Calen Beaune

I'm trying to estimate stench (Ethyl Mercaptan) clearing times at a mine high recirculation. I've modelled stench by introducing a contaminant with a logarithmic decay over 30 seconds, introduced at a concentration of 100 units to represent 100% gas exiting the bottle. Using the dynamic simulation, I tracked the gas propagation and dilution but cannot record a long enough window to estimate levels returning to below the odor threshold of 0.6 ppb. First, is this the appropriate setup for modelling a stench test and estimating clearance times? Second, a few questions that arose: i) Is it possible to add ethyl mercaptan as a gas instead of a contaminant? ii) Is gas dispersion modelled in a way that I could add in Stench Bottle 1 through 10? There are multiple release points for stench in this mine and I wanted the option to view when each airway was effected by stench from which source, ideally in a stacked area view on the graph. I considered cheating by assigning CO to Stench 1, CO2 to Stench 2, NOx to Stench 3, etc. but that loops back to question 'i' iii) I tried to increase dynamic data logging beyond 50,000 but could not copy those values to excel. On a similar note, if I decreased the frequency of logging, I 'missed' the event and the data logger remained blank. My third attempt to circumvent these limitations was to drop my contaminant from 100 to 0.001 but only use integers. iv) Are there any recommendations on the use of anti stench or wintergreen and their estimated effective time? Similarly, are there any high level estimates on the decay or breakdown of ethyl mercaptan under standard mining conditions- all sources I found were solely related to ehtyl mercaptan's molecular properties.

An admittedly very minor problem. When I digitize numerous fan curves for the same fan, they occasionally refuse to go in sequential order. I'll drag and drop but the changes don't save, so I'll have 20 deg, 30 deg, 40 deg, 10 deg, for example.

Using the "Search Internet for Fans" tool is very convenient and a great addition. However, I've realized that it doesn't update the Fan Tool page with the corresponding engine hp, creating the potential for an unlimited motor. I've taken to adding it in after the fact but it would be easier if it automatically updated.

Just curious how appropriate it is to reduce fan power to control airflow quantity? For example, if I have a fan that produces 100 m3/s in an airway but I only require 90 m3/s, can I reduce fan power to ~90% or is this cheating reality?

I've noticed a bug in the past few versions (currently using 5.4.3.5) with the 'fan motor capacity exceeded' warning. Specifically, I need to simulate air twice to remove the warning after changing the fan curve. For example- if I insert a fan to an airway and the pressure exceeds the motor capacity, an appropriate warning pops up; however, when I then reduce the fan curve to a possible duty point, the warning pops up the first time I simulate airflow, requiring me to simulate the flow again. This isn't a terrible issue but I wanted to flag it nevertheless.

Jumping onto this thread to also ask for an option to make a detached copy of airways between stages and assign airways to other stages.

I searched the existing topics and found the following question/answer dealing with evaporative cooling. http://ventsim.invisionzone.com/topic/465-setting-up-a-heat-simulation/?tab=comments#comment-877 Are there any other ways to simulate evaporative cooling (swamp coolers/ atomizers), than by changing the airway wetness fraction? And is there any way to simulate an indirect evaporative cooling system? I saw the update on the new New Ventsim Cooling Feature (5.4.3.0) but couldn't find a reference on how to access it.

I exported a set of centerlines from Deswik 2018.2 as an imperial Ventsim file. However, when I opened the file in Ventsim, the program assumed I was working in metric. So my 3000 ft shaft is now 3000 m, and if I switch my units in Ventsim, I now have a ~10,000 ft shaft (3.2808 m : 1 ft). I double checked that I had chosen "Imperial Project" on the Deswik export and there is too much attribute information that I wanted captured to export my centerlines as a DXF file/ a series of DXF files. I'm not sure if this is a glitch on the Deswik side or Ventsim side. The Deswik file default is metric but project is imperial, for the record. My work-around: I wrote down all of my presets (airway size, friction factors, etc) in Ventsim. I toggled my ventsim file to metric so my absolute values were correct (3000 m shaft). I modified my Units from 1 ft: 3.2808 m to 1 ft : 1 m. I toggled my units to imperial. So my shaft is 3000 ft but my presets are messed up by a factor of 3.2808 (or more if there is an exponent in the equation) I re-wrote my presets based on the information written down in step 1. However, I have no idea if this is a legitimate work around. My unit conversion is stuck to 1 : 1, and I have to import all files as 'metric' files.