Materials Handling and Engineering Specialists
DOS SANTOS
NEW CONVEYOR SYSTEMS UPGRADE OF EXISTING CONVEYOR SYSTEMS PLANT MODIFICATIONS AND FIELD ASSISTANCE TECHNICAL AND ECONOMIC STUDIES AND EVALUATIONS
INTERNATIONAL
DSI SNAKE SANDWICH CONVEYOR A PRODUCT OF EVOLUTION In 1979 Joseph A. Dos Santos undertook a major study to develop a means of moving and elevating large quantities of bulk materials, including coarse products such as rocks, aggregate, coal, etc. at the steepest possible inclines. It was also his intent to use only existing and generally available hardware in order to achieve the most economically feasible and easily maintained steep-angle conveyor design. Mr. Dos Santos conceived, researched and developed his sandwich belt design, with the help of a grant from the U.S. Bureau of Mines. While such concepts had been tried over the years with mixed results, Dos Santos investigated & analyzed the many forces generated in this seemingly simple concept, and created the formulas which guaranteed the successful design of such equipment. The DSI Snake Sandwich Belt Conveyor represents the ultimate achievement of this aim. Mr. Dos Santos’ research articles have been published in world-wide journals such as: • • • •
Bulk Solids Handling Mining Technology World Cement Bulk Materials Handling Review International Bulk Journal
WHAT IS A SANDWICH BELT CONVEYOR A sandwich belt conveyor uses two conveyor belts, face-to-face, to gently but firmly contain the product being carried, hence making steep incline and even vertical-lift runs easily achievable.
Sandwich Belt Model
SPECIALIZING IN HIGH TECHNOLOGY CONVEYING SOLUTIONS High Angle Conveyors We are the world’s foremost authorities on high angle conveyor applications and design of sandwich belt type high angle conveyors. Our experience begins with research and development, the foundation that led to commercial success. We are proud to offer the DSI Snake Sandwich Conveyor, the most technologically advanced high angle and vertical conveyor system for your highest tonnage requirements in the harshest environments. Founded on solid, worldwide experience, Dos Santos International now offers the latest engineering solutions for your materials handling, transport, and project needs. The experience of our people covers the globe, spanning the civilized continents. This has included: • • • •
Basic research and development, leading to state of the art systems and techniques Technical economic studies and evaluations leading to implementation of optimal systems and equipment Engineering and supply of the most modern conveying systems and equipment Sales and service before, throughout, and after the project.
LONG OVERLAND HIGH LIFT AND HIGH CAPACITY CONVEYORS We offer conventional conveying systems of simple or complex profile to high capacities and high lifts. Our conveyor systems will exploit the latest in equipment to deliver optimal solutions. Our experience in integrated design will be exploited to produce elegant, effective plant conveyor solutions while utilizing the best and most efficient equipment and structural systems.
DSI EXPANDED CONV ExConTec
Tail End
Conveyor Profile
Belt Travel Carrying Side
Head End
Return Side
More than an analysis tool, the DSI Expanded Conveyor Technology reflects a philosophy. Our comprehensive approach takes the conventional conveyor technology beyond the currently perceived limits. Utilizing derived load equivalents we are first to address and predict the extra flexural and shear resistances along vertical and horizontal curves. Our analysis models and software incorporate added features including the “Engineers Discretionary Factors”, an allowance for incorporating the results of field testing or simply our client’s philosophy.
