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TopDry System

TopDry is basically a dryer located in the top of a grain bin. A layer of grain in the overhead drying chamber is dried by a large fan and heater then dumped to a holding area below. A smaller aeration fan below captures heat from this previously dried grain, and pushes it upward to help dry the next load. This recycling of heat increases efficiency, which greatly reduces drying costs.
All heat drying while cooling in a cooling bin has proven to be one of the most efficient ways to dry grain. With the GSI TopDry System, we go one step further by capturing the heat normally blown out the top of the cooling bin and reuse it in the drying process. In addition, TopDry allows filling, drying and dumping operations to be run automatically in the AutoFlow models. TopDry is also a storage bin providing up to 30,000 bushels of storage. One complete package that saves time and money!
TopDry's all have large volumes of grain in process with low airflow rates compared to other drying systems. This allows for gentler handling that with additional management can even make the drying of Food Grade grain possible. Diversity, flexibility and field proven controls make TopDry a reliable and convenient solution for grain drying and storage.
Download TopDry Animation video

BATCH - One or two fan(s) and Heater(s) force hot air through an even layer of wet grain in the drying chamber directly or through ductwork.

AUTOFLOW - One or two fan(s) and Heater(s) force hot air through varied depth layers of wet grain in the drying chamber directly or through ductwork.

BATCH - Outside air from the cooling fan captures heat from previously dried grain and that heat and aeration air is used to help dry the next batch.

AUTOFLOW - Outside air from the cooling fan captures heat from previously dried gain and is then reused in the continuing drying process.

BATCH - When the column of grain above has dried to a predetermined temperature the fan(s) & heater(s) stop and the operator manually opens the dump chutes letting the hot dried grain fall into the cooling and storage area below. The drying chamber is then manually refilled and the operator can start the next batch drying.

AUTOFLOW - When the grain above has dried to a predetermined temperature the actuator opens the dump chutes automatically letting 1/4 of the hot dried grain in a 36’, or 1/3 in the 24’ or 30’ fall into the cooling and storage area below. The drying chamber is then automatically refilled and the drying process continues without interruption until the wet grain supply is empty.

Autoflow Control System
The Autoflow control system is exclusive to the Maxim TopDry and is available on all the diameters. Autoflow features include an easy to read, backlit LCD display, automatic shutdown when out of grain, the ability to run continuous flow, or batch dry and cool. It has plenum hi-temperature protection, auger fill delay, and automatic or adjustable staged starting of fans and heaters. It monitors fan and heater conditions (8 total), indicating what caused the malfunction, can control 2 separate load augers and automatically closes the chutes in the event of a power loss. Autoflow includes four sensors for grain moisture averaging (more sensors = better accuracy), motor starters for fill systems, batch counter, reliable rotary fill switches (power paks mounted externally on the bin for easy service), and has a 25 memory recall to keep track of unit shut down times and dates. Autoflow is totally microprocessor based (no moving parts), and is completely driven by software which is easily upgraded. Dump chutes are controlled with an industrial strength 24 volt screw-type actuator.
All control boxes are galvanized, with the main control box powder coat over galvanized, featuring heavy duty sealed doors with UV resistant Plexiglas windows for easy viewing and to protect the displays and electrical circuitry.
Another Autoflow feature allows control boxes to be installed in a separate location from the drying bin with just a few wires. This can help prevent dryer controls from being tampered with or vandalized.


Batch Control System
The optional Series 2000 manual control center is available for use with the
Series 2000 fan and heater units. This control center offers control
of dry time, cool time and grain temperature (moisture).
An Important feature of this control center is the ability to set plenum temperature and other settings remotely from the fan(s) from a more convenient location.
Batch TopDrys include four sensors for grain averaging (more sensors = better accuracy).
Hand Crank
On Batch TopDrys, a simple and dependable cable winch is used to dump each batch. Lower the chutes for a minute or two until the drying chamber is empty and immediately refill and continue drying.

