Plate cooler

[The Agrarian]

Bore hole water in the UK is pretty stable at around 12C. If you can pre-cool to 10C, you are doing rather well! From experience in manufacturing and selling milk cooling tanks with integral data logging, an average would appear to be around 18C after pre-cooling. Of course, the surface area of the heat exchanger and the cooling water flow rate has an influence.

Agreed . Our tank reads just over 15 degrees on milk fed in by the robots after collection, and before the condenser kicks in. That's going through a lely tube cooler, whith 30 seconds of water flow after the pump stops.

 

[Fergieman]

All interesting stuff. Is there an easy way of checking temperature of the water and milk pipes before and after the plate cooler? Is there temperature strips you attach or something like that?

 

[upnortheast]

All interesting stuff. Is there an easy way of checking temperature of the water and milk pipes before and after the plate cooler? Is there temperature strips you attach or something like that?

Our milk pipes have insulation on them ( Its a Lely thing ) so i tucked the thermometer probe inside the insulation & left it for 10 minutes.. Not ideal but gives an idea of temp.
Used have temp strips on the wash line of the old parlour. Not sure how accurate they are

 

[arbel]

All interesting stuff. Is there an easy way of checking temperature of the water and milk pipes before and after the plate cooler? Is there temperature strips you attach or something like that?

Well, obviously I am biased, as my company designed and manufactured the equipment to do this task accurately.
Temperature strips, like those used on aquariums cannot give very accurate results, as they are highly influenced by ambient temperature and are not in any case calibrated or guaranteed to be accurate. Many plate coolers are installed high up and it is not easy to get a reading, without resorting to ladders. But do they work? After a fashion they do of course, in the same way as a mother will check her child's temperature by putting her hand on his/her brow. But the doctor will use an accurate medical thermometer.
At the end of the day, it all comes down to how high a value you place on seriously reducing your milk cooling costs and how much you are prepared to invest in the right equipment to give you the information required.
Quite apart from this aspect, our equipment has already in 2019, identified 27 situations where the dairy operative (farmer or hired hand) has accidentally failed to even switch on the milk cooling or has experienced major equipment failure.
In all cases, the farmer received a timely warning so that no milk was ever lost. In one case, we were able to identify the cause of a complete farm power failure when the main incoming fuse blew, even down to which compressor had burn out. That probably saved not only the milk, but considerable time late on a winters night, in atrocious weather conditions, with the farmer hoping that his torch battery lasted!
It's the same in all aspects of life really - you get what you pay for. Temperature strips just don't cut the mustard when it comes to monitoring pre-cooling equipment.
Every degree that the incoming milk to the vat can be lowered by the pre-cooling equipment, saves the dairy farmer a lot of money. It's a no brainer really.

 

[upnortheast]

Every degree that the incoming milk to the vat can be lowered by the pre-cooling equipment, saves the dairy farmer a lot of money. It's a no brainer really.

But earlier you questioned pre cooling - here

Those of you using a chiller or ice builder are presumably taking into account that the ice is being made during the cheap rate tariff. If not, the only advantages that I can see from using a chiller is that the milk temperature going into the vat is near collection temperature

??????

 

[arbel]

No, I was questioning the use of chilled water, presumably being pumped from an ice builder, rather than water coming from a bore hole. Sorry, I may not have made the point very clearly. Most milk tanks are perfectly capable of doing the complete cooling job of bringing the milk down to collection temperature of 3.5 - 4.0 degrees C. But usually they are running outside the E7 period. Whereas most ice builders are designed to take advantage of the lower rate E7 rates.
Pre-cooling with water from a borehole provides the very cheapest option, but it cannot of course lower the temperature below 12 degrees C. In fact, it's usually no lower than 15C, more often 18 - 23C. The data that we have collected over the last 5 years substantiates this.
Another cost saving factor is heat recovery. When first introduced back in the late '70's, this was hailed as the miracle energy saving technology. Many dairy farms were singing the praises of these systems that appeared to produce vast quantities of 'free' hot water. This was achieved by valves that forced the refrigeration compressors to work much harder, producing high discharge temperatures and pressures. Yes, there were some gains to be made, but equipment wore out more quickly and the electricity bills were higher too! There are energy savings to be made with heat recovery, if fitted correctly.

The same as with pre-cooling equipment.

 

[upnortheast]

Another cost saving factor is heat recovery.

Looked at that in the passed & thought the sums didn`t add up.

However latest leccy contract renewal is up 3p kwh + the climate levy is going up 0.8p kwh
Heat recovery was included in the last small grant scheme.when the standard cost was about £7k New scheme due soon so if it is on the list again intend to do the sums again & see if it is a goer

 

[arbel]

Another consideration.

