TRANSPORTATION SYSTEMS IN BUILDINGS. Mohd Rodzi Ismail

Transcription

1 TRANSPORTATION SYSTEMS IN BUILDINGS Mohd Rodzi Ismail

2 MOVEMENT SYSTEMS Forms of mechanical transportation may be found within, around and in general association with modern buildings and developments Lifts Escalators Travolators or moving pavements

3 LIFTS

4 Introduction A lift or an elevator is a transport device used to move goods or people vertically Considered a requirement in all buildings over three storeys Minimum standard of service one lift for every four storeys with a maximum distance of 45 m to the lift lobby Floor space estimates and car capacity can be based on an area of 0.2 m 2 per person

5 Various speeds of lifts

6 Location of lift Positioning of lift should be at locations which provide easy means of access for all building users central entrance lobby of offices, hotels, apartments, etc. Grouping of lifts is essential for user convenience

7 3 Possibilities of lift grouping arrangements 1 2

8 The former World Trade Center's twin towers used skylobbies, located on the 44th and 78th floors of each tower.

9 Lift performance Lift performance depends on Acceleration Retardation Car speed Speed of door operation, and Stability of speed and performance with variations of car load

10 The assessment of population may be found by allowing between one person per 9.5 m 2 of floor area to m 2 of floor area. For unified starting and finishing times - 17% of population per 5 minutes may be used. For staggered starting and finishing times - 12% of the population may be used.

11 The number of lifts will have an effect on the quality of service. Four 18-person lifts provide the same capacity as three 24-person lifts but the waiting time will be about twice as long with the three-car group.

12 The quality of service may be found from the interval of the group. 23 to 35 seconds excellent 35 to 45 seconds - acceptable for offices 60 seconds acceptable for hotels 90 seconds acceptable for flats

13 Further criteria for the comfort and convenience of lift users: Directional indication of location of the lift lobby for people unfamiliar with the building. Call buttons at landings and in the car positioned for ease of use with unambiguous definition for up and down directions. Call buttons to be at a level appropriate for use by people with disabilities and small children.

14 Call display/car location display at landings to be favourably positioned for a group of people to watch the position of all cars and for them to move efficiently to the first car arriving. Call lights and indicators with an audible facility to show which car is first available and in which direction it is traveling. Lobby space of sufficient area to avoid congestion by lift users and general pedestrian traffic in the vicinity.

15 A method for estimating and comparing efficiency and effectiveness of lift installation is by calculating the round trip time (RTT): An average period of time for one lift car to circulate, incorporating statistical data for time lost due to stops It is measured from the time the lift doors begin to open at the main terminal to the time they reopen when the car complete its cycle

16 Example A building having five floors at 3 m floor to floor spacing, a car capacity of 6 persons and 2 ms -1 speed of travel

17 1. Probable number of stops (S 1 ): S 1 = S S S 1 S where, S = maximum number of stops n = number of people or car capacity n 4 1 S 1 = 4 4 = , i.e. 3 stops

18 2. Upward journey time (T u ): L T u = S 1 + 2V SV where, L = lift travel, 4 x 3 = 12 m V = car speed, 2 ms T u = 3 + [2 x 2] = s 4 x 2

19 3. Downward journey time (T d ): L T d = + 2V V = [2 x 2] = 10 s 4. Passenger transfer time (T p ). Allow 2 3 s per person to transfer, depending on the depth of car. At 2 s: T p = 2 n = 2 x 6 = 12 s

20 5. Door opening time (T o ). Assume door speed (V d ) = 0.5 ms -1 and door width (W) = 1.2 m: T W = V 0.5 ( S + 1) = 2 (3 + 1) 19. s o = 2 6. Round trip time (RTT): RTT = T + T + T + u d d p = = 57.7 s T o

21 Estimation of the interval and quality of service Example An office block with 20 storeys above ground floor having a group of four lifts with unified starting and stopping times is to have a floor area above the ground floor of 8000 m 2 and floor height of 3 m. Each car of the lifts has a capacity of 20 persons and a speed of 2.5ms -1. The clear door width is to be 1.1 m and the doors are to open at a speed of 0.4 ms -1. Estimate the interval and quality of service that is to be provided.

