Historical photos from North Norfolk

[sjt01]

Another interesting part of the install was the 17 m span travelling crane, not a normal part of a tea factory but for weighing the withering skips for research purposes.
Alan made shear legs from eucalyptus poles, strapped with wire to stop splits.

Every opportunity we chocked the beam with anything at hand!

Eventually reached working height and bolted in place on the travelling carriage

 

[Clive]

@Chris F @Clive - do our techies have the ability to scrape this thread for @sjt01 ?

This has become my Thread Of The Year

you could simply “copy and paste” pictures and all ?

 

[sjt01]

We built 3 parallel manufacturing lines in miniature to do experiments on.
First stage is to get the withered leaf into the system, sift out any stones and feed it into the subsequent process

It then goes into a modified hammer mill originally developed by Christy & Norris called a Laurie Tea Processor (LTP). There is no screen, the leaf goes in on one side, then round and round until it comes out the other side of the machine.

The mashed up leaf, now known as dhool, is somewhere between green paint and grass clippings, and goes into the fermenter where air allows the oxidation reaction which turns it brown. If you need to know the chemistry, ask my wife as she did her PhD on this.
The trailing arm is a temperature sensor.

It is on the fermenter for 30 minutes to an hour, depending on the leaf quality, being continuously aerated and occasionally turned and fluffed up. You can see it is now turning from bright green to pale brown, before going up a conveyor into the dryer

 

[sjt01]

The dryer was my particular area of interest. To stop the "fermentation" at the right point the moisture content had to be dropped quickly without burning the tea. Our dryers were more sophisticated than the industry standard, and recirculated air from the dry end exhaust into the wet end inlet. This shows the hot air ducting coming from the steam heat exchangers into the bottom of each dryer section.

This is inside the dryer where the particles are fluidized by the upflow of hot air. The drying process has turned the particles black, as we would recognise it in a tea bag.

This shows the discharge end or the dryer, with the tea down from 72% moisture to 3% in less than 30 minutes. The blue thing is my research NIR moisture meter.

After that, while the leaf is still warm, the fibre is extracted by electrostatic means. A bit of plastic water pipe rotates with a felt pad rubbing on it, just the same as rubbing a baloon on your jerstey. The brown, lighter fibre particles are attracted to the drum, and the black particles continue on to the grader.

You can see the heaps of the various grades.

When there is enough of one grade, it is packed into sacks to make up an "invoice" of tea. Then it is shipped to the auction floors.

 

[JWL]

Wow

 

[bumkin]

The dryer was my particular area of interest. To stop the "fermentation" at the right point the moisture content had to be dropped quickly without burning the tea. Our dryers were more sophisticated than the industry standard, and recirculated air from the dry end exhaust into the wet end inlet. This shows the hot air ducting coming from the steam heat exchangers into the bottom of each dryer section.
View attachment 845533
This is inside the dryer where the particles are fluidized by the upflow of hot air. The drying process has turned the particles black, as we would recognise it in a tea bag.
View attachment 845534
This shows the discharge end or the dryer, with the tea down from 72% moisture to 3% in less than 30 minutes. The blue thing is my research NIR moisture meter.
View attachment 845535
After that, while the leaf is still warm, the fibre is extracted by electrostatic means. A bit of plastic water pipe rotates with a felt pad rubbing on it, just the same as rubbing a baloon on your jerstey. The brown, lighter fibre particles are attracted to the drum, and the black particles continue on to the grader.View attachment 845537
You can see the heaps of the various grades.
View attachment 845538
When there is enough of one grade, it is packed into sacks to make up an "invoice" of tea. Then it is shipped to the auction floors.View attachment 845540

what a life you have had fantastic makes mine seem mundane, is this work still going on ?

 

[sjt01]

what a life you have had fantastic makes mine seem mundane, is this work still going on ?

Tea manufacture continues, but with the lack of funding, the research lines were sold for scrap and the building is being used by the next door tea estate as storage. Makes me want to weep, as it was a facility unrivalled in the world.

 

[sjt01]

The reason I was recruited was to instrument the research manufacturing lines, but this time I was able to use the guts of an Amstrad portable PC as the basis, and put it in an enclosure with the data logging hardware.