TopDry Fans and Heaters
TopDry’s Series 2000 fan and heater combination is taking grain conditioning into the next century with computerized components that allow the operator better control and access to vital information. The TopDry specially designed heaters feature backlit LCD displays for night viewing, providing constant read-outs of plenum temperature, grain temperature, or drying time. Drying can be controlled manually by Time or automatically by temperature based moisture control. Built-in flame detection circuitry notifies the operator of emergency situations and shuts down the dryer in the event of a dryer malfunction. TopDry fans utilize a high efficiency, light weight, composite blade for reduced motor stress at startup. A clear view panel on the side of the housing provides easy access to the burner for ignitor and flame probe adjustment or burner disassembly for cleaning and inspection. Vinyl fan covers are standard to completely enclose fan openings preventing weather or other unwanted material from entering the bin. TopDry fans and heaters are available in 36" dia. (15 HP) up through 42" (40 HP). All single phase TopDry fans have single rotation motors to prevent the fan from rotating backwards.

Built-in Thermostat
GSI 2000 series fans and heaters offer a built in thermostat for plenum and grain temperature, with the plenum and grain temperature, with the plenum thermostat differential being adjustable and programmable from the ground. The sensor is mounted in a weather proof "UL" approved housing, impervious to weather, rodents and insects.

1750 RPM Centrifugal Fan

Inline Centrifugal Fan
Aeration Fans
Before storing, grain must be dried down to the proper moisture level. The grain must then be cooled and then maintained through aeration for long term storage. The TopDry's design allows this aeration air to also be used as additional drying air while reusing all the heat removed from the dried grain. The aeration fan will be working against the static pressure of both the stored grain and drying fan(s). It is important that the airflow remain even no matter how much grain is in the storage chamber so GSI uses only Centrifugal Fans for aeration. Both Inline and 1750 RPM Centrifugal fans can be used depending on the size of the system and the aeration rate desired.
GSI's 1750 RPM centrifugal fans are built with a heavy galvanized steel, scroll-type housing and inverted inlet venturi. A non-overloading backward-inclined airfoil wheel provides high airflow with a long motor life. These fans operate at a greatly reduced noise level and are perfect for the larger TopDry models where efficient delivery of large volumes of aeration air is needed and or the quietest operation is desired. To assure adequate static pressure capability models between 10 hp and 20 hp will work best for use with a TopDry.
GSI's Inline Centrifugal fan operate at 3500 RPM and are the most economical choices for all but the largest TopDry installations. These fans operate much quieter than a traditional axial bladed fan, but not as quiet as a 1750 RPM Centrifugal fan. Inline Centrifugal fans are very good at providing the same amount of air across a wide range of static pressures.
Ventilation
A large 30 inch diameter peak opening allows for easy filling. GSI’s hingeless, galvanized cap slides on rods to open and close and is held securely closed with a spring loaded latch. Peak ring flashing tabs between roof ribs help further seal the roof.

Flatop 3 Vent
The Flatop 3 Vent assembly mounts like a traditional Flatop providing a strong base for downspout support while allowing physical access and full vent opening with the peak closed to weather.
In the event that the peak cap must be closed and the Flattop 3 Vent assembly cannot be used, high mount roof vents may be used as an alternative.

Auto-Vent
The Auto-Vent is a revolutionary concept in vent design eliminating any restriction from a screen or grill and reducing the chance of air restriction due to trash build up or frost. When fans are running, air passes freely above and below a special wing-shaped damper, allowing it to pivot open and float in mid-air. The damper drops down and closes when the fan is not in operation, also blocking wind, snow, birds, etc. from entering. Auto-Vents are assembled with a heavy duty lock seam and attach to prepunched roof panels which have a tall extruded lip detouring moisture around the vent and down the roof panel. For additional protection, a special die-cut gasket is placed between the vent and roof panels to further seal against water penetration.



TopDry Bin Access
Easy access walk-in door. All inner door panels on GSI’s walk through door open completely with no horizontal bars or braces to unbolt or remove. Specially designed lever latches multiply the inner door opening force by 20 times to counteract friction set from grain loads, requiring no use of wrenches or tools. The outer door cover swings completely open with the door cover hold-back and closes tight with the use of an exclusive weather seal. Other features include a probe opening for easy grain inspection and factory caulked door frames reducing installation time.
Large One-Ring Door
All TopDrys feature a large one ring access door in the second ring from the top. The door offers access for monitoring grain stored in the TopDry bin. The door is shipped completely pre-assembled for ease of construction. Large platforms provide a stable work area for monitoring or servicing the crop dryer units.
Sturdy Platforms and Sidewall Ladders
GSI platforms provide a large, stable work area for monitoring or servicing the crop dryer units. Sturdy sidewall ladders are available for easy access to and from the bin roof or inspection platforms. Ladder sections are die formed from a single piece of galvanized steel to provide strength, stability, and quick assembly. Sections come in 22" or 44" lengths.

