1、BRITISH STANDARD BS 5502-66: 1992 Buildings and structures for agriculture Part 66: Code of practice for design and construction of chitting housesBS5502-66:1992 This British Standard, having been prepared under the directionof the Technical SectorBoard for Building andCivil Engineering (B/-), waspu
2、blished under the authorityof the Standards Boardand comes into effect on 28 February 1992 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference B/549 Draft for comment 90/14585 DC ISBN 0 580 20488 X Committees responsible for this British Standard The pre
3、paration 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 British Precast Co
4、ncrete 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 Royal Institute of
5、 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 publication Amd. No.
6、Date CommentsBS5502-66:1992 BSI 09-1999 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 Environment 2 6 Services 3 7 Fire precautions, safety, welfare and hygiene 3 8 Safety signs and notices 4 Index
7、 5 Table 1 Heat output of potatoes 3 Publication(s) referred to Inside back coverBS5502-66:1992 ii BSI 09-1999 Foreword This Part of BS5502 has been prepared under the direction of the Technical Sector Board for Building and Civil Engineering. It comprises a partial revision to BS5502-2.3, which is
8、withdrawn. While BS 5502 is being revised 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 5
9、9: Livestock buildings; Parts 60 to 79: 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 proc
10、essing buildings; Part 66: Code of practice 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; Pa
11、rt 72: Code of practice for design and construction 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 obj
12、ect of introducing the new structure is 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 expand
13、ed 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 entrusted to appropriately qualified and experienced people, for whose guidance it has been prepared. A British Standard does not purport to include all
14、 the necessary provisions of a contract. 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
15、ii, pages1 to 6, an inside back cover 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.BS5502-66:1992 BSI 09-1999 1 1 Scope This Part of BS5502 gives recommendations
16、 for the design and construction of buildings and structures used for chitting potatoes (controlled sprouting of seed potatoes prior to planting). It covers naturally lit stores, stores with artificial lights and refrigerated stores. NOTEThe titles of the publications referred to in this standard ar
17、e 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 Potatoes are usually dormant for several weeks after lifting. They will break dormancy once they have accumulated sufficient degree days 1) , from the time
18、 the tubers were lifted from the field. This period will vary with different varieties. Sprouting may be restricted by storage below4 C or by the application of chemical inhibitors. The start and rate of sprouting is governed by temperature. The greening and strengthening of the sprouts is controlle
19、d by light intensity. Chitting stores allow and control the formation of chits by control of light and temperature. Controlled ventilation, refrigeration, heating and lighting may be required. 3.2 Siting Consideration should be given to the siting of buildings for chitting potatoes (see BS5502-20).
20、In particular consideration should be given to: a) the proximity to potato grading, packing and storage units; b) the proximity to the land to be planted; c) the availability of services; d) ease of access. 3.3 Type of store 3.3.1 Stores used for chitting potatoes are either naturally lit, artificia
21、lly lit or unlit. Choice of system should be determined by the size of the enterprise, consideration of alternative uses, capital and running costs. 3.3.2 Naturally lit stores may be glasshouses or structures clad in an alternative transparent material (see4.3.2). 3.3.3 Insulated stores utilizing ar
22、tificial lights give more positive control of temperature and may reduce energy costs. Incorporating refrigeration will enable greater control over environmental conditions. 4 Design, materials and construction 4.1 General 4.1.1 The design, choice of materials and construction should be in accordanc
23、e 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 withstand loads from the stored crops and mechanical transport in accordance with BS5502-22. 4.1.3 Structures should be designed to minimize differential se
24、ttlement, deflection and structural movement that could cause fracturing of surfaces and permit moisture ingress or infestation so putting the stored 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 Mater
25、ials and treatments used in the construction should not impart odour or taint the produce. 4.1.6 All parts of the structure should be constructed in accordance with the recommendations given in BS8000. 4.2 Floors Floors should be level with an even surface. They should be designed and constructed to
26、 withstand loads from the crop, pallets or bulk bins and transport. The surface should be hard wearing, capable of being cleaned and not susceptible to cracking or crazing. A damp-proof membrane should be incorporated. Thermal and shrinkage movement should be minimized by the correct placing of cons
27、truction, expansion and contraction joints. 4.3 Wall and roof cladding 4.3.1 Walls and roofs should protect the crop from weather. 4.3.2 For naturally lit stores the following materials may be used: a) horticultural glass, or glass with low emissivity coatings; b) rigid PVC, bubble plastics polycarb
28、onate acrylic sheets; c) polyethylene 1) Degree days should be taken as the sum of the crop temperature ( C) and the storage period (days).BS5502-66:1992 2 BSI 09-1999 4.3.3 Choice of material should be determined by the required durability and capital cost. Materials may be in double or triple laye
29、rs to aid insulation. NOTEIncreasing layers and differing materials will alter light transmission capabilities. 4.3.4 Artificially lit stores may be clad in any material that excludes or controls the admission of light. 4.4 Insulation 4.4.1 Where thermal insulating materials, other than double or tr
30、iple glazing are used, they should be continuous over all surfaces. Care should be taken to avoid thermal bridging at eaves/wall interfaces and at door openings. Thermal insulating materials should be protected from impact damage, not harbor pests and should be durable for the intended life of the s
31、tore. 4.4.2 Double or triple glazing should increase insulation capabilities and reduce the temperature peak values. 4.4.3 For insulated stores a minimum thermal transmittance of0.45 W/(m 2 C) is recommended for walls and the roof. For refrigerated stores the insulation should be increased to provid
32、e a minimum value of0.35W/(m 2 C) for the walls and of0.30W/(m 2 C) for the roof. 4.4.4 Moisture penetration into insulation reduces its efficiency. Vapour checks should be provided for high storage humidities. Joints in the vapour checks should be lapped and sealed, nailed fixings should be taped.
