Welcome everybody to the expert's guide to vapor degreasing now i'm kevin paulowski marketing manager for ITW Chemtronics i'll be your moderator today okay i'm also an application specialist so i know my way around vapor degreasing but not like our speakers today okay first of all we got pierce pilan he's the senior field engineer for itw and formerly the lab manager so he can definitely add unique insight to the solvent side of this topic pierce has been with the company representing chemtronics and tech spray for about 18 years pierce is very active with snta and ipc and has been on the board helping the draft industry specifications that many of you have to live by every day.
Okay and then also we have patrick oliver who is the sales manager for baron blakeslee a tight a top name and vapor degreasing equipment patrick has been in the precision cleaning industry for almost 30 years and will be taking you through the nuts and bolts side of the topic uh so we're going to go through an overview so pierce is going to take you through an overview of vapor degreasing in a brief history and explain how vapor do greasing work so just a a very overview for those of you who are not familiar with the technology at all then patrick is going to go a deep dive into the equipment itself so the equipment overview the process set up and then pierce is going to circle back into the solvent side of the business because they go hand in hand so he's he's gonna and that's why this is such a nice opportunity here to get experts on both sides of the business and so he's gonna take you through the cleaning solvent challenges and how to select a solvent some of the key things you have to keep in mind for selecting a solvent and then we're going to go through the questions as i mentioned a little history on vapor degreasing it was developed in the late 19th century most of the published accounts list germany so that's what we'll go with the technology migrated over to the u.s uh during the 30s and uh it just revolutionized critical cleaning i mean at that point there really wasn't critical cleaning as we know it today but it was a fairly large step up from what they were doing during world war ii obviously it did flourish during that time with all of the added manufacturing that was going on here in the US.
The first solvents that were predominantly used were perchloroethylene or people known as perg for PCE and also TCE or trichloroethylene other common solvents that have come and gone over the years are the various freons HCFC-141B AK-225 all of those are no longer available so over the years there's been a lot of good ones that have come and fell out of favor with the government vapor decreasing today well continuing pressures from the various regulatory agencies has driven the equipment manufacturers to refine their technologies come up with newer technologies newer ways to capture emissions a lot of different ways to improve the environmental footprint let's say of the equipment and at the same time the chemistries have changed over the years uh again due to a lot of the regulatory requirements and it seems like every time we find a good solvent it goes on for a while and then you know obviously the government finds some way to take it away from our toolbox so it's an ever-changing world uh with both the equipment manufacturers and the chemistry suppliers it's in almost every industry you can think of and i've just listed a few here automotive aviation aerospace electronics medical fine machining uh firearms you name it if it needs to be cleaned you will find vapor degreasing in that industry so let's just go through some some real basic uh operation principles.
What we're going to do is we're just going to use the basic two sump system a boil sump and a rent sump and just one primary set of coils without going too deep into into the weeds and as you can see here this is just kind of a flow of how this works and we'll take you through uh in the next few slides exactly how each section works okay the boil sump the the heat is applied to the to the bottom of the boil sump which uh includes the liquid it starts out everything is virgin in these units the rinse sump solvent the boil sump solvent are all brand new and virgin never been used so the heat is supplied to the boil some and all of the cleaning is done over the boils up so it can contain all of the concentrated waste now as this liquid boils it it vaporizes and it goes up and it covers all that empty space between the boil salt and the coal trap or the cooling coils up on the top so i want to take you through a little bit about how this this part is cleaned this is the main cleaning zone what they call a vapor zone and as this part is lowered either individually or in a basket of parts those parts are cooler than those hot vapors and this is the essence of how it works those vapors come up hit these cool parts and it condenses to a liquid back onto these parts which dissolves the contaminants and then continued liquid condensing on there rinses uh the contaminants off and then they're captured in the boil some now once this part reaches equilibrium and temperature with those vapors the cleaning stops the dripping stops the condensation stops that cleaning cycle is over hopefully your part is cleaned by that point but if it's not that's okay we have a plan b all you have to do is raise that part or basket of parts back up into that cooler area let them cool off and create that that temperature delta again and then lower them back into the saturated vapors and it will will start a new cleaning cycle the coils run a refrigerant through there of some sort some of the very very old models will run water through it most of them are running a refrigerant of some sort now hfc-134a some of the ones with secondary coils are running 404a which is a considered as a sub-zero chiller but what that does is those vapors come up and hit that cold uh those coils up in