Patent Publication Number: US-11641870-B2

Title: Roasting system with clean emissions and high thermal efficiency

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/835,547, filed Mar. 31, 2020, now U.S. Pat. No. 11,013,253, which is a continuation of U.S. application Ser. No. 16/525,328, filed Jul. 29, 2019, now U.S. Pat. No. 10,602,764, which is a continuation-in-part of U.S. application Ser. No. 15/949,903, filed on Apr. 10, 2018, now U.S. Pat. No. 10,362,798, which claims priority to U.S. Provisional Application No. 62/485,206, filed Apr. 13, 2017, each entitled “ROASTING SYSTEM WITH CLEAN EMISSIONS AND HIGH THERMAL EFFICIENCY” each of which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure pertains to the roasting of food products, particularly to beans, and more particularly to coffee beans. Yet more particularly the present disclosure describes a roasting system that has improved gas or air handling to improve both emissions and energy efficiency of the roaster in a compact size. 
     BACKGROUND 
     Food roasting machines are in wide use. One particularly common roasting machine is utilized to prepare coffee beans to be either packaged or ground and brewed. The roasting process consumes considerable energy and, without some emissions treatment, emits noxious gases. To reduce the emissions, various solutions have been employed such as those that utilize high temperature incineration of the output stream along with costly filtration. The incineration adds to the energy consumption and complexity of the roasting system. In addition, the practice of incineration also often involves installation of costly ventilation systems, which some buildings are unable to accommodate. There is an ongoing need to find better designs that reduce energy consumption and provide a clean output. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    is a block diagram schematic of a first embodiment of a roasting system. 
         FIG.  2    is an electrical block diagram of an example roasting system. 
         FIG.  3    is a flowchart representing an example sequence of operation for a roasting system. 
         FIG.  4    is a graphical representation of an example of a roasting profile including graphs of temperature (solid) and humidity (dashed) versus time. 
         FIG.  5    is a flowchart representing a process that can take place during a roasting operation. 
         FIG.  6    is a flowchart depicting an example method by which a controller modulates temperatures for catalytic converter and roasting chamber for a given operating mode, according to an embodiment. 
         FIG.  7    is a block diagram schematic of a second embodiment of a roasting system. 
         FIG.  8    is a flowchart of an embodiment of an embodiment of a method for starting up the system of  FIG.  7   . 
     
    
    
     SUMMARY 
     In an aspect of the disclosure, a bean roasting system includes a roasting chamber, a plurality of components, a drum bypass valve, and a controller. The roasting chamber has a gas inlet and a gas outlet coupled to a recirculating gas flow path. During operation, gas flows out of the gas outlet, through the recirculating gas flow path, and back to the gas inlet. The plurality of components are fluidically coupled to and at least partially define the recirculating gas flow path. The plurality of components includes a cyclonic separator, one or more heaters, a catalytic converter, and a main blower. The drum bypass valve couples the main blower to the cyclonic separator while bypassing the roasting chamber. The controller is configured to at least control a state of the one or more heaters and the drum bypass valve to define a plurality of operating states. The operating states are defined by temperatures of at least the roasting chamber. 
     In one implementation, the one or more heaters includes a main heater and an auxiliary heater. The main heater can be fluidically coupled between the cyclonic separator and the catalytic converter. The auxiliary heater can be fluidically coupled between the main blower and the roasting chamber gas inlet. The controller can be configured to separately control a state of the main heater and a state of the auxiliary heater to define the plurality of operating states. 
     In another implementation, the main blower is coupled between the catalytic converter and the roasting chamber. The controller can be configured to control a state of the main blower to define the plurality of operating states. 
     In yet another implementation the system includes an inlet valve and blower unit coupled between an ambient air inlet port and the roasting chamber. The inlet valve and blower unit provides added ambient air to the main blower to replace air that is released from the system. 
     In a further implementation one of the operating modes is a startup operating mode in which the drum bypass valve is closed or diverts less than 10 percent of a gas flow from the main blower to the cyclonic separator. This allows most or all of heat from the main heater to quickly raise a temperature of the roasting chamber. 
