Case 2188 Combine gets relief from overwhelming heat and "dust storms" of dirt in cab
After years of working in the hot, contaminated air of a combine, this farmer decided to use RESPA-SD to fix the problem:
The Problem Every time we turned on the HVAC, the cab turned into a dust bowl, kicking up a dirt storm of debris inside the cab. It was so bad that it was making my combine operator sick. The heat was overwhelming, and he was breathing air full of dirt and chemicals. In the operator's own words:
We tried everything. We sealed the doors again, we changed the filter, we cleaned out the inside of the cab, we sealed every penetration in the cab we could find, and it did not matter! While sitting in the cab, the combine operator discusses the problem during this video interview:
The problem, it turns out, had to do with the design of the cab. Make-up air was drawn from the outside through a screen in the upper part of the ROPS (roll over protection system), then the air went down through the ROPS into a tube body precleaner, which was actually mounted inside the ROPS. Until the guys from Sy-Klone pointed this out to us, we did not know it was there! In fact, the local CNH folks did not know about it either. Sy-Klone said that the tube bodies were completely impacted and were not allowing air to pass through to the blower fan, which was trying to draw air into the cab from the bottom of the ROPS post.
Sure enough, when we opened the fresh air filter housing, the filter that we put in 1 year ago looked brand new; no air had passed through it. The fan motor was also burned out as it was not able to drawn air over the motor and consequently overheated.
The fresh air plenum, located under the jump seat in the cab is full of dirt - in fact the whole cab is covered in dirt. Normally a fresh air plenum would be very clean, as air comes through a precleaner and an air filter before entering the plenum. The air goes on from here to the coils, located under the driver's seat.
This shot is taken inside the fresh air plenum. The burnt-out blower motor has been removed, revealing the opening where fresh air comes in from the ROPS.
Removal of Clogged Tube Body Precleaner We disconnected the scavenger tube from the ROPS at the point that it connected to the internal tube bodies, reached up into the ROPS and after a few minutes of pulling and tugging we were able to dislodge the tube body and pull it out. It was a curious design; there were six small, say ¾”, tubes with cork screw shaped plastic inserts in them, all mounted in a rectangular box. The dirt inside the tubes was hard and the rectangular box was completely full of dirt and debris. The ROPS post above the tube body precleaner was completely full of debris all the way up to the air intake screen at the top of the ROPS. Clearly no air could pass through this mass of debris and the completely clogged tube body precleaner. The final analysis was that the Sy-Klone guys were dead on, no make up air was getting into the cab.
The Tube Body precleaner was completely filled with solid dirt and debris. No air was able to pass through the ROPS, so no air was getting to the air filter or blower motor, which had burned out.
After the tube body was removed, we took a photo looking up inside the ROPS, revealing a solid blockage of impacted dirt and plant debris. We had to chip out 18 inches of this to clear the ROPS.
Cleaning and Sealing Following careful instructions from Sy-Klone we thoroughly cleaned out the cab right down to Windex on the windows. We sealed the plenum which runs under the jump seat and the driver’s seat, completely cleaned out the evaporator coil located under the driver seat, replaced the burned out blower motor, completely removed the factory HVAC filter, tube body assembly and fresh air screen which had been located at the top of the ROPS. We cleaned out the ROPS of 18 inches of debris and blew it out until it was completely clean.
This mounting plate was fabricated to hold the RESPA-SD. The mounting location did not allow access to the screw holes from below once installed, so the RESPA-SD unit was bolted to the plate prior to mounting the plate on the combine. Brackets were also fabricated to mount to the front of the plate to increase rigidity.
This flanged plate replaced the screen that previously covered the opening into the ROPS. Power was brought up through the ROPS. A bead of RTV was run around all openings to ensure that an airtight seal was formed.
Fabricating Parts and Installing RESPA-SD At this point we built a mounting plate and brackets to hold the RESPA unit and a flanged adaptor to allow it to connect to the ROPS. We mounted the new flanged adaptor over the fresh air opening near the top of the ROPS. We mounted the RESPA-SD to the plate, then attached the mounting plate just outside the driver’s door, aligned with the flanged adaptor. We then attached the outlet of the RESPA-SD to the flanged adaptor. We replaced the seal on the old fresh air filter housing, sealed off the scavenger tube holes in the ROPS and remaining misc. screw holes, and wired the RESPA to the ignition circuit so that when the key is on the RESPA-SD is running. We wrote the machines current operating hours, date and operators name on the end of the MERV 16 filter which we installed in the RESPA-SD and the installation was complete. Scroll down to hear what the operator has to say about the difference in cab conditions!
In this interview, a farm equipment operator talks about how much better life is with the improved cab air quality after installing RESPA-SD.