the center but not in Deuterium?

Display More

I was considering doing the same thing. The leads to the sheath heater might need some ceramic insulation to withstand the heat.

Quote from Desireless

I am new here and cant post outside the Guest forum.

My intention is to replicate Mizuno R20 reactor.

I already have everything. Except I am welding reactor shell during these days.

Then checking vacuum tightness will take several days.

Photos will come soon.

Question - do you think it will play any role if the sheath heater will be placed inside another stainless steel tube?

What if the heater is still at the center but not in Deuterium?

Display More

If the sheath heater is placed inside a stainless steel tube, the sheath heater will become extremely hot at low input power. The sheath heater in the stainless steel reactor vessel is already getting borderline, because the inside is also reflective to IR. The emissivity of stainless steel is very low. Since convection inside the vessel is basically non-existent, and both the internal and external surfaces are highly reflective, the heat will be very slow to escape a stainless steel tube encapsulating the sheath heater. The stainless steel vessel is already a poor radiant emitter of heat, but at least forced air convection keeps it cool.

I expect that a sheath heater inside a stainless steel tube would fail surprisingly quick, possibly just during calibration at fairly low input power.

Since the sheath heater itself doesn’t seem to cause any reactor contamination problems, installing the sheath heater inside an Inconel tube may work reasonably well.

I have some info. on the Japanese supplier's mesh. I have some samples but they are already promised to various people. One will be tested and compared to a mesh from China. Attached is the inspection form from the company that manufactured the mesh, Sakakura Kanaami Inc. Their web site is here:

https://sakakura-swn.co.jp/company

Manufactured 2009 in Osaka. The top says metal type Nickel-200, dimensions 0.055 mm, weight 248.70 kg, specifications matte finish.

I expect you can see the first table is chemical composition. Batch number 6T752.

The second table is "mechanical nature" (specifications).

When I prepare the equipment should I do it in a glove box? Must the glove box be filled with inert gas?

Quote from dartin

When I prepare the equipment should I do it in a glove box? Must the glove box be filled with inert gas?

I do not know about inert gas, but you should use a glove box or something similar to avoid inhaling nickel powder or nanoparticles. They are toxic. This is a dangerous experiment. Unless you are experienced and you have all the proper equipment, I strongly advise you NOT to try this.