9.0 Notes (page 7)
F.22.214.171.124.1 Control Location Data
This function provides control of all operational tasks at the location, including those Habitation and Transport tasks not controlled internally to their respective elements. An example of this would be deferring Habitation clothes washing to manage peak location power requirements. Internal control of elements is provided as needed. For example, a local controller may monitor the temperature of a kiln, and communicate with the outside to get new tasking and report status. The control function includes human future planning and retrospective analysis, generating real time commands to elements, displays, observation of conditions, and operations data collection. It also includes tasks like accepting outside sales orders, acquiring outside supplies, and internal bookkeeping and output allocation. It is implemented by a mix of local and remote controls, and a mix of human, automated, and software commands and actions.
Control Location Requirements
- 2.3 Automation - The goal is to reduce human labor hours by 85% relative to the 2013 US average for similar tasks. The expectation is this will require extensive control software at the location and individual element levels, and linking sensors and effectors across the whole location to enable operation as a coherent system. Initial levels of automation will not reach the 85% goal, but we will incorporate what already exists and is possible, with an eye to increasing it over time as the location develops. This requirement is also distributed across the rest of the location functions as far as each individual element including necessary sensor and control hardware to meet the higher level automation goals.
- 2.3 Autonomy - The goal is to control at least 85% of production operations and maintenance locally. This places decision-making mostly in the hands of the location residents and local project members. We consider this desirable in itself, but also shortens decision and response times from a human and technical standpoint. During early growth a higher level of outside planning and real time control may be needed, due to lack of people and systems locally. This requirement imposes needs on human skills and the control network to reach the desired level.
Control Location Alternatives
- Control of External Flows - This includes managing input and output flows at the location level. It collects resource needs from lower level functions, such as power and data bandwidth, determines how much is not being supplied internally by the location, and acquires sufficient outside supply to meet the needs. It also tracks delivery of products to customers, and waste outputs which are not recycled and ensures they are properly disposed of. External inputs and outputs from the standpoint of the location can be divided into:
- - Outside the program, which includes the natural environment and human civilization,
- - Other program phases, which will be only Phase 0 at the start of building this location,
- - Other environment ranges than Temperate, which there likely will be none at first, and
- - Other locations in the Temperate range, which we also expect none at first, since this is the first location, but can add new ones later.
- This task conventionally is performed as part of Manufacturing Resource Planning (MRP II), a factory planning method. We are unlikely to invent a new method for this task, so it seems more feasible to adapt existing methods to our situation, where part of the factory output goes to building more factory. MRP II can be used for other parts of the control function. We will use it where it applies, and we may build custom spreadsheets, databases, websites, and software where needed. The task will require human labor to interact with outside entities, and at a minimum oversee the control task. At first it is expected to require more manual data inputs and calculations, but the goal over time is to automate this task along with the other control jobs.
- Location Control of Production - This includes issuing production orders to individual elements, either manually through humans, or preferably automated through an electronic network. The production orders are based on the Planning and Scheduling tasking for complete jobs, such as "build a new solar furnace". The design and assembly drawings or files are used to identify specific production elements to carry out the production sequence. Where not fully automated, instructions are given to humans to carry out. Where no production element can do the task, a request for outside supply is made. Where inventory is needed by a production element, additional production orders are generated in a cascade. For example, if the furnace requires structural steel parts, then orders for more steel inventory are generated along with fabricating the parts, and in turn orders for ore reduction or scrap purchase. The production orders are based on known capacities for the various machines and processes.
- To the extent they are automated, the production elements will have their own local control software to do the discrete operations, and will report back status to the control system. The system elements to perform this task will include humans, control software, which is likely to be custom, and computers and a network to deliver the orders and track progress.
- Location Control of Habitation - This sends commands and collects data from Habitation elements as needed for general location operation. Examples are street lighting and landscape watering. Private living space will mostly be controlled by the residents who live there, but scheduling resource loads like laundry can help manage overall location power demands. Data collection for things like water use will feed back to the water supply elements. As noted under the Habitation/Provide Information function, the data network will be shared across the location.
- Location Control of Transport - This sends commands and collects data from internal and external Transport elements as needed for location operation. Fixed transport like clean water supply and waste water collection will be mostly controlled by this function. Mobile transport will use a mix of element control via internal sensors and computers, and higher level control and tasking from this function. Items such as a robotic farm vehicle may operate mostly without human intervention. External transport will need to follow local laws regarding their operation, and some humans will prefer manual operation. This function will do less in these circumstances, but may do support tasks like route and maintenance planning, and traffic and weather monitoring.
- Location Planning and Scheduling - This task maintains location operation, maintenance, and site growth plans. It uses overall program and project goals, resident inputs, outside orders, and current status data as inputs. Planning and scheduling is future-oriented, whereas the previous Location Control items deal with immediate operations. It also disseminates planning information to residents, project participants, and others. In particular, planning and scheduling of human tasks for location operation is needed, both in response to the needs of the people who can perform the work, and what work needs to be done. If tasks cannot be performed by residents or participants, then it has to be delegated to outside supply under the External Flows function. Planning and scheduling will use a mix of human and automated/software elements to implement.