33、Depending upon storage conditions these vapour checks may be required to both faces of the insulation. 4.5 Doors Doors should be wide enough to permit efficient access, usually4.5m 4.5m, and be suitably sited. Doors for insulated stores should be insulated to the wall U value and be well fitted and
34、sealed. Addition of personnel doors will assist inspection. The door threshold should be designed to keep out water. External access areas should slope away from the doorway. 4.6 Layout and dimensions 4.6.1 General Potatoes for chitting are stored in either bulk boxes or in plastic trays on pallets.
35、 The following factors should be considered when determining dimensions: a) the volume of crop to be chitted; b) the space required for loading and unloading; c) the space required for equipment; d) management techniques. 4.6.2 Naturally lit stores For naturally lit stores the layout should be based
36、 on conventional1500mm 900mm pallets with four750mm 450mm 150mm trays per layer. Each pallet may be stacked10 trays high with pallets stacked2 high. Pallets should be placed in lines500mm apart with150mm between each pallet. The stacking arrangement should allow access for loading and unloading. 4.6
37、.3 Artificially lit stores The stacking arrangement for artificially lit stores should be similar to naturally lit stores except that pallets may be stacked higher, usually three pallets is the maximum, depending on the stability of the pallets and trays. 4.6.4 Unlit stores For stores without lights
38、, trays on pallets or bulk boxes for mini-chits may be placed close together. Bulk boxes are usually nominal1 t potato boxes,1830mm 1220mm 915mm. NOTEA British Standard is being prepared for pallet based potato boxes. Access should be allowed between groups of boxes for inspection. The height of the
39、 stack should be determined by the stability of the stacking arrangement, usually6 boxes or3 pallets is desirable. 4.6.5 Bulk density The density of the crop in trays or boxes will vary with variety, size of tuber and management. The approximate weight of potatoes in containers may be taken as follo
40、ws: Tray: 16.6kg (666kg/pallet of40trays). Box:1250kg (using1830mm 1220mm 900mm ware potato box). 5 Environment 5.1 General After harvesting, potatoes undergo change. The environmental conditions within the store will determine the rate of change. 5.2 Lighting 5.2.1 In naturally lit stores artificia
41、l lighting will not be required other than for inspection. There should be access ways between the trays to aid inspection, see4.6.2. The bottom of the trays should be white to assist the light transmission to inner trays.BS5502-66:1992 BSI 09-1999 3 5.2.2 In artificially lit buildings fluorescent m
42、ovable light units should be suspended vertically in the alleyway at every second pallet. If path widths are kept below500mm, each light will service four pallets, two on either side of the path. Fluorescent tubes should be installed in accordance with Health and Safety Executive (HSE) recommendatio
43、ns. The intensity of light required will depend on the sprouting capabilities of the potato variety. To achieve a balanced light level the length of the tubes should be equal to the stack height. It is an advantage for the lights to be capable of being moved on an overhead catenary wire system. 5.3
44、Temperature and ventilation 5.3.1 Potatoes produce heat as a result of respiration. The rate of heat produced is dependent upon storage temperature and potato maturity. This heat should be removed or recirculated to maintain the required environmental conditions. Likely heat output is given in Table
45、 1. Table 1 Heat output of potatoes 5.3.2 For all stores an even air temperature distribution should be achieved by the use of a forced air ventilation system incorporating full or partial recirculation with an air mixing unit. Automatic control with powered louvres may assist store management. 5.3.
46、3 Condensation or free water on the surface of the crop should be avoided as this will cause rot. 5.3.4 In naturally lit stores the system should be capable of giving15 to20 air changes per hour. 5.3.5 In artificially lit stores the system should be designed to remove or redistribute the heat produc
47、ed by the lights as well as the crop. 5.3.6 For an unlit store using a mini-chitting system the air distribution system should remove temperature gradients from the stack. 5.3.7 Sectional walls or letter box systems have been proven to reduce temperature gradients. 5.3.8 Refrigeration plant may be i
48、nstalled to give flexibility and control. For an artificially lit store it may be used to cool the crop to soil temperatures before planting. 5.3.9 Frost protection should be provided. If heaters are provided these can be mounted in the ductwork after the fan. NOTECalculation of heating requirement
49、should be based on the stores expected heat balance equation. Factors such as the interior surface area of the store, insulation standards and heat input from the crop and associated plant and equipment should be taken into account. 6 Services 6.1 Electrical installation 6.1.1 Electrical installation should be carried out in accordance with BS5502-25 and the current Institute of Electrical Engineers (IEE) Wiring Regulations. 6.1.2 Refrigeration systems and fans may require a3-phase power supply. 6.1.3 The switch-fuse and distri