High Tensile Sidewall
The 4" wide corrugated sidewall design is standard on the GSI TopDry. These 44” tall sheets are constructed using high tensile steel with 65,000 PSI minimum strength. All sidewalls feature G-90 bright spangle galvanized coating to ensure a long tank life. GSI also uses graded, zinc plated, high strength, dichromate coated bolts at all connections. Each bolt has a special sealing washer to keep out the elements.
Sidewall Strength with Stiffeners
TopDry utilizes strong vertical stiffener columns to carry the vertical load of the bin and system to the foundation. Stiffeners are manufactured from high strength 65,000 PSI (450 MSA) steel. The stiffeners are mounted on the outside of the tank to allow you unimpeded grain flow inside and feature strong splice joints and a large cross sectional area for increased strength.
TopDry stiffeners are fitted with heavy base plates which bolt directly to the concrete. These plates give the stiffeners a larger load bearing area to transfer the load to the foundation and anchor the bin securely.
Specifications
Batch Series |
24' Dia. One Fan |
30' Dia. One Fan |
30' Dia. Two Fan |
36' Dia. One Fan |
36' Dia. Two Fan |
|||||||
Fan and Heater Unit(s) |
Plenum Temp. |
Moisture Content Wet Basis |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
15 H.P. 36" Fan 3.5 mil. BTU |
140° F |
20% |
398 |
2.5 |
461 |
3.3 |
728 |
1.9 |
521 |
4.1 |
841 |
2.6 |
25% |
252 |
3.8 |
292 |
5.1 |
461 |
3.3 |
330 |
6.5 |
533 |
4.0 |
||
30% |
157 |
6.1 |
182 |
8.2 |
288 |
5.2 |
206 |
10.4 |
333 |
6.5 |
||
160° F |
20% |
474 |
2.0 |
550 |
2.8 |
869 |
1.8 |
622 |
3.4 |
1004 |
2.1 |
|
25% |
300 |
3.2 |
348 |
4.4 |
550 |
2.7 |
394 |
5.4 |
636 |
3.4 |
||
30% |
178 |
5.2 |
218 |
6.8 |
344 |
4.4 |
246 |
8.7 |
397 |
5.4 |
||
180° F |
20% |
607 |
1.6 |
677* |
2.4* |
1112 |
1.4 |
694* |
3.4* |
1284 |
1.6 |
|
25% |
384 |
2.6 |
429* |
3.7* |
704 |
2.1 |
440* |
5.2* |
814 |
2.7 |
||
30% |
240 |
4.0 |
268* |
6.0* |
440 |
3.4 |
274* |
8.3* |
508 |
4.2 |
||
15 H.P. 40" Fan 6.25 mil. BTU |
140° F |
20% |
486 |
2.0 |
562 |
2.7 |
650 |
3.3 |
1022 |
2.1 |
||
25% |
308 |
3.1 |
356 |
4.2 |
411 |
5.2 |
647 |
3.3 |
||||
30% |
192 |
4.9 |
222 |
6.7 |
257 |
8.4 |
404 |
5.3 |
||||
160° F |
20% |
580 |
1.6 |
670 |
2.2 |
775 |
2.8 |
1219 |
1.8 |
|||
25% |
367 |
2.6 |
425 |
3.5 |
491 |
4.4 |
772 |
2.8 |
||||
30% |
230 |
4.2 |
265 |
5.6 |
306 |
7.1 |
482 |
4.5 |
||||
180° F |
20% |
742 |
1.3 |
858 |
1.8 |
890* |
2.6* |
1560 |
1.4 |
|||
25% |
470 |
2.0 |
543 |
2.7 |
564* |
4.1* |
988 |
2.2 |
||||
30% |
294 |
3.3 |
339 |
4.4 |
352* |
6.5* |
617 |
3.5 |
||||
30 H.P. |
140° F |
20% |
638 |
