Cold Store Racking Design
Hi, am new to the forum and so, this is my first post. I am currently starting construction of a 950m2 cold store and I would appreciate any advice on racking layout standards. the M&E consultant has shown the evaporator units blowing across the top of racking at right angles to it and I was wondering is this the 'only' way to do this.
Looking at an elevation, the storeroom is 8375mm high, however we are loosing a level of pallet storage at the top due to the direction that the air is blowing. Can the fans blow down aisles? rather than across the pallet racking? and how high to the ceiling can you go and still maintain the required temp?
Thanks
Ashley
Re: Cold Store Racking Design
Hello Ashley,
There is no fixed rule for racking inside a Cold Store. The pallets should be so located so as to ensure proper circulation of air through them and round them. Further depending on the product, the heat load, room dimensions and the conditions required, the Evaporator has to be selected. Air throw and the air volume are to be ensured. Less air will harm the product and at same time more air will do the same.
If you want to know more then please send the details of the products to be stored alongwith the dimensions of the rooms.
Re: Cold Store Racking Design
Is it a freezing or a real cold store?
A good rule of thumb is that you don't stack in the zone where the air is blowing, so underneath the evaporators.
Therefore, I should install in the case of fixed racks the evaporators in the corridors and blowing in these corridors.
Blowing downwards is out of the question: cold air is falling down and you will even blow it down. You will see non-uniform temperatures in the cold-room.
Air throw at least the length of the cold store (air speed of the blown cold wind reduced to 0.5 m/s)
You can go as high as you want (we service one of 12 m or 36 ft high), as long as the air distribution is well engineered. Eventually installing additional fans to improve air distribution or install air guidances.
Re: Cold Store Racking Design
It is 2-8 deg C. My idea is that if we blow along the aisles rather than across them, then we could get another row of pallets higher, however these pallets would be at the same level as the evaporators. i.e. the bottom of the evaporator will be approx half way up the top pallet. Do you understand what I mean?
Ashley
Re: Cold Store Racking Design
Ashley.
I am not a design or process Engineer, but I do have rather a lot of years experiance working in Cold stores as a site engineer.
Although the temperature matters ie. the more heat to be extracted the longer the product has to be in the "colder enviroment " to reach temperature. Your main consideration is air flow.
The closer together the product is stacked the harder it is for the cold air to extract heat fom the product.
System designs vary with some stores having what is called a phlenum ceiling.
Basically there is a horizontal shelf across the store ( or blast freezer chamber). This shelf is just below the fan height (air off) of the evaporators, which are at 1 end of the store.( you can have evaps at both side with a plenum vented in the middle also.) And it separates the cold air off from the warm product below. So the cold air is forced to flow across the shelf to the far end of the store. Where the shelf is vented.
As the air on side of the evaporator is ducted from below the evap. There is a air stream /cycle created.
Whereas the cold air off is drawn back through the product absorbing heat as it flows back through the store. Until it is once more cooled prior to being blown across the phlenum and startin the cycle once again.
On other systems the same thing happens but without the phlenum. Where the air flows across the top of the racking mixes with the warm air returning back at the evap. To start the cycle once again.
Some of these stores do have racking in front of the evaps, but the spaces are rarely filled because if you do you short circuit the air flow. Creating the situation where only the product in front of the evaps get the full cooling effect!
As stated I am only an Engineer but my advise is don't give the customer the option of being able to block your evap airflow. And you wont get the problems associated with it , in the future.
Cheers Grizzlyhttp://www.refrigeration-engineer.co...ons/icon14.gif
Re: Cold Store Racking Design
If you can send me the basic details of the cold store / evaprator location, I can do the designing of the racking for you. What is the palet size, wt of the pallet ( euro pallet or USA pallet). We typically keep 500mm gap between the evaporator & the rack top.
But also have put inthe units betwwwen raking members & have worked very well for over 10 years. I shall try & port few photos here
Re: Cold Store Racking Design
2 Attachment(s)
Re: Cold Store Racking Design
I have attached a plan and elevation of the proposal that has been done to date. Hope it explains and helps. Thanks for everyones contribuition so far
Ashley
Re: Cold Store Racking Design
You have 4 corridors and 4 evaporators, I should preferring to install those in the corridors.
Another thin: are those 4 connected to 1 compressor or 1 rack/pack or 2 independent units (redundancy)?
Heat reclaim needed? I ,noticed some sort of shop where heat can perhaps be used.
Re: Cold Store Racking Design
I think this should work without any problems. ofcourse as Peter_1 has pointed out the coolers coming in the aisle space would have been much better option.
Our experience with such design is acess to the evaporators in case of any problems. Then you may have to remove the pallets etc to do the repairing work.
But over 80% of our projects finally land up with such a design & technically it doesn not have any issues whatsoever. All the best & you should get the order. Which racking do you use? we are using esmena - Spain & find it very professional & good.
Re: Cold Store Racking Design
Setup is 4evaps onto 2 units giving 100% redundancy.
We looked into the heat recovery option but were told that the energy calcs didn't add up due to the temps involved.
Thanks for the suggestion of the fact that the evaps could blow down the aisles. To me it looks a better option, however we are concerned that there would be a 'warm' spot at the ceiling height where the product would be above the discharge level of the evaporator. Didn't think about the maintenace thing. Will use that as a help to try and get the design to go look at the whole layout design again.
Re: Cold Store Racking Design
Quote:
Originally Posted by
Ashley
Setup is 4evaps onto 2 units giving 100% redundancy.
We looked into the heat recovery option but were told that the energy calcs didn't add up due to the temps involved.
Thanks for the suggestion of the fact that the evaps could blow down the aisles. To me it looks a better option, however we are concerned that there would be a 'warm' spot at the ceiling height where the product would be above the discharge level of the evaporator. Didn't think about the maintenace thing. Will use that as a help to try and get the design to go look at the whole layout design again.
Hello Ashley:)
better blowing down the isle. If height is an issue you could fit penthouse coolers and ducting with nozzles down into the store, expensive, but it depends on how valuable the space in the store is.
Also anything that restricts the air movement will mean larger fans and more fan and compressor input power.
Kind Regards Andy:)
