Alternate Equipment Selections

P09713 Grant Garbach & Andrew Tsai

Sifting and Screening Equipment Analysis February 13, 2009

Customer Needs:

I. Determine the appropriate sifting and screening equipment.

II.  Improve product quality by reducing contaminants.

III.  Maintain or decrease the process time.

IV.  Maintain or improve process ergonomics.

Specifications from Customer:

A.  The equipment will use the 460 volts power source available at the Wegmans’ facility. This type of generic power source is the easiest to install in manufacturing facilities.

B.  The equipment will fit within a three-pallet size area to minimize the footprint to allow more room for short-term ingredient storage.

C.  The equipment will be mobile. This will allow the machine to be more adaptable for changing conditions.

D.  The equipment will meet OSHA standard for noise level under 85dB.

E.  The equipment should be washable and air-dry, possible use of compressed air at 90 to 100 psi.

F.  The equipment will be able to handle the throughput of dry ingredients including the 5% annual growth rate for the next four years.

G.  The equipment will not have parts that will contaminate the product.

H.  Can be safely operated by workers without special protection.

I.  All parts are stainless steel food grade compatible.

J.  Screen size to be mesh 10.

Customer Needs I: Benchmarking Equipments for Alternate Equipment Selections

To find the optimum equipment for Wegmans’ bread and roll scaling area, we first benchmarked the existing equipments on the market designed for this application. Below is a list of three alternative machines and reasons why they were not chosen for this project.

Option 1:

Company:

Kemutec Powder Technologies Inc.

130 Wharton Road

Bristol, PA 19007

Tel: 215-788-8013

Model Number:

K300C

Figure 1 –Kemutec Model K300C

Benchmarking Results for This Model:

·  Provides a centrifugal sifter that is non-vibrating. However, as can be seen from figure 1, the opening is too small. The operator will not be able to empty bags of dry ingredients easily. This will slow down the production process, violating customer needs III listed above.

·  The unit is not movable and will need to be installed in a set location. This violates specification C.

·  The unit requires constant feeding of dry ingredients. The machine should be on and operating at all times. This is noot suitable for Wegmans’ current process.

Option 2:

Company:

Rotex

1230 Knowlton Street

Cincinnati, OH 45223

Tel: (513) 541-1236

Model Number:

M2120

Figure 2 –Rotex Model M2120

Benchmarking Results for This Model:

·  This unit is too large for Wegmans. This violates the space requirement identified in specification A.

·  There is no easy access for dumping dry ingredients on top of the machine.

·  The equipment is not mobile, violating specification C.

·  The cost of the unit is too high to justify. Will seek equipments at lower cost.

Option 3:

Company:

Minox Elcan

325 Waverly Avenue

Mamaroneck, NY 10543

Phone: 914.381.7500

Fax: 914.381.8500

Model Number:

SXE Round

Figure 3 –Minox Elcan Model SXE Round

Benchmarking Results for This Model:

·  This unit has painted surfaces. The paint might chip off and contaminate the products. This violates specification G.

·  This unit vibrates with four corner shocks. Will need safety screens around the equipment when it is operational similar to the equipment at Wegmans. This will exceed the space requirement identified in specification B.

·  This unit has a lid as shown in figure 3. The lid cannot be removed during operation because the material inside will spill out. This will slow down the process time identified in customer needs III.

Customer Needs I: Selected Equipment

Below is the equipment chosen as compared to models from other manufacturers.

Company:

SWECO

NY representatives for SWECO

Jonathan P. Ansley

Rochester, NY Upstate

Direct: (585) 330-1754

Office: (585) 473-7848

Fax: (585) 473-2971

Model Number:

MX48

Figure 4 – SWECO Model

Benchmarking Results for This Model:

·  This model offers two power source options of 240 and 460 volts, satisfying specification A.

·  Smaller footprint compared to other models. This model has a 48-inch diameter and 8-inch port. This unit requires an equivalent of 3-pallet size area. This satisfies the space requirement identified in specification B.

·  This machine weights 820lb, but is attached to caster wheels for mobility. Since the process does not require constant movement of the machine, this should satisfy specification C.

·  Based on the conversation with the company sales representative, the noise produced by operating the machine is around 82 to 83 decibel, which is under the OSHA limit of 85 decibels. This fits specification D.