2.4 |
717 |
2.9 |
1142 |
1.9 |
||||
25% |
405 |
3.6 |
454 |
4.7 |
723 |
2.9 |
||||||
30% |
253 |
5.9 |
284 |
7.5 |
452 |
4.7 |
||||||
160° F |
20% |
762 |
2.0 |
856 |
2.5 |
1363 |
1.5 |
|||||
25% |
482 |
3.1 |
542 |
4.0 |
863 |
2.5 |
||||||
30% |
302 |
4.9 |
338 |
6.4 |
539 |
4.0 |
||||||
180° F |
20% |
975 |
1.5 |
1095 |
2.0 |
1744 |
1.3 |
|||||
25% |
618 |
2.4 |
694 |
3.1 |
1105 |
2.0 |
||||||
30% |
386 |
3.9 |
433 |
4.9 |
690 |
3.2 |
||||||
40 H.P. 42" Fan 10.25 mil. BTU |
140° F |
20% |
726 |
2.1 |
810 |
2.7 |
||||||
25% |
460 |
3.3 |
513 |
4.2 |
||||||||
30% |
287 |
5.2 |
320 |
6.7 |
||||||||
160° F |
20% |
867 |
1.8 |
966 |
2.2 |
|||||||
25% |
549 |
2.7 |
612 |
3.5 |
||||||||
30% |
343 |
4.4 |
382 |
5.6 |
||||||||
180° F |
20% |
1110 |
1.4 |
1263 |
1.8 |
|||||||
25% |
702 |
2.1 |
783 |
2.7 |
||||||||
30% |
439 |
3.4 |
489 |
4.4 |
||||||||
*Insufficent burner BTUs for 45 deg. ambient temp.
Batch capacities exclude loading time. Final moisture 15% after complete cooling.
Estimated at 45 deg. F. ambient temperature, 65% relative humidity. 1/3 CFM/Bu. Cooling Rate.
Use only as a guide, grain densities and weather conditions will vary capacities.
Batch Series |
24' Dia. One Fan |
30' Dia. One Fan |
30' Dia. Two Fan |
36' Dia. One Fan |
36' Dia. Two Fan |
|||||||
Fan and Heater Unit(s) |
Plenum Temp. |
Moisture Content Wet Basis |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
BPH |
Batch Time Hours |
15 H.P. 36" Fan 3.5 mil. BTU |
160° F |
20% |
528 |
21.6 |
557 |
31.9 |
939 |
18.9 |
993 |
25.8 |
||
25% |
334 |
34.1 |
353 |
50.4 |
595 |
29.9 |
629 |
40.7 |
||||
30% |
209 |
54.6 |
220 |
80.8 |
371 |
47.9 |
393 |
65.2 |
||||
180° F |
20% |
675* |
16.8* |
713* |
24.9* |
1202 |
14.8 |
1271 |
20.1 |
|||
25% |
428* |
26.6* |
451* |
39.4* |
761 |
23.4 |
805 |
31.8 |
||||
30% |
267* |
42.6* |
282* |
63.1* |
475 |
37.4 |
503 |
51.0 |
||||
200° F |
20% |
791* |
14.4* |
835* |
21.3* |
1407* |
12.6* |
1488* |
17.2* |
|||
25% |
501* |
22.7* |
529* |
33.6* |
891* |
19.9* |
943* |
27.2* |
||||
30% |
313* |
36.4* |
330* |
53.9* |
557* |
32.0* |
589* |
43.5* |
||||
15 H.P. 40" Fan 6.25 mil. BTU |
160° F |
20% |
648 |
17.5 |
711 |
25.0 |
1154 |
15.4 |
1269 |
20.2 |
||
25% |
411 |
27.7 |
450 |
39.5 |
731 |
24.3 |
803 |
31.9 |
||||
30% |
256 |
44.4 |
281 |
63.3 |
457 |
39.0 |
502 |
51.1 |
||||
180° F |
20% |
830* |
13.7* |
909* |
19.5* |
1477 |
12.0 |
1623 |
15.8 |
|||
25% |
525* |
21.6* |
576* |
30.9* |
936 |
19.0 |
1028 |
24.9 |
||||
30% |
328* |
34.7* |
360* |
49.5* |
584 |
30.4 |
642 |
39.9 |
||||
200° F |
20% |
971* |
11.7* |
1065* |
16.7* |
1730* |
10.2* |
1901 |
13.4* |
|||
25% |
615* |
18.5* |