- Location Analysis - This task measures past location performance against goals and plans, and reports progress to local project members and the overall program. It also identifies needs for improvements or new technology, which are fed to Phase 0 Develop Technology. Compared to Planning and Scheduling, this task is history-oriented - looking at what has already happened.
F.126.96.36.199.2 Supply Power Data
This function provides electrical, thermal, hydraulic, and other forms of energy for all parts of the location, plus a large surplus. The high output ratio comes from the program level goal of expanding the material and energy resources of civilization as a whole. It also supports a high quality of life for project members by having ample available energy for their needs, and income from sales of the surplus. Finally, we want to make a positive contribution to environment impact by relying on renewable sources where possible.
Power supply can be divided by type (electrical, thermal, etc.) and parameters within a type: voltage and current for electrical; temperature, duration, and accuracy for thermal; pressure and flow rate for hydraulic. It can also be divided into service classes by reliability: residential and control functions should be more reliable than industrial tasks that can be deferred. Finally it can be divided into fixed and portable.
Supply Power Requirements
- 2.3 Local Resources - This sets a goal of providing 85% of continuing energy needs from local resources, as measured by economic value. We apply this as a source requirement, that 85% of the capacity for energy production is made from local resources. Otherwise requirement 2.6 supersedes this one with the much larger output goal. Local supply may use outside delivery where land parcels are separated and it makes sense. For example, a wind turbine may be placed on a remote leased location on a ridge for higher output, and deliver the power to the external electric grid. The location then gets the power for it's own needs from the grid.
- 2.6 Resources - The higher level Production requirement for 2.6 Resources sets a goal of 10.5 times internal needs, or a surplus of 9.5 times. The energy portion of the requirement is allocated to this function. At the start of construction there will be no power elements in place, so we would rely on outside sources. As an initial goal we would like to meet 1.0 times internal needs with a population of 75, and ramp up the surplus to meet the final level by the time the location has 660 residents. Energy production would therefore be growing faster than population. The actual growth rate will be set by analysis as to what actual needs are, and the most efficient growth path.
Supply Power Alternatives
- Power Integration - The selection of power sources is not done in isolation from the rest of the location. Other location functions present input needs in terms of power type, parameters, service classes, and mobility. In return, availability of power options and their cost and difficulty of production will affect the design of the other functions. Integrating multiple uses for a power source will increase overall efficiency. For example, excess heat from a furnace or generator can be used for lower grade thermal processes. Since we cannot predict the future needs in detail, we should provide for flexible delivery and arrangement of the power sources to make the best use of them. This means keeping the distribution wires and pipes accessible so they can be changed as needed. Since renewable power is typically intermittent, we should consider multiple power sources and storage to increase reliability.
- External Power: - We assumed outside power at the start of construction, and further assume we keep outside power connections as a backup to internal power sources, and for later delivery of surplus power. Conventional options for external power are utility electric and natural gas lines, tanked liquid fuels such as propane, and generators with an outside fuel supply for early construction. External power sources should be available for a Temperate location near a developed area. If they are not supplied to a particular land parcel, the cost of installation will need to be factored into construction.
- High Concentration Solar Thermal:
This alternative uses a large mirror area to focus sunlight onto a small target to reach high process temperatures or generate large amounts of electricity. We will define concentration ratios of more than 4:1 as high. Some means accommodating the Sun's daily motion is needed. We will use Atlanta, GA as a "typical" location for calculation purposes, but other locations need to adjust for their actual circumstances:
- Solar Resource - Hours/day of total sunlight for Atlanta GA: 4.09 winter, 5.16 summer, 4.74 average. For direct sunlight, average = 4.2 hours (suitable for thermal concentrator). Assume similar range for direct as for total hours by season, thus 3.55 to 4.62. Terrain and nearby objects can affect this.
- Unit Spacing - For year-round operation, you do not want winter shadows from one unit to affect the next too much. For a latitude of 34 degrees North for Atlanta we assume a tilt of 34+15=49 degrees for the mirrors, and therefore a unit spacing of 1.15 times the difference between highest and lowest points of a unit mirror array to avoid shadowing, in addition to their ground footprint at that tilt angle. If the array dimension is D, the ground footprint will be cos(49 degrees) x D = 0.65D. The height difference will be sin(49 degrees) x D = 0.75D, and thus the extra spacing will be 0.87D. The total unit spacing for a north-south line of units is then 1.52 D. For east-west spacing, solar intensity due to atmosphere absorption falls 20% at 65 degree zenith angle (25 degrees above the horizon) and 50% at 80 degrees zenith angle. The unit spacing will then depend on whether you want to maximize output per unit, or output per ground area, and how many continuous hours of sun you need for a given process. For calculation purposes, we will assume a 65 degree zenith angle as an operating limit. Then the array spacing needs to be 1.94H + 0.43W, where H is the maximum array height (0.75D in our case) and W is the array width east-west. Combining spacings, we find that mirror area is about 35% of ground area. The remainder can be filled with short plants which do not require a lot of direct sun or secondary industrial tasks which benefit from small amounts of sunlight.