that cold trap those vapors will condense just like it did on the part it will condense on those coils and then it drips off into a collecting now as it goes into the trough that actually empties out into the rinse sump or the distillate receiver is what it's called in a lot of cases and so that is a recovered solvent it is clean and as that fills it it should be kept liquid full at all times so as it fills it overflows or wears back over into the boil sump to replenish that so it's just a cycle over and over and over okay so you can see there's a lot of different cleaning methods that are available to the operator and a lot of that depends on number one what options your unit has does it have a wand does it have ultrasonics does you know just various different options that are available on the degreaser unit itself but primarily it's dependent on the part geometry the contaminant itself the chemistry you're using and the heat mass of that part and the heat mass of that part is actually very critical you can have a small part or you can have an extremely large part and that's going to determine the time of your cleaning cycle the large parts are going to take longer for that that temperature delta to decrease and so the part equalizes with the vapor so you'll get a longer cleaning cycle at that point smaller part won't take very long it could just be a matter of a minute or so and that parts reach each equilibrium and that cycle is over we'll turn it over to patrick to get into all of the nuts and bolts thank you pierce appreciate it um what you're looking at here is a cutaway of a conventional open top vapor degreaser and you can see all the parts here they're labeled and it is somewhat busy but they're you know there are relatively uh you know few parts it's it's a fairly simple system uh again as was described previously in in the graphic you saw the boiling sump is is uh the tank on the left um where the heat is applied and the phase of the solvent changes from liquid to vapor the vapor is going to float up inside the tank and come in contact with the primary condensing system this is the lowermost set of coils as pierce mentioned these are the evaporator coils from a refrigeration system they're cool again normally run those around 45 degrees fahrenheit so this extracts the energy that's applied by the heaters and then the condensing liquid falls by gravity into a trough below there's a gutter if you will that runs around the perimeter of the internal area of the tank collecting the condensing solvent and then we flow into the water separator and the water separator is an external tank in this case and it fills with the distillate and then the water is less dense than the solvent and it can be separated by gravity it floats on top you open a valve drain the water out from the water separator it flows into a tank we call the distillate receiver this is where distilled solvent that has been dried free of water accumulates and it may be sprayed onto parts surfaces with a manual spray wand this is a common feature in open top vapor degreasers not every machine has it but many units do have a manual spray wand that the operator can use controlling with a foot switch to direct low pressure low flow spray of clean fresh distilled solvent onto part surfaces to enhance the cleaning of areas of geometric complexity or if you need to focus on a certain soil that you see on a surface the wand can help with that again the spraying is done below the vapor line and the vapor line is right at the midpoint of the primary condensing coil set so if there's you know four wraps the vapor will be fixed between say wrap two and three it's held there in tension and then the condensing solvent the fresh clean distilled solvent overflows from the distillate receiver into the immersion sum which is the clean sum so parts may be placed in there uh generally that sump is filtered to remove insoluble particulate and the cleaning in that sump may be enhanced by the use of ultrasonics which can be beneficial in providing a scrubbing action where the ultrasonic cavitation is focused specifically on areas of geometric complexity blind holes capillaries porosity so it can help to sort of scrub soils away from the surface and again the tank you you have it in is fresh clean distilled solvent now one of the merits of this is that the temperature in that immersion sump is slightly colder than the zone of saturated vapor above it so when you elevate parts out of the immersion sump you pause them in that zone of saturated vapor you'll get a final condensing rinse a fresh clean pure solvent and this condensing rinsing action occurs until the part temperature warms to that of the vapor at the time when vapor and part temperature equal condensation stops cleaning stops the parts are dry and then you can elevate them into the freeboard zone which the free board is the uppermost set of coils and again these are typically uh the evaporator side of an r404a refrigeration system they run at about minus 20 degrees fahrenheit so this particular degreaser has two refrigeration systems the purpose of the upper freeboard refrigeration system is to create a very heavy dense blanket of cold air that lays down on top of the solvent vapor to suppress it it helps confine the vapor in the degreaser but it also by virtue the fact that air is very dense can minimize the effects the drafts may have potentially displacing solvent vapor when the cover is open so just to recap what i said one of the the benefits of doing that final condensing vapor rinse post immersion it adds repeatability and consistency to this process the potential for the redeposition of soils in a vapor degreasing process is correctly maintained properly operated is is virtually nil in many other types of cleaning processes take a water cleaning process for instance where say you have like a conveyorized washer a belt washer if you will where you're washing it rinsing and