Practical run time calculation
The formula gives the run time's for your Sodium Chlorate cell, based on the number of amps and the total amount of Chloride that you have added to the cell. When this run time is used you will not get all of the Chloride converted into Chlorate. The time is calculated such that there will be about 100g/l of salt left in the electrolyte when the run is complete.
This is what we want because at about 100g/l of NaCl the current efficiency starts to get effected due to low Chloride concentration (pH control or not) and is considered too low to tolerate. Anodes may also get excessively erodes. The total amount of salt
in the cell minus the 100 grams per liter that we are not going to convert is called the
'available Chloride'.
If you are getting higher current efficiency from your set up (say you are controlling pH) then you will have shorter run times.
If you are using salt solution (recommended if you are going to take out a crop of solid chlorate) to top up your electrolyte, it simply means that you will have to recalculate your run time each time you add some solution taking into account the extra salt that you have added to the cell. If the cell has a lid this will
not be realizable as there will not be enough evaporation.
A quick way to calculate run time is to note how many moles (58.5 grams) of 'available Chloride' there is in the cell. It will take 12 moles of electricity (322 Amper Hours) per mole (58.5 grams) of 'available Chloride' to finish the cell. [This is at 50% current efficiency and leaving 100g/l of Chloride
in the cell at the end of the run.]
![[RUN TIME EQUATION. RUN TIME = [TOTAL GRAMS SALT ADDED TO CELL ---(100 * VOLUME OF CELL IN LITERS)] * Figure in table ]](_img/runtime.gif)
| Figure in minutes(decimal) per ('available')gram NaCl for different current efficiency's |
|---|
| Amps | 40% Current efficiency | 54% current efficiency | 60% current efficiency | 80% current efficiency |
| 2 | 206.25 | 152.70 | 137.43 | 103.07 |
| 4 | 103.07 | 76.35 | 68.72 | 51.54 |
| 8 | 51.54 | 38.16 | 34.36 | 25.77 |
| 10 | 41.23 | 30.54 | 27.48 | 20.61 |
| 15 | 27.49 | 20.36 | 18.32 | 13.74 |
| 20 | 20.61 | 15.27 | 13.74 | 10.31 |
| 30 | 13.74 | 10.18 | 9.16 | 6.87 |
| 50 | 8.25 | 6.12 | 5.50 | 4.12 |
| 75 | 5.50 | 4.07 | 3.66 | 2.75 |
| 100 | 4.12 | 3.05 | 2.75 | 2.06 |
| 150 | 2.75 | 2.04 | 1.83 | 1.374 |
| 200 | 2.06 | 1.53 | 1.37 | 1.031 |
![[DIAGRAM OF TABLE CALCULATION]](_img/calcxxx.gif)
It can be illuminating to know how much Chlorate you are getting per minute of operation of your cell. If you are getting 54% current efficiency you will get 1 gram of Sodium Chlorate per amp going into your cell every 167.76 minutes, or if you like, 0.00596 grams Chlorate formed per minute per amp.
So if you are running your cell at 10 amps you will get 10 grams Sodium Chlorate every 167.76 minutes, or 0.0596 grams per minute. At 100 amps you will get 0.596 grams per minute of Chlorate forming, that's 858 grams per day.
The following is a useful little program for calculating run times for cells and also will tell you at the press of a button what amounts of Chlorate to expect from your cell in a given time.
Chlorate cell calculation program (106K).
It is not a good idea to download programs from the INTERNET "willy nilly" and run them, as they may contain viruses
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