- Economics - Peak sunlight has a standard value of 1000W/m2. Therefore average solar input is expected to be 1000 W x (4.2/24 hours per day) x (35% ground fill area) = 61 W/m2 of ground area. Net useful power depends on efficiency losses in the mirrors and later steps in using the energy. Over the course of a year, 61 W average power yields 1925 MJ. At an energy cost from conventional sources of $0.03/MJ, the land area then yields up to $57.75/m2/year ($233,700/acre/year).
- Sandia National Laboratory estimated the cost of a tracking heliostat at $125/m2 in 2006. Adjusting for inflation and ground coverage, we obtain a cost of $50.5/m2 of ground area. This implies the concentrator assembly would theoretically pay for itself in 0.875 years, or a return rate of 114%. This does not count whatever equipment is at the focus to use the collected energy. This is a promising rate of return. If self-production can lower the cost of the equipment, this is potentially very promising.
- - Central system - This uses a set of individually steered heliostats (mirrors) aimed at a central target. Depending on size and distance the heliostats can be flat, curved, or segmented. At least 10 curved heliostats are likely needed for 400:1 concentration, or the ability to adjust the shape to compensate for off-axis pointing as the Sun moves. Alternately a group of flat heliostats move on a circular track to track sun azimuth, and tilt for elevation, with a curved secondary to reach a fixed target at ground level. The secondary is elevated for average latitude tilt. This keeps most of the mirrors at ground level, and they can share a common tilt mechanism. Terrain will affect the design of any solar concentrators system.
- - Dish System - This uses a single steerable dish with either an elevated target or a secondary mirror to direct the light to a fixed or ground level target. Using a single dish limits the size because of the support structure required, and an elevated target is more difficult to use. However, a fixed shape dish can more easily reach higher concentration ratios.
- - Linear System - This uses a parabolic trough or linear Fresnel mirror arrangement oriented East-West to reach moderately high concentrations. A long device minimizes end losses from the Sun's motion, and only requires minor seasonal adjustment daily.
- - Polar System - This is a flattened layout of mirrors on a polar axis mount, with the focus or secondary towards the lower end. It is effectively a segment of a circular dish, but the flat layout and keeping only the upper end of the dish lowers the focus and support structure. The polar axis tracks daily Sun motion, and a seasonal tilt adjustment accounts for the Sun's declination in the sky.
- Low Concentration Solar Thermal:
This uses fixed or seasonal reflectors with mirror/target area ratios of 0.0 to 4.0. A zero mirror area means the target is directly exposed to the sun with no extra help. Some examples are greenhouses or lumber drying sheds with moderate reflector areas to increase winter growth or speed drying. Building air and water heating and direct solar cooking can be done at these ratios.
- Thermal Storage:
Direct sunlight in an average location is only available about 4 hours/day, and in the best locations for 8 hours/day. Thermal storage allows extending high temperature processes or power generation for more hours per day, at the expense of more collector area and a storage system. Various thermal storage media have been tried, including high temperature oils, molten salt, either of those with solid fillers, and dry rock. Heat transfer media can include the oil or salt directly, piped water/steam, unpressurized humid air, or dry air. Heat exchangers are required if the transfer medium is not the same as the point of use medium.
- - From Specific Heat Data, ordinary rock has a specific heat of 800 Joules/kg-K, and a cubic meter of crushed rock has a mass of about 1400 kg. If you heat the rock by 500 K, then one cubic meter can store 560 MJ, or 155 KWh or about $19 worth of electricity at typical utility rates. It is equal to 90 Prius battery packs.
- - Insulation is required so the stored heat does not leak to the surroundings too quickly. Rock wool has a conductivity of 0.045 W/(m-K), and a use temperature up to 1000 C. Insulating Firebrick has various properties depending on composition and temperature rating. If we use the lowest grade (1260 C rating), it has a hot load capacity of 69 kPa, which allows 5 meters maximum gravel load, and 3 meters design load. Conductivity vs temperature C is [260,0.13], [538, 0.17], [816, 0.22], [1093, 0.24] W/(m-K). Concrete and stone have conductivity of 1.7 W/(m-K), and concrete has a maximum working temperature of ~400C under load (this varies by mix type).
- An assembly of gravel at 1000C hot storage temperature, 0.25 meters of firebrick, and 0.15 meters of concrete would lose 450W/m2. For a 1 meter cube, the storage time constant is 200,000 seconds. Refractory concrete is a special mix which can withstand higher temperatures.
- - An option is vacuum/powder insulated storage. The vacuum reduces heat transmission, and the powder fill supports the storage vessel against the pressure difference. This is likely to be more expensive than concrete storage units, but may be useful for portable applications.
