Author Topic: Vacuum Kiln (Read 19061 times)

Den Socling · « **Reply #40 on:** February 20, 2004, 04:20:56 am »

Oakie,

One Torr equals one millimeter of mercury. One Torr equals 1000 microns of mercury.

Den

woodhaven · « **Reply #41 on:** February 20, 2004, 04:37:13 am »

To support Va-Sawyer.
I have been wondering the same thing. Most all these questions can answered by a local heat and air conditioning guy. Most of the parts and controls can aquired the same way.The Kreuter Engineering Co is one of the lower end companys that make digital controls. Like VA-Sawyer I have my place loaded with digital controls the ground is full of 24 volt wiring. In previous post we talked about this. From my perspective it dosen't matter what you want to control or how you want to happen you can take a PLC and start your car, turn on you house lights, turn off your shop heat, start the coffee pot or load logs on the mill all while at your computer.
And do all of these at any variable, sequence, time or condition.
Yea Yea I'm a digital control guy.
In fact on my web site before I took it down that was part of my advertisement To Control Almost Anything, From Almost Anywhere, To Do Almost Anything.

Den Socling · « **Reply #42 on:** February 20, 2004, 07:51:37 am »

This is the control screen for a boiler control at a woodworking plant about 100 miles from. We built the controller and the modules have RS485 interfaces.

The 'analog' meter show the output to a freq drive that controls the speed of an auger that feeds dust, chips and shavings. The image below that represents the Partlow at the plant. It shows the setpoint and steam pressure. The up and down arrows let me change the setpoint from here. Below that is a list of program tune parameters. I periodically check their boiler. When the weather changes or the species in the silo changes, I sometimes need to tweak the parameters. To the left is a historical log. I can look at any period from seconds to weeks. I can look at this year or last year or the year before. The graph shows firebox temperature, stack temperature and steam pressure. I can zero in on any of the three for more detail.

This is what is possible with WonderWare. The free MMI software can do similar stuff.

shopteacher · « **Reply #43 on:** February 20, 2004, 08:05:03 am »

It seems some folk feel that I'm asking a lot of questions that could be answered elsewhere and the information is so common sense anybody should be able to do it. If that's true I'm sorry for taking up valuable server space. The fact that I don't know the answers to the question lead me to ask more questions. Those who are so priviliaged to be familiar and competent in the electronics field, I applaud you. I find it rather difficult to understand the inner working of controllers, plc and PIC's and how to setup and run them.
I had the impression the concept behind this forum was to exchange ideas and knowledge.

Den Socling · « **Reply #44 on:** February 20, 2004, 08:24:11 am »

The discussion is currently trying to determine the best way for the laymen to develop a custom control system. My opinion is that you should use loop controllers that already have the electronic stuff done. You should extend the range of the loop controllers with relay logic. You could add a computer interface. If you want to do the computer interface, look at Future Designs' FDC9300. It comes with free man-machine-interface software.

Buzz-sawyer · « **Reply #45 on:** February 20, 2004, 10:43:27 am »

Teacher..
for my part I enjoy this thread and appreciate the questions and answers...
It is interesting and a multiple view and input is the key to True inovation, variation and implementation of new or existing technology....so let the info flow!!
(all this post is soley the opinion of buzz sawyer...country hick and mad inventor)

Norm · « **Reply #46 on:** February 20, 2004, 11:00:20 am »

This has been a great thread, I sure appreciate Den helping out with his knowledge. Industrial control is one level of electronics I have no experience in. To simplify it for me has been great. This is more along the line of engineering design than fixing my furnace. It is not simple. Keep asking questions Teach, I'm learning too.

oakiemac · « **Reply #47 on:** February 20, 2004, 01:58:12 pm »

Den

You are right. I was thinking of microns.

Oakie

Fla._Deadheader · « **Reply #48 on:** February 20, 2004, 03:55:06 pm »

I can build near anything, but, the electronics part is beyond me.

Let the info flow, and, if someone actually gets one working, I will buy the second one

Might even consider buildingYOUR chamber in exchange

woodhaven · « **Reply #49 on:** February 20, 2004, 04:26:40 pm »

FD
How much money you got?

