Category: Construction

Gearing up for growth – Mega Chicks invests in a New Mobile racked Freezer Store

Barpro Storage conducted an interview with Mega Chicks after the completion of their new Mobile Racked Cold Store Facility in Johannesburg.

Background of Mega Chicks

Mega Chicks is a Family run business that started from humble beginnings in the early-80’s out of Lenasia in Southern Johannesburg. Now, in its 2nd generation, Mega Chicks has their own retail outlets which supplies high-quality Halaal Chicken & Frozen Foods to Wholesalers, Retailers & Informal Restaurants across South Africa.

Interview

Q1: Tell us about your new facility? What was the reason for making this fairly large investment in a Mobile Racked Freezer Holding Store?

Due to our focus on efficiency, we have seen growth in the past 5 years in our business We identified the need to increase our stockholding & create a buffer to serve our customers better during peak times.

Q2: What made you chose mobile racking as opposed to any other racking system?

Space is at a premium in our facility, so after careful assessment of all options, we decided on a high density ‘Mobile racked’ Cold Store facility. We wanted to maximise the amount of pallets we could store in the limited space available. It allowed access to every pallet. Accessibility was critical as we have a wide range of ever-changing products.

We also considered the potential saving on power that mobiles offer due to more product & less open space in the freezer cube & when calculating the payback period this solution offered potentially quick paybacks on our investment.

Q3: Was the installation of the Mobile racking satisfactory?

We had the right professionals around us who knew what they were doing. Step by step we managed the complete project in stages. Everything went according to plan & when we deviated good communication & teamwork got us on track.

Q4: Were you happy with the service you received from Barpro?

We were very happy with Barpro as everything was attended to. I must commend Corne Stapelberg the Barpro Joburg GM & Project Manager for going the extra mile. He offered advice & support over & above the mobile racking. Projects like this can be stressful & having the right people advising you & helping make decisions is key. Thank you, Corne.

Q5: How will the mobile racking & cold store facility help you to service your customers moving forward?

The additional stock on hand & buffer storage will definitely help us to avoid missing opportunities top supply our customers & improve our service.

Barpro Storage wish to thank Mega Chicks for the feedback & information. We look forward to working with you to maintain & keep the mobiles & racking in good working condition & on track.

What’s so different about cold store floors?

What’s so different about cold store floors?

Normal warehouse floors are designed to carry the loads that will be imposed on them, including forklifts, pallet racking systems or bulk product. These concrete floors are reinforced both to carry load and to stop unwanted cracking both during the curing process and thereafter for the life of the store. Storing new products should be done with care. I once visited a good friend whose office was on the third floor of an old CMT (cut, make and trim) building. All of a sudden his office door wouldn’t close. It didn’t take much investigation to reveal the cause. 12 pallets of sugar weighed rather more than fabric and were forcing the concrete floor downwards.

All concrete floors will crack. However this process can be managed by way of fibre, reinforcing, anti-crack mesh, expansion/contraction joints and saw cut joints. If rails are installed in the concrete floor either for cranes or mobile racking, then increased reinforcing is likely both to assist in carrying and spreading the increased rail point loads and to prevent the concrete floor from cracking around the rails. This can happen as embedded rails are crack inducers.

What’s so different about cold store floors?
Don’t under do the reinforcing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The actual design of normal concrete warehouse floors depends on the supporting ground beneath. If it is of a variable nature or not weight supporting, and the imposed loads will be relatively large, then piling may be needed.

 

Freezer store concrete floors or wearing slabs must incorporate all the requirements of normal warehouse floors with a few extras for freezing. If the temperature of the subfloor approaches freezing, usually plus 4 degrees C is taken as the danger point, then any water moisture in the subfloor will freeze. When water becomes ice, it expands in volume and has to be accommodated. This normally leads to the concrete floor rising and cracking as the rise is variable over the floor area. Ice will lift just about any weight which is particularly important when pallet racking is present.

 

What’s so different about cold store floors?
Section through a typical freezer floor with rails for Storax mobile bases.

 

What’s so different about cold store floors?
Heater mat control box – Shows current being used by each circuit

As well as underfloor insulation, all freezer floors should have added protection from frost heave. In South Africa the current standard is the electric heater mat which is normally laid in three circuits in case there is a circuit malfunction. The mat only uses energy if the subfloor temperatures reaches 4 degrees or less. Some larger freezer stores are now using a warm piped glycol/water mixture which absorbs the waste heat given off by the condensers. These run continuously. The Australians favor underfloor 200mm diameter pipes through which warm air should be blown via a fan system. The pipes are laid at a slight angle to prevent moisture from lying in them as this might freeze, gradually closing the pipe.

 

 

I was in one freezer where frost heave had raised portions of the floor by over 800mms. The store had a good underfloor air ventilation system but the openings had been blocked with checker plate to stop rats from entering.

Mobile racking is especially affected by “frost heave” as the drive systems are designed to only operate on reasonably level floors. Freezer floors also experience a secondary contraction when cooled to below zero temperatures and it’s not unusual to see a 10 to 15mm gap between the concrete floor and the insulated wall panels. It is not a good idea to ‘cool’ a new freezer store quickly as it’s more likely to crack – especially around the door, a high traffic area.