22 1. Peak demand for a 5-minute period: = m 17% 2 11m / person 100 = 124 person 2. Car travel = 20 x 3 m = 60 m

23 3. Probable number of stops (S 1 ): S 1 = S S S 1 S where, S = maximum number of stops n = number of people or car capacity (usually approximately 80% of capacity) S1 = = n

24 4. Upward journey time (T u ): L T u = S 1 + 2V SV where, L = lift travel, 20 x 3 = 60 m V = car speed, 2.5 ms T u = 11 + [2 2.5] = 79 s

25 5. Downward journey time (T d ): L T d = + 2V V = [2 2.5] = 29 s

26 6. Door operating time (T o ). Door speed (V d ) = 0.4 ms -1 Door width (W) = 1.1 m: W 1.1 To = 2 1 = 66 V 0.4 ( S + 1) = 2(11+ 1) s d

27 7. The average time taken for each person to get into and out of a lift car may be taken as 2 seconds. Passenger transfer time (T p ) = 2n = 2 x 16 = 32 s 8. Round trip time (RTT) = T + T + T + T u d p o = = 206 s

28 9. Capacity of group = = 5 mins persons per 5 minutes 10. Interval for the group = 206 = s The capacity of the group of lifts and the interval for the group are satisfactory (Note: Car less than 12 capacity are not satisfactory)

29 Electric/roped lifts In these elevators, the car is raised and lowered by traction steel ropes rather than pushed from below Components: 1 - Control system 2 - Electric motor 3 - Sheave 4 - Counterweight 5 - Guide rails

30 Motor Located in lift motor room On anti-vibrations mountings

31 Lift motor on motor room-less lift

32 Motor room Highly efficient permanent magnet (PM) motors for high-speed and super highspeed elevators (Mitsubishi)

33 Roping High tensile steel ropes driven through traction sheaves attached to the motor shaft, a system of pulleys and a counterweight Available in various combinations to suit different occupancy requirements

34 Single wrap 1 : 1 The simplest but will be prone to slipage if subjected to heavy loads

35 Single wrap 2 : 1 Improvement of single wrap 1 : 1 Number of pulleys and the wrapping ratios increased to improve resistance to slipage

36 Single wrap 3 : 1 More pulleys used

37 Effect of wrap ratio on car speed as the ratio increases, the car speed decreases

38 Alternative roping arrangements to maintain high speeds and sufficient traction Double wrap Underslung

39 In very tall buildings the effect of bounce and spring from the rope load can be balanced and compensated with ropes suspended below car and counterweight Compensating ropes

40 Emergency braking While moving the car is retained upright and carried smoothly by guides and channel each side Car guide (plan view)

41 In the unlikely event of rope failure, an overspeed governing mechanism will effect an immediate brake Safety gear - alternatives

42 The emergency brakes are activated by a continuous rope passing over a pulley in the pit and an overspeed governor pulley in the motor room. The governor locks in response to flyweight inertia from the centrifugal force generated by excess speed, thus jerking the rope in process. The position of the governor rope and pulleys, relative to car travel

43 Active Roller Guide (Mitsubishi) This greatly reduces lateral vibration of highspeed elevator. An accelerometer detects car vibration during operation and actuators cancel the vibration with optimally controlled electromagnetic force. The result is much better ride comfort than with a conventional roller guide.

44 Lift doors Required in two components: Fitted to the lift car Fitted to the landing Landing doors must be incombustible, preferably of sheet steel construction over a light steel framework of about 30 mm overall thickness They usually slide sideways (although vertical movement is used for some industrial applications)

45 Door-opener system

46 Various functions of lift doors

47 Passenger and service lift doors Vertical lift doors

48 Multi-Beam Door Sensor (Mitsubishi) Prevents passengers from being caught by the doors, using multiple infrared light beams mounted along the entire length of car door edge. Doors reverse and open if beams are blocked during door closing

49 Constructional dimensions Lifts manufactured to individual dimensional specification are possible but very expensive BS 5655 provides standard dimensions which have been coordinated with manufacturing process and building applications to suit all but extreme clients or obscure building requirements

50 Section through typical small car single lift well

51 Machine/Motor room Normally located above the well, containing: winding gear traction sheave control panel overspeed governor, and other components Section through lift motor room

52 Noise from motors and winding gear must be contained with adequate insulation and absorbent bedding for machinery An overhead universal beam for raising and lowering equipment and parts during maintenance is essential Adequate daylighting and supplementary artificial light Fan assisted ventilation to remove excess heat from electric plant A locked door (key with security staff) provides the only access to the machine room, except for a trap-door over the landing area this is specifically for raising and lowering items of machinery