- Solar Electric:
This is primarily photovoltaic (PV), or solar panels, which have reached mass production levels. Sun-facing fixed panels are the least expensive to set up, but tracker units are an option. Concentrator PV can reach higher area efficiency for the panel, but requires spacing of the tracker units to not shade each other. Using only purchased concentrator cells and self-building the rest of the system would increase percentage of local production. This would combine with the high concentration designs above. Some lower efficiency technologies should be considered if they offer low cost and are producible: dye or oxide cells, integrated roofing/PV, window integrated cells.
- - Polar Axis Mount - The purpose of this option is to get increased output from purchased panels relative to stationary mounts. The polar axis mounting allows following the Sun. An average tilt is used, since seasonal declination is a small loss. Depending on thermal limit of the panel, side reflectors or placing the panels at a reflector focus will increase output. Active cooling may keep the panels from overheating. Compare to using concentrator cells designed for high flux.
- Wind Turbines:
One concept is a tower with volute turbine units on a circular track mount. Track is L shaped, with upright and sideways rollers for support and position, and a cover to keep debris off. Turbine units are paired, set behind center of rotation, with dihedral, so they auto-point into the wind. Larger units may use a drive motor for pointing. Units are stacked vertically on the tower to get more total output. Tower height is used to get above trees and into higher wind velocity.
This is using plant wastes, microorganisms, external trash, or other organic sources either to create a liquid fuel for transport, or direct combustion of solid, liquid, or gas products for heating or power. This may be in parallel with wood or food production from plants. An option is to use CO2 byproducts from combustion or other production processes to increase growth rates. Bioenergy is limited to about 6% solar efficiency in the best case, and much lower for unmodified plants, so on the whole is much lower efficiency than solar options, even when storage losses are included. Reasons to use it include portable power, and off-hours when other energy sources are not functioning. Organic sources are likely to be more useful as chemical feedstocks than as fuel, so the value in alternate uses should be considered.
- Other Sources
We do not assume the location has special features like hydroelectric or geothermal potential, but if such an option is available when selecting land it should be considered as a plus. Fossil energy sources are unlikely to be found, but we would prefer to use them, if available, for non-energy uses so as to not add to atmospheric CO2. Other storage options like compressed gas, large batteries, and deep well gravity can be investigated to see if any done as self-built would be economical.
F.188.8.131.52.3 Extract Materials Data
Extracting raw materials covers steps before a material is in inventory and ready for further processing or use. It includes tasks like mining, water, and air collection from the environment, and harvesting organic products from living things. After extraction it usually requires transport to another production function. It includes doing this on owned or leased location land, or from other property using internal equipment to do the extraction and transport. Materials mined and delivered by others using their equipment is an external supply, accounted for elsewhere.
Extract Materials Requirements
- 2.3 Local Resources - Like the previous Supply Power function, we have a goal of providing at least 85% of continuing raw materials from local sources, as measured by economic value. This does not cover initial construction, which may require more outside supplies.
- 2.6 Resources - The higher level Production Capacity requirement passes down a long term goal of 10.5 times internal needs, or a surplus of 9.5 times. The surplus is sold or used in later stages of production and then sold, to support the resident quality of life and project owner's income. We interpret this requirement as providing 1.0 times internal needs at 75 people, growing to the higher goal when the population reaches 660. Since a given location will only have a finite amount of land and raw material resources, the high surplus requires obtaining raw materials from other property, outside waste sources, or abundant sources like growing plants, air, and rainfall. This would be in addition to high levels of recycling within the location itself.
Extract Materials Alternatives
- Outside Supply vs Local Extraction - The first decision is between getting raw materials from outside sources, or from owned land, or leased mining rights on other land but using location equipment. This in turn is related to the amount of owned land, and it's geology and other resources. While energy from sources like wind and sunlight renew themselves constantly, physical resources are finite and must be more carefully accounted for. We can divide these resources into:
- - Generalized resources: These are ones generally available in most locations and not particularly specialized, such as local rock, soil, plants, air, and water flow.
- - Specialized resources: These include nearby mineral deposits, outside recycling, scrap, trash, and waste sources, and commercial raw materials suppliers.
- Waste Extraction - This is external waste which is not ready for transport, such as landfill or sewage sluge, and require collection before transport by location equipment. Wastes delivered by outside equipment are counted as external supply.
- Excavation and Mining - We can estimate quantities of materials needed during construction, assuming we extract them under this function rather than from outside sources.
- - Habitation foundations: 27 m3/person x 75 people/year = 2,025 m3/year of suitable gravel and sand aggregates, of which 15% needs to be limestone and shale for cement making.
- - Habitation Roofing: 3 m3/person x 75 people/year = 225 m3/year of clay or cement ingredients for roof tile.
- - Habitation Siding: 24 m3/person x 75 people/year = 1,800 m3/year of suitable clay and sand for brick making.
