Author Topic: KapoK gas roaster  (Read 17214 times)

Offline 9Sbeans

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KapoK gas roaster
« on: December 27, 2014, 05:33:08 PM »
Background

As discussed in 1-lb Sample Roaster Options,  I’ll document my experience, the purchasing of KapoK K500 gas coffee roaster from Taiwan, for the reference of our group members.


KapoK?

Many coffee roasters are made in Taiwan (e.g. HotTop, Quest M3, Aillio, Huky, BellaTW/Yang-Chia, and KapoK) and they occupy diverse market segments.  For the three 1-pound gas roasters, Huky 500 (~$1400) is an economical home roaster, whiles both BellaTW (Mini-500plus, ~$3400) and KapoK (KapoK K500, ~$6000) are more oriented toward commercial setting.  KapoK continuously sponsored regional coffee roasting competition, and gained most of its popularity after Yu-Chuan (Jacky) Lai got the World Coffee Roasting Championship in 2014 - Jacky owns three coffee roasting shops and uses KapoK 1-kg and 5-kg roasters.  Since Jacky operated BellaTW roasters in the Taiwan regional competition and eventually got his title by the using of a Giesen W6, it should be fair to say that both BellaTW and KapoK are capable commercial roasters.


Hearsay

Some hearsay while I was researching KapoK.  It is said that KapoK made and exported wood heating stoves or something to Germany, and thus KapoK had better safety features/build quality.  I have never confirmed this with the owner, because it could be merely marketing strategies and I didn’t base my buying decision on it. 
Some people claim that, KapoK use a computer-based aerodynamics simulation to design their fan/air flow, whiles most other roster makers still go with the old-school, trial-and-error approaches.  It is interesting to know other roasters with solid/perforated drum options for distinct air flow control and roasting profiles.  However, I’m no expert to know which roaster has superior internal air flow/minimized turbulence design. 


Communications

I emailed several companies in Taiwan regarding detail specs/pricing discounts of their roasters.  Among these companies, KapoK was the slowest responding one.  For example, Mr. Jet Huang, the sales manager of BellaTW, almost always responded my inquiries within couple of days.  On the other hand, Mr. Frank Lin, the owner of KapoK, could have delayed answering my questions for up to two months, to a point that I almost forget the existent of our “conversation”.  In the bright side, Frank did address most of my question or even some of my harsh critics.  In my opinion, the slow responding was due to his pondering of answer, and he wouldn’t reply if he doesn’t have the answer yet.  During the evaluation phase, the communication was not good, but adequate.  After I decided to purchase KapoK, there was about 50-days of build time without exchanging e-mails between us.
I got notice when they were performing the final testing of the roaster, received the UPS tracking number, and the communication had greatly improved since then.  Frank asked me to inspect the outlook of the package for potential shipping damage, and answered my installation questions immediately.  He also gave me his personal Line and Skype contacts even with the 12-hours time zone difference.  I did not bother to call him though, because I did not encounter any installation issue.  The user’s manual was concise with several typos; the illustrative pictures explained virtually everything.     


Pricing

Recently the US dollars are gaining strength in exchange of a basket of Asian currencies.  It was around 1:30 (USD: New Taiwan Dollars) last year and now reaching 1:31.8.  My price quote was in US dollar though.  If you really want to buy a KapoK roaster, ask Frank nicely and try to negotiate some discounts even without a group-buy.  YMMV. 


Delivery

I checked several shipping companies including UPS in Taiwan.  Since I did not have the actual size of the package at the time, I only had estimated quotes from these companies.  Basically KapoK chose UPS air freight delivering to my door, and prepared all necessary documents.  I got tracking number, signed the package, received statement from UPS for US customs duties (2.7%) & brokerage charges ($7), and made my payment to UPS by phone.  I think the package had been inspected when imported.  Shipping took about 10 days, and there was no damage occurred.