drying parts that move on a conveyor you're constantly being challenged with keeping the detergent out of the rinse water keeping the rinse water out of the drying stage so it's it's difficult to prevent the redeposition of soils but consistency of that process may not be quite as is as high as you like whereas in a vapor degreaser it's very consistent very repeatable because you're always cleaning in fresh clean pure distilled solvent and the final part of that process that the parts see or come in contact with is clean vapor which is essentially pure virgin solvent so basically this is the the layout of a vapor degreaser one thing i will mention on open top degreasers we always use a sliding cover that way when the cover is open you do not create a draft that can pull solvent out or you don't create a draft that can displace solvent when the cover closes in the old days degreasers had a lift off cover or a hinged cover and that's a design we no longer use we use the sliding cover all the typically equipment that we make as well as other manufacturers in this regard generally are compliant to the us epa knee shaft regulations which govern the design of vapor degreasing equipment and you know these are features that impart efficiency now what we're looking at here this is an actual photograph of the interior of a vapor degreaser an open top degreaser and you can see there are two sumps on the left there's the boiling sump again we're looking down into the tank this is like the plan view of the system looking straight down into the tank the boiling sump is on the left again that's where the heaters are located that's where the energy is applied to boil the solvent generate vapor change the phase from liquid to vapor all of the soluble contaminants oils grease anything that will dissolve in the solvent eventually migrate to the boil sump and they are sequestered there again where they cannot redeposit on parts the sump on the right is the clean sump the immersion sump generally filtered to remove insoluble particulate often ultrasonics are installed in there to enhance cleaning and as you're moving up into the plane of the photograph what you can see there is the primary condensing coil that's the lowermost set of coil this again is where the load is applied by the heaters and where that load of energy is extracted uh this is actually what's changing the phase of the solvent from a vapor back to the liquid thus confining it in the degreaser and providing the um the mode of force if you will behind the distillation process which ultimately purifies the solvent then up above those coils is the secondary subzero freeboard refrigeration system again running at -20 if you look closely you can see a little bit of frost forming on that coil because it operates below the freezing point of water again this is creating that heavy dense blanket a cold air that's laying down on top of the vapor suppressing it and because those temperatures of the evaporator are so cold we have to run a defrost cycle once an hour for a few seconds we'll do a hot gas bypass on the refrigeration system melt that frost in other words we want to keep those coils running at minus 20 fahrenheit if you allowed a layer of ice to build up suddenly now the temperature is 32 degrees fahrenheit and the efficiency is dramatically decreased so that's a very important feature for solving conservation in larger degrees sometimes the coils have a thinned uh geometry as opposed to being smooth-walled and in even larger open-top degreasers we actually split the uppermost freeboard refrigeration system into two banks so one defrost while the other continues to cool and then in the foreground you'll see the distillate spray wand where it's accessible by the operator they can pick up that wand spray parts in the vapor and again sort of enhance cleaning this is again an immersion degreaser basically two sumps some variations of this technology do not have liquid immersion it's just true vapor degreaser where parts are processed only in the zone of saturated vapor but this is is i think by far the most common where you have a dual sump unit so again in some cases you can immerse in the boil sump if you want to put the parts right in contact with the solvent which is the hottest however it is the dirtiest sometimes if you're trying to soften things like wax or heavy grease you may want to park the parts in the boil sump initially as pierce mentioned oftentimes parts are initially allowed to dwell in the vapor above the boiling sub for just a vapor degreasing process a pre-clean if you will prior to immersing in the clean sump and you can do that um and then you know that mitigates the contaminant loading into the boiling sub because the contaminants fall by gravity and into the boils up you can transfer to the clean side and that's where you get more of a precision cleaning or again you can use it to remove particulate or enhanced cleaning through the use of ultrasonics so the spray one can be used either before or after immersion depending on where you're trying to pre-clean or just do a final clean again the distillate that is dispensed by the spray wand is colder than the vapor temperature so you can cool the parts down once more and provide an extra long cycle where the parts are exposed to the final vapor rinse for a higher level of purity in the cleaning process so there's a lot of versatility hey patrick a quick question on the spray on this is coming from an attendee it's my understanding from past experience that manual spray wands can disrupt the vapor blanket and create solvent loss what's your views on that option you know spray and sometimes we use like um you know fixed spray manifolds and vapor that are programmable that come on automatically we've even done things like articulating spray wands but the manual spray wand for one thing the pump that powers the spray wand we do not allow that pump to energize until we know that the vapor