     In a yet further implementation one of the operating modes has the drum bypass valve diverting 50 to 90% of air from the main blower to the cyclonic separator. This allows the main heater to more rapidly raise a temperature of the catalytic converter. 
     In a second aspect of the disclosure, a bean roasting system includes a roasting chamber, a plurality of components, a drum bypass valve, and a controller. The roasting chamber has a gas inlet and a gas outlet coupled to a recirculating gas flow path. Gas flows out of the gas outlet, through the recirculating gas flow path, and back to the gas inlet. The plurality of components are fluidically coupled to and at least partially define the recirculating gas flow path. The plurality of components includes a cyclonic separator, a main heater, a catalytic converter, a main blower, and an auxiliary heater. Along the recirculating gas flow path, gas flows out of the roasting chamber through the gas outlet, through the cyclonic separator, through the main heater, through the catalytic converter, through the main blower, through the auxiliary heater, and back into the roasting chamber through the gas inlet. The drum bypass valve couples the main blower to the cyclonic separator. The drum bypass valve diverts a percentage of the air flow from the main blower to the cyclonic separator while bypassing the roasting chamber. The percentage can vary from zero to 90 percent. The controller individually controls some or all of the plurality of components to effect or produce operating states. Operating states are defined in part by various parameters including two or more of a roasting chamber temperature, a catalytic converter temperature, and a flow rate of gas through the roasting chamber. 
     DETAILED DESCRIPTION 
       FIG.  1    is a block diagram schematic of a first embodiment of a roasting system  2 , according to an embodiment. Roasting system  2  includes a roasting chamber  4  having a gas outlet  6  and a gas inlet  8 . A gas conduit  10 , in combination with other relevant components discussed below, defines a recirculating gas flow path (referenced herein interchangeably as gas conduit  10  or recirculating gas flow path  10 ) and is coupled to and includes the roasting chamber  4 . The recirculating gas flow path  10  performs a number of functions including removing debris and noxious gases from the roasting process and regulating a temperature of the roasting chamber  4 . The roasting system  2  also includes a bean hopper  12  for a loading unroasted beans before they are inputted to the roasting chamber  4 . Between the bean hopper  12  and the roasting chamber  4  is a load valve  14  for releasing the beans from the hopper  12  into the roasting chamber  4 . An unload valve  16  is for releasing the beans to a bean cooling system (not shown). 
     During operation of the roasting system  2  a flow stream  18  of gas is established in the recirculating gas flow path  10  from the gas outlet  6  to the gas inlet  8  of the roasting chamber  4 . After leaving the gas outlet  6  the flow stream  18  passes to a cyclonic separator  20 , which removes debris from the gas flow stream  18  that is collected below the cyclonic separator  20 . 
     The flow stream  18  then passes to a variable diverter  22 . Variable diverter  22  splits the gas flow path  10  into at least two flow path segments including a treated flow path segment  24  and a bypass flow segment  26 . The variable diverter  22  controls a “bypass percentage,” which is a percentage of the flow stream  18  that is diverted into the bypass flow segment  26 . The bypass percentage can be varied between zero percent to 100 percent of the mass flow of the flow stream  18 . When the bypass percentage is zero then all of the mass flow of the flow stream  18  is flowing through the treated flow path segment  24 . When the bypass percentage is X, then 100−X percent of the mass flow of the flow stream is passing through the treated flow segment  24  and X percent of the mass flow of the flow stream  18  is passing through the bypass flow segment  26 . When the bypass percentage is 100, then all of the mass flow of the flow stream  18  is passing through the bypass flow segment  26 . 
     The treated flow segment  24  includes a heater  28  and a catalytic converter  30  in a fluidic series. In the embodiment shown in  FIG.  1   , the heater  28  is the main heater  28  for the catalytic converter  30  and the roasting chamber  4 . The catalytic converter  30  has an operating temperature (referred to as a catalyst temperature T CT ) that is used for catalysis. A catalyst temperature T CT  is typically in a range of 500 to 1000 degrees Fahrenheit. On the other hand, the roasting chamber  4  has a roasting chamber temperature T RC  that can vary between 150 and 500 degrees Fahrenheit depending upon a desired roasting process and a step within the process. 