- Water Collection - This includes new water collected from rainfall, condensation, flowing water, and ground water to the extent it does not exceed natural recharging. Water either in clean or contaminated form could be collected from outside locations. Recycled water which does not go directly to internal transport and has to be extracted from storage ponds would be included here.
- - Total Water Use - Data from Water Footprints (Mekonnen - 2011) indicates USA total water use for all purposes was 2840 m3/year/person. This does not include any recycling, and includes water used in agriculture, so should be considered an upper bound on water collection.
- - Domestic Water Use - Data from several sources indicate US residential use averages 0.6 m3/day/person (220/year). Again, this should be considered an upper bound with no re-use.
- Air Collection - We will start by assuming this is compressed air for vehicle and production use, which has small requirements unless pneumatics is used extensively in the design. Extraction of Carbon Dioxide, Oxygen, Nitrogen, and other gases for now is given a rate of zero unless some process needs it.
- Harvest Timber and Plants -
- - Framing Lumber: During construction we need (40 m3/person for living space + 10 m3/person for roof support) x 75 people/year = 3,750 m3/year of finished lumber. Assuming 75% conversion of raw logs to finished lumber, that means harvesting 5,000 m3/year of logs.
- - Food Plants: (Needs data)
- - Other Plants: Includes harvesting fruits from trees, non-food plants used for fibers, feedstock or combustion.
F.184.108.40.206.4 Process Materials Data
This function includes the conversion of raw materials to finished materials inventory, which is ready for storage, parts making, or consumption. It can include a series of chemical, electrolytic, mechanical, thermal, or other processes, either continuous flow or batch. Some measurable change in the materials properties needs to be made, but no special shaping or forming to designed parts. Thus generic metal bar stock is an output of this function. Because of the large number of materials and processes, this function is sub-divided further. Note that the same hardware may be used for multiple sequences and materials. This starts with a functional breakdown telling what needs to be made, the design telling how it is done follows.
Process Materials Requirements
- 2.3 Cyclic Flows - In addition to processing new materials either extracted or supplied from outside, we have a goal of re-processing at least 85% of waste outputs from the location. Other functions will need to be designed with this requirement in mind. We prefer to consume more outside waste than we generate, so that the location as a whole has a negative waste production, although individual types of waste may be positive mass flow.
- 2.6 Resources - Like other production functions, we have a long term goal of processing 10.5 times continuing needs for 660 people. This starts at 1.0 times needs for 75 people and ramps up. The division between sale of inventory stock directly vs using it in later production steps will be determined later. Quantities processed for initial construction is in addition to this requirement
- Make vs Buy - For any given material, and a given state of production equipment and schedules, we have a choice of doing the processing ourselves, or purchasing ready materials from outside. We cannot give a fixed answer to this choice, but rather assign it to the Control Location tasks for External Flows, and Planning and Scheduling.
- Process Selection - A location of 660 people is likely too small to process every type of material from local sources. Therefore we rank processes on total mass flow, economic value, how well they enable growth, and the cost of the process in terms of new equipment and recurring operation. Ones that score highly on these factors are considered first, but final selection depends on how they integrate with the rest of the production elements and location, and the growth sequence.
- Process Integration - Integration is connecting separate processes into complete flows, and using surplus or waste outputs from one process in another. An example is using waste heat from a furnace to do drying in another process. The design integration sequence should first consider recycling flows: Used water, excess CO2, repair, replace, and remodeling return mass, and internal manufacturing wastes. Following that consider new production flows for internal needs, and finally for surplus production/outside sales. At each step, consider how the various inputs and outputs can be connected.
- Growth Sequence - The facility growth sequence, from starter set to final factory, also needs to be put in a logical order. It is not obvious how to do that, but we can attempt various approaches and see what works best. Our provisional approach is to include Process Materials along with the rest of a location's parts, and score the total result according to our evaluation criteria. Since there are many possible combined sets of elements, we will need to use methods like trade trees or iterating across options to find good candidates.
F.220.127.116.11.4.1 Process Stone and Concrete
This function includes preparing materials for direct stone use, in the form crushed stone for gravel beds and aggregates, sand or finer crushed rock for aggregates, filter, or thermal beds, larger rubble or dimension stone for construction, and indirect use as lime or cement.
- Cement Making - The NIST Reference Material for Portland Cement shows about 68% CaO + MgO, 30.75% Silica, Aluminum, and Iron Oxides, and trace amounts of other ingredients. A small amount of Gypsum (CaSO4⋅2H2O) is added as a grinding aid and setting retarder. Many variations of the basic formula are made with different ingredients, or with additives afterwards. To make standard Portland cement requires grinding and mixing the ingredients, heating to 1450 C, then grinding the resultant clinker again. Mass loss occurs from the conversion of dolomitic limestone: (CaMg)(CO3)2 (molecular wt = 152) to the oxides (molecular wt = 48), therefore about 50% more raw mass is required than finished product.