53 Pit Located below the lowest landing level, containing buffers For slower lifts spring-type buffers For higher-speed lifts oil loaded buffers Depth of pit varies from 1.4 to 2.8 m, depending on lift specification

54 Brake The traction sheave drive shaft is fitted with an electromechanical brake When the lift is moving, the electrically operated brakes are lifted clear of the brake drum, but as the electricity switches off to disengage the motor, spring retainers activate the brake In addition to the overspeed governor, this provides another safety feature which would activate if the electricity supply failed

55 Shaft A lift shaft should incorporate the following features: Water tightness Means of drainage Plumb, vertical sides Smooth painted finish Ventilation void for emission of smoke Permanent inspection lights Have no other services except those necessary for operation of lift

56 Lift controls Possibilities of control arrangements: Operator Automatic Down collective Directional collective Group collective Programmed control

57 Operator In prestige buildings and hotels for the benefit of special guests. Automatic Response to one call from either lift car or landing. No further calls are accepted until the car is at rest. Only suited to light occupancy and low-rise buildings up to five floors. Down collective A call button is located at each landing entrance and a set of buttons in the car corresponds to each floor. Landing calls are stored and answered in sequence as the lift car descends. In upward direction, passengers are distributed in floor sequence by selection within the car.

58 Directional (up and down) collective Two call buttons are provided at each intermediate landing, one for up and the other one for down. The lowest and the highest landings only require one button. A full set of destination buttons are provided in the car. Landing callers simply press the direction button and the call is stored On a downward journey, the lift stops at all floors where downward callers are waiting or where passengers want to go out. Likewise upward, operating in sequence in response to stored calls.

59 Group collective Applied where groups or banks of lifts occur in large buildings, using an interconnected collective stored control system This permits the closest lift traveling in the desired direction to respond, rather than passengers waiting for one specific lift or having to press every lift s button.

60 Programmed control This is an improvement of the group collective system, incorporating time-controlled functions, where demand is known to be particularly high on some floors at certain times. The lift cars can be programmed to be available at the ground floor during arrival times and at upper floors during departure times. This lends itself to routines found in office blocks, where regular hours are worked.

61 Elevator buttons

62 Hydraulic lifts Hydraulic lift/elevator systems lift a car using a hydraulic ram, a fluiddriven piston mounted inside a cylinder For low-rise buildings Hydraulic lift components

63 Oil hydraulic lift - principles Oil hydraulic lift - application

64 DOUBLE SIDE ACTING Oil hydraulic lift - variations SINGLE SIDE OR JIGGER ACTING

65 Holeless Hydraulic (Otis) 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 (4.3 m) of travel from one floor to the other. Its above-ground Holeless configuration responds effectively to the risk of soil and groundwater contamination, and greatly reduces environmental concerns. This package-type unit is most practical for those 2-story buildings where handicap access is required.

66 Advantages of hydraulic lifts: Capacity for very heavy loads Accuracy in floor levelling Smooth ride characteristics Low-level plant room No structural loads from winding gear Pump room can be located up to 10 m from the shaft

67 Fire-fighting lifts For rapid emergency access The original concept was a variation within conventional passenger lift, which contained a priority break-glass key switch This was normally at the ground floor, and when activated it brought the lift to that floor immediately

68 Independent fire-fighting lifts are required in offices, shops and other commercial premises exceeding 18 m in height Typical fire-fighting accommodation in a shaft located no more than 60 m from any part of that floor level

69 Shared shaft fire-fighting lift the lift must be marked for that purpose only Requires specific provisions: 630 kg minimum duty load to accommodate fire-fighting equipment Minimum internal dimensions of 1100 mm width, 1400 mm depth and 2000 mm height An emergency hatch in the car roof Manufactured from non-combustible material A two-way intercom 1 hour fire-resisting doors of 800 mm minimum width x 2 m height A maximum of 60 s capability to run the full building height Dual power supplies, one direct mains and the other an emergency generator

70 Fire-fighting lift shared shaft Fire-fighting lift control diagram

71 Observation/panoramic/ scenic lifts Wall climber lift The glass-walled cars provide a focus of interest for the casual observer, a degree of security for occupants, a mobile observation platform and floor access for the user Very popular in atrium malls, complementing the glass architecture These lightweight structures lend themselves to hydraulic lifts, freeing the building designers from superimposed motor room loadings