     The bypass flow segment  26  is coupled to a mixing chamber  32  (also referred to herein as a junction  32 ). The mixing chamber  32  (junction  32 ) defines the point at which the separated or split flow paths recombine into one flow path. Between the junction  32  and the gas inlet  8  of the roasting chamber  4  is a main blower  34 . 
     Coupled to the bypass flow segment  26  is an inlet component  36  to allow ambient air to enter the recirculating gas flow path  10 . The inlet component  36  includes an inlet control valve and inlet blower coupled in series to allow and force ambient air into the recirculating gas flow path  10 . Coupled to the mixing chamber  32  is a outlet component  38  to release gas from the recirculating gas flow path  10  to the ambient environment. The outlet component  38  includes an outlet control valve, a condenser, and a filter in series. 
     The roasting system  2  employs various sensors  40  including temperature sensors T. These sensors  40  are utilized to enable a closed loop control of various processes within the roasting system  2 . 
     In alternative embodiments the bypass flow segment can include an auxiliary heating and/or cooling temperature modulator  44 . In another alternative embodiment the main blower  34  can be located at other locations in the recirculating gas flow path  10  or multiple blowers can be employed. In yet another alternative embodiment, the inlet component  36  may be integrated into the mixing chamber, and the outlet component  38  may be moved to a point in the fluid flow path that is immediately after the catalytic converter. 
       FIG.  2    is an electrical block diagram of the roasting system  2  of  FIG.  1   . Some reference numbers in  FIG.  2    correspond to reference numbers in  FIG.  1   . Roasting system  2  includes a controller  42  that receives signals from sensors  40  and provides control signals to various components including valves  14  and  16 , variable diverter  22 , main heater  28 , main blower  34 , inlet component  36 , outlet component  38 , and optionally an auxiliary temperature modulator  44  (providing heating and/or cooling). 
     Controller  40  includes a processor  46  coupled to an information storage device  48 . The information storage device  48  includes a non-transient or non-volatile storage device (e.g., non-transitory processor-readable medium) storing software (e.g., instructions) that, when executed by processor  46 , controls the various components of roasting system  2  and provides functions for which the controller  42  is configured. The controller  42  can be a located at one location or distributed among multiple locations in roasting system  2 . For example, controller  42  can be disposed within a housing (not shown) of roasting system  2  and/or a housing of an appropriate component of roasting system  22  such as a housing of the variable diverter  22 . The controller can be electrically and/or wirelessly linked to the various components of roasting system  2 . 
     The controller  42  is configured to define and activate a plurality of different predetermined or predefined operating modes. Each operating mode can define a step or process in a sequence of steps and processes that are executed during the operation of the roasting system  2 . An example sequence will be described with respect to  FIG.  3   . 
     A particular operating mode can be defined, for example, in part by a time duration and a state of various components of the roasting system  2 . States that are directly controlled are those of components that receive direct control signals from the controller  42 . Examples of directly controlled states include the bypass percentage of the variable diverter  22 , an output power of the main heater  28 , an airflow rate of the main blower  34 , and a control of the inlet and outlet components  36  and  38  respectively. An optional example would be control of auxiliary temperature modulator  44 . 
     States that are indirectly determined are those states that are a consequence of those states that are directly determined. These include a temperature of the roasting chamber  4  and an internal temperature of the catalytic converter  30 . These temperatures are determined (and thereby indirectly controlled) through the control of the main heater  28 , the main blower  34 , and the variable diverter  22 . 
     Controller  42  reads signals or data from sensors  40  indicative of various temperatures within the roasting system  2 . These signals or data may be indicative of a temperature of the roasting chamber  4 , the catalytic converter  30 , or various portions of the recirculating flow path  10 . The controller  42  then modulates the directly controlled states to maintain desired temperature set points. 
       FIG.  3    is a flowchart representing an example sequence of operation  50  for the roasting system  2 . Each step of the operational sequence is based upon a predetermined operating mode an indicator for which is stored in controller  42 . For each of these steps the controller  42  controls various components as discussed with respect to  FIG.  2   . 
