The Laundry Forum

[PI Guy]

It works at much lower PPMs and alkalinity than H2O2 or chlorine in addition to lower temps.Substantially lower water usage can also be achieved.
No other side effects with correct application. However PAA must be handeled very carefully,
the raw material has a strong vinegar like smell and will burn skin on contact. It is also highly reactive
with any other chemical.

[laundryman]

It works at much lower PPMs and alkalinity than H2O2 or chlorine in addition to lower temps.Substantially lower water usage can also be achieved.
No other side effects with correct application. However PAA must be handeled very carefully,
the raw material has a strong vinegar like smell and will burn skin on contact. It is also highly reactive
with any other chemical.

Sorry, just started a new topic in "Chemicals" on Pera acid...

[BobHalpin]

To be open and honest, I am a competitor to Milnor and I'd like to know more about how the pulse flow tunnels are working in the field because I must sell against them. I'm not a believer in very short tunnels and have a concern with 6 and 8 chamber tunnels especially with healthcare. There, my bias is on the table!

Many years ago, the Europeans made shorter chamber tunnels with longer transfer times and used some of the chambers for double duty. They did this by pumping water to tanks built on top of the tunnels and used gravity to quickly fill the chambers with water when it was needed for a second fill after draining. The more they tried to reuse water, the more redeposition became an issue and eventually new water needs to enter the system. The Milnor pulse flow uses higher gpm pumps instead of tanks so I understand the wet down being achieved a little quicker. I then saw the Europeans actually pump water between chambers like the pulse flow but I never knew what results they achieved.

Today, we are seeing well tuned tunnels of virtually all manufacturers operating at .7 gpp and even .6 gpp in some lighter soil cases. I feel we as equipment people are beginning to push the abilities of the chemical companies to reasonably produce good quality linen. In truth, it's the chemical guys that make things tick in the laundry and it seems like by dropping chambers, we are taking tools away from these guys to do their jobs. I don't see pumps doing anything to radically change the wash pie chart we are all familiar with. I've seen all the marketing literature including the manufacturers PowerPoint to distributors but still don't get it. Can somebody explain it to me in simple terms that is getting .3 gpp avg over all products with the system being in longer than 6 mos. and is happy with the quality?

Milnor is hands down the best marketing company in our industry so I'm wondering whether I'm chasing a .3 gpp marketing statement (or lab environment) or whether everyday operators like you are supplying these numbers to them. Thanks in advance for the information!

[BobHalpin]

Thanks very much for the private responses. I look forward to hearing from more operators!

[The Laundry List.com]

Bob, contact Western Linen in Las Vegas.
I expect they can tell you how their pulse flow has worked for them.
They have had it about 1 year.

[Escape]

Thanks very much for the private responses. I look forward to hearing from more operators!

Secrets? I think we all would appreciate on how operators do see the performance of the Milnor pulse flow tunnels.

[LaundryDesignGroup]

I've been reading the discussion related to pulse flow and would now like to add what I can. The original question was posed how does it work? While I will leave it to the operators to indicate how the PulseFlow is operating for them individually under their given circumstances, I can provide a little bit of history and background on how the system operates.
In the short simple assessment of how it works, it comes down to active transfer of water, versus passive transfer of water. Tunnel tech provided a key detail in noting that the main transfer pump was over 300 GPM flow rate. The active transfer of water at a high rate of speed during machine oscillation provides an additional mechanical effect, which allows both rinse water as well as wash water to penetrate loads more effectively.
The modern history of this effect was actually proven first by Jensen with their Senking compact tunnel and later Kannegiesser’s Jet press and Jet spin compact tunnels. The engineering principles for either of these systems were to maximize water recovery during the rinse cycle. By capturing all the rinse water as well as the absorbed water and linen, and then reintroducing it into the wash process to achieve much lower water consumptions.
So on the surface you begin to understand, that this is not magic, but one more step trying to efficiently use all water introduced then reintroduced into the wash process within a tunnel. Including the absorbed water within the linen, along with the other press water, helps to reduce the overall water use.
I'm not certain it Milnor does this, but the Europeans took advantage of the squeezing effect of their standing bath design, allowing for 30 to 45 seconds of open drain drum rotation prior to transfer into the rinse area. This squeezing out of the last little bits of absorbed water at the end of the wash cycle, allows for lower dilution moving into the rinse area. Considering the lower dilution combined with the rapid fill rate results in a faster penetration of the load and quicker more effective rinsing.
The innovation of the Milner pulse flow is that they did not simply stop at the rinse section. They chose to apply active transfer of water throughout the whole machine. Washing faster in an automated system takes into account that water has been preheated, pretreated with chemical (if possible) and therefore what you have is not faster washing, but more effective use of time in process.
The Europeans could not or would not conceive of faster wash times, only lower consumptions and more compact tunnels. The strict rules governing proper disinfection of textiles through washing are very rigid in Europe and therefore any introduction of faster wash times meant a battle the governing authority.
So to wrap up my contribution to this discussion this moment, you begin to see that lower consumptions are entirely dependent upon effective absorption rate of what, in fact, you are washing. Tunnel tech pointed out that sheets for processing at .22 GPM, but the net aggregate average over time was in the .3 to .4 range. I suspect that terry items and color changes play a role in that possibly.

[suds-n-blood]

Thanks for the input. What is your opinion on the possible effect on TDS levels as the overall water consumptions are continually lower and lower?? Where do you reach a point of no return?

[LaundryDesignGroup]

Good question. I think we are at about the limit since this latest process is attempting to utilize the latent absorbed water in the linen. Every innovation in tunnel water management within the past 12-15 years are really improvements in how tunnels use water. Counter flow to standing bath design really just eliminated the waste in the counter flow, by controlling the bath per type of linen and load size, and added color control and bath capture tanks. These innovations added flexibility, added heavy soil capability and for light soil applications (hotel and healthcare), cut water 30-50%.

Every technological reduction in water use has increased the concentrate in the discharge. I worked with a customer a few years ago who used water recycling (which I did not recommend) for the rinse water input. He experienced massive foaming issues which caused transfer faults and system delays. Not to mention quality issues on his ironers. I think we recorded 3000 tds in the press tank (might be mistaken but that sounds right). He would not listen until we ran with fresh water for 1 hour and the entire system balanced. The production interruptions for one month that resulted from these conditions cost considerably more than his water/sewer bill for the same month.

There is a point where water conservation and water concentrate will cost you more than the water itself is worth. Operators and or equipment builders obsessed with water conservation are missing the point, this is a system - find the balance and run with it. But as mentioned several posts ago, I wonder if operator’s assumption on consumptions are based on soil weight and not clean dry. I’m in a lot of plants and this is a common error.

[suds-n-blood]

One other thing. In looking at the traditional washing pie, there are four components that have to make the circle complete; shortening one, increases the others. What is the pulseflow response to that? To operate at the very short formula times, something has to give. quality? redeposition? excess chemistry? linen damage? Gat any thoughts or facts on that?