72 Observation lift

73 Panoramic lift design

74 Panoramic lift applications

75 Paternoster A paternoster or paternoster lift is an elevator which consists of a chain of open compartments (each usually designed for two persons) that move slowly in a loop up and down inside a building without stopping Passengers who are agile enough can step on or off at any floor they like The speed is limited to no more than 0.4 ms -1 for safety reason

76 Not suitable in public buildings and other locations where the elderly and infirm are likely to gain access Most suited to single occupancy buildings such as offices, where familiarity with the system and a high degree of staff mobility is a feature Paternoster lift

77 Paternoster lifts

78 Stair lift A means of vertical transport in homes for the elderly and disabled, hospitals and conventional homes containing physically infirm people Developed for simple application to domestic chairs The chair moves up an inclined rail parallel with the stair gradient at about 0.15 ms -1 powered by 230 V AC electric motor The rail is a standard steel joist bracketed to the wall and supported by the stair Transformed 24 V DC controls provide push-button directional and stop facilities

79 Stair lift approximate dimensions

80

81 Other types of lifts Double-deck elevators They are elevators designed such that two elevator cars are attached one on top of the other. This allows passengers on two consecutive floors to be able to use the elevator simultaneously, significantly increasing the passenger capacity of an elevator shaft. Such a scheme can prove efficient in buildings where the volume of traffic would normally have a single elevator stopping at every floor. Example: Lifts at Menara Telekom, Taipei 101 Taipei 101

82 Freight elevator An elevator designed to carry goods, rather than passengers

83 Car elevator An elevator designed to carry cars (e.g. for parking)

84 Dumbwaiter A small box elevator designed for the carriage of lightweight freight is called a dumb waiter (or dumbwaiter) Service lift/dumbwaiter

85 Platform lift For disable

86 Aircratft elevator

87 ESCALATORS

88 An escalator is a conveyor transport device for transporting people, consisting of a staircase whose steps move up or down on tracks that keep the surfaces of the individual steps horizontal Where large numbers of people are anticipated, such as airports and railway terminals, department stores and shopping malls, several escalators will be required and can be grouped in a number of ways to suit the building functions The angle of inclination is normally 30 o, but may increase to 35 o if the vertical rise does not exceed 6 m and the speed is limited to 0.5 ms -1

89 Escalator arrangements

90 Escalator dimensions

91 Escalator s components

92 Step Speed Escalator speeds vary from about 90 feet per minute to 180 feet per minute (27 to 55 meters per minute) An escalator moving 145 feet (44 m) per minute can carry more than 10,000 people an hour -- many more people than a standard elevator The individual steps from an escalator

93 Westminster escalator Long escalator in Washington Metro

94 Conventional escalator Spiral escalator

95 Escalator capacity The following formula can be used to ascertain capacity and compare efficiencies and suitability of escalators at building design stage: N = 3600 x P x V L x cosθ Where, N = number of persons moved per hour P = number of persons per step V = escalator speed (ms -1 ) L = length of step (m) θ = angle of incline

96 Example An escalator of 30 o incline, one passenger per step, a speed of 0.5 ms -1 and 400 mm tread or step length N = 3600 x1 x x cos 30 o = 4500 x cos 30 o = 3897 nos. persons moved per hour

97 Spread of fire The void containing escalators could encourage fire to spread rapidly through building. Therefore the following precautions could be considered: Sprinklers, installed to provide a continuous curtain of water down the escalator void Fire curtains or shutter mechanism released by fusible link or smoke relay to seal the top of the escalator shaft Compartmentalisation or separation of escalators into a well or fire-protected enclosure

98 TRAVELATORS

99 A moving walkway, moving sidewalk, or travelator is a slow conveyor belt that transports people horizontally up to the practical limitations of about 300 m. They work in a similar manner to an escalator. In both cases, riders can walk or stand. The walkways are often supplied in pairs, one for each direction. They are particularly useful in large railways and airports terminals, as well shopping complexes, and may be inclined up to about 15 o where level differentials occurs.

100 Speed range between 0.6 and 1.3 ms -1, limitations being imposed because of the difficulty in getting off. Combine with walking, the overall pace could be about 2.5 ms -1. Materials for travelators must be flexible or elastic and include reinforced rubber or composites and interlaced steel plates or trellised steel. The latter two have the facility to deviate from the conventional straight line.

101 Inclined travelator Parisian high speed walkway

102 REFERENCES Greeno, R.(1997). Building Services, Technology and Design. Essex: Longman. Hall, F. & Greeno, R. (2005). Building Services Handbook. Oxford: Elsevier