     Step  52  represents an initial state of the roasting system  2  after it has been off long enough to equilibrate with an ambient environment. The heater power is zero, meaning that no power is being sent to main heater  28 . The main blower  34  is off. As a result the catalytic converter  30  temperature and the roasting chamber  4  temperatures are both at ambient temperature which can be about 70 degrees Fahrenheit. 
     Step  54  represents a pre-heat mode for the roasting system  2 . This operational mode can have a time duration of about 30 minutes. During this mode the power delivered to the main heater  28  is in a “high” state. In one implementation the power delivered to main heater  28  is more than 75 percent or even 100 percent of the maximum power level that is used for the main heater  28 . The main blower  34  is operated in a “high” state. In one particular implementation the main blower  34  is operated with a flow rate of 200 cubic feet per minute, and the bypass percentage starts out at a low value or less than 10 percent or even zero and then ramps up to bypass percentage of more than 50 percent, more than 75 percent or about 85 to 90 percent. In another implementation, the bypass percentage is kept at a low value throughout preheat, and the blower speed is decreased as the system heats up in order to reduce the delivery energy to various parts of the system. In this case, the heater temperature remains high, but the energy drawn and outputted by the heater is lower due to the decrease in energy transport. During the pre-heat mode the temperature of the catalytic converter  30  ramps up from ambient temperature to an effective catalytic temperature in a range of 500 to 1000 degrees Fahrenheit. In one implementation the catalytic temperature is about 800 degrees Fahrenheit. The roast chamber  4  temperature also ramps up to a temperature range to begin the roasting process. In one embodiment this temperature is in a range of 300 to 400 degrees Fahrenheit or about 350 degrees Fahrenheit. 
     Step  56  represents a standby mode that has an indeterminate duration. During this operational mode the power delivered to the main heater  28  is in a “low” state. In one implementation the power delivered to heater  28  is less than 50 percent in a range of about 5 to 15 percent of the maximum power level that is used for the main heater. This low main heater  28  power is all that is used to maintain the catalytic converter  30  temperature and the roasting chamber  4  temperature. In one implementation, the main blower is operated in a “low” state. In one implementation the main blower is operated with a flow rate of 100 cubic feet per minute (CFM). In this case, the bypass percentage is more than 50 percent, more than 75 percent, or in a range of about 85 to 90 percent. In another implementation, the main blower operates at an output less than 100 cubic feet per minute (CFM), and the speed is modulated to control the energy distribution throughout the system. In this case, the bypass percentage is kept low, around 0-10 percent. In all cases, catalytic converter  30  temperature is in a range of 500 to 1000 degrees Fahrenheit or about 800 degrees Fahrenheit. The roasting chamber  4  temperature is in a range of 300 to 400 degrees Fahrenheit or about 350 degrees Fahrenheit. 
     Step  58  represents an operational mode in which the valve  14  is opened to load beans from the hopper  12  to the roasting chamber  4 . The component states for step  58  are the same as those of step  57  except that the main blower is operated in a “high” state. In one implementation the main blower  34  is operated with a flow rate of 200 cubic feet per minute. 
     Steps  60 ,  62 , and  64  represent a complete cycle for bean roasting. During these steps the main blower  34  is operated in a “high” state which can be 200 cubic feet per minute. The combined time duration for steps  60 ,  62 , and  64  is about 10-15 minutes. 
     Step  60  is an operational mode for drying the beans, which can last about 1-3 minutes. The main heater  28  is operated with a “low” power level, which can be in a range of 10 to 20 percent of maximum power. The bypass percentage is in a range of 50 to 90 percent or about 71 percent. The catalyst temperature in a range of 500 to 1000 degrees Fahrenheit or about 800 degrees Fahrenheit. The roast chamber  4  temperature is in a range of about 170 to 180 degrees Fahrenheit or about 175 degrees Fahrenheit. 