This was the analogue multiplexing card, taking 16 channels in. 16 cards gave 256 data logging channels for temperatures, humidities, pressures and the like. I used 4-20mA analogue transmission for the electrically noisy factory environment.

The interface card selected the multiplex card and the channel on the card, and converted the value to digital for storage, analysis and plotting.

This is the temperature and humidity measurement module

Rather than hand taping the boards and using a UV light box as we had done at Tobacco Research, I evolved a technique using a pen plotter to apply ink as an etch resist directly to the copper boards.

There was also a hand held remote monitor which could be plugged in to monitor values on the factory floor

As well as the electronics, I also managed to do a bit of ploughing!

 

[colhonk]

Getting far too techy for me now,apart from the last picture

 

[sjt01]

We also developed a Mini Processing Unit, for kilo batches of experimental stuff.
Withering was in tea chests (on the left, hanging from weigh scales) with mesh floors, and hot, ambient or cold air. I used electric jacks from satellite TV dish steering to move the air valves.

Maceration by the wall, fermenting in buckets with controlled air supply, gas fired tray drier in the corner

Infra-red heated scales for moisture determination

 

[d williams]

The reason I was recruited was to instrument the research manufacturing lines, but this time I was able to use the guts of an Amstrad portable PC as the basis, and put it in an enclosure with the data logging hardware.
View attachment 845630View attachment 845631
This was the analogue multiplexing card, taking 16 channels in. 16 cards gave 256 data logging channels for temperatures, humidities, pressures and the like. I used 4-20mA analogue transmission for the electrically noisy factory environment.
View attachment 845632
The interface card selected the multiplex card and the channel on the card, and converted the value to digital for storage, analysis and plotting.

View attachment 845633
This is the temperature and humidity measurement module
View attachment 845634
Rather than hand taping the boards and using a UV light box as we had done at Tobacco Research, I evolved a technique using a pen plotter to apply ink as an etch resist directly to the copper boards.

There was also a hand held remote monitor which could be plugged in to monitor values on the factory floorView attachment 845635

As well as the electronics, I also managed to do a bit of ploughing!
View attachment 845636

Do you have a conclusion as to why the disc ploughing never took off in gb???

 

[sjt01]

As part of my drying research, I did Equilibrium Relative Humidity measurements on tea at varying moisture content and temperature. Used an old gas chromatography oven for temperature control, with my PC based data logging system.

Also built a thin layer drying rig, measuring weight of drying tray as the tea dried.
Most apparatus was built from scrap, or from the plumbers merchants. To get instruments or electronic parts took 4 to 6 months.

Also spent quite a bit of time trying to calibrate NIR moisture measurement.

Eventually trialled it for driving the steam valves on the dryer heat exchangers

I also built a batch dryer, which could take tea from 72% moisture down to 3% in 5 minutes without compromising quality

 

[sjt01]

Do you have a conclusion as to why the disc ploughing never took off in gb???

Disc ploughs get penetration in very hard dry conditions. When it is at all wet, the discs do not scour and end up a plate of mud. You need to set the disc angles to suit soil conditions, both in the horizontal and vertical planes.
As they have no landsides, they need quite a bit of setting up to balance the side forces from the discs with the opposing force from the tail wheel. The college farm tractor drivers did not bother with that, and just tightened the check chains. When they hit an obstacle, the result was often a bent front axle or other serious damage.

 

[sjt01]

1998 left Malawi, back to the farm in N Norfolk. As well as farm work, my colleague ex-Tobacco Research asked me to instrument a curing system for him in Estramadura in Spain.
This is the farm

Tobacco with centre pivot irrigation

Farmyard and guest house where we stayed

Curing unit with grading shed in the middle - this was a big operation

Not sure how farm assurance would view this method of spraying

 

[sjt01]

Tobacco harvest - the farm had devised its own system, the leaf was picked and put on an old conveyor belt on the ground.

This was then wound in towards the tractor, and the leaf manually loaded onto an elevator

The elevator filled curing trollies laid on their sides

These were then taken back to the curing system and loaded into an empty unit.

The units were in groups of 8, one emptied and reloaded each day, the hot air at 70° going into the 7 day old one, then into the 6 and so on so the new leaf was not damaged by the hot air, but the cured (biological ageing) leaf would have its midribs dried out. The cured leaf was then moved to the big central shed, unpacked, graded and baled into 2 m3 bales.