Den Socling · « **Reply #50 on:** February 20, 2004, 04:30:22 pm »

The control part is the easy part.

shopteacher · « **Reply #51 on:** February 20, 2004, 05:01:31 pm »

sezz you

Den Socling · « **Reply #52 on:** February 20, 2004, 06:33:34 pm »

I wouldn't kid ya

All we have to do is heat wood and watch the temp with an RTD. When the wood is warm, turn off water with a solenoid, turn off a fan with a contacter, close a bleed valve with a solenoid, close a drain valve with a ball valve, start a vac pump with a contacter, start seal water with a solenoid valve.

hmmm, we'll get what I forgot when we smoke test this bugger.

I do it all the time.

Den Socling · « **Reply #53 on:** February 20, 2004, 06:38:23 pm »

Or you could do it all by hand in your spare time and add automation later.

shopteacher · « **Reply #54 on:** February 20, 2004, 06:39:11 pm »

Den,
That part I understand and won't have any problem installing or hardwiring those components. The part that I get lost is connecting that stuff to the controller and setting it to do the things you just mentioned.

Den Socling · « **Reply #55 on:** February 20, 2004, 06:51:50 pm »

A loop controller might have one input and one output. The input might be an RTD. This is an international industry standard measurement of temperature from resistance. You tell the controller that it is going to measure an RTD and the only question it will ask is degrees C or F.

If the controller has one relay output, that relay will close when the temperature drops past the setpoint. The relay is a switch. You put 120 VAC on one side of the relay and, when it switches, 120 goes to all the places you want. If you want something to start one minute after everything else, you put a time delay relay (delay on) in series with that device. If you want some to turn off one minute after everything else, a TDR again. And you can set those TRD's for any time period you want. Easy?

shopteacher · « **Reply #56 on:** February 21, 2004, 05:09:59 am »

Den,
You make it sound easy enough and I think I'm getting a pretty good picture of it in my mind (the picture ain't to big though, fits my brain).
How do you set the controller to react when the RTD signals a drop to a certain temp? Do these controllers come with more than one output? Say a NO and a NC so when say the water stops flowing the vac pump starts? Or could that be done with the time delay relay you mentioned?
Thats something I was thinking about the other day; these hot and cold water systems will needs pumps for circulation, right? I was thinking like B&G circulators from boilers.
Got a price on a 20 cfm sihi liq. ring pump $3600.00 new, kind of pricey.

Den Socling · « **Reply #57 on:** February 21, 2004, 05:54:14 am »

When you order a loop controller, the supplier should ask what you want for inputs and outputs. When you get it, you might be ready to power it up and set some program parameters. If it isn't set up, you might need to enter a model code. Or you may need to set some DIP switches. They are all different but none are too difficult. I may use a couple different brands and models in the same day and I can't always remember what's what. You either pick up the manual or poke, poke and poke the buttons until it does what you want.

These things are very forgiving.

The smallest loop controllers usually have at least two or three outputs. They can be double-throw relays with one N.O and one N.C. contact.

Circulator pumps can be small. I usually use Crane/Deming centrifugal pumps.

Somebody wants to make some money off that SIHI. Was it a LPH 25007? Mine cost $1324 but I had to buy a single phase motor for $261 and coupling for 17. Still a long way from $3600.

From the HVAC industry, I'm using some actuators from Belimo. They are designed to operate dampers but I mounted them to ball valves. They are really cheap compared to the stuff I normally use. I have a couple set for open/close control and one is used to control steam proportionately. That one gets bumped one way or the other to give very good control.

shopteacher · « **Reply #58 on:** February 22, 2004, 07:16:43 am »

Well, I think I've run out of questions for the time being. My search is now on for a suitable chamber. I'm thinking in the area of 5' to 6' dia. X 12' or better long. Would prefer stainless steel, but will make due with carbon steel or Aluminum if necessary. Any body know of anything that might fit the bill. I've been looking on ebay and doing some searches on the net, but find the prices a little high. Any and all help appreciated.

Den Socling · « **Reply #59 on:** February 22, 2004, 08:15:11 am »

I think that we need to take a close look at that heating cycle. The wood must be heated evenly and yet, quickly. If you are planning to dry lumber, air flow has to go in and out the sides. Last summer, when I was considering end to end (of the chamber), we were looking at drying round billets for baseball bats. If you are planning a small chamber for carving blocks, furniture parts or anything else small, you might want to consider end to end. What you need to avoid is small areas of high velocity surrounded by areas that aren't getting heated. Baffles will help but the job might be easier if the fan(s) isn't too close to the wood.

News:

Author Topic: Vacuum Kiln (Read 19061 times)