     Step  62  is a “recovery ramp” mode during which the roasting chamber temperature is increased to a roasting development temperature. The “recovery ramp” mode can have a duration of about 3-6 minutes. The main heater  28  is operated with a “high” power level which can be in a range of 75 to 100 percent of maximum power. The bypass percentage is in a range of zero to 10 percent so that some gas having a higher temperature from the main heater  28  is directed to the roasting chamber  4 . As a result, the roasting chamber temperature increases to a roasting development temperature, which can be about 390 degrees Fahrenheit. During step  62  the catalyst temperature may fall to about 650 degrees Fahrenheit. 
     Step  64  is a roasting development mode during which the temperature of the roasting chamber  4  is increased. The roasting development mode has a duration of about 3 minutes. The main heater  28  is operated with a “low” power that can be 20 to 30 percent of maximum power. The bypass percentage is in a range of 50 to 100 percent or about 76 percent. The bypass percentage can be increased while the heater input is decreased during this mode. The roasting chamber  4  temperature increases from about 390 degrees Fahrenheit to about 460 degrees Fahrenheit. The catalyst temperature increases from about 650 degrees Fahrenheit to about 750 degrees Fahrenheit. Also as part of this mode, the inlet  36  and outlet  38  components are operated to allow a one to five percent gas exchange with the ambient air environment. 
     During step  66  the valve  16  is opened to drop the roasted beans into a cooling chamber. During step  68  the beans are cooled and the system states are returned to those of the standby mode of step  56  after a preheating operation. 
     As a note, the specific states described above with respect to  FIG.  3    can vary depending on a desired “roasting profile.” In particular, the roasting chamber  4  temperature states are a function of such a roasting profile. Thus, the described sequence  50  can have variations in terms of component states and the temperatures indicated with respect to  FIG.  3    are examples for a particular roasting profile or set of roasting profiles. 
     Referring to  FIG.  1   , the sensors  40  can include humidity (designated H) and oxygen (designated O 2 ) sensors. The controller  42  can use information from these sensors to track progress of the roasting steps  60 - 64  (of  FIG.  3   ). As a unique example, the controller  42  can infer information about the roast process by analyzing the humidity versus time of gas that is exiting the outlet  6  of the roasting chamber  4 . 
     A milestone event during roasting steps  60 - 64  is a “first crack” of the beans. Once this begins, the remaining time and temperature of the roasting profile can be more accurately determined. The added time and temperature is dependent on the type of roast (e.g., light roast versus full French roast). 
       FIG.  4    is a graph of an example of temperature and humidity versus time. The dashed line represents the humidity versus time curve; the solid line represents the humidity temperature versus time curve. The values in this graph are generated using sensors  40  that are placed at or proximate to the outlet  6  of the roasting chamber  4 . As shown, a relatively sharp peak in the graph of humidity versus time corresponds to the “first crack” milestone of the roasting development step  64 . This peak in the humidity curve can be a factor in deciding subsequent steps in the roasting process. 
       FIG.  5    is a flowchart depicting an example roasting process  70 . Roasting process  70  can be similar to and/or preformed in conjunction with the roasting steps  60 - 64  except that it incorporates additional operations. According to step  72 , the humidity is monitored by the H sensor  40  at the outlet  6  of roasting chamber  4 . As part of step  72 , the controller  42  analyzes the graph of humidity versus time (or an equivalent such as a look-up table stored in memory, an equation presenting the humidity-time curve) to identify rapid changes in a magnitude of the slope and a localized maximum. 
     According to step  74 , a humidity peak is identified. This corresponds to the “first crack” of the beans. This identification of the humidity peak indicates a certain progress of the roasting process  70 . 
     According to step  76 , a response or action is activated in response to the identification of the first crack milestone. This can take any number of forms. 
     In one implementation the roast development duration is automatically adjusted based upon the milestone identification and a desired roast type. In this implementation parameters such as the heater power, airflow, and/or bypass percentages can also be adjusted. 
     In another implementation an alert can be automatically sent to a person who is responsible for the roasting operation. For example, this can be a message wirelessly sent to a mobile device that is utilized by the person. The message can provide an option for the person to adjust the roast profile based upon the timing of the milestone. 
