lifts final

8/10/2019 Lifts Final

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Elevators

ELECTRIC TRACTION ELEVATORS

HYDRAULIC ELEVATORS


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History of lifts

Since the day of pyramids hand powered lifts and hoists were there

Hand powered winches were used in China to lift water

In colosseum lifts were used to lift gladiators and wild animals.

Otis Elisha Graves was an American who invented first lift with an

automatic safety device in 1854 and demonstrated in Crystal

Palace.

150 years later, the basic components of a typical lift installation

remains the same.

Mechanical parts such as machine, suspension system, guide shoes

and rails, gearing sheave, car and counterweight are the same.

Changes- drive control, signaling, monitoring

In the past lift services were almost an afterthought with Machine

rooms located in out of way places.

Today lifts are regarded as one of the buildings main services


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Lift capacity and performance

A detailed analysis of the morning peak traffic-up peak traffic , down peak traffic and

inter floor traffic is required for taking a decision regarding the system to be

installed.

Three sets of data are required for the calculation of lift performance

1. Building data

No of floors

Distance between floors

2.

Lift system data

No of cars

Rated capacity

Flight times between floors

Door opening times

Door closing times

Traffic control systems

3. Passenger data

No of passengers boarding form specific floors

No of passengers alighting at specific floors

Traffic mode- uni or multi directional

Time required for passengers to leave or enter the cars


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Quantity of service

No of people to use the lift system in the defined

period of time is the handling capacity, and is the

quantity of service

The number of occupants vary according ot the

purpose of the building- residential, commercial,

institutional

The quality of accommodation

more space for

occupant for more prestigious spaces.


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Quantity of service

Estimation of population

Building type Estimated population

Hotel 1.5-1.9 persons/room

Flats 1.5-1.9 persons/room

Hospital 3 persons/room

School 0.8-1.2 persons/room

Office (multiple) regular 10-12 sqm. net area/room

Office (multiple) Prestigious 15-25 sqm. net area/room

Office (single) Prestigious 8-10 sqm. net area/room

Office (single) Prestigious 12-20 sqm. net area/room


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Quality of service

Actual average waiting times i.e., the time period

between the instant of passenger arrival until the instant

of time of the arrival of the lift is the indicator of the

quality of service.

The lesser the average waiting time of a passenger the

better the service.

20 seconds or less excellent system

25 seconds good system

30 seconds satisfactory system

40 seconds poor system

50 seconds unsatisfactory system


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Applications in Building types

Office buildings

Traffic peaks- starting of working hours

The handling capacity requirement is calculated based

on

Unified tenancy 15 to 25 % of the total building population

entering in a five minute period

Diversified tenancy 10 to 15 % of the total building

population entering in five minute period


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Hotels

Peak traffic during mornings and evenings

10 % of the total hotel population using it in 5

minute period

Modern international hotels waiting time 30

seconds

There should be elevators for staff, catering

supplies, linen and other purposes



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Residential

Peak traffic density usually occurs in the early

morning, but peak will vary both in time and span

and in intensity

Peak traffic value-6% of total building population

Should be safe and easy to access

Children and elderly and physically challenged

should be provided with convenient and safe means

of transport



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Specialized buildings

Leisure centres, shopping malls, retail

developments, air terminals, entertainment centres-

specialized buildings.

Vertical transport facilities-Elevators and Escalators.

Panoramic elevators used for aesthetic reasons and

to provide viewing platforms.



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Hospitals

The lifts serve two functions transportation of

patients, staff and public.

The waiting time for bed lifts should be

minimum for emergencies

Should provide for smooth ride, levels of

acceleration and jerks should be kept low.

The lift groups for visitors should perform well

during visiting hours.



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Location of elevators

The efficient method of locating

elevators to serve an individual

building is to group them together.

It is very important to group them

if they are the main means of

vertical transport within a

building.

The position should towards the

centre of the building

Walking distance should not be

more than 45 m from any point of

the building.

If the distance to travel to the

elevator core is large it may be

efficient to install additional lifts

for local are inter floor traffic.


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Grouping of elevators

A group of elevators should be designed to be located

close to each other.

Minimize the walking distance between lifts.

Waiting passengers can react quickly and access cars

swiftly.

Lobby areas the main ones should not be in the path of

the passageways.

There should not be any confusion between waiting

passengers and passers by should be avoided by having

separate lobby areas


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GROUPING OF ELEVATORS


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Elevators- operation mode

Down collective operation one car

Down collective operation Two cars

Full collective operation one car

Full collective operation Two cars


16/43Down collective operation one car

The car normally rests at the main floor

Main floor has

UP call button

Floors above have- Down call button

When more than one landing call received the car will

travel to the highest call and comes down

This system is suitable only for light traffic

Interfloor traffic is poorly served by this system.