blanket is fully established and we require that spray happened below the vapor line however it is manual and it is up to the operator completely incumbent upon the operator to use it correctly and properly but to your point you're right spray does potentially increase emissions because you're you're creating turbulence in the vapor you're spraying cold solvent relatively cold solvent compared to the boiling temperature of the solvent and the solvent vapor and the vapor does to some extent condense and coalesce on that those droplets of solvent in the vapor we we try to uh provide spray systems that are very low pressure very low flow with the nozzle selected with the intent not to atomize the solvent but to provide more of a kind of a gentle stream um you know we don't want to create an aerosol we don't want to make the this like like refrigerant go into an expansion valve we don't want that we just want it to kind of spritz and you know it's not like you're at the car wash or you're blasting moss off your deck i mean this is a very very low pressure low flow but i think that manual spray is something that should be used judiciously and maybe uh as a necessary part of a specific cleaning process but you're right you have to balance whatever benefits the spray may provide versus the potential emissions that may be associated with it all right so here we are with a slide of the condenser coils and i kind of touched on this a little bit again over to the right hand side you see a section of the degreaser again the lowermost coils are the primary condensing system which is used to extract the energy supplied to the system by the heaters the purpose there is to essentially confine the solvent in the degreaser older model machines may only have one set of coils only that primary set we make some very small machines like bench top size degrees is where the tank opening is very small and in those we we can get by with a single set of refrigeration coils by virtue of the fact that the tank opening is small when tank openings get larger we have to go to a system where you've got the the dual refrigeration system where you have the uppermost set of the secondary subzero freeboard coils again in most applications these coils are the evaporator side of a refrigeration system again r134a for the primary r44a for the secondary subzero free board when we get into much larger machines oftentimes the primary cooling we use water it's circulated some people use tap water that's very inefficient water from a cooling tower like an evaporative cooling tower but most commonly it's a water that's circulated through a hydronic chiller or maybe a glycol water mixture and just for the sake of efficiency on large degreasers that's normally the way the primary condensing is accomplished with water and again on larger machines we would be using thin coils instead of a smooth wall but one of the things that's a real benefit to that secondary subzero freeboard refrigeration system the second set of coils if you had two degreasers comparably equipped with the only difference being one was equipped with the secondary subzero free board refrigeration system that degrees are so equipped would have solvent emissions approximately half that of the degrees are not so equipped so this is a very important feature for solvent conservation especially in the modern era where solvents that are fluorinated generally have higher vapor pressures lower boiling temperatures are generally more evaporative than the legacy solvents such as trichloroethylene perchlorate so from a perspective of mitigating impact to operator environment reducing process costs the use of secondary sub-zero freeboard refrigeration brings tremendous benefits in that regard and here we have the distillate recovery sump also known as the clean sump or the immersion sump again the solvent that is in this sump has already been through the process of evaporation condensation in other words distillation it's been through a water separator to dry it to remove the moisture and it's constantly spilling into the sump this sump is clean by virtue of the fact that clean fresh distilled solvent is constantly flowing into it there's a mass flow of solvent all around the degreaser from the process of boiling evaporation condensation accumulation in this sump in other words so if you if you're processing parts in here and they've got soluble contaminants oil grease solder flux solder paste it will dissolve in the solvent in this sump and this sump is constantly being over filled with fresh clean distilled solvents so the soluble contaminants cascade across the weir separating this from the boiling sump so there's a constant displacement of soluble contaminants into the boiling sump and through the process of dilution with fresh clean distilled solvent this sump stays clean and when we design vapor degreasers we're sizing them to process a specific mass of a metal of given specific heat steel aluminum whatever per hour okay but we're also taking into account attempting to maintain a specific distillation rate as well as accounting for you know radiational losses of the metal and whatever but for the most part we provide an abundance of energy to process the massive parts you need to process but also keep this sump clean and to have a fresh clean plentiful supply of vapor because you've got to have vapor established to make the whole process work or to clean or to dry so um that's that's one of the things that we think about from a design perspective but again this sump is generally filtered to remove insoluble particulate we'll have a circulation pump that turbulates this this sump it suspends particles in the flow of fluid which is drawn into the pump suction and those entrained particulate may be captured on the filter element and therefore removed from the process again ultrasonics can be used to enhance cleaning in this regard for parts that would benefit from from this