       FIG.  6    is a flowchart depicting an example method  80  by which the controller  42  modulates temperatures for the catalytic converter  30  and the roasting chamber  4  for a given operating mode. As discussed above, the catalytic converter  30  temperature T CT  can be maintained at an optimum temperature for catalysis that tends not to change as a function of an operating mode of the roasting system  2 . On the other hand, the roast chamber  4  temperature T RC  is a function of the operating mode. 
     According to step  82  the method  80  begins with a receipt of operating parameters for an operating mode including a specified roast chamber setting T RC . The method  80  then includes two independent temperature control loops that can be executed concurrently. An example catalytic converter  30  temperature T CT  control loop is depicted by steps  84  to  88 . An example roasting chamber  4  temperature control loop is depicted by steps  90  to  94 . 
     According to step  84  a temperature T CT  of the catalytic converter  30  is monitored. As part of step  84 , the controller  42  receives temperature T CT  data for the catalytic converter  30  from a temperature sensor  40  that is within or proximate to or receiving air exiting from the catalytic converter  30 . 
     According to step  86  a determination is made as to whether the temperature T CT  of the catalytic converter  30  is within a specified range. This specified temperature range is within an overall temperature range of for example 500 to 1000 degrees Fahrenheit. In one implementation the specified temperature range is narrower and centered around a temperature of about for example 800 degrees Fahrenheit. If the temperature T CT  of the catalytic converter  30  deviates from the specified range, then the method  80  proceeds to step  88 . According to step  88  a power delivered to the main heater  28  is adjusted to counteract the temperature deviation determined in step  86 . As part of step  88  the controller  42  sends a control signal to adjust a power input to the heater  28 . Then steps  84  and  86  are repeated. When according to step  86  the temperature T CT  of the catalytic converter  30  is within the specified range, the loop proceeds to step  84  to continue monitoring the temperature T CT  of the catalytic converter  30 . 
     According to step  90  a temperature T RC  of the roasting chamber  4  is monitored. As part of step  90 , the controller  42  receives temperature T RC  data for the roasting chamber  4  from a temperature sensor  40  that is either within or proximate to or receiving air exiting from roasting chamber  4 . 
     According to step  92  a determination is made as to whether the temperature T RC  of the roasting chamber  4  is within a specified range. This specified range is based upon the specified roast chamber temperature setting T RC  for the current operating mode from step  82 . If the temperature T RC  of the roasting chamber  4  deviates from the specified range, then the method  80  proceeds to step  94 . 
     According to step  94 , the variable diverter  22  is adjusted to counteract the deviation. As part of step  94  the controller  42  sends a control signal to the variable diverter  22 . In response to the control signal, the variable diverter  22  increases or decreases the bypass percentage. For example, if the temperature is too high then the bypass percentage will be increased. Then steps  90  and  92  are repeated. When according to step  92  the temperature T RC  of the roasting chamber  4  is within the specified range, the loop proceeds to step  90  to continue monitoring the temperature T RC  of the roasting chamber  4 . 
     The two temperature control loops for the catalytic converter  30  and the roasting chamber  4  continue independently of each other from the perspective of a control system operation. However, they do have an indirect dependency. When the heater  28  is adjusted according to step  88  this will impact the temperature T RC  of the roasting chamber  4 . Then the control loop for the roasting chamber  4  will most likely need to respond. 
       FIG.  7    is a schematic block diagram of a second embodiment of a roasting system  100 . Roasting system  100  is similar to roasting system  2  except that certain components have been added or reconfigured to add additional flexibility in defining operating modes. Thus, the previously-described operating modes can all be defined and effected using system  100 . 
     System  100  includes a roasting chamber  102  that is fluidically coupled to a recirculating gas flow path  104 . The roasting chamber  102  has a gas inlet  106  and a gas outlet  108 . Recirculating gas passes out of the gas outlet  108 , through the recirculating gas flow path  104 , and to the gas inlet  106 . 
