GB2082039A

GB2082039A - Treating plant materials with ammonia

Info

Publication number: GB2082039A
Application number: GB8121906A
Authority: GB
Original assignee: Maskinfabriken Taarup AS
Current assignee: Maskinfabriken Taarup AS
Priority date: 1980-07-28
Filing date: 1981-07-15
Publication date: 1982-03-03
Also published as: GB2082039B; FR2487175B3; FR2487175A1

Abstract

For the treatment of chopped straw and similar plant materials with ammonia, the ammonia is fed from a pressurised container, and the ammonia, before being conveyed to the location of treatment, is relieved of pressure to provide for a particularly effective mixing of the chopped straw and the ammonia. To obtain such a pressure relief in a simple manner, the ammonia is fed to a chamber (1) of circular cross-section, and the ammonia is fed tangentially through inlet opening (6) into the chamber so as to provide for an effective separation between vapour and pressure relieved liquid ammonia, which is discharged at the bottom (3) of the chamber and conveyed to the location of treatment, while the ammonia vapour is discharged through a discharge opening (11) communicating with a pipe (2) which is centrally disposed in the chamber and terminates shortly below the top (4) of the chamber, the ammonia vapour being either discharged or being passed to a location of treatment for the material. Water may be fed to the chamber through opening (5). <IMAGE>

Description

SPECIFICATION Treating chopped straw with ammonia The invention relates to a method of treating chopped straw and similar plant materials with ammonia fed from a pressurised container and fed to the material, preferably immediately after the chopping operation. In