type of process so and again here are some additional components of the system um we talked about the uh for example um as i mentioned thermal capacity there is a feature of these systems a technical specification if you will that we assign to the systems they're all rated to process a given number of pounds per hour um in terms of placing baskets into and out of the degreaser we want to control that motion in other words if you put a basket in too fast or pull it out too fast you could create a draft that could potentially displace vapor um when the basket is in the neighborhood of 50 percent of the vapor volume volumetrically speaking dimensionally speaking that speed must not exceed 11 feet per minute there are some cases where we've got systems that the basket may almost approach that of the tank opening in terms of its horizontal area in those cases we actually slow it down to three feet a minute so 11 feet a minute sounds like it's a lot but it's not it's fairly slow but we regulate all of our programmable material handling systems to operate at less than 11 feet per minute um to the next point the freeboard area and this is again the uppermost set of coils um beyond providing additional efficiency in in confining the vapor in the degreaser that super cold air there can be beneficial in recovering minute amounts of solvent or solvent vapor that may be localized around parts surfaces like in the internal diameter of a tube porosity blind holes things like that so oftentimes it's not unusual after the part has allowed to or been allowed to dwell in the vapor until drying occurs and condensation is observed to stop the part may be paused in the free board for final recovery of minute amounts of solvent that might otherwise escape the process so again another efficiency feature of the free board the cover is used to prevent vapor loss when you are not processing you close the cover and oftentimes when we have um a programmable material handling system the cover will open to allow the hoist to approach run the process when the hoist extracts the cover closes we've even got some designs where the cover can close around the mast to the hoist sometimes we have enclosures around machines sometimes we have vacuum degreasers so there's different ways to isolate the solvent from the environment but even the most basic degreasers all have a sliding cover and then of course the water separator um how does water get into the process well the fact that you've got you know two sets of coils running well below the dew point in the room you're going to draw some moisture in the air the uppermost set of coils running at minus 20 fahrenheit naturally they're going to frost so we defrost and that moisture which does not evaporate in the defrost cycle accumulates in the degreaser and it's removed by the water separator if you don't remove water from the process you can create an aerosol of water in the vapor and the vapor will look hazy foggy white like a pond in the morning it looks it looks like fog mist and what can happen is you can remove parts from this hazy. misty watery vapor and the water spots can remain on the parts surfaces after the solvent evaporates it can cause water spotting streaking staining visual defects not to mention there's a significant difference in the specific heat of the water versus the solvent so the water is going to compete thermally for the available energy in that in those regions but for the sake of efficiency consistent processing you definitely want to get water out of out of the process it's very easy to do the water separator you open a valve and even on the largest of degrees is you're collecting a relatively small amount of water this degrees are here that's that's depicted in this cutaway the overall footprint of this thing is about the size of your desk and you might get an ounce of water out of there a day you know if you're operating in an air conditioned environment very little water uh in the summer where dew points are higher you may get a little bit more but generally that amount of water that comes out is minimal uh the water must be disposed of in accordance with local regulations it's essentially pure water but there could potentially be a few parts per million of solvent in it um but in terms of managing water effluent from a vapor degreaser as compared with a an aqueous cleaning process it's negligible i mean you're talking a few drops of water honestly hey patrick you brought up an interesting point which i it was it was new to me so it's great i'm learning things as well um is if you get a hazy appearance in the salt the the vapor zone is that symptomatic is that a general symptom of uh too much water in the system absolutely and and it can happen when the water separator is not emptied in other words what can happen and it's counter-intuitive because again the the the difference in density between water and the solvent these solvents are probably pierce help me out here ten and a half pounds per gallon maybe for some of the fluorinated stuff okay where's water 8.375 the water is going to float on top but if you allow enough water to accumulate and we've seen this a cap of water can form in the separator and eventually force the solvent level down and the water can flow into the into the degreaser it'll get into the immersion sump it'll get into the boiling sump and then you kind of get this aerosol of water going you know it's entering the vapor you know to some extent i guess by partial pressure but it's also that rolling boiling action in the boiling sump creates an aerosol and the water droplets get suspended in the vapor and when you look at it looks just like fog and some of the legacy solvents trichloroethylene perchloroethylene especially n-propyl bromide had the potential to form their corresponding acids hydrochloric hydrobromic acid if the water causes a hydrolysis reaction and this can be devastating you know you can have acidity uh