1、BRITISH STANDARD BS 5502-70: 1992 Buildings and structures for agriculture Part 70: Code of practice for design and construction of ventilated on floor stores for combinable cropsBS5502-70:1992 This British Standard, having been prepared under the directionof the Technical SectorBoard for Building a
2、ndCivil Engineering (B/-), waspublished under the authorityofthe Standards Boardand comes into effect on 31 January 1992 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference B/549 Draft for comment 90/14586 DC ISBN 0 580 20356 5 Committees responsible for
3、 this British Standard The preparation of this British Standard was undertaken by Technical Committee B/549, upon which the following bodies were represented: British Cement Association British Commercial Glasshouse Manufacturers Association British Precast Concrete Federation Ltd. British Veterinar
4、y Association Department of Agriculture Northern Ireland Farm and Rural Buildings Centre Farm Buildings Association Health and Safety Executive Institution of Civil Engineers Ministry of Agriculture, Fisheries and Food National Farmers Union Royal Institute of British Architects Royal Institution of
5、 Chartered Surveyors Scottish Office (Agriculture and Fisheries Department) Steel Construction Institute Transport and General Workers Union Water Services Association of England and Wales Amendments issued since publication Amd. No. Date CommentsBS5502-70:1992 BSI 10-1999 i Contents Page Committees
6、 responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 General 1 4 Design, materials and construction 1 5 Environment 5 6 Services 7 7 Fire precautions, safety, welfare and hygiene 8 8 Safety signs and notices 8 Index 9 Table 1 Bulk densities (for determining volumes) 4 Table 2 Angl
7、e of repose for crops 4 Table 3 Slopes for crop flow 4 Table 4 Recommended storage period for grain at or below 16 C and at various moisture contents 5 Table 5 Equilibrium moisture content and relative humidity for wheat and barley 5 Table 6 Maximum drying temperature for grain 5 Table 7 Maximum air
8、 temperature for 90% germination of grass seeds 6 Table 8 Maximum storage of wheat with respect to germination 6 Table 9 Ventilation rates 6 Table 10 Air velocity 6 Table 11 Maximum air speeds 7 Table 12 Resistance to airflow (in Pascals) per metre depth of crop 7 Publication(s) referred to Inside b
9、ack coverBS5502-70:1992 ii BSI 10-1999 Foreword This Part of BS 5502 has been prepared under the direction of the Technical Sector Board for Building and Civil Engineering. It comprises a partial revision to BS 5502-2.3 which will be amended on publication of this Part. While BS 5502 is being revise
10、d and added to, the opportunity is being taken to restructure the standard into the following broad subject areas: Part 0: Introduction and consolidated index; Parts 10 to 19: Reference information and legislation; Parts 20 to 39: General design; Parts 40 to 59: Livestock buildings; Parts 60 to 79:
11、Crop buildings; Parts 80 to 99: Ancillary buildings; More specifically, the crop building series will comprise: Part 60: Code of practice for design and construction of buildings for mushrooms; Part 65: Code of practice for design and construction of crop processing buildings; Part 66: Code of pract
12、ice for design and construction of chitting houses; Part 70: Code of practice for design and construction of ventilated on floor stores for combinable crops; Part 71: Code of practice for design and construction of ventilated stores for potatoes and onions; Part 72: Code of practice for design and c
13、onstruction of controlled environment stores for vegetables, fruit and flowers; Part 74: Code of practice for design and construction of bins and silos for combinable crops. A more detailed description of the new structure of BS5502 is given in Part 0. The object of introducing the new structure is
14、to allow subject areas to be broadly characterized, and related subject matter, whether in the form of recommendations, guidance or supporting data, to be rationalized and brought together. It will also allow sufficient flexibility to enable BS5502 to be expanded and developed in a logical way in th
15、e future. It has been assumed in the drafting of this Part of BS 5502 that the execution of its provisions is entrusted to appropriately qualified and experienced people, for whose guidance it has been prepared. A British Standard does not purport to include all the necessary provisions of a contrac
16、t. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 10, an inside back cover
17、 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5502-70:1992 BSI 10-1999 1 1 Scope This Part of BS5502 gives recommendations for the design and construction of v
18、entilated on floor stores for combinable crops. NOTE 1For bin and silo storage see BS 5502-74. NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this standard, the definitions given in BS6100 apply. 3 General 3.1
19、Storage The function of crop storage buildings and structures is maintenance of crop quality by control and retardation of the natural biological processes of the crop. The quality is maintained by controlling storage temperatures and relative humidity. Drying usually precedes storage by the applica
20、tion of heat from a continuous flow or batch bin drier. Alternatively, drying can take place on the floor storage area. For small quantities of grains and herbage seeds, sack drying and storage may be considered. 3.2 Siting Consideration should be given to the siting of crop stores (see BS 5502-20).
