FR2844583A1 - Preservation procedure for cut flowers uses bath of hot sand that is recuperated and recycled after drying - Google Patents

Abstract

The procedure consists of drying the flowers, after cutting the stems to 10 cm and inserting wires, in a bath of hot sand having a grain size of 0.3 - 1 mm, poured into a perforated container with a cloth lining. Drying is carried out in a ventilated oven at 35 - 50 deg C and relative hygrometry of under 25 per cent.

Description

i

PRESENTATION OF THE PROCESS

  Our naturalization process (*) of flowers by hot sand bath has been developed as an alternative to the industrial freeze-drying process or

  domestic processes using desiccants.

  (*) Naturalization: (Hachette dictionary) "Operation by which we give to

  a cut plant or a dead animal the appearance of living nature. "

  The idea of the sand bath is not new: it is well described in a document from the 170 century. Very many contemporary publications take it up thanks to the current fashion for naturalized flowers. Among the dozens available on the Internet, we will only select that of the University

  from Florida (USA) under the title "Drying and Preserving Plant Material" (June 1997).

  This publication, particularly well documented and almost exhaustive, says in the SABLE paragraph:

  "The oldest, least expensive and yet one of the best drying agents is fine, dry and washed sand which is almost free of salt.

  The major problems with sand are that it is heavy and sometimes bruises the delicate petals and that it acts slowly in comparison with the

other agents ... "

  Our contribution is the rationalization of drying by sand bath so that it becomes efficient, economical and rapid, that is to say that it retains its qualities and

  let him lose his alleged flaws.

  Our results are comparable to those of other naturalization processes that do not use coating or recolouring chemicals. In particular, our flowers seem very close to freeze-dried flowers (some say sublimated) with the same limitations of use: sensitivity to humidity, to light, to parasites. But our process has certain advantages: --Lower fragility of dried flowers: plant cells are not

  not damaged by the water crystals of the sap due to freezing during freeze-drying.

  - speed: less than 4 days for roses, 3 days for carnations and

  phalaenopsis, 8 days for the cattleyas.

  - investment cost in equipment: at equal production, perhaps 10% of

lyophilization option.

  - very low maintenance cost in temperate climate, because the technology used is very simple, the temperature moderate, the atmosphere not

  corrosive and the wearing part, a fan belt, very inexpensive.

  - operating cost: for an oven which can dry 5000 roses per

  week, the installed power is 1.4 kW. The sand is immediately recycled.

  - no harmful effect of power cuts of less than 12 hours: this lengthens the drying time all the more without further deterioration.

DESCRIPTION OF THE PROCESS

A-Details of the manipulations:

  The process only works well with fresh, invigorating flowers.

  1 - As soon as you pick the flowers, without refrigerating them, cut the stem about 10 mm 10 from the head and dip it in a flower conservation liquid

  cut to keep the turgor.

  2 - Insert the metal spike (described in the following paragraph) into the

  tail stump remaining and, in the same movement, bend it square.

  So the flower has no extra height.

  This pick has two purposes: For packaging, the dried flower is fixed by

  this hooked rod, planted in polystyrene using bent pliers.

  And for the subsequent use of the flower, the rectified stem is glued with glue

  hot on a florist wire.

  3 - Line the drying basket with a veil, pour a bed of sand about 20 2 cm thick and arrange the flowers standing one by one and side by side.

  Gradually pour the sand around and inside the corollas, keeping

the natural position of the petals.

  4 - The flowers completely covered by the sand, enclose the basket in

  the hot oven set at 41 0 + b- 50C for 3 to 8 days depending on the variety and the color.

  - When the drying is finished, take the basket out into the open so that the sand cools for a few hours, typically 3 hours at 200 C. 6-Firmly fit a lid on the full basket flush with the sand

  and turn everything over on the perforated table (described in the following paragraph).

  Lift the basket and the veil. The flowers are then accessible. Enter them by

their stem.

  7 - Straighten their spike and push the hook into a polystyrene plate using bent pliers.

  8 - With the polystyrene plate fully filled, spray an insecticide lacquer on the flowers and store.

  B-Detail of the material used: 1 - a wide and shallow container with 1 cm of a conventional solution of

  conservation for drinking flowers.

  2 - wire spikes, diameter 0.7 +/- 0.3 mm, developed length about 50 mm, bent about 13 mm from one end at an angle of 400 with a radius of curvature of 1 , 5 mm to 2 mm. This radius of curvature allows them to be held effectively when they are planted in an expanded polystyrene plate whose grains have a diameter of 3 to 4 mm. Plan a spade

by rose.

