1、BRITISH STANDARD BS5502-71: 1992 Buildings and structures for agriculture Part71: Code of practice for design and construction of ventilated stores for potatoes and onionsBS5502-71:1992 This British Standard, having been prepared under the directionof the Technical SectorBoard for Building andCivil
2、Engineering (B/-), waspublished under the authorityof the Standards Boardand comes into effect on 31March1992 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference B/549 Draft for comment90/14588 DC ISBN0 580 20500 2 Committees responsible for this British
3、 Standard The preparation of this British Standard was entrusted by the Technical Sector Board for Building and Civil Engineering (B/-) to Technical Committee B/549, upon which the following bodies were represented: British Cement Association British Commercial Glasshouse Manufacturers Association B
4、ritish Precast Concrete Federation Ltd. British Veterinary 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 R
5、oyal Institute of British Architects Royal Institution of Chartered Surveyors Scottish Office (Agriculture and Fisheries Department) Silsoe Research Institute Steel Construction Institute Transport and General Workers Union Water Services Association of England and Wales Amendments issued since publ
6、ication Amd. No. Date CommentsBS5502-71:1992 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 General 1 4 Design, materials and construction 1 5 Store geometry 3 6 Environment 4 7 Services 6 8 Fire precautions, safety, welfare and hygiene
7、7 9 Safety signs and notices 7 Index 8 Table 1 Recommended thermal transmittance values 3 Table 2 Storage volumes of potatoes and onions 3 Table 3 Maximum airspeeds in ventilating systems for potatoes and onions 5 Table 4 Storage temperatures and relative humidity of potatoes 5 Table 5 Heat output o
8、f potatoes in store 5 Table 6 Ventilation rates for potatoes 5 Table 7 Storage temperatures and relative humidities of onions 6 Table 8 Heat output of onions in store 6 Table 9 Ventilation rates of onions 6 Publication(s) referred to Inside back coverBS5502-71:1992 ii BSI 08-1999 Foreword This Part
9、of BS5502 has been prepared under the direction of the Technical Sector Board for Building and Civil Engineering. It comprises a new Part of BS5502. While BS5502 is being revised and added to, the opportunity is being taken to restructure the standard into the following broad subject areas: Part0: I
10、ntroduction and consolidated index; Parts10 to19: Reference information and legislation; Parts20 to39: General design; Parts40 to59: Livestock buildings; Parts60 to79: Crop buildings; Parts80 to99: Ancillary buildings. More specifically, the crop building series will comprise: Part60: Code of practi
11、ce for design and construction of buildings for mushrooms; Part65: Code of practice for design and construction of crop processing buildings; Part66: Code of practice for design and construction of chitting houses; Part70: Code of practice for design and construction of ventilated on floor stores fo
12、r the storage of combinable crops; Part71: Code of practice for design and construction of ventilated stores for potatoes and onions; Part72: Code of practice for design and construction of controlled environment stores for vegetables, fruit and flowers; Part74: Code of practice for design and const
13、ruction of buildings for bins and silos for combinable crops. A more detailed description of the new structure of BS5502 is given in Part0. The object of introducing the new structure is to allow subject areas to be broadly characterized, and related subject matter, whether in the form of recommenda
14、tions, 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 the future. It has been assumed in the drafting of this Part of BS5502 that the execution of its provisions is entr
15、usted 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 contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard do
16、es 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 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. Th
17、is will be indicated in the amendment table on the inside front cover.BS5502-71:1992 BSI 08-1999 1 1 Scope This Part of BS5502 gives recommendations for the design and construction of buildings and structures for storing potatoes and onions in bulk and in boxes utilizing forced ambient air ventilati
18、on and/or refrigeration. NOTEThe 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 Storage The function of potato and onion storage buildings and structure
19、s is the control and retardation of the natural biological processes of the crop. Quality of the crop is maintained by controlling the storage temperatures and relative humidity. The store design, selection of equipment and monitoring devices are critical in achieving precise environmental condition
20、s. 3.2 Siting Consideration should be given to the siting of crop stores (see BS5502-20). 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 transpor
21、t; d) the availability of services; e) noise nuisance arising from transport and equipment; f) integration with grading and packing buildings; g) allowing for future expansion. 3.3 Type of store Ventilated stores fall into one of the following three categories. a) Bulk stores In these stores the cro
22、p is loaded in bulk onto the floor by tipping trailer or moveable elevator. The atmosphere is controlled from a fan house linked to a main duct distributing air via either lateral ducts or drive over floor units. b) Box stores (circulating ventilation) In these stores the crop is stored in boxes wit
23、h slotted sides. The boxes are stacked in groups and the store atmosphere is controlled by distributing air from either freestanding chimney vents or vents linked to high level ductwork. c) Box stores (positive ventilation) In these stores the crop is loaded into boxes with solid sides. The boxes ar
24、e closely stacked and the atmosphere is controlled using a “letter box” plenum chamber that distributes positive ventilation. Refrigeration can be added to all systems. Its requirement being determined by: 1) the type of product; 2) the need for chemical sprout suppressant; and 3) the storage period
25、. 4 Design, materials and construction 4.1 General 4.1.1 The design, choice of materials and construction of ventilated stores should be in accordance with BS5502-20, BS5502-21, BS5502-22, BS5502-23 and BS5502-25. 4.1.2 Foundations and support structures should be designed and constructed to withsta
26、nd loads from the stored crops and mechanical transport in accordance with BS5502-22. 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
27、product at risk. 4.1.4 Store interiors require cleaning 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 produce. 4.1.6 All parts of the structure should be constructed i
