Posted by Ben Proudlove on Tue, Jul 13, 2010 @ 10:18 AM
Merrow Scientific are the UK representative for Autoclave Engineers, who have been designing and manufacturing high pressure systems since the 1940s.
Autoclave Engineers, who lead the way in terms of innovation, design quality and custom configuration, also lead in terms of value for money! Sure there are companies who'll offer to make a pressure vessel or stirred reactor for a slightly lower price, but I wonder if these same companies can say they've never had a failure of a vessel in their 70 year history, or that they have customers running stirred reactors still that were supplied in the 1960s?
All Autoclave Engineers systems have serial numbers on all components, metal to metal precision engineered seals used on all VFT components, and all systems supplied since the 60s have detailed drawings in pdf format quickly available. These makes it easy to keep all of our customers, even those with 50 year old systems, supplied with spares when needed.
One benefit of metal to metal engineered seals on the VFT is the fact that this means there are no welded ports (when they break that's it for the reactor), no teflon tape and compression threads (not a high temperature or precision pressure sealing method), so when a customer needs to replace a component they can do that easily and quickly.
So the return on investment when a £10K reactor lasts for over 50 years is pretty impressive!!
Posted by Ben Proudlove on Tue, Jul 06, 2010 @ 11:05 AM
Autoclave Engineers have added a new reactor to their extensive range of custom configurable stirred reactors (available in the UK through Merrow Scientific).
Featuring the inline Mag3 magnedrive this results in a very small footprint stirred reactor that can easily be configured to suit many research applications. Rated to 454degC and 227bar using metal to metal engineered seals throughout this unit can be easily integrated with MFCs, back pressure regulators, automated sampling systems and other devices.
Available in a range of materials and with 10 ports that can be set up with whatever fittings are required, plus a wide range of catalyst baskets.
Further information can be seen on the Mini-Ezeseal HTHP page or by contacting Merrow Scientific
Posted by Ben Proudlove on Fri, Sep 04, 2009 @ 08:58 AM
From time to time we get a call from one of our customers who has an Autoclave Engineers stirred reactor in their lab to let us know that the system has started to make a weird squeaking noise.The first question we ask is “when did you last check the bearings?” – this is normally met by silence on the other end of the line… (so you’re not alone!!)
So let’s start off with a few basics, beginning with a photo of an example reactor, the mini reactor from AE (small scale stirred reactor rated to 200 bar and 315degC):
As you can hopefully see the arrangement is something like this:
- » Inline motor at the top, which is connected to the
- » Magnedrive magnets, these spin round at your required and specified rpm and through the cover (via the magnetic field coupling) accurately rotate the
- » Encapsulated inner magnet assembly which leads to the
- » Shaft and impeller
So the cover means that the reactor is a completely sealed environment and the use of the magnets allows accurate and positive control of the stirring of the product inside the reactor.(hope that makes sense!)This is the same throughout the range of reactors although sometimes the motor can be bigger and linked to the magnedrive via a belt. (more…)
Posted by Ben Proudlove on Tue, Aug 18, 2009 @ 02:24 PM
If you google Teflon Tape the very first result is the wikipedia page that describes Teflon tape as
“Thread seal tape — commonly known as “Teflon tape”, “PTFE tape”, “tape dope”, or “plumber’s tape” — is a polytetrafluoroethylene (PTFE) film cut to specified widths for use in sealing pipe threads. The tape is wrapped around the exposed threads of a pipe before it is screwed into place. Since the PTFE is malleable, deformable and impermeable, it acts a little like putty under compression, being forced into small gaps between threads in order to create an air- and watertight seal when threaded into a joint. The tape is commonly used commercially in pressurized water systems, such as central heating systems, as well as in air compression equipment and thread joints with coarse threads.”
And then futher on in the same chapter
“Over-use, or mis-application of thread tape may be a hazard. As the tape material is so soft, excess or overhangs may easily break off and form a foreign body contaminant that could jam a valve seat etc.
Thread sealing tape is almost entirely applied by hand, owing to the ad hoc nature of most repair work”
Teflon also has a melting point of around 327degC, but its properties degrade above 260degC according to DuPont (the manufacturers of teflon).
We get asked about this a lot, so let me explain, the Autoclave Engineers range of reactors that we supply in the UK (see our Merrow Scientific reactor page) use a Metal to Metal engineered sealing for all of their valves, fittings and tubing, so no teflon tape.
The benefits of this method include:
- » Precise, repeatable and highly rated sealing
- » All parts are serial numbered so you can easily swap or replace
- » High temperatures and extremely high pressures are no problem
- » No welding (which could potentially have weak points which could lead to failure under pressure and are permanent and not easily replaced or repaired)
- » And no plumber’s tape……