  3 - drying baskets of 8 to 10 liters capacity, if the use is manual, and 10 cm in height, very openwork (more than 40% of days) on all their faces, likely to support their full sand. Their upper edge

  must be in a plane to be able to close them with a cover.

  Their sides must have a large draft angle, which improves the circulation of air in the oven when they are side by side.

  Provide a basket for 30 medium roses. Their lifespan is long,

a few years.

  4 - sail rectangles, of strength between 13 and 25 g for

  line the inside of the baskets and retain the sand, drying agent. 20 The choice can be made on the agricultural forcing veil PP1 7.

  Provide one rectangle per basket, its lifespan is 5 to 10 uses.

  - quartz sand, with a particle size of 0.3 to 0.1 mm, preferably not dusty. The choice can be made on the sand which exists in the trade

  under the name of sand for sanding no 0, in 50 kg bags.

  The stock must correspond to approximately 10 kg per 10 liter basket. The sand is

recycle indefinitely.

  6 - one hand shovel per person, to draw the sand from the cans which

  contain it then pour it over the flowers to dry.

  7 - an electric drying oven with adjustable temperature from 35 to 500C, with overheating safety, internal ventilation and adjustable ventilation.

  A temperature exchanger between the incoming air and the air leaving the oven

  decreases power consumption.

  The interior equipment consists of a set of shelves in round steel (and not in sheet metal) which support the baskets filled with flowers embedded in the sand. 35 The free volume around the baskets when the maximum load is reached must be at least equal to 40% of the envelope volume of the shelves. It's a

  necessary condition for good air circulation and good drying.

  The control equipment consists of a thermometer and a hygrometer.

  The relative humidity inside the oven must be less than or equal to%, preferably 20%, which corresponds to approximately 13 g of water per m3 of air, a condition generally fulfilled in a climate tempered by ambiant air. An adjustable extractor maintains the rate of 20% RH of the internal air. In the case of a tropical atmosphere, the humidity being generally higher than 13 g / m3, the oven cannot operate in an open circuit as previously but with an internal dehumidifier circulating the air in

  closed circuit and a cooler to control the temperature.

  8 - a device to recover the sand from the baskets at the exit of the oven when the flowers are dry. It can consist of a table with a perforated or wire mesh tray above a receptacle provided with a sieve to remove sand the

  any impurities before it is reused.

  9 - a rigid and sand-tight cover, which fits over the top of the 15 baskets filled to the brim with sand where the dried flowers are drowned, and which allows the baskets to be turned over without the flowers being disturbed inside. - rectangular plates of expanded polystyrene with a thickness of mm, the grains of which have an average diameter of 3 to 4 mm, plates where the dry flowers will be pricked for packaging. Their dimensions are

  adapted to those of the cardboard boxes.

  11 - bent pliers to handle the flowers during packaging. Provide one pair per employee.

Claims (6)

  1 - naturalization process of fresh flowers by a sand bath   characterized by the use of hot sand.   2 - naturalization process according to claim t characterized by the use of sand to sand of particle size between 0.3 and 1 mm.   3 - naturalization process according to claims 1 and 2 characterized   by the use, for the sand bath, of an openwork container with more than 40% of days on all its faces and lined with a veil of force between 13 and 25 g.   4 - naturalization process according to claims 1, 2 and 3 characterized   by using the technique of silting up flowers standing in a container, then turning the container over after drying without disturbing the flowers by closing the said container. This removes the   container by lifting it up, then sand the flowers by grabbing them by the stem while the sand flows without damaging them.   - naturalization process according to claim 1 characterized by the use of drying in a ventilated dry oven, regulated at a   temperature between 35 and 500C and a relative humidity less than 25%.   The drying temperature, which varies with the variety and color of the flower, is generally 41 +/- 50C.   6 - naturalization process according to claims 1, 2, 3 and 4   characterized by the fact that the sand is collected on a perforated or screened table with, below, a collector terminated by a removable screen, which   allows immediate recycling of sand.   7 - process for conditioning naturalized flowers characterized by the use of a hooked metal wire, engaged in still fresh flowers, and which is planted in expanded polystyrene. To do this, preferably bent pliers are used. This hook is described as follows: the diameter of the wire is 0.7 +/- 0.3 mm, the developed length of about 50 mm, the radius of curvature of the hook is that of the grains of expanded polystyrene, preferably 1.5 to 2 mm, the length of the return approximately 13 mm, the angle of the   back with the part engaged in the flower is about 400.