- Cement makes up about 15% by mass of concrete, this requires 7.5% additional mined mass relative to final concrete ingredients. We estimated 2250 Habitation + 2250 Production = 4500 m3/year of concrete products during construction, which implies 1800 tons of cement, and thus 2,700 tons/year (7.4 tons/day) cement-making ingredients. The enthalpy of formation is 1.757 MJ/kg, and actual energy without heat recovery is about 3.6 MJ/kg. This requires an average of 308 kW power, or 4.1 kW/person/yr construction rate. This requires about 0.5 hectare solar collector area, if that is the energy source.
- Concrete Making - Concrete mixtures vary greatly according to the purpose and strength desired, but a basic mix contains 400 kg cement, 1275 kg coarse aggregates (10-20 mm gravel), 725 kg fine aggregate (sand), and 160 kg water for each cubic meter of final product. For our estimated concrete production rate, we therefore need 9,000 tons/year (24.7 tons/day) of sized aggregates, and 720 tons/year (2 tons/day) clean water.
- Cement Making - The conventional alternatives are Rotary and Vertical Shaft kilns, with ball mills and sieves or cyclone separators used in the grinding steps. The kilns use combustion as the main energy source. We will consider solar heating as an alternative energy source, with auxiliary heating if needed. An alternate process is plasma discharge cement making. Finally, alternate binders like epoxy, or different chemistry than mainly calcium oxide can be considered.
- All cements need furnace heating to change the raw ingredients to the final product. The required temperature varies according to the ingredients. Metakaolin, derived from kaolinite clays, needs 500-800C calcination temperatures. It can be used to replace up to 30% of Portland cement without loss of strength. Pulverized Fuel Ash and Fly Ash are fine particles produced by fuel combustion, usually in power plants, and condense in the exhaust stream. They can also substitute for Portland cement. We do not want to generate power by burning fossil fuels, but alternatives are biofuel combustion and buying commercial ash products. Portland cement requires the highest temperatures to produce, about 1450C, thus higher concentration ratio of sunlight is needed, or supplemental heating.
F.18.104.22.168.4.2 Process Metals
In modern civilization, Iron and steel make up about 95% of total metals use. We can therefore treat this function as first supplying that metal, and then consider other metals as additions. Quantities beyond reinforcing steel are presently undetermined.
- Reinforcing Steel - This is steel reinforcing for concrete. The amount required is heavily dependent on the purpose and loads of the concrete. Pending more detailed data, we will adopt 200 kg/m3 as an overall estimate for the location. This amount to 2.5% reinforcing steel by volume of concrete. When better estimates are made, use the actual amounts for known concrete volumes they apply to, and retain the 2.5% reinforcing estimate for the portions not yet designed. Given our total requirement for 2,250 m3/year during construction, that implies 450 tons/year reinforcing.
- Structural Steel - This is steel used for buildings, in the form of plates, columns, beams, bracing, fabricated shapes, bolts, anchors, screws and other fasteners, aside from concrete reinforcement.
- Cast Iron - Cast iron contains a high carbon content, and as the name indicates, is easily cast into complex shapes, can be machined to a good finish, and has good vibration damping. Castings can include harder alloy inserts for wear surfaces. It is often used for the bodies of heavy duty machines, piping, and other items where ease of manufacture is important. Where strength and temperature properties matter more, other alloys are often selected. Absent other ways to estimate, we will assume a block that is 1.0L x 0.5L x 0.1L = 0.05 L3 is needed for major machines, where L is the principle dimension. This needs to be replaced with detailed estimates.
- Alloy Steel - All Iron and steel except for the pure element is an alloy with other elements. This category is for the alloys made for their specific properties beyond the typically low carbon reinforcing and structural grades. High alloy grades range to those with less than 50% Iron content.
- Light Metals - This group includes aluminum, titanium, and magnesium alloys, chosen for their relatively light weight and higher strength-to-weight ratio. Advanced versions include reinforcing fibers for even higher strengths.
- Other Metals - This includes copper, brass, bronze, zinc, tin, and any other metals outside the groups listed above.
- Reinforcing Steel - The conventional alternative is to simply buy reinforcing steel from commercial suppliers. Local choices are to recycle scrap metal, especially scrap rebar, into fresh wire and bar, or reduce ore to new metal. A different alternative is to replace metal reinforcing with fiberglass or basalt epoxy, which again have the alternatives of purchase or make.
- Cast Iron - The obvious and conventional alternative is to make castings by melting sufficient cast iron ingredients in a furnace and pouring it into molds in a foundry area. Foundry casting is a basic process for all types of industry, and we expect to include it as one of the first fabrication items, and heating the metal is then a basic process plant function. Variations are then in the type of furnace, and sources of ingredients for the cast iron.
F.22.214.171.124.4.3 Process Ceramics
This function includes preparing clay and sand for bricks, roof tiles, paving, household wares. It also includes other ceramic mixes for high temperature linings and containers, and carbides and mineral oxides for cutting and abrasion tools. The equipment to implement this function is shared with Process Stone and Concrete where the materials overlap.
