Questions and Answers with pictures.docx

12805B24Q0444 USDA - Hydraulic Power Unit Questions Suncore Distribution

· Could you provide what operating pressure the system will be set at?

· We would need that to ensure you would be getting the correct horsepower for your unit.

· Operating pressure is dependent upon the phase of operation. In tramping mode in which the speed of the main ram is critical, the system operates at much lower pressures – 3000 psi max. In final bale compression mode where ram force is critical, the system operates at higher pressure – 5000 psi max. These pressures are approximate but should be considered maximum operating pressures.

· Additionally, does this unit need to be enclosed and we have two different designs we could provide, L-Shaped Skid which is typically for stationary units or our 4-point lift Skid which ensures the unit can be lifted from top and bottom.

· The unit does not need to be enclosed as it will be housed in the basement of the gin plant building. The unit should be designed so that it can be lifted by both a lift truck and/or crane for final placement.

Servo Hydraulic Solutions

· Are you located in Ft. Collins? I am in Boulder and would like to get a chance to talk about what you guys are looking for in the hydraulic pumping unit. The HPU itself is not a problem, we have been in the servo hydraulic system business for 25 years, but I am un-familiar with the controls that you are looking for. I can drive to your place, and probably be done in an hour of talking. Can we arrange for this sometime today, or early next week?

· The unit will be in service in Lubbock, TX. Please contact the contracting officer to arrange a site visit.

Integrated Solutions Worldwide Can you please give insight into the following questions?

Per the hydraulics:

· What size of directional valves are needed – D05, D08, D10?

· The size of the hydraulic valves will be dependent upon the sub-system that the valve is controlling. For example, the valve controlling the main ram should be capable of the specified max flow rate of 150 gallons per minute. Other sub-system valves can likely be smaller in flow capacity but must not limit the baling capacity of the press which is approximately 12 bales per hour.

· Are there load holding valves downstream?

· Load holding valves are required in the HPU design.

· Are the directional valves to be standard solenoid or powered or proportional?

· Typically standard solenoid valves are used but your design may call for a different valve specification.

· Is there a machine schematic available?

· If not, what is the manufacturer of the existing baler?

· We cannot provide schematics of the existing system due to copyright protection by the OEM. The existing press system was manufactured by Lummus Industries, Inc. in Columbus, GA.

· What are the cylinder bore sizes and strokes?

· Main ram (single acting) – 14 in bore x ~144 inch stroke (approx. stroke length)

· Front and rear door lock cylinders – 6 in bore x 5 in stroke

· End door lock cylinder – 6 in bore x 5 in stroke

· Bale out door cylinder – 2 in bore x 57 in stroke

· Charge door cylinders – 4 in bore x 54 in stroke

· What cylinder speeds are needed and cycle times?

· As required to meet 12 bale per hour pressing rate

· What is the target working pressure?

· Operating pressure is dependent upon the phase of operation. In tramping mode in which the speed of the main ram is critical, the system operates at much lower pressures – 3000 psi max. In final bale compression mode where ram force is critical, the system operates at higher pressure – 5000 psi max. These pressures are approximate but should be considered maximum operating pressures.

· Are any safety valves needed for spool position monitoring for enable?

· Safety is of utmost importance in the design of this HPU. There are many ways to achieve valve lockout. This decision is to be made by the hydraulic designer but load holding and positive lockout is critical.

Per the Press Console controls:

· Is there an existing PLC program that we are to duplicate or are we to design an entire new program/logic?

· The PLC logic program should be designed to function with the specific components and design of the HPU.

· What is the desired HMI touch screen size?

· 20 inch minimum

· Are there existing sensors on the cylinders today that indicate position or are we to supply these?

· You must supply all limit switches and sensors to enable the design of the HPU you design.

· Does the PLC need to be safety rated?

· Yes

· What is the distance between the press console and the hydraulic pumping unit?

· The offset is approximately 10 ft vertical and 25 ft horizontal.

· As it relates to the cylinder stroke position, what accuracy is needed? ¼”…?

· +/-0.125 inch position accuracy is needed.