Eg. Residential buildings

Elevators- operation mode

T p f l t b d


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Types of elevators basedon operation mode


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Down collective operation Two cars

One car normally rests at the main floor

The other rests at the last floor

When a landing call is received, the

microprocessor calculates and sends the

car nearest to the call.

If a series of landing calls are received, the

car will be dispatched to the highest call

and then work down.


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Full collective operation one car

UP and DOWN call buttons are provided

on all floors.

Lowest floor- only UP call button

Highest floor has only Down call button

Landing calls and car calls are handled in a

logical sequence

Handles Interflow traffic well


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Full collective operation Two cars

One car normally rests at the main floor

The other rests at the last floor

When a landing call is received, the

microprocessor calculates and sends the

car nearest to the call.

Each car responds to its own car calls in

logical sequence


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Comfort of lifts

Passengers judge a lift on the basis of the following

Mechanical safety

The motion of the doors should be smooth and safety

devices should be provided to ensure that passengers

entering or leaving the lift car will not be hurt if the

doors start to close.

The leveling of the car to the landing floor should not

constitute a tripping hazard and should allow easy

movement of trolleys and wheelchairs.


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Comfort

The ride between floors should have acceptable levels of

acceleration, jerks and vibration should be kept to a

minimum

Quiet operation of doors

Noise levels at landings should also be minimal

Service

Passengers waiting time should be minimum

Comfort of lifts


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Elevator types

Based on working principle:

Electric Traction elevators

Hydraulic elevators

Based on the building type:

Passenger elevators

Panoramic elevators

Hospital elevators

Automobile elevators

Freight elevators

Home elevators

Dumbwaiters


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Types of lifts Based on working

principle

Traction

Hydraulic

Traction- Geared traction

- Gearless traction


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components of an elevator

an elevator car,

a counterweight,

drive means including a drive motor connected to a

drive sheave, drive sheave having a periphery rotatable

about a drive axis,

cable groove means on the periphery of sheave which

defines at least one cable groove,

and a cable interconnecting elevator car and

counterweight while disposed about drive sheave

C t f


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Components of

an elevator


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Geared Traction Elevators

Geared Traction machines are

driven by AC or DC electric

motors

Geared machines use worm

gears to mechanically control

movement of elevator cars by

rolling steel hoist ropes over a

drive sheave which is attached

to a gearbox driven by a high

speed motor.

These machines are generally

the best option for basement or

overhead traction use for

speeds up to 350 ft/min.


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Gearless Traction

machines are high

speed electric motors

powered by AC or DC

current.

In this case the drive

sheave is directly

attached to the end of

motor.

Gearless Traction Elevators


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Machine roomless traction elevators


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TRACTION

ELEVATORS-

PLAN AND MACHINEROOM DETAILS


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Hydraulic elevators

Hydraulic elevator

systems lift a car using a

hydraulic ram, a fluid-

driven piston mounted

inside a cylinder

The cylinder is connected

to a fluid-pumping

system (typically,

hydraulic systems like

this use oil, but other

incompressible fluids

would also work). The

hydraulic system has

three parts:

A tank (the fluid reservoir)

A pump, powered by an electric motor

A valve between the cylinder and the reservoir


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Types of hydraulic elevators

Holed

hydraulic

elevators

Holeless

hydraulic

elevators


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Holed Hydraulic

system

In Holed Hydraulic

systems, a car is

connected to the top of a

piston that moves up and

down in a cylinder.

Movement is controlled

by a hydraulic valve. As

fluid is pumped into the

cylinder, the car rises; as

the fluid returns to the

reservoir, the car lowers.


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Holeless Hydraulic

system

The Holeless Hydraulic

system eliminates the

need for either a well

hole or buried piping.

The best application for

the Holeless product is

most any 2-story

building with less than

14' of travel from one

floor to the other.


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Hydraulic elevators

Holeless hydraulic elevators

Holed hydraulic elevators

HYDRAULIC ELEVATOR PLAN AND


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HYDRAULIC ELEVATOR-PLAN AND

MACHINE ROOM DETAILS

HYDRAULIC


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HYDRAULIC

ELEVATOR

ELEVATOR TYPES- and their


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ELEVATOR TYPES- and their

recommended applications


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Dumb Waiters

Use of dumb waiters : totransfer food materials,linen, loads, etc. todifferent floors

View of a dumb waiter


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HANDICAPPED/

ANTHROPOMETRICS-

ELEVATORS

lifts final

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