- Construction Brick and Tile - For Habitation siding we have an estimate of 24 m3 of clay brick/person x 75 people/year = 1,800 m3/yr (5 m3/day). Solid concrete brick can be the same volume, or hollow concrete block with twice the thickness.
- Household Ceramic Ware - A rough estimate is 100 kg/person.
- Refractory Linings and Containers - These are mostly for Production elements. A rough estimate is 5% x 4000 tons of other materials processed = 200 tons refractory required.
- Industrial Carbides and Oxides - Also used for Production elements. A rough estimate is 100 tons required, but needs better data.
- Brick Kiln - The conventional alternative is a furnace where temperatures above 950 C are reached for long enough that the clay fuses, and then gradually cooled down so they do not break. The time required is typically longer than a day, so a solar furnace would need to be augmented by other heating.
- Concrete Brick and Block - These do not require a kiln in the fabrication stage (they do to make the cement). The mix is molded into brick or block shapes, then wet or steam cured until they are strong enough to stack, then allowed to finish gaining strength in stacks. This takes ~28 days for standard cement.
F.126.96.36.199.4.4 Process Glass
This function includes making soda-lime (ordinary) glass, and possibly specialty glasses using Boric or Barium Oxides and other additives.
- Greenhouses - Glass area depends on light requirements of the plants
- Solar Collectors - Mirror area is based on 1000 W/m^2 peak incident sunlight/(cos a), where a is the mirror tilt to the incoming light. Type of glass is not important as long as it can take a reflective coating and be cast flat. Low-iron glass has lower losses.
- Containers - Glass containers include process vessels and piping, production storage, and household food and drink containers.
- Soda-Lime Glass - This is the ordinary glass found in most common articles. It consists of a mix of mineral oxides as noted in the title link, usually in the form of raw minerals rather than pure oxides, for cost reasons. They are melted together at ~1500 C, at which chemical changes of the ingredients happen, formed by one of several processes (floating or blowing), and allowed to cool slowly so as not to break the item from heat stress. Once made, glass has a melting point ~900C, and can thus be formed into new shapes from base stock. The hardware required is primarily a high temperature furnace to make the glass batch, a heated forming or molding device, and an annealing oven to slowly cool the finished item. The thickness of the glass determines the cooling rate.
F.188.8.131.52.4.5 Process Wood
After raw wood in log form is extracted from the tree, it must be cut to the correct size pieces, and then dried to a preferred moisture level, typically 8-19% depending where it will be used. Because it is a natural product, it has variations and defects, and is anisotropic: having different properties like strength as a function of direction. The properties of wood also vary by species. Therefore pieces may be glued together with adhesives and reinforcement to form larger and stronger timbers and sheets as inventory stock.
- Framing Lumber - During construction, we estimate 0.2m thick x 200 m2 Habitation + 0.15m thick x 200 m2 Production wood required. The lower figure for production is some of the buildings are only sheds, and side walls in general may not be finished, needing less framing. This amounts to 70 m3/person/year, or 5,250 m3/year total.
- Indoor Lumber - This includes furniture and interior finish lumber for Habitation, and shelving, workbenches, and similar items for Production. Assumed amount is 40 kg/m2 of floor area x 400 m2 combined floor areas/person = 16 tons/person. Given an average density of 0.4 for dry wood, this comes to 40 m3/person/year, or 3,000 m3/year total.
- Total Lumber - Adding the above wood needs gives a need for 8,250 m3/year. This is the final cut and dried volume. The raw log volume needs to be about 11,000 m3/year to account for defects, bark, saw waste, and shrinkage during drying. The material lost in conversion can be recycled into other biological inputs. Moisture lost on drying can represent 200-400 kg/m3 of finished wood, or 4.5-9 tons/day. Since this is evaporated, it is relatively clean, and should be considered for recycled use.
- Since trees that supply good lumber take 25 years or more to grow, early construction will depend on existing forest inventory. A forest inventory of 125 tons/hectare @ average density of 0.7 green implies 0.8 hectare/person forest for initial construction. This is much larger than the sustaining amount, so either harvest rights, using the location land itself as a source, or buying excess land and reselling it would be options for the initial wood supply. A mix of these methods can be used. Sustainability will depend on replanting or selective harvest, to maintain a continuing supply. Once harvested, the "green" wood needs to start drying as soon as possible, and be protected from rot and moisture then, and thereafter.
- Where to Saw - Early steps in wood processing may be done in the field, before transport. This saves transporting defective or waste material, and makes the pieces to be moved smaller. The downside to working in the field is variable terrain and weather. To some extent this choice will depend on equipment available and what uses the waste material is put to.
- Seal and Debark - Trees transport water vertically in pores, and so evaporation and shrinkage happens faster from the ends of a log or board. Differential drying can cause cracking at the ends, so a freshly cut log should be sealed with paint or other means. This will also reduce decomposition from fungi or other organisms. Bark and the living cambium layer are not normally used in lumber, so they are stripped off. This also keeps dirt off the resulting log. Debarking tools can be as simple as a sharpened shovel blade, or use mechanized toothed grinders. In some cases, clean bark can be left in place until after sawing.