Setup

The assembly of the machine was easy: electricity (wall socket to roaster, roaster to cyclone), gas (propane), and vent.  The body of the roaster was heavy though; need two people lifting it from the ground.  I sent KapoK a standard Low Pressure Propane Regulator Assembly (http://gashosesandregulators.com/lowpressureregulators.html) for the fitting test.  Plug-in-and-Play.
« Last Edit: April 27, 2016, 02:42:41 PM by Joe »

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #1 on: December 27, 2014, 05:38:22 PM »
pic-01
The package was secured; no wobbly parts

pic-03
The venting outlet and gas inlet were sealed by aluminum tape (left side of the roaster). All parts packed well (bottom shelve). 

pic-07
Cyclone.  Tools at the background were included with the shipment. 

pic-08
The white LED lamp is turned on with the main power.  K500 is a miniature of K1.0.  The bean hopper and the handle of bean trier of K1.0 are decorated by a designer, and those are plain in K500. 

pic-09
Temperature in Celsius.  BT (red numbers at the center panel; the green 250 is the alarm temperature) and ET (lower right corner of this picture)

pic-10
Gas pressure control dial & gauge (made in Germany, units in mmAq)); fire observing window

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #2 on: December 27, 2014, 05:42:00 PM »
pic-11
The trap door (hold by strong magnet) is to access motors and for the adjusting alignment of the drum.

pic-12
The chaff collecting drawer below the bean discharge door is also hold by magnet.  Most of the chaff is collected by the cyclone, and not much here.

pic-13
Powerful cooling fan under this cooling tray.  Notice the red circle I highlighted - the plate is not cut in straight edge nearby the screw bolt.  This is an example of aesthetic design in addition to the function.

Offline hankua

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Re: KapoK gas roaster
« Reply #3 on: December 27, 2014, 09:10:43 PM »
Awesome!

Pretty slick controls; what kind of burners does it have?
Roasting drum construction?

That's one sophisticated roaster......


Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #4 on: December 28, 2014, 05:13:25 PM »
Awesome!

Pretty slick controls; what kind of burners does it have?
Roasting drum construction?

That's one sophisticated roaster......
I have the KapoK K500 specs:

Capacity: 200g ~ 600g
Roasting System: Hybrid (direct heating on bin & heated air)
Fuel Source: GAS (LPG or LNG)
Burner: Low gas consumption burner
Heat Isolating Layer: Non-asbestos fiber isolation
Gas Safety Interlock: Gas detection prior to ignition
Overheating Protection: Temperature setting with alarm
Flow Volume Control: Step-less adjustable blower motor
Material of Bin: Stainless inner drum
Bin Drive: AC motor with metal chain
Cooling Blower: Independent cooling blower
Temp. Display: 4 digit display with 0.1 degree resolution
Temp. Detection: 2x at Bean & Exhaust
Paint Coat: RoHS Compliant Metallic gloss

AFAIK, it’s a single-pass roaster with a solid drum (304 stainless steel inner drum).  However,  the circular plate at the inside end of the cylinder is meshed.  The hot air flow is likely coming from that mesh end to the exhausting chimney at the bean loading end (observing end).
The burner is arranged in array.  I will try to take several pictures of them tomorrow.

Offline hankua

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Re: KapoK gas roaster
« Reply #5 on: December 29, 2014, 07:32:20 AM »
I see the rear of the roaster has a trap door by the cyclone. The cyclone itself is interesting in that the curved part is integrated into the unit rather than the cylinder w/inverted cone like many others. Space saving design?

Do you think the airflow is front to back or back to front?

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #6 on: December 29, 2014, 03:05:54 PM »
The Drum
This is from the bean charging side (pic-08).

pic-14 
I opened the bean discharging door and took a picture of the drum.  The pencil was for scaling. 

pic-15 
I removed the bean loading hopper (top-center of pic-08) and took a picture from the opening.  As can be seen, the wall of the drum is solid, and I think the hot air can flow into the drum from the mesh.

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #7 on: December 29, 2014, 03:08:37 PM »
The drum-driving motor
pic-16  (open up the trap door in pic-11)
A motor drives the drum by chain.  Upper left (with silicone tubing connection) could be a pressure sensor.  Pencil for scaling.

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #8 on: December 29, 2014, 03:12:03 PM »
Burner

pic-17 flame (two rows)
pic-18 flame (three rows)

I took the pictures from the flame observing window.  The burner is in 3 x 8 arrays.  It could be in two rows or three rows.  The red rod at the left on top of the flame (in pic-18) could be the igniting device.

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #9 on: December 29, 2014, 03:16:01 PM »
pic-19

Cyclone
Frank sent me the picture of a K500 prototype showing the setup of the cyclone.  The cyclone (more than 20 pounds) is supported by the exhausting pipe as marked in red circle.  For long-term maintenance, it should be un-mounted by loosening the three screw bolts in this red circle to clean the exhausting hose.  The chaff collecting container at the bottom of the cyclone is floated for easy access. 

Color coded buttons - Green
The blue arrow is pointed at a green “main electric power” button.  The green button will light on as long as there is juice.  Press this button to power up the system, including the drum motor and the white LED lamp.