674* |
26.4* |
1096* |
16.2* |
1204 |
21.3* |
||||
30% |
384* |
29.6* |
421* |
42.2* |
684* |
26.0* |
752 |
34.1* |
||||
30 H.P. |
160° F |
20% |
740 |
15.4 |
806 |
22.0 |
819 |
31.3 |
1452 |
17.6 |
||
25% |
469 |
24.3 |
511 |
34.8 |
519 |
49.4 |
920 |
27.8 |
||||
30% |
293 |
38.9 |
319 |
55.8 |
324 |
79.1 |
574 |
44.6 |
||||
180° F |
20% |
947 |
12.0 |
1032 |
17.2 |
1048 |
24.4 |
1858 |
13.8 |
|||
25% |
600 |
19.0 |
653 |
27.2 |
664 |
38.6 |
1177 |
21.7 |
||||
30% |
375 |
30.4 |
408 |
43.6 |
415 |
61.8 |
735 |
34.8 |
||||
200° F |
20% |
1109 |
10.2 |
1208 |
14.7 |
1227 |
20.8 |
2176 |
11.7 |
|||
25% |
702 |
16.2 |
765 |
23.2 |
777 |
32.9 |
1378 |
18.6 |
||||
30% |
439 |
25.9 |
478 |
37.2 |
486 |
52.8 |
861 |
29.8 |
||||
40 H.P. 42" Fan 10.25 mil. BTU |
160° F |
20% |
920 |
19.3 |
950 |
26.9 |
||||||
25% |
583 |
30.5 |
602 |
42.6 |
||||||||
30% |
364 |
48.9 |
376 |
68.2 |
||||||||
180° F |
20% |
1178 |
15.1 |
1216 |
21.0 |
|||||||
25% |
746 |
23.8 |
770 |
33.3 |
||||||||
30% |
466 |
38.2 |
481 |
53.3 |
||||||||
200° F |
20% |
1379 |
12.9 |
1424 |
18.0 |
|||||||
25% |
873 |
20.3 |
902 |
28.4 |
||||||||
30% |
545 |
32.6 |
563 |
45.5 |
||||||||
*Insufficent burner BTUs for 45 deg. ambient temp.
Batch capacities exclude loading time. Final moisture 15% after complete cooling.
Estimated at 45 deg. F. ambient temperature, 65% relative humidity. 1/3 CFM/Bu. Cooling Rate.
Use only as a guide, grain densities and weather conditions will vary capacities.
Batch |
Autoflow |
Maximum Storage (BU) |
||||||
Bin Diameter |
Batch Size (BU) |
Grain in Process (BU) |
Dump Size (BU) |
Rings |
Eave Height |
Peak Height |
Batch |
Autoflow |
24' |
1,000 |
560 |
187 |
5 |
18'5" |
25'0" |
4,813 |
4,373 |
6 |
22'1" |
28'8" |
6,198 |
5,758 |
||||
7 |
25'9" |
32'4" |
7,583 |
7,143 |
||||
8 |
29'5" |
36'0" |
8,968 |
8,528 |
||||
9 |
33'1" |
39'8" |
10,353 |
9,913 |
||||
10 |
36'9" |
43'4" |
11,738 |
11,298 |
||||
30' |
1,500 |
845 |
282 |
5 |
18'5" |
26'9" |
7,459 |
6,804 |
6 |
22'1" |
30'5" |
9,623 |
8,968 |
||||
7 |
25'9" |
34'1" |
11,787 |
11,132 |
||||
8 |
29'5" |
37'9" |
13,951 |
13,296 |
||||
9 |
33'1" |
41'5" |
16,115 |
15,460 |
||||
10 |
36'9" |
45'1" |
18,279 |
17,624 |
||||
11 |
40'5" |
48'9" |
20,443 |
19,788 |
||||
36' |
2,160 |
1,215 |
304 |
6 |
22'1" |
32'6" |
13,859 |
12,914 |
7 |
25'9" |
36'2" |
16,974 |
16,029 |
||||
8 |
29'5" |
39'10" |
20,089 |
19,144 |
||||
9 |
33'1" |
43'6" |
23,204 |
22,259 |
||||
10 |
36'9" |
47'2" |
26,319 |
25,374 |
||||
11 |
40'5" |
50'10" |
29,434 |
28,489 |
||||
Maximum storage estimated with 12" aeration floor, level to bottom of fan entrance, with upper batch filled