The atmosphere in the grading shed was horrendous, like breathing snuff.

 

[sjt01]

Back at the farm, I noticed that the way we were measuring grain store temperatures was slow, so adapted the "one-wire" technology I had been using in Spain.
Developing the PC and Psion software

Psion hand held system - leave the wires in the grain store and connect the Psion once a week to download

After messing around looking for agents, I met Gavin Lishman from Martin Lishmans who took it on, and we sold a great many systems, including to @Clive . I developed an insect counting trap which also incorporated temperature measurement

 

[sjt01]

Lishmans then asked me to develop a floor store dryer control

Which then developed into a more general purpose controller for cooling and ambient air drying

 

[sjt01]

In 2003 we moved back into the farmhouse, but as it was started in 1650 and has had additions ever since, it is large and cold and draughty. From my grandparents time there was a small oil boiler and 4 radiators, and a couple of ancient rads on iron pipe. We were determined to be warm, so found a wood chip boiler and had it installed with 24 radiators

This worked well, but in the summer, overheated as there was not enough demand, so we dug a trench and connected up the dairy hot water. Now we are saving money - I got a small Clear Skies grant, but it was before the days of RHI and would have paid well without the grant.

I also looked at the Calor gas bill for grain drying in our floor store, and replaced the Harvest burners with a big radiator and a Dragon straw boiler.

The controls on the Dragon were almost non-existent, and I could not get the promised performance out of it. Upping fan size helped, but with only a thermostat to control it, not the real answer.
So I developed a more sophisticated boiler controller, which we sold to Dragon once it had been proven on the farm. It was available in various configurations - single phase with pulsed fan, single phase with inverter control of 230v three phase fan, and 400v 3 phase.

After Pete retired from Dragon and they were taken over, I fell out with them on another project, and when I got a court order for my bill, they phoenixed. It is too long and contentious a story to go into here, but I continued supplying controllers to Robbie Lindsay, often one offs for special applications.

 

[JP1]

In 2003 we moved back into the farmhouse, but as it was started in 1650 and has had additions ever since, it is large and cold and draughty. From my grandparents time there was a small oil boiler and 4 radiators, and a couple of ancient rads on iron pipe. We were determined to be warm, so found a wood chip boiler and had it installed with 24 radiators
View attachment 846355
This worked well, but in the summer, overheated as there was not enough demand, so we dug a trench and connected up the dairy hot water. Now we are saving money - I got a small Clear Skies grant, but it was before the days of RHI and would have paid well without the grant.

I also looked at the Calor gas bill for grain drying in our floor store, and replaced the Harvest burners with a big radiator and a Dragon straw boiler.View attachment 846356View attachment 846357

The controls on the Dragon were almost non-existent, and I could not get the promised performance out of it. Upping fan size helped, but with only a thermostat to control it, not the real answer.
So I developed a more sophisticated boiler controller, which we sold to Dragon once it had been proven on the farm. It was available in various configurations - single phase with pulsed fan, single phase with inverter control of 230v three phase fan, and 400v 3 phase.
View attachment 846360

After Pete retired from Dragon and they were taken over, I fell out with them on another project, and when I got a court order for my bill, they phoenixed. It is too long and contentious a story to go into here, but I continued supplying controllers to Robbie Lindsay, often one offs for special applications.

View attachment 846361View attachment 846362View attachment 846363

I just have the feeling reading this that if you'd been put in to run British Leyland, we'd still have a truly British car, truck and tractor maker !!

 

[sjt01]

Then I got tired of shovelling woodchip for the house and dairy, and the cheese was running out of the remaining Calor gas for the combi boiler that was providing hot water and heating, so I got a bigger boiler for the house and dairy that could be filled weekly by JCB bucket, and moved the original one into the granary to heat the cheese room.

We then connected them together with another underground pipe, so in summer we could run one while doing maintenance on the other. This meant that when we put in the digester, we already had a hot water ring main to connect into, and we put the initial heat into the digester with woodchip, both boilers running flat out 24 hours a day. Once we started to make gas, we moved over to the biogas boiler and then the CHP, and the woodchip boilers and Dragon are now gone. Unfortunately the advent of RHI meant that they were pretty much worthless as second hand.