·  Easy to clean. Fully sanitizable by spraying it down with hose and air-dry. This satisfies specification E.

·  There is no paint on the machine. The unit is made of 304-stainless steel and has continuous ground welds for reliability. This satisfies specification G and I.

·  Minimal vibration. The machine oscillates within 1/8-inch lateral and transversal. Safe to load while operational. This satisfies specification H.

·  The machine can be fitted with any size mesh screen. The test run results that follow will explain the recommended screen size.

·  Based on the following analysis, the machine will meet the necessary daily capacity. This satisfies specification F.

·  Quoted for USD 17,300.

Customer Needs II: Improve Product Quality

Based on Wegmans’ Foreign Material Report, there are a total of nine incidents that can be attributed to the scaling area. Eight of the incidents were related to pieces of the ingredient bags found in the products and one of the incidents was the result of wood chip from a pallet. The customers found all nine contaminants described, causing adverse effects to the Wegmans brand. The sifting and screening equipment will prevent future contaminants from the scaling area reaching up in the products.

Due to limited data, no cost reduction can be transcribed from these nine incidents. However, sifting and screening dry ingredients is a best practice common in the food production industry and should be implemented in Wegmans.

Customer Needs III: Maintain or Reduce Process Time

Based on the customer need to maintain the process time and based on an 8 hour shift for the employee to sift, the machine would need to be capable of handling 95 bags per hour (this is in the worst case scenario). When only a portion of a bag was used each day, it was rounded up to a whole bag to account for growth factors and make sure the machine would not be a bottleneck in the process. For example, if 0.3 bags were used per day, and over an 8-hour shift it would truly only require 0.0375 bags each hour, the number was rounded up to 1. So based on the calculation that was performed this would show 8 bags per day. This occurred several times in the calculations, and doing this helps take into account the dramatic increases in material use during peak times.

All of the calculations that were performed were done using the peak usage. This was done to verify that Wegmans could use the recommended equipment anticipating 5% growth per year at peak times. All estimates were rounded up to the nearest whole unit.

The equations below were used to calculate the total bags per hour:

Equation 1:

Equation 2:

Equation 3:

Equation 4:

Equation 5:

A smaller model of the 48-inch diameter machine from SWECO had been brought to Wegmans for test runs. Below are the test results.

Table 1 – 10 lb Special Stone Ground Wheat in Mesh Size 11

This test run shows that the machine equipped with a mesh size 11 has difficulty handling specialty stone ground wheat. With a run of 30 seconds, only an average of 5.19 lbs. out of 10 lbs. passes through the machine. There is also good product loss of 0.60 lbs. out of 10 lbs., or 6.02%, with a size 11 mesh screen. Figure 5 below shows the good product remaining on the screen after the test run was complete. The sifted dry ingredients are in the white bucket above the machine.

Figure 5 – Good Product Left on the Screen (Size 11)

Another test run result with mesh size 4 can be seen below. This time rough stone ground wheat was used because it has the largest particle size, so if the machine can handle this material the rest of the material will pass through as well.

Table 2 – 10 lb Rough Stone Ground Wheat in Mesh Size 4

The second test run shows that with mesh screen size 4, the machine can handle the rough stone ground wheat with larger particles than the specialty stone ground wheat. Based on the test run, the scaled down machine can sift through 10 lbs. of rough stone ground wheat in approximately 10 seconds, but the flow rate of the dry ingredients out of the machine is much slower than the ingredients passing through the screen. This will not be an issue for the recommended 48-inch machines because the exit port is much larger at 8-inches, and SWECO can fit two openings as needed. The scale factor from the smaller machine to the 48-inch machine is 10 times. That means based on the test run, with a screen mesh size of 4, the recommended 48-inch machine can sift through a 50 lb bag of the rough stone ground wheat in 5 seconds. The port where the material exits the equipment limits the machine’s capacity to approximately 8100 lbs or 162 bags per hour assuming the machine is running constantly.

A third test run of brown sugar was done. The results show that due to the stickiness of the material, brown sugar cannot be sifted. Figure 6 below shows how the brown sugar clumps together on the outside edge of the screen.

Figure 6 – Brown Sugar on the Screen with Respect to a Pen

A screen size of 4 is recommended for the machine. The table below indicates that a weekly loss of $291 will occur if a mesh size screen of 11 were to be implemented.

Table 3- Material Loss Base on a Weekly Amount