21、 In particular, consideration should be given to the following: a) choosing a level site where there is no risk of flooding; b) choosing ground with adequate bearing capacity; c) ease of access for large transport; d) availability of services; e) nuisance arising from transport, machinery noise and
22、the creation of dust; f) allowing for future expansion. 3.3 Type of store 3.3.1 The design of the store will be determined by the following factors: a) type of produce stored; b) storage duration; c) drying system employed; d) sophistication of the mechanical handling. 3.3.2 Crops may be either: a)
23、pre-dried and stored simply in a weatherproof, structurally sound building with sufficient ventilation to keep the crop conditioned; b) dried in a store consisting of a building fitted with a ducted air system comprising a fan house, main duct and lateral ducts, or a prefabricated drying floor syste
24、m. 3.3.3 The handling system may range from the basic tipping trailer/mobile elevator/auger through to the complete fully automated mechanical system of reception pit, elevators and high- and low-level conveyors in and out of store. 4 Design, materials and construction 4.1 General 4.1.1 The design,
25、choice of materials and construction of ventilated crop stores should be in accordance with BS 5502-20, BS 5502-21, BS 5502-22, BS 5502-23 and BS 5502-25. 4.1.2 Foundations, support structures and retaining walls for stores should be designed and constructed to withstand loads from the stored crops
26、and mechanical transport in accordance with BS 5502-22. 4.1.3 Structures should be designed to minimize differential settlement, deflection and structural movement that could cause fracturing of surfaces and permit moisture ingress or infestation, so putting the stored products at risk. 4.1.4 Store
27、interiors require cleaning or fumigation after the storage period and this should be considered in the choice of materials. 4.1.5 Materials and treatments used in the construction should not impart odour or taint to the crop. 4.1.6 All parts of the structure should be constructed in accordance with
28、the recommendations given in BS8000. 4.2 Floors 4.2.1 General Floors should be level with an even surface. Floors should be designed and constructed to withstand the load from the crops as well as dynamic loads from mechanical transport, plant and equipment. The surface should be hard wearing, capab
29、le of being cleaned and not susceptible to cracking or crazing. To prevent moisture ingress to the crop, the floor should be impervious or a damp-proof membrane should be provided. Thermal and shrinkage movement should be minimized by the correct placing of construction, expansion and contraction jo
30、ints.BS5502-70:1992 2 BSI 10-1999 4.2.2 Lateral ducts Where provided, lateral ducts are fed from the main duct and distribute air through the crop. Ducts set below the floor level should be constructed to resist soil pressure and the ingress of moisture. Covers should support the loads from both cro
31、p and machinery whilst preventing the crop penetrating the air voids. NOTERemovable ducts for installation above floor level are available. 4.2.3 Drive over floors When fully ventilated prefabricated systems are provided, they should be designed and installed to withstand the loads from the crop and
32、 machinery and to provide access for cleaning. 4.2.4 Brick ventilating floors Brick floors should be constructed of regularly sized and shaped bricks of appropriate structural strength. Because the bricks are fitted closely together over a series of ducts formed by a lower level of bricks, cleaning
33、entails removing and resetting bricks. 4.3 Walls 4.3.1 Walling systems should protect the crop from the weather and be structurally adequate to contain the bulk crop. 4.3.2 In order to ensure the structural integrity of the wall, surcharging or heaping the crop should only be permitted when the wall
34、ing has been designed to withstand such forces. 4.3.3 The design of relocatable retaining walls should comply with the recommendations for fixed retaining walls in all aspects. 4.3.4 Proprietary galvanized profiled steel grain walling is a common choice for the walling system. Care should be taken t
35、o minimize corrosion of the steelwork in contact with concrete. 4.4 Roof and upper wall cladding The roof and upper wall cladding should be fixed so as to prevent entry of rain and driven snow. Louvred outlets or rope-operated centre pivot airdoors should be provided at high level for ventilation. C
