Storage Equipment

Storage Equipment

Storage equipment used for holding or buffering materials over a period of time.

The most common reason for storing a product allows the other elements of production to operate more efficiently on a per-unit basis because the fixed costs associated with utilizing the element can be spread over more products; e.g., storing up to a truckload of product in a facility reduces the per-unit costs of shipping; and buffering or storage of WIP enables batch production which reduces the per-unit setup costs.


Other potential reasons for storage include: time bridging—allows product to be available when it is needed (e.g., storing spare machine parts at the facility); processing—for some products (e.g., wine), storage can be considered as a processing operation because the product undergoes a required change during storage; and securing—e.g., nuclear waste storage.

Below is the various types of storage equipments used in various warehouse.


1. Selective Pallet Rack



Information:

• Most popular type of storage rack.
• Pallets are supported between load-supporting beams
• Special attachments and decking can be used to make the racks capable of supporting other types of unit loads besides pallets (e.g., coils, drums, skids).
• Selective racks can be used for the following types of storage:

• Standard—single-deep storage using a counterbalanced lift truck.
• Narrow-Aisle—storage using a narrow-aisle lift truck.
• Deep-Reach—greater than single-deep storage (typically double-deep storage).

2. Drive Through Rack



Information:

• Allow a lift truck to enter the rack from either side to pick up or pull out pallets.
• Loads are supported by rails attached to upright frames.
• Lift trucks are driven between uprights to reach pallets.
• This is done because pallets can slide backwards on a continuous rail.
• It's open at both ends, allowing first-in, first-out storage (FIFO).

Drive Through FIFO

• Free access from both sides allows materials to be stored from one end and retrieved from the other.
• Used where there is expiration dated material or wherever shelf life is of major concern.

3. Drive-In Rack

Information:

• Ultimate in high-density storage.
• No other form provides more storage capacity per square foot of room than drive-in.
• A viable alternative to expanding one’s facility.Provides a very low cost yet efficient means of high volume storage.

4. Push Back Rack



Information:

• Offer the same storage density as drive-in & drive-through racks but greater selectivity.
• All loads are stored and retrieved from the aisle.
• Loads in each lane rest on a cart on a rail that slopes gently toward the front.
• When a new load is deposited into a lane, it ‘pushes back’ the one already at the face and all those behind.
• Then, when that load is picked, the contents of the lane all move gently forward again, hence the term "push back rack".

The objective of push back rack is to eliminate honeycombing or empty pick faces. Obviously, the ideal application for Push back Racks will be where all loads in a lane are identical and first-in/first-out stock rotation is not crucial.

5. Cantilever Rack



Information:

• Loads are supported by cantilever "arms".
• Used to store long loads (e.g., bar stock, pipes, lumber).
• Similar to pallet racks, except the front upright beams and the front supporting beams are eliminated.

6. Automatic Storage/Retrieval Systems (AS/RS)

Information:

Consists of an integrated computer-controlled system that combines the storage medium, transport mechanism, and controls with various levels of automation for fast and accurate random storage of products and materials.
Storage/retrieval (S/R) machine in an AS/RS operates in narrow aisle, serving rack slots on both sides of aisle; can travel in horizontal (along the aisle) and vertical (up and down a rack) directions at same time

Advantages:

• Fewer material handlers,
• Better material control (including security)
• Efficient use of storage space.

Disadvantages:

• High capital and maintenance costs
• Difficult to modify.

Unit Load AS/RS

• Used to store/retrieve loads that are palletized or unitized and weigh over 500 lbs.
• Stacking heights up to 130 ft. high,
• Most ranging from 60 to 85 ft. high; 5 to 6 ft. wide aisles
• Single- or double-deep storage racks

Miniload AS/RS

• Used to store/retrieve small parts and tools that can be stored in a storage bin or drawer.
• End-of-aisle order picking and replenishment.
• Stacking heights range from 12 to 20 ft.
• Bin capacities range from 200 to 750 lbs.

Man-On-Board AS/RS

• Used for in-aisle picking.
• Operator picks from shelves, bins, or drawers within the storage structure.
• Manual or automatic control

7. Mezzanine

Information:

• Inexpensive means of providing additional storage or office space.
• Makes use of clear space over activities not requiring much headroom (e.g., restrooms, block storage, etc.).
• At least 14 ft. of clear space is needed for a mezzanine.

8. Flow-Through Rack

Information:

• Loads are supported on an incline to enable gravity-based movement of the loads within the rack (via, e.g., a gravity roller conveyor)
• Loaded at the higher end.
• Unloaded at the lower end (FIFO)

Sources:
http://www.ise.ncsu.edu/kay/mhetax/StorEq/index.htm
http://estore.sjf.com/sjf.nsf/vwHelp/Drive-In+&+Drive-Thru+Rack?OpenDocument
http://conceptstorage.com/push_back_racking.html
http://www.mezzanine.co.uk/