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This article is presented by:
Mayank bhardwaj
PG/FT/9218/07

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Cold Store Designing

Historical background
Insulating materials-
-> earliest were wood chippings lined with timber boards/ metal claddings.
-> for land cold storage-
- concrete structures
- concrete structures with cavity walls
- cork slab ( in situ cold storage)
… Early 20th century

Modern developed Insulating Material
* Expanded poly-styrene
-bead form sugar like material, made from crude oil + benzene + ethylene, most rigid.
* Extruded poly-styrene
-manufactured by continuous extruded process, for composite panels.
* Poly urethane & Poly iso-cyanurate
- Highly cross linked polymer, chlorofluromethane gas contained within walls.
e.g. Phenolic foam, Cork board, Glass fiber
Cold storage rooms
1. Bulk storage rooms
Food is frozen unwrapped / non moisture proof material.
To minimize weight loss air movement is kept minimum, uneven.
Horizontal refrigeration coils mounted in free space between racks.
Pseudo ceiling is made for uneven distribution of air.
Cold storage rooms..
2. Jacketed cold store
- refrigerated jacket provided either by embedding pipe coils/ by double skin construction.
- allow storage at near 100% relative humidity at constant, uniform temp.
- reduce weight losses in packaged food and frost formation in packaged food.
- this technique reduce maintenance and increase life of store.
Cold storage room..

1.Storage room,2.jacket system,3.addition fan for air circulation,4.sulphur diox. Tank,5.s.o. dosimeter,7.fan,8.air inlet,9. water flowmeter,10. air washing tower,11. condenser
Designing of cold storage
As per the requirement, three stages in obtaining correct refrigeration system-
1. Determining the process specifications
2. Converting process specifications to engineering specifications.
3. Procurement of plant.
Designing of cold storage
1. Process specifications
there should be clear specifications by user for proper usage.
a) Throughput
- complete specifications for stored material.
( wrapped/ unwrapped, in boxes/ on pallets, number of material to be stored, proper dimensions etc.)
- maximum product load of store be specified.
Designing of cold storageProcess Specifications..
b) Temperature requirements
these be clearly stated
- as per legislative requirement
- as per customer requirement
- as per personal requirement
c) Weight loss
- unwrapped/ permeably wrapped food have tendency to loose weight.
- reason: warmer storage temperature and moving air substantially increase weight loss.
- can be overcome by small increase in operating cost, low temperature maintenance.
Designing of cold storageProcess Specifications..
d) Plant layout
- design must be made flexible to cover conditions of marshalling area.
- products may be loaded into and out of frozen store by continuous batch / semi continuous batch.
- condition within the storage room( of air temperature, velocity, relative humidity) be specified.
- refrigeration load need to be specified( for load profile).
- maintained temperature of sink and defrost regime be specified.

Designing of cold storage
2. Engineering specifications
it represents the process requirements in engineering form based on the basis of process specifications.
a) Environmental conditions
- product stored and storage time determine the internal temperature.
- if store to be used for prefrozen food minimum air velocity maintained.
- if store to be used for warmer food, high air velocity is maintained with variable/ dual speed evaporator fans.( for heat extraction, temp. maintainence)
Designing of cold storageEngineering Specifications..
b) Room construction and size
- size determined on user specifications
- desired racking, stacking and loading system determine internal space required.
- vary from small room with manually loaded racking to automatic loaded system with movable racking.
Designing of cold storageEngineering specifications..