[Stoves] Wood-fired masonry heaters - training

Mon Aug 21 16:21:03 CDT 2017

Dears,

    The Rolls Royes under the vacuum cleaners is DAYSUN with a cyclone and no bag; a HEPA filter of about 8x12 cm/ 3x5 inch .

Cost 400€  Motor 120 €  . To find out its secrets ….;You need hours because the bandit screws are 5 inch deep in ¼ inch wide …So you must construct tools to get inside .   Brushes are low resistance and only sold in China !!! Not in GB .

I used this motors + snail  invers at 15-20 V AC for a chimney JET .

Our TESTAANKOOP  =TEST BUY is not so positive about the absolute filtering !!! 

        For laser scatter on micron particals NEFELOMETRY a small PC uP fan will do …..But for special AIROSOL (NUC ) measurement filter of 1-2 inch you need a 300 watt vacuum pump with exentric rotor with grafit blades  .

Other constructors use 1200 Watt  to do the same job!

       Crispin a hair drayer fan is Not 100 watt with no pressure but flow only . The flow RETURNS on a resistance of a filter .

         Cyclones and elutriation is used to separate powders.    O-2 microns diamond to polish .

COULTER COUNTER for blood cells  

      Andrew congratulations to find cheap particle counters! What more do you need  ?FLUORECEINE powder ?

Canada construct it also for a nice $ price .( Also MIL RANGE FINDERS with Nd laser for 10 Km far particles with a canon ..

Of coarce I have put my nose inside that .peace of toy )

       To reduce the smoke particles danger ,you best inject 7KV negative IONS into the air . Dust is charged and drops down glued together !   Make it from 20 diodes and capacitors to multiply 230V  or use a TV  THT transformer on 2N3055 transistors on 12V

Inverse the diodes to get a negative output  to steel wool ion injector to your breathing air    An sleep better!Like in sea air .

Regards

F.

Van: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] Namens Crispin Pemberton-Pigott
Verzonden: maandag 21 augustus 2017 13:41
Aan: Discussion of biomass cooking stoves
Onderwerp: Re: [Stoves] Wood-fired masonry heaters - training

Dear Frank

The filters are 100mm and the EPA filters are 47mm.  The additional ‘catch’ is largely responsible for the improvement in repeatability.

I think they catch far below 0.3 µm. It depends on how much is loaded and how sticky it is.

The flow is kept constant using a rather clever trick which is that the sample tube has a branch to the side just before the entrance into the large diameter holding mechanism. This branch is a known distance from the body, tapping into a tune with a known size. There is created a low pressure related to the suction pressure. This is monitored and the motor of the fan/pump is electronically or manually to keep the pressure constant as the filter gets loaded. The automatic one is really good at doing this.

There is a second mechanism or approach available which is to have a variable hole on the pump suction which can be opened or closed by hand. This ‘wastes’ the suction pressure and permits the gauge pressure in the sample pipe to be held constant.

It is very simple. They used to use a vacuum cleaner though any air pump will do. I think a vacuum cleaner is overkill. A hairdryer would be enough.

The flow rate measurement is accomplished by the very simple method of measuring the flow of air into the fire. This is surprisingly easy to do when there is a door over the fire itself (to see it) and the air enters through some or other entrance below the fire. They put a board with a round tube through it and measure the velocity of the air passing through the tube. This is far more accurate than measuring exhaust gas velocity and calculating the volume because the input is constant in character. 

Add a bit of math and you get the combusted volume of the fuel. Technically, this method is not as perfect as applying the decombustion theory that I am espousing these days. It is capable of providing ‘a very good guess’ as to the combustion gas volume, much better than either system (Condar or EPA) and also provides the real time HHV and LHV, moisture content of what just burned and its ultimate analysis.

We intend to incorporate that into a Condar system so as to provide a cheap performance and PM determination at an accessible price. 

In addition, the MDA has copied the HTP system of placing an electronic scale under the fire which gives real time mass change. As anyone who has used it knows (Jiddu and all the rest) this is how to develop a stove and tune it in real time. It provides the ‘mass’ of the chemical mass balance method. 

Regards

Crispin

Dear Crispin, Stovers,

The HEPA filters down to 0.3 um. 

When measuring suspended solids in water the filter is 47 mm across and filters out particles > 1.5 um. The filters are pre-washed, dried and placed in a descanter. They weigh about 0.14xx grams each. Using a balance good to 0.1 mg means you need a weight of > 1 mg for an accurate actual reading (I am thinking). 

Problem:

Your filter is 100 mm diameter. Is it pre-washed or pre- air flow treated? I would think the 1 mg would be the low limit to report an accurate reading. Below that you report ‘less than 1.0 mg per air volume’. 

Your thinking of using a pump having a standard pull. Adjusted with the filter getting loaded up with particles(?). That could be tricky. And then you have the location of where the air is being pulled from. Temperature, pressure, air flow, dilution, leaks etc all needing to be factored in. You need to know the total air volume going up the stack. Any small error in one of the measurements and the final reading is blown way out of accuracy. 

Solution:

Helium is bleed in with the primary at a constant and known rate. This should be easy and accurate. 

The volume of the gasses leaving the filter paper is recorded and plotted. It is not adjusted. The gases are also tested for helium concentration and the total helium volume during the ‘run’ is determined. So now we have mg particles per liter helium. Knowing the amount of helium we bleed in with the primary we have a very accurate measure of the total particles released into the room during that time of combustion.   

Helium is easy to get in the U. S. Used for party balloons and sold in many places. Same as in other countries? 

The expense is the equipment to measure it, personal running it and maintenance. Equipping a lab with such a machine is my suggestion of where funding could go. 

Regards

Frank

On Aug 20, 2017, at 11:49 AM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:

Dear Andrew

The Condar uses a 100mm diameter filter. 

The links below are to ambient air machines - 1 mg limit which is pretty low. It would require a significant amount of dilution to bring it under that limit. 

The Condar works using ambient air as a dilutant, so the ambient level has to be really low. Really good stoves are so clean the diluting air has to be either very good or filtered. As LBNL found out in Ulaanbaatar, even a HEPA filter is not as good as a top line stove at removing PM. 

I am discussing a new approach using the Condar that will remove the need for dilution. It samples with a small tube maintaining a standard 'pull' from a pump. The automated ones have an electronic pressure sensor/compensator on the pump to keep it very constant. There are a couple of ways it can be done. The Dusttrak uses such a system, diluting (sheathing, actually) using the incoming gases which it first filters. 

Regards
Crispin

Would one of you care to expand on this Condar with a few pointers?

I've been considering inexpensive sensors for background levels and their variation as well as direct testing

http://tinyurl.com/y8cmwmxv

http://tinyurl.com/y8zfhzjw

This is from Aliexpress which seems to be the retail arm of alibaba.

Andrew

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Thanks

Frank

Frank Shields

Gabilan Laboratory

Keith Day Company, Inc.

1091 Madison Lane

Salinas, CA  93907

(831) 246-0417 cell

(831) 771-0126 office

fShields at keithdaycompany.com

franke at cruzio.com

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