Variable Drum Speed
This prototype K500 is equipped with a variable drum speed motor, with the white speed control panel above the green button.  My hunch is that it can control drum speed between 50 to 140 rpm, and they are still testing the roasting profile correlations between drum speed and the final taste. 

Variable Fan Speed
Most of the 1-pound sample roasters have an exhausting fan rotating at a fixed speed, and a mechanical shutter (or damper) is installed to restrict the airflow rate.  K500 is more sophisticated.  It is said that its design of the linear variable fan speed controller ensures the longevity of the fan motor and the reproducibility of the fan speed. 
I considered between BellaTW mini-500plus (with 12-steps mechanical damper) and K500 several months ago.  For me, variable fan speed is a feature of “it would be nice to have ”,  :P but I’m no engineer to know if it’s overkill.

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #10 on: December 29, 2014, 03:38:25 PM »
Air flow

pic-20
I removed the bean loading hopper as described in user’s manual.  There are 4 screw bolts to loosen (the 4 red circles and 4 orange circles).  Green beans can come out of the rectangular opening (green oval) and drop into the drum. 
In my guess, the hot air (blue arrows) flows cross the drum from the mesh to the hopper, and turns into the chimney.  The ET probe might be the rod located in the entrance of the chimney (between the blue arrow point and the upper-left red circle).

The distance between the flame to the drum wall is fairly close (direct heating), and the hot air flow is more resemble the indirectly heated drum roaster.  I guess it’s the reason called “hybrid”.   ::)

Offline hankua

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Re: KapoK gas roaster
« Reply #11 on: December 29, 2014, 09:26:22 PM »
Those look like ribbon burners, do they change from two row to three by gas pressure adjustment? What's the maximum Kpa possible? 3Kpa is the max on the Mini500+.

 I don't think there is a big difference between the variable fan control and precise damper; so long as the speed control adjusts proportionally.

Adjustable drum speed is nice to have, I follow manufacturer guidelines: 65 rpm for 1lb, and 80 rpm for 1/2lb charges. It can also be adjusted during the roast, something rarely discussed.

wideasleep1

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Re: KapoK gas roaster
« Reply #12 on: December 29, 2014, 09:28:29 PM »
Just wanted to thank you for sharing your sexy roaster pron! Cheers! :)

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #13 on: December 31, 2014, 01:32:42 PM »
Just wanted to thank you for sharing your sexy roaster pron! Cheers! :)

You are welcome, wideasleep1
I knew of GCBC several years ago when I read the ESPro Press Roadshow over CG, and I had an ESPro press since then.
I knew of Pharos from HB years ago and had one with serial number < 100.  Yet I haven’t registered on HB.
I learned a lot but didn’t consider myself could contribute anything, hence only a long time lurker. 

Now it’s my community service time.  ;D 

Offline 9Sbeans

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Re: KapoK gas roaster
« Reply #14 on: December 31, 2014, 01:38:33 PM »
Unit conversions

TL;DR --
Pressure: It fits a standard low pressure (propane) regulator assembly as we get in any department stores in US.
Temperature: multiply the Celsius readouts by two to get approximated Fahrenheit numbers.   
These should be customizable when you place your order; just specify your preferred readout units.


***

Here are some unit conversions:

Pressure

11 inch water column (11”WC) = 280 millimeter water (mmAq) = 2745.8 pascal (Pa)

Most of the low pressure PRESET propane gas regulator valve in US reduces the tank pressure to 10.5”WC.  Frank suggests KapoK connect to a standard 280 mmAq regulator.  On the Mini-500plus, the maximum is 3kPa.  Hence all manufacturers suggest the same propane pressure.

As can be seen on pic-10, the regulator equipped on K500 can take up to 600 mmAq, which translates to 6kPa or 20”WC.  I mention earlier that I use Steve’s “two-stage super charge” regulator which has higher pressure output than a standard one.  I can manually control gas pressure (dialing the black disk in pic-10), change the gas pressure on the fly, and easily get it higher than 350 mmAq.  However, I found it unnecessary because the burner already provides more heat than I need.
 
Frank once told me the BTU of the burner, but I couldn’t dig it out now and had just asked him again.  IIRC, it’s really a low BTU burner.  If you have Rao’s new book, on page 34 he mentions the efficiency of the most single-pass roasters are 10% - 15%.  K500 has an insulation layer outside the drum, and I expect it be at the high efficiency end.  In the home use settings, I personally prefer a lower BTU burner, presumably less hazard.  :)