28、n accordance with the recommendations given in BS8000.BS5502-71:1992 2 BSI 08-1999 4.2 Floors 4.2.1 General Floors should be level with an even surface. Floors should be designed and constructed to withstand loads from the crop and dynamic loads from mechanical transport, plant and equipment. The su
29、rface should be hard wearing, capable of being cleaned and not susceptible to cracking or crazing. A damp-proof membrane should be incorporated to prevent moisture ingress to the crop. Thermal and shrinkage movement should be minimized by the correct placing of construction, expansion and contractio
30、n joints. 4.2.2 Lateral ducts Where provided, lateral ducts, fed from the main duct, distribute air through the crop. Ducts set below the floor should be constructed to resist soil pressure and the ingress of moisture. Covers should be designed to withstand loads from the crop and machinery. NOTERem
31、ovable ducts for installation above floor level are available. 4.2.3 Drive over floor When fully ventilated prefabricated floor systems are provided, they should be designed and installed to withstand the loads from the crop and machinery and provide access for cleaning. 4.2.4 Brick ventilating floo
32、rs Brick floors should be constructed of regularly sized and shaped bricks of adequate structural strength. The bricks are fitted closely together and span a series of ducts formed by a lower level of bricks. Cleaning entails removing and resetting bricks. 4.3 Walls Walling systems should provide th
33、ermal insulation, protect the crop from the weather and contain the bulk crop. The structural integrity of the wall should be maintained at all times and surcharging should only be permitted when the walling has been designed to withstand such forces. 4.4 Roof and upper wall cladding The roof and up
34、per wall cladding should be insulated and weather-proof. Louvred outlets or rope operated centre pivot airdoors should be provided at high level where required for ventilation. Consideration should be given to the exclusion of natural light to discourage birds. 4.5 Doors Doors should be insulated an
35、d have an internal finish equivalent to that of the walls. Doors in bulk stores should be situated in the centre of each storage area to be served. Two or more doors may be required for large stores. In box stores the position of the door will be determined by the stacking pattern of the boxes. The
36、door dimensions should be determined by the layout and use of the store. An opening of4.5m 4.5m is usual, 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.
37、 The door threshold should be designed to keep out water. External access areas should slope away from the doorway. 4.6 Main air ducts Main air ducts are generally used as dividing walls between the stored crop. The top forms a walkway for inspection. Ducts should be designed and fixed to withstand
38、the pressures of air, single and double sided lateral thrust from the crop, as required, and walkway loads. In the case of plenum ducts for positive ventilation, the ducts should be designed to withstand the loads associated with impact and the loads arising from the positioning of boxes against the
39、 face of the duct. They should be of adequate size to enable the operator to enter and open and close control flaps to lateral ducts. Entry to ducts should be by airtight doors fitted with handles operable from both sides. Internal lights should be provided for inspection of the duct. Doors should b
40、e of a minimum size of600mm 900mm opening outwards. They should be capable of being locked in open and closed positions. NOTENumbering of each lateral duct may be desirable. 4.7 Fan housing Fans should be housed inside the store or in an outside fan house. Louvred inlets or top-hung airdoors should
41、be provided to ensure the unrestricted access of air to the fan. The opening should be screened to keep out birds and pests. Nuisance due to noise levels should be prevented by insulation, increasing mass and correct siting. 4.8 Access and walkways Potato storage installations should include all wal
42、kways, stairs and platforms necessary to allow safe access for inspection of the crop during storage, for cleaning and for maintenance. Handholds should be provided at the top of all ladders. Ladders should be fixed. Rails and kicker boards should be provided to all accessways.BS5502-71:1992 BSI 08-
43、1999 3 4.9 Exhaust vents The position of exhaust vents should not allow air to be pulled back through the fan intake. Their free area should be greater than the area of air intake to the fan house. 4.10 Thermal insulation 4.10.1 Stores should be insulated. The insulation should be continuous over al
44、l surfaces. This includes the fan house, the main duct when outside the store and any covers, louvres or shutters used on ventilation air intakes or exhaust openings. Care should be taken to avoid thermal bridging at eaves/wall interface and at door openings. Recommended thermal transmittance values
45、 are giveninTable 1. Table 1 Recommended thermal transmittance values 4.10.2 Condensation within the store should be avoided. Thermal transmittance values lower than those given inTable 1 should be determined by the store temperature, humidity and likely minimum ambient temperature. 4.10.3 Insulatio
46、n materials should be protected from impact damage, should not harbour pests and should be durable for the intended life of the store. 4.10.4 Moisture penetration into insulation reduces its efficiency. Vapour checks should be provided because of high storage humidities. Joints in the vapour checks
47、should be lapped and sealed, fixings that penetrate the vapour check should be taped. Depending on storage conditions these vapour checks may be required on both faces of the insulation. 5 Store geometry 5.1 General dimensions The following factors should be considered when determining dimensions of
48、 bulk and box stores: a) the volume of stored crop; b) the requirement for a uniform ventilation rate through the store; c) the space required for loading and unloading; d) the space required for equipment; e) management techniques. The layout should allow the efficient movement of the crop from the
49、 field to the store and subsequently from store to processing and packing or to the market outlet. 5.2 Bulk density 5.2.1 Potatoes The storage volume of potatoes varies according to the tuber size and shape.Table 2 gives approximate storage volumes. 5.2.2 Onions The storage volume of onions will vary according to the size of the onion bulb and the amount of the top left on from harvesting.Table 2 gives approximate storage volumes. Table 2 Storage volumes of potatoes and onions (approximate) 5.3 Bulk store layout 5.3.1 The store