corroding the degrees or you can have corrosion on parts with the modern fluorinated solvents it's really not an issue but again it can be a problem having water in your vapor as i said this can cause streaking staining spotting and it also reduces the overall efficiency of the degreaser in respect to vapor generation distillation rate um but you know if you can devote literally 10 to 30 seconds a day you will not have water in your vapor degrees or it's just that easy to drain okay so we get into auxiliary cleaning options again as i mentioned ultrasonic so ultrasonics which i think a lot of people are familiar with does provide sort of a scrubbing action that enhances the cleaning process ultrasonics are available in a variety of frequencies with the lowest frequencies being the most powerful the highest frequencies being most gentle if you will normally we are sizing to a watt density of 40 watts per gallon so the ultrasonic energy we try to hit that target of 40 watts per gallon in the immersion um and and our standard frequency is 40 kilohertz that's normally what we use although for heavier metal cleaning more difficult cleaning we may go down to 25 kilohertz and then higher frequencies can get up to 132 kilohertz is pretty much where it goes but we've also got some selectable frequency where you could have like 40 80 40 80 120 you know in case you have the need to try different frequencies to see what works the best um the offset boiling sump you can actually have a degreaser with more than two sumps sometimes the boiling sump is offset in other words if you look down into the tank you don't see the boiling sub it's offset and the vapor enters through a slot in the wall there's a couple reasons you may want to do this in other words you may want a precision process where you eliminate the ability for the operator to place baskets in dirty solvent the offset boiling sump accomplishes that objective or you could create a degreaser with multiple immersion sums each successive immersion sump is cleaner than the sump preceding it because it's got more distillate more pure solvent in it lower contamination so you know more sumps can equal more cleaning but again this is certainly the most common uh configuration one boil sump one immersion sump uh manual spray wand as we discussed we offer that on a lot of degrees except the very small units um and as the other attendee asked yes it can increase emissions so you have to kind of be wise how you use it um sometimes people rely very heavily on the manual spray wand and for this reason we provide increased capacity distillate receivers this is the tank that holds the fresh clean solvent that the spray pump is supplying to the wand and you know your spray time is a function of the flow rate of the pump the distillation rate of the degreaser so sometimes you need more spray um heated condensate sump sometimes we do heat the clean sump in in an effort to reduce the cycle time warm the part closer to vapor temperature to minimize the amount of time it must dwell for drying purposes and sometimes we even cool the sumps sometimes we'll have submerged evaporator coils that can chill solvent in downtime modes very interesting uh you'd mention those that rely on the spray the manual spray which is interesting to me because uh if as part of the process if they're relying on it over and over and over again you're moving something that's a very um reliable very um low variability process in in adding variability to it um so it it would behoove you if you do rely on this uh to to reach out to oliver to pat to pierce on the solvent side to an expert to really take a look at your process take a look at your solvent see if there is a better way to do it to strip out that variability in your process and then we go to operational enhancements desiccant is something which is um like typically we use something called molecular sieve it's used to chemically adsorb water sometimes there's cases where degreasers are operated in very humid environments it's difficult to control the humidity or certain formulations of solvent may contain an alcohol for example in the deflexing of circuit boards or printed circuit boards electronic assemblies oftentimes alcohol is added to help dissolve some inorganic components of those soils and the alcohol will actually dissolve in the water which accumulates in the water separator so when you drain the water the alcohol comes out too the desiccant can slow this process down and prevent the extraction of alcohol but desiccant only provides benefit to that extent which it is maintained in other words most people have their desk and split into two parts one half is baking constantly in an oven to dry the other's in the degreaser then you switch but it takes a lot of desiccant to absorb a very small amount of water so but it's very commonly used again in electronics type applications uh filtration especially of the immersion sump again to remove insoluble particulate and we've done filtration that absolutely runs the gamut um even absolute filtration where you get into like 0.22 micron or less for medical or other high precision type applications the secondary subzero freeboard coils definitely used in larger degreasers or you know for enhancement efficiency etc important feature there um programmable material handling there's a lot of ways to automate this process some are very simple some can be quite sophisticated interfacing with accumulation conveyors we've got rotational processing monorail vibratory i mean you name it there's a lot of material handling options which increase efficiency and consistency and redirect labor so just about any degrees or even our small benchtop degreaser we offer a material handling system which is programmable the vacuum degreaser essentially performs the same basic process functions as the open top the main difference is that the entire process occurs in a vacuum chamber in other words in an open top