bs 2 lift presentation 2
TRANSCRIPT
BUILDING SERVICES TWO (BLD60503)
VERTICAL TRANSPORTATION
SYSTEM
BUILDING | SERVICES | TWO (BLD60503)
Vertical Transportation System
Hydraulic lifts
Hydraulic Elevators - How Elevators Work _ HowStuffWorks.html
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts
Hydraulic systems has 3 partsA tank (fluid reservoir)A pump, powered by an electric motorA valve between the cylinder and reservoir
BUILDING | SERVICES | TWO (BLD60503)Hydraulic liftsHow it worksLift car by hydraulic ram, a fluid driven piston mounted inside a cylinderCylinder connected to a fluid pumping system (Oil)Pump forces fluid from the tank into the cylinder through pipeWhen valve is opened, pressurized fluid return to the reservoir
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts
When valve is closed, fluid flow into the cylinderAs the fluid collects in the cylinder, it pushes the piston up, lifting the elevator car.When the car approaches the designated floor, the control system sends a signal to the electric motor to gradually shut off the pump
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts
The fluid remain in the cylinderPiston stays on the fluid and the car remain still.To lower the car, the elevator control system sends a signal to the valve The valve is operated electrically by a solenoid switch
BUILDING | SERVICES | TWO (BLD60503)Hydraulic lifts – usage
Most suitable for slower speed operation (0.2 to 1 m/s)Shorter travel distance (20 to 24m)Suitable for hospitals and retirement homes – motion is smooth and almost jerk free.Popular for shopping centres and for refurbishment schemes – where headroom is limited
BUILDING | SERVICES | TWO (BLD60503)Hydraulic Lift System – Direct acting hydraulics
BUILDING | SERVICES | TWO (BLD60503)Hydraulic Lift System – Side acting hydraulics
BUILDING | SERVICES | TWO (BLD60503)Hydraulic Lift System -
BUILDING | SERVICES | TWO (BLD60503)Hydraulic Lift System -
BUILDING | SERVICES | TWO (BLD60503)Hydraulic Lift System -
BUILDING | SERVICES | TWO (BLD60503)Hydraulic Lift System -
BUILDING | SERVICES | TWO (BLD60503)Hydraulic Lift System -
BUILDING | SERVICES | TWO (BLD60503)Principal advantages of hydraulic lifts:
Lift loads directly transmitted to the ground. Motor room can be anywhere nearby. Save on structural costs if building height kept
minimum.Simplicity of operation reduces maintenance costsNo brakes or windings are necessaryCables or pulleys are not always required.
BUILDING | SERVICES | TWO (BLD60503)Principal advantages of hydraulic lifts:
Motor room is relatively small or not needed.No counterweight; larger lift carAccurate floor levelling is possible (important in hospitals & old people’s home)
BUILDING | SERVICES | TWO (BLD60503)
Safety requirements For Electric Lifts:
BUILDING | SERVICES | TWO (BLD60503)Safety requirements
For electric lifts:Substantial enclosure for the carGates and locks that remain locked until the car is stationery.Automatic devices to prevent over-runningBuffers in the pit for car and counterweightCar suspended by at least separate cablesEmergency brakes operating on guides capable of supporting the car in the event of total cable breakage.
BUILDING | SERVICES | TWO (BLD60503)Safety requirements
For electric lifts:Alarm or telephone for emergency with a separate power supplyAdequate ventilation and lightingSafety exit should have an interlock to prevent lift moving if the safety exit is open.Over-speed governors are used and their operation causes the motor, brake and emergency guide brakes to operate simultaneously.Upper and lower terminal switches to stop over running also cause emergency brake operation
BUILDING | SERVICES | TWO (BLD60503)
Lift Car Construction
BUILDING | SERVICES | TWO (BLD60503)
Lift cars designed to serve one storey at a time Internal finishes
wide range of finishes to match interior design Strong and durable lasting for many years of wear and tear
Cars made of steel frame with mild steel panels having cellulose paint finish.
Alternative – demountable and replaceable panels can be fitted.
Floor finishes: passengers lift – easily cleanable
goods lift – steel plate for strength and impact resistance
BUILDING | SERVICES | TWO (BLD60503)
No open panels permitted in enclosure (except ventilation panels) within .8m of car floor.
Openings in ventilation panel should not exceed 13mm
Fan ventilation is also used. Minimum height for car is 2m
BUILDING | SERVICES | TWO (BLD60503)
Lift doorsTwo sets of lift doors are required for each lift entrance/exit:
Car doors fitted to the car; Landing doors fitted to the lift shaft enclosure
Landing doors form part of fire compartment and have appropriate fire resistance rating to BS 476. Qualified maintenance personnel have special keys to release the landing doors for access to shaft.On locking the doors, electricity supply is cut off and disables lift.
BUILDING | SERVICES | TWO (BLD60503)
Doors may be:Single side openingTwo speed side openingSingle speed centre openingTriple speed side openingTwo speed, centre opening
BUILDING | SERVICES | TWO (BLD60503)
BUILDING | SERVICES | TWO (BLD60503)Lift Doors
https://youtu.be/Bux6mzJovbw
BUILDING | SERVICES | TWO (BLD60503)Lift Door
BUILDING | SERVICES | TWO (BLD60503)Door control:Vertical infra red beamsUltra sonic sensors or electro static passenger detection
BUILDING | SERVICES | TWO (BLD60503)Guides
Shoes or Roller assemblies
BUILDING | SERVICES | TWO (BLD60503)
Car and Counterweight buffersOil loaded buffers – for lifts having speeds of 1.5m/s or overSpring buffers – for speeds of between 0 and 1m/sTimber or cellular polyurethane buffers for slow speed lifts – between 0 and 0.25 m/s
BUILDING | SERVICES | TWO (BLD60503)Car and Counterweight buffers
Buffer design to stop a descending car or counterweight beyond its normal limit andTo soften the force with which the elevator runs into the pit during emergency
BUILDING | SERVICES | TWO (BLD60503)
Door drive systems
BUILDING | SERVICES | TWO (BLD60503)
Door drive systems
Fixed speed systems – driven by ac motors - used mainly on low to medium
speed small capacity lifts with a less intensive duty demand.
High speed, fully adjustable systems • Use controllable dc motors – permit optimum tuning to
applications• Energy efficient • Consistent door cycle times
BUILDING | SERVICES | TWO (BLD60503)
Door drive systems
Door closing• Safety requirements – car drive system may not start
while doors are open• Limit kinetic energy of closing doors of two panels,
centre opening door 1100mm wide take 2.5 seconds to close
• Same size single panel side opening door take about 4 seconds
BUILDING | SERVICES | TWO (BLD60503)
Door drive systems
Door opening• Permitted to begin door opening when car
approaching 0.25m of final stop to reduce transfer time.
• Higher performance installations – permit to open doors at much high speed than for closing
• Single panel, centre opening door 1100mm wide to open in 1.5 seconds
BUILDING | SERVICES | TWO (BLD60503)
Tutorial
1.Compare the internal finishes of the lift car by 3 elevator companies. 2.Compare the door drive systems of lift car by 3 elevator companies.
BUILDING | SERVICES | TWO (BLD60503/QSB2714)Vertical Transportation System
The End