Driving TE = T1 - T2
Tensions Running Loaded
T1 Tensions Carrying Side
T4 T3
Tensions Return Side
Tensions Accelerating Loaded
Tensions Braking Loaded
Braking TE = T3 T T4
T1 T3 T2
Tensions Drifting to Stop Loaded “Slack Belt” Carrying Side
Material - Density Conveying Rate CEMA Sct.-20°Sur. % CEMA Load
coal
Belt Width Belt Speed Tension Rating Amb. Temperature Temperature Factor
55 pcf 850 stph 0.980 Sq. ft. 87.5 %
T2
36 inches 600 fpm 1000 PIW 0 Deg. F 1.35
Tensions Summary Empty Accel Brake (lbs) (lbs) (lbs) 20014.1 41951.0 4369.4 7877.4 6482.0 22362.9 20014.1 41951.0 23009.4 555.9 1165.3 639.2
T1 T2 Tmax PIW
Running (lbs) 31096.9 8208.3 31096.9 863.8
Drift (lbs) 11466.4 8512.2 11466.4 318.5
Accel/Decel Time (secs)
N/A
N/A
19.5
6.9
10.6
Shaft HP 7.0 % Losses Motor(+)/Brake(-) HP
421.6 29.5 451.1
224.9 15.7 240.7
682.5 47.8 730.3
-327.3 22.9 -304.4
0.0 0.0 0.0
Selected Motor HP
525
525
525
525
525
NODE 1, T-U Tens. (lbs) Conveyor Stretch (ft) Take-Up Stretch (ft)
8500 30.3 15.1
8500 27.5 13.8
8500 39.4 19.7
8500 23.2 11.6
8500 14.9 7.4
VEYOR TECHNOLOGY Special Features of the DSI ExConTec "Expanded Conveyor Technology" 1. Each run produces a complete tension and power analysis under steady state, starting and stopping conditions. Stopping is by braking and by drifting. Starting and stopping analyses utilize rigid body dynamics. 2. Sequential runs, using macros, allow real time analysis and graphical display of changing load conditions including load-on, trailing-off and any discontinuity of material flow. This feature allows us to spot, quickly, the aggravations of flow discontinuities. 3. Virtual material loads, or "load equivalents" are used to account for belt line resistances associated with the curving profile or plan of the conveyor line. These (previously unaccounted for) resistances become significant at horizontal curves where the effect is always increased resistance. 4. Ky, flex and shear resistance factors differ from CEMA reflecting DSI experience and philosophy. 5. In the analysis, belt tension becomes negative (compressive) when it drops below 0. This, though not realistic (as belt becomes slack), allows continued analysis indicating the tension increase required to correct the slack belt problem. 6. An in-put section entitled "Discretion by Responsible Engineer" offers the user an opportunity to affect the analysis by use of adjustment factors on the Ky and Kx values and on the terminal resistances. These factors can be used to alter the results according to known characteristics of the conveyors being analyzed, to reflect the user's design philosophy or to achieve matching of field monitored data. 1000
Conveyor Profile 500 0 1000
2000
Be lt Width: Belt Wt:
3000
4000
36 ins
5000
7000
Conveyor Le ngth:
13.7 lbs/ft
Tensions Running Loaded
40000
500 400 300 200 100 0 -100
9000
10000
Take-Up Movement (Feet) 1
30000
0
10
20
30
77.5 ft
LOAD
750 FPM Primary Drive HP
Booster Drive HP
12000
10 ft - Re turn
BELT SPEED:
1
11000
Lift:
5 ft - Trouh
1800 STPH
60000
8000
9250 ft
Idle r Spacing:
CONVEYING RATE:
50000
6000
40
500 400 300 200 100 0 -100
UNLOAD -17.599982 87.731559
1
50
Real time analysis quickly reveals the tension and power aggravations due to flow discontinuity at overland conveyor with “smart” booster drive
20000
10000
0 1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
Discretion by Responsible Engineer:
RUN
Ky Adjust:
0.83 Input
0.83 Default
Kx Adjust:
1.5 Input
1.5 Default
Term. Adj.:
Input
1 Default
T-U Tension
8400 lbs
AT NODE 1
12000
Discretionary input factors can reflect the customer’s experience and engineering philosophy
DSI SNAKE SANDWICH PROFILES Snakes are available in widely ranging profiles of C and S-Shape. A long bottom belt approach is possible to the sandwich entrance, and discharge may be on the high incline or may be after the extension of the carrying belt beyond the mouth of the sandwich.
DSI SNAKE SANDWICH BASIC PROFILES
The Dos Santos sandwich belt conveyors have been proven in more than eighty successful conveyor systems installed throughout the world over the past eighteen years. Dos Santos’ expertise will continue to advance the state of the art and assure our clients of the finest conveyor systems available today. The DSI Snake Sandwich is the most reliable and economical solution to your steep angle and vertical high-tonnage conveying requirements.
ADVANTAGES OF DSI SNAKE SANDWICH DSI Snake Sandwich conveyors offer the following advantages: ● ●
●
●
●
Unlimited conveying capacity A system suitable for the most rugged mine applications, yet gentle on sensitive and friable materials. High availability and low operating and maintenance costs Smooth surfaced belts allow continuous belt cleaning by scrapers and plows. This also facilitates intermediate material discharge by belt plows, as appropriate, before and/or beyond the sandwiched part of the Snake profile. Use of all conventional conveyor hardware insures economy and fast delivery of replacement parts.
DSI SNAKE FOR WOODCHIPS
ELEVATING WOOD CHIPS FROM SCREEN TO MILL
ELEVATING FROM SILO TO SILO
DSI SNAKE FOR MARINE APPLICATIONS
MOBILE SOFT LOADER FOR SHIPS AND BARGES
ELEVATING TRAILER TO SHIP LOADER
531 Roselane Street NW Ste 810 Marietta, GA 30060 USA Phone: +1 770 423 9895 Text: +1 916 US SNAKE www.dossantosintl.com