The borehole water that passes through your plate cooler will be going in at about 12C. After cooling the milk, it will have gained some heat energy from the milk. So, what do you do with this water afterwards? Does it go into holding tanks for washing down and perhaps into drinking troughs?
It might be interesting for you to measure the temperature of the water leaving the plate cooler. Compare this with the temperature of the cold water going into your hot water supply cylinder in the dairy. This may be mains or borehole water fed.
The higher the temperature differential between the two may mean that there is scope for heat recovery in this area too.
I as given to understand some years ago that on some larger German dairy farms, heat recovery from cooling the milk was used to provide partial central heating in the farmhouse and that lower grade heat from pre-cooling water was used to take the chill off the incoming mains cold water supply.
As energy cost can only go up (until we can generate unlimited electricity from fusion reaction ) those of you dairy farmers who have the inclination, the time and are handy with rigging up heat exchange systems, can almost certainly make useful savings. It's a fascinating subject.

Just out of interest, our new Commander milk cooling tank control system has been designed with all the built in data logging necessary to accurately monitor both vat and pre-cooler performance that we previously marketed as the EasiData.

 

[Fergieman]

Whats the sort of instalation and running costs of the easidata?

 

[arbel]

Whats the sort of instalation and running costs of the easidata?

Best that you email me - [email protected]

 

[upnortheast]

Best that you email me - [email protected]

Then make sure you are sitting down when the reply comes

 

[arbel]

That is an interesting remark! I am sure that dairy farmers, like all of us, weigh up the cost of equipment against the advantages. In the same way as they are cautious when it comes to ticking the options list when they buy their new tractors.
As a matter of note, we export about 50% of the product we manufacture to 15 countries worldwide. That includes New Zealand, Australia, Russia and China. With over 8,000 milk cooling tank control systems and data logging units working 24/7 on what is a mission critical industrial application, we rarely ever see product returns and most of those are due to over enthusiastic use of pressure washers.
Milk cooling equipment may not be so sexy as that shiny new green or red tractor, but having just paid out £47 for the PTO lever pawl on my Fendt, a simple piece of steel pressing with a hole in it for the expensive 'special' rivet, I believe that our products offer exceptional value for money. But I would say that, would't I !

 

[upnortheast]

Just me getting old & cynical

 

[arbel]

Just me getting old & cynical

That's perfectly ok. I would not have expected any less. We all need to put bread on the table and I am very proud of our British designed and manufactured products, as I am of our farmers who contribute in no small measure to the very high standard of living that most of us have in the UK.

 

[Devon lad]

Sorry to hijack thread but we have a large ice water and pumped water fabdec floor standing plate cooler that we have had it leak between milk to water plates and a 2nd plate milk to ice water plates. This has cost us a lot of money in poor bacto readings for months. Are some plate coolers better quality than others or dodgy quality of stainless used for the plates. As far as we know it’s all plumbed up fine.TIA

 

[arbel]

Sorry to hijack thread but we have a large ice water and pumped water fabdec floor standing plate cooler that we have had it leak between milk to water plates and a 2nd plate milk to ice water plates. This has cost us a lot of money in poor bacto readings for months. Are some plate coolers better quality than others or dodgy quality of stainless used for the plates. As far as we know it’s all plumbed up fine.TIA

I have seen no evidence that there is much of a difference in quality of the stainless steel used in the manufacture of plate coolers. Manufacturers tend to promote the water flow arrangements. Of course, stainless steel is not totally impervious to corrosion and dairy cleaning chemicals can have an adverse effect. It would be interesting to know what you discovered when you stripped it down.

Like everything else, plate coolers need periodic stripping down, cleaning and inspection to replace defective plates and the separation gaskets. But this is a tedious and time consuming task, which must usually be undertaken between milkings. It would be costly to have a standby plate cooler, ready to swap periodically, so that maintenance could be more leisurely. But you have to weigh this up with the financial hit of having poor bactoscan readings.

I hope that you can overcome your problems in this instance and get those readings back to acceptable levels.

 

[Devon lad]

I have seen no evidence that there is much of a difference in quality of the stainless steel used in the manufacture of plate coolers. Manufacturers tend to promote the water flow arrangements. Of course, stainless steel is not totally impervious to corrosion and dairy cleaning chemicals can have an adverse effect. It would be interesting to know what you discovered when you stripped it down.

Like everything else, plate coolers need periodic stripping down, cleaning and inspection to replace defective plates and the separation gaskets. But this is a tedious and time consuming task, which must usually be undertaken between milkings. It would be costly to have a standby plate cooler, ready to swap periodically, so that maintenance could be more leisurely. But you have to weigh this up with the financial hit of having poor bactoscan readings.

I hope that you can overcome your problems in this instance and get those readings back to acceptable levels.

Thanks for your input. The last time a plate split was a hairline crack, wasn’t easy to find either

 

[arbel]

Thanks for your input. The last time a plate split was a hairline crack, wasn’t easy to find either

The plates are quite thin of course and subject to pressure stress from both the milk and the water side, as pumps stop and start. So this was a stress fracture. These can be aggravated too by chemical attack. Like car engine cylinder heads and their gaskets, maybe pressure testing after maintenance might not be a bad idea. It would not be too difficult to do. I imagine that the pipe type coolers would not be so prone to cracking.