Per the installation:

· Is there a scope of work defined already for the installation?

· Yes, please contact the Contracting Officer for additional details on the specified scope of work and project requirements.

· If there is no scope of work defined yet for installation, then who is responsible for the following tasks?

· Running and landing high voltage electric to the hydraulic pumping unit

· High voltage electric service is located at the installation site. It is the responsibility of the awardee to make necessary connections between existing electrical service location and the new HPU.

· Running and connecting the necessary hydraulic hoses between the hydraulic pumping unit and the baler

· The contractor.

· Mounting/installing the hydraulic pumping unit to the designated area

· The contractor.

· Are there any pictures available of the baler today and the area for the hydraulic pumping unit?

· Pictures can be provided as needed – please specify what you want to be shown in the images.

Wilson, Solutions in Motion

· Do you have an existing hydraulic schematic for this unit or any drawings?

· The schematics and drawings of the existing unit are copyrighted by the OEM and we are not able to release them for any reason without their written permission. They denied our request to release them for bidding purposes.

· Do you have an operating narrative for the PLC/controller

· The written operation of the existing unit is under copywrite protection also. However, the basic operating sequence for the baling system is:

1. The baling system operation is initiated when the hydraulic power unit is powered on to provide hydraulic flow/pressure and the human-machine interface (PLC) system is booted up.

2. Feeding Cycle: When sufficient lint has accumulated on the lint slide, the charge door is opened by the two charge door cylinders and the electrically powered feed belt and drum feed lint into the charge box for a preset period of time. After the preset feeding timer has expired on the feed belt and drum the charge door is closed by the charge door cylinders.

3. Tramping cycle: Once the charge door is closed, the single acting 14” diameter main ram extends to push the lint into the main press box before it retracts under gravity. The spring loaded “dogs” located at the base of the press box restrain the lint in the press box until the next charge of lint is pressed in by the main ram. Tramping cycles repeat until the main ram pressure reaches a preset level indicating that there is sufficient lint in the main box to press out a full bale weighing approximately 500 lbs.

4. Final compression cycle: Once the main box contains sufficient lint to form a 500 lb bale of lint, the main ram extends to compress the bale to maximum density. The final position of the main ram holds the bale in maximum compressed form so that metal bale ties can be applied to the lint from outside the baling chamber. The main ram holds the bale in compressed form until the ties are applied and the press operator manually signals the system to lower the main ram to the bale eject position at the base of the main press box.

5. Bale eject sequence: When the system receives the signal from the operator to lower the main ram to eject position, the front and rear door lock cylinders and the bale end door lock cylinders release the doors to allow the bale to lower when the main ram lowers into bale eject position at the base of the press box. When the main ram is lowered into eject position, the bale out door cylinder extends to open the main press box door so that the bale can be removed from the press box manually. The bale out door is closed manually after the bale is removed. Once the bale out door is closed, the front/rear door locks and bale end door lock are engaged. The system then returns to the Feeding and Tramping cycles.

· All of these main functions should be programmed to run both manually and automatically in the PLC program in the HMI. Manual control buttons should be included on the HMI to allow control of all press functions in manual mode.

Existing System Photos:

Control console with HMI display.

Lint slide on left side of bale press.

Front view of press showing main bale out door and lower track.

Bale out door track with limit switch at end. Pressure gauge shown indicates main ram pressure 0-5000 psi.

Rear view of bale press showing rear door with steel bale ties ready to be manually installed. Door lock cylinders are located on top of rear door assembly.

Image of lint charge box located below the main floor of the gin plant building. Pipe work extends from the existing HPU to the base of the 14” diameter main ram. High voltage and control wiring located in conduit and channel box mounted to floor beams.

Side view of the charge door, charge door cylinder, charge box, and strain rod.

Existing HPU installed in the basement of the gin plant building.

Rear view of the existing HPU showing main lines running to the water jacket oil cooler.

Back view of the existing HPU showing pump and valve assemblies.

Opposite side view of the charge door, charge door cylinder, charge box, and strain rod.

Rear view of the existing HPU.

Full rear view of the existing HPU and bale press system below the main floor of the gin plant building.

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