36、onsideration should be given to the exclusion of natural light in order to discourage birds, and to the screening of ventilators to keep out birds and vermin. 4.5 Doors The door dimensions and position should be determined by the layout and use of the store. An opening of 4.5m 4.5m should normally b
37、e used, but larger access may be required. Personnel doors and emergency escape doors should be included. Provision should be made for securing side-hung doors when open to prevent damage by high winds. The door threshold should be designed to keep out water. The external access area should slope aw
38、ay from the doorway. 4.6 Reception pits 4.6.1 Reception pits should be self-emptying and should be designed to hold the required tonnage of crop relative to the throughput of the system. Where ground conditions restrict the size, a powered intake should be considered. Sloping surfaces should be not
39、less than 45 from the horizontal. Pits should incorporate a damp-proof membrane or, where the water table is likely to rise above base level, they should be constructed either using concrete which is fully waterproof or with a fully anchored waterproof lining. The top of the pit should be fitted wit
40、h a grille to act as a safety guard which should be designed to support the discharging machinery, if required. 4.6.2 Pits not designed to support vehicles should have a300mm high kerb along the edge that would be approached by vehicles. 4.7 Elevator pits Elevator pits should be constructed large en
41、ough to provide access to elevators for maintenance, repair and replacement. Pits should incorporate a damp-proof membrane or, where the water table is likely to rise above base level, they should be constructed either using concrete which is fully waterproof or with a fully anchored waterproof lini
42、ng. A fixed ladder and lighting should be provided. The pit cover should permit access and should be designed to carry at least the minimum floor loading (seeBS5502-22). 4.8 Grain conveying The delivery rate of the harvesting and handling equipment should be balanced to ensure a compatible and effic
43、ient flow. Discharge conveyors should spread the grain evenly to avoid the formation of compaction and/or separation columns. NOTE 1This rate is determined from the capacity of the combined-harvester/tractor-trailer capacity and the capacity of the intake pit at the store. NOTE 2The capacity of elev
44、ators and conveyors should be greater than the maximum discharge rate from the drier. Overhead hoppers for filling of lorries should be able to refill between arrivals of lorries.BS5502-70:1992 BSI 10-1999 3 4.9 Main air ducts Main air ducts are generally used as dividing walls supporting the crop,
45、with the top forming a walkway for inspection. Ducts should be designed and fixed to withstand the pressures of air, single and double-sided lateral thrust from the crop, as required, and walkway loads. Entry to ducts should be by an airtight door fitted with handles operable from both sides. Intern
46、al lights should be provided for inspection of the duct. Doors should be of a minimum size of 600 900mm, opening outwards. They should be capable of being locked in open and closed positions. NOTENumbering of each lateral duct may be desirable. 4.10 Fan housing Fans should be housed either inside th
47、e store or in a structure built externally. Louvred inlets or top-hung airdoors should be provided to ensure the unrestricted access of air to the fan. The openings should be screened to keep out birds and pests. Nuisance due to noise levels should be prevented by insulation, increasing mass and cor
48、rect siting. 4.11 Access and walkways Crop storage installations should include all walkways, stairs and platforms necessary to allow safe access to areas for loading and unloading, for inspection of the crop during storage and for cleaning out and maintenance. Handholds should be provided at the to
49、p of all ladders, and ladders should be fixed. Parapet rails and kicker boards should be provided to all areas where access is provided. 4.12 Store geometry 4.12.1 General dimensions The following factors should be considered when determining the dimensions of bulk stores: a) volume of stored crop; b) need for a uniform ventilation rate throughout the stack and ductwork; c) space required for loading and unloading; d) space required for equipment; e) management techniques. 4.12.2 Store layout 4.12.2.1 General The store l