degreaser you're basically bringing the parts to the solvent whereas in a vacuum degreaser we bring the solvent to the parts the solvent is stored in sealed vessels and the product is placed into a chamber think of like an autoclave or you know you may be familiar with vacuum oven vacuum brazing oven essentially we put the parts in a vessel and close the door we pull a vacuum and we pull it down to nearly one torr and essentially when the parts are under vacuum there's no air in between the solvent and the substrate to a certain extent air can be a barrier that may present or prevent a pro the solvent from coming in contact with the parts surface imagine if you had a blind hole in other words if you can't displace the air from the interior of that hole solvent can't come in contact with it but in airless degreaser we pump all the air out so when we introduce the solvent either as liquid or vapor it rushes in to fill all of those spaces it can get into porosity blind holes capillary the internal diameters are very long very narrow tubes um honeycomb that's used in aircraft structures uh it it comes in intimate contact with every space on the part the surface underneath a bga on a circuit board it gets right in there and then in this type of process you can expose the parts to vapor spray immersion ultrasonics and rotation rocking tilting whatever you need to do at the end of the process we drain out the liquid and then we pull another vacuum so under vacuum there is some residual solvent in the chamber on the part but at the vacuum that we're operating the boiling point of the solvent is dramatically decreased the vapor pressure is dramatically increased and essentially the latent heat of the part flashes off the solvent and it dries so you're getting nearly complete total recovery of the solvent these systems also provide continuous distillation and they have a means where you can boil the solvent down and recover just about 100 of the oil in grease with virtually no solvent in the waste stream in fact these systems are so efficient they're generally acceptable for use anywhere in the world regardless of whatever regulations may be in place locally certainly federally and these systems can be used with a variety of different types of solvents halogenated hydrocarbon vapor degreasing solvents as well as aliphatic hydrocarbons petroleum distillate type materials alcohol like isopropyl alcohol acetone as well as some of the modified alcohol chemistries so chamber size on these can be very small up to extremely large some of the largest vapor degreasing equipment in the world is vacuum so there's a lot of a lot of options here and this has by far and away the most minimal impact to operators to environment and in many cases emissions so low they're virtually immeasurable so solving savings running something like this is dramatic these these systems are very very efficient um again the unit location we're talking about here obviously we normally like to have like a 24 inch envelope around the system for ventilation maintenance axis operator access we want the system to be level because we're relying in many cases on gravity for certainly for the open top degreasers so we want everything to be predictable in terms of the level the final point is probably the most important we don't like drafts with open top degreasers you would not want to install these near open bay doors fans hvac ducts areas where there's lots of traffic forklift or whatever passing again if you create a draft over the top of an open top degreaser you could potentially displace the cold air blanket maybe displace vapor so we like to minimize drafts this basically describes how you you power up a degreaser from from start obviously you're making sure all the valves are closed we turn on the main power the refrigeration system comes on and then um essentially what's happening is you're cooling the air above the area where the solvent will be placed to minimize evaporation when you're transferring the solvent initially to fill the degreaser you know grounding connections the system is grounded through its electrical enclosure and then we're adding solvent to the recovery sub it overflows the boiling sump and then once you turn the heaters on and the process begins the interstitial volumes of piping will fill the distillate receiver the water separator and the level in the boil some may drop a little bit and then so you add a little bit more back to the boil sump to bring it up to operating level which is normally maybe two inches below the we're separating the boil and immersion sumps close the cover let the system come up to temperature and when the um we have a control that we call vapor up which indicates ready to process when the vapor up condition is met you can start cleaning parts and essentially this is um basically uh how you begin uh heating the degreaser initially to start up the process um you know we've got temperature we're measuring temperatures all over the machine um we're we're comparing those two set points to make sure all proper conditions are met and the degreaser will create an alarm condition if there's any problem with that just to make sure that everything's operating safely and predictably and again we set temperatures based on the boiling point of the solvent so that's how we establish control uh the boil sump maintenance okay eventually you're going to saturate the solvent in the boiling sump with soluble contaminants normally when the temperature in the boiling sum elevates approximately 5 degrees fahrenheit above the boiling point of the pure solvent it's normally considered to be saturated to about 30 percent by weight with soluble oils it's a lot now when you add uh soluble contamination to any solvent the boiling temperature elevates this is how we know that the soil or the the solvent in the in the boiling sub is saturated with soils so in this regard um you know if you if you create too high