 

What’s so different about cold store floors?
Rails in a recently cured floor before the Storax mobile bases are installed

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In freezer stores there can be either contraction or construction joints. I have seen freezer stores up to 1600m2 without contraction joints where the reinforcing is designed to make the floor shrink inwards. In this situation one would expect to have about 120 to 130 kgs of reinforcing per m3 of poured concrete. Contraction joints should be designed so that both sides of the joint can move, but that the same level is maintained. These should be armored when in high use areas like gangways. We try and design mobile layouts s that any contraction joints are under fixed racks. In such instances where a double fixed rack spans a joint, the one side should only be bolted down once the floor has stabilized at its sub- zero temperature. Although tempting in a mobile store, construction joints should not be placed at rails as this encourages cracking and voids.

Cold store floors are the most important part of a freezer store and should be seen not just as a wearing surface but also as a foundation for the racking system. It is therefore worth taking time to get the floor right as subsequent repairs on a large scale at subzero temperatures are extremely difficult. For those who do have the occasional floor problem, Barpro stocks Spalpro 2000 and Febset 45.

 

Complete this form to enquire about Febset and Spalpro

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Read more: Issues to consider when building a new cold or freezer store

Read more: New innovations at Novo Fruit Packers

Read more: Would you like to reduce energy usage in your freezer store?

Preventing fire in freezer stores

FX PREVENT – An alternative to sprinklers in colds stores and warehouses?

Sprinklers in cold and freezer rooms, whether they be ceiling mounted ESFR (Early suppression fast response) or in rack, are, as everyone knows, problematic. First there is the cost. If fire main pressures are considered too low, storage tanks, pumps and generators are required, which add significantly to project costs and not infrequently put projects on “hold”. ESFR sprinklers are of the dry pressurized variety, but each sprinkler head must penetrate the insulated ceiling. Improper sealing, especially with EPS panels, will cause water/ice saturation problems in the medium term.

Sprinkler activations are far more likely to occur from accidental impacts than from fire.

In a freezer store this turns the floor into a skating rink, stops the mobiles from moving and writes off stock. It can take days to remove the ice and get the store back into operation. In the unlikely event of a fire, even if the sprinklers control the blaze until the fire brigade arrives, the stock will still be written off either through temperature gain or smoke and water damage.

 

Precisely because sprinklers are so problematic in freezer stores, not to mention archives and museums, there has been a concerted European initiative to find better alternatives. One solution has been to pump gas into a freezer chamber as soon as smoke or heat is detected. One of these systems has been installed in Gauteng but the gas must be held on site in bottles which take up space. If there is a fire after several years system performance will depend on how well routine maintenance has been carried out.  Another option is to lower the oxygen content of the air inside the freezer chamber so that fires cannot start.

 

FX Prevent sprinkler alternative

 

FX Prevent of Honselersdijkin in the Netherlands has been making LOX, or low oxygen systems for over 10 years. FX Prevent partners with Presscon which has been supplying nitrogen expansion systems for green house heating for over 20 years.  FX Prevent manufactures HP pressure swing absorption systems, which produce nitrogen efficiently for various sizes of building.

 

FX Prevent warehouse sprinkler alternative
Overview LOX room

 

The nitrogen is mixed with the air in the cold chamber to reduce the oxygen content from 21.5% at sea level to approximately 17-16% (depending on the flammability of the goods stored in the room). At this level there is insufficient oxygen to allow a fire to start. The atmosphere in the cold room is similar to that experienced by the human body on a commercial aircraft so personnel can still breath normally. The EU is currently finalizing standards on their use and LOX systems have been successfully installed at many facilities including several owned by Kloosterboer.

 

FX Prevent warehouse sprinkler alternative
Horizontal Nitrogen generator (for saving space on the building)

 

In South Africa, LOX system costs would depend on exchange rates as well as the size of the freezer store. The number of doorways are critical and should be kept to a minimum. This is because the density of the air is slightly reduced through the process of replacing oxygen with nitrogen, and will suck normal air into the store when the door is open. The fitting of high speed doors to cold store entrances makes a significant difference (between 30 to 40%) to the capacity and cost of the LOX system required. For a Joburg freezer store of 15,510 m3 a FX prevent system with one entrance and high speed doors should cost between R3.0M and R3.5M to install.

 

While the type of insulation panel used is not critical, proper sealing of these panels definitely is, as the ingress of air via faulty panel joints will compromise the system design. Running costs must also be considered. On the store mentioned above, electricity costs should average 58,000 kWH per year. Maintenance would require 12 hours per year and could be done by trained local technicians. Replacement parts, mainly gaskets and filters, should not exceed R15 000 to R16 000 per annum.

 

While the running costs are not insignificant, at least the LOX system is in constant use. This is better than having a gas system to where you will only if it works  when you need it in an emergency.

 

Nitrogen generator and filter unit
Nitrogen generator and filter unit

 

There are no known LOX fire suppression systems operating in South Africa. However, they are becoming very popular in the larger European stores and the market is now taking off in China.

 

Agristo FX Prevent Reference
Agristo Nazareth also uses the FX Prevent fire prevention system

If anyone is interested in considering the approach of preventing cold store fires form ever starting in freezer chambers, they can either contact Barpro Storage or Arthur Ammerlaan at FX Prevent directly on arthur.ammerlaan@fx-prevent.com


Read more: Why are these panels going up in flames?!

Read more: Preventing fire in freezer stores

Read more: Death of the sprinkler cartel