     A plurality of components  110 - 120  at least partially define the recirculating gas flow path  104  including a cyclonic separator  110 , a main heater  112 , a catalytic converter  114 , a mixing device or chamber  116 , a main blower  118 , and an auxiliary heater  120 . In the illustrated embodiment, gas flows out of the gas outlet  108 , through the cyclonic separator  110 , through the main heater  112 , through the catalytic converter  114 , through the mixing device  116 , through the main blower  118 , through the auxiliary heater  120 , and back to the gas inlet  106 . 
     The plurality of components  110 - 120  are coupled to the recirculating gas flow path  104 . Being coupled to the gas flow path  104  means that the gas flow path  104  individually and sequentially passes through the components  110 - 120 .  FIG.  7    depicts a particular sequence, but other sequences are possible and may provide the same function. Compared to the system  2  of  FIG.  1   , the system  100  of  FIG.  7    provides an added ability to define operating modes. 
     A drum bypass valve  122  defines a bypass recirculating gas flow path  124  that bypasses the roasting chamber  102 . The bypass valve  122  diverts a percentage of the gas flow received from the main blower  118  (e.g., from zero to up to 90 percent). In the illustrated embodiment, the bypass valve  122  directly couples the main blower  118  to the cyclonic separator  110 . 
     An inlet valve and blower unit  126  couples an ambient inlet port  128  to the main blower  118 . This allows outside ambient air to enter system  100  to replace air that exits system  100 . 
     A bean hopper  130  is coupled to the roasting chamber  102  by valve  132  for initially dispensing beans into the roasting chamber  102 . After a roasting process takes place, the beans can be transferred to a cooling chamber  134 . During a cooling process, air from the cooling chamber  134  can be routed through various components including a final filter  136  before being ejected into an outside atmosphere. The exit of air from the final filter  136  is offset by the air received by the inlet valve and blower unit  126 . 
     A controller  140  is controllably coupled to components of the system  100  including any or all of roasting chamber  102 , cyclonic separator  110 , main heater  112 , catalytic converter  114 , main blower  118 , auxiliary heater  120 , drum by pass valve  122 , inlet valve and blower unit  126 , bean hopper  130 , valve  132 , sensors T and/or other components. The controller  140  includes a processor  142  coupled to an information storage unit  144 . The information storage unit  144  includes a non-transient or non-volatile storage device (e.g., non-transitory processor-readable medium) storing software instructions. When executed by the processor  142 , the software instructions operate components of system  100  during a bean roasting process. The operation includes operation of a plurality of the components of system  100  to effect different operating modes. The different operating modes can be at least partly defined by a temperature of the roasting chamber  102  and/or the catalytic converter  114 . 
       FIG.  8    is a flowchart of an embodiment of a method  150  for starting up system  100 . According to  152 , system  100  has components that are cooler than is desirable during operation. Controller  140  receives operating parameters such as a bean development roasting temperature. According to  154 , controller  140  monitors signals from temperature sensors (T). “Step  154 ” actually occurs continuously during further steps and operations. 
     According to  156 , the roasting chamber  102  is raised to a specified operating temperature. During  156 , the drum bypass valve  122  is either closed or diverts less than 10 percent of a flow of gas from the main blower  118 . The main heater  112  and auxiliary heater  120  can operate at near full power levels to maximize the temperature rate increase of roasting chamber  102 . 
     According to  158 , the roasting chamber  102  is at or near the specified operating temperature. During  158 , the drum bypass valve  122  is opened to divert 50 to 90 percent of the gas flow from main blower  118  directly to the cyclonic separator  110 . Then, the main heater  112  can be used to further raise a temperature of the catalytic converter  114  (which had been partially raised during  156 ) until it reaches a desired operation temperature. During  158 , the auxiliary heater  120  is primarily used to maintain the roasting chamber  102  at the desired operating temperature. 
     Earlier-discussed methods such as method  50  of  FIG.  3    can apply to system  100 . Compared to system  2 , system  100  has more degrees of freedom and to provide various temperature-related operating modes. Thus, with system  100 , all operating modes previously discussed are enabled. 
     The specific embodiments and applications thereof described above are for illustrative purposes only and do not preclude modifications and variations encompassed by the scope of the following claims.