- Sawing - In most cases the original log size and shape are not what is needed in the final products, and an uncut log will usually split radially from drying shrinkage. Splitting the log using wedges is a simple process, and creates little cutting waste, but leaves an uneven shape as a result, so most wood is sawed. A band saw generates less sawdust waste relative to circular or chain saws because the blade is in tension and can be thinner. This is the main conventional method. A laser is generally not powerful enough to cut a thick log. The sawing process can be automated in two parts: scanning the log to determine the best way to cut it, and moving the saw and log to make the cuts. Sawing requires space for the uncut logs, the sawmill itself, sawdust generated, and the cut boards to be dried. For seed level production, a band saw can use the same frame as other 3D working heads. For the 75 person construction rate, a dedicated set of equipment is likely needed because of the volume.
- Drying - The simplest option is to stack the cut boards with spacers, and sheltered from rain, and allow open-air drying. For high volumes, like producing lumber for 75 people, this requires a large amount of drying space, since air-drying can take a year per inch of board thickness. Solar kilns collect sunlight into a chamber to warm the boards, with a fan and condenser to remove the water that evaporates. In good weather, they can reduce the drying time to about a month per inch. Conventional kilns use a combination of any heat source to warm the boards, and vacuum or air flow to remove the moisture. This can reduce the drying time to days. The drying rates must be controlled to prevent stress build-up internally to the boards, and all sides of the board needs to be exposed for even drying. Usually this is done with spacers between layers. Clamping the lumber stack can also reduce warping from uneven drying. Some loss on drying is to be expected. Once the boards have reached the desired moisture content, they can go to storage, where they continue to need protection from decay. Moisture content can be determined by meters, or by weighing samples before and after oven drying to reach 0% moisture. Final moisture content will always tend to equilibrium with the environment, and wood requires sealing if the expansion and contraction with outside changes is a problem for a given use.
F.184.108.40.206.4.6 Process Fibers
Natural fibers include items like cotton and wool. Growing and processing them to the point of threads and fabric are already large and mechanized industries, and we don't think we can improve on them enough to be worth doing. Sewing finished items from the point of fabric is worth considering. Synthetic fibers include glass, basalt, carbon, and polymers. These have a number of industrial uses as high strength reinforcement and insulation, and the quantities and market price make them a more attractive option to do internally.
- Building Insulation - We estimated 71 m3/person fiber or rock wool insulation. For 75 people/year we therefore need 5,325 m3/yr. Insulation density is relatively low, since small air pockets reduce heat flow, in the range of 10-60 kg/m3. Therefore the mass required is in the range of 50-320 tons/yr.
F.220.127.116.11.4.7 Process Electronics
F.18.104.22.168.4.8 Process Organic Compounds
F.22.214.171.124.4.9 Process Inorganic Compounds
Includes purified gases, liquid solutions, and solid inorganics. Metals extraction can be by thermal, chemical, or electrolytic means, the exact process depends on the ore and element being extracted.
F.126.96.36.199.4.10 Process Fertilizers
F.188.8.131.52.4.11 Process Water
F.184.108.40.206.5 Fabricate Parts Data
F.220.127.116.11.5.1 Fabricate Stone and Concrete
F.18.104.22.168.5.2 Fabricate Metals
F.22.214.171.124.5.3 Fabricate Ceramics
F.126.96.36.199.5.4 Fabricate Glass
F.188.8.131.52.5.5 Fabricate Wood
F.184.108.40.206.5.6 Fabricate Fibers
F.220.127.116.11.5.7 Fabricate Electronics
F.18.104.22.168.5.8 Fabricate Organic Compounds
This includes parts made from plastics, rubber, and related organic materials
F.22.214.171.124.5.9 Fabricate Inorganic Compounds
Includes parts made from non-metallic compounds not covered elsewhere.
Process subfunctions 10 Fertilizers and 11 Water are bulk materials, and not fabricated into parts as such. They go from process to storage or direct use.
F.126.96.36.199.6 Store Inventory Data
- Modular Floor Concept - Footer posts or pads at corners of concrete floor modules (i.e. 1 meter square), set to whatever depth is needed. Gravel fill, plastic liner, and insulation as needed. Modules rest on support corners, and grouted if needed to close gaps. Lift points included for modules which will be moved often (over utilities), using embedded pipe and recessed J-bolt. Infrequently moved blocks are plain, and moved by removing adjacent units first for access. Module thickness and support height adjusted to expected load. For severe loading slabs are laid edgewise at required depth and bolted to make rigid assembly.
- Building Structure - Rough estimate for foundations and floors is Heavy Industrial Floor @ 100 m2/person x 0.2 m thick + Standard Floor @ 100 m2 x 0.1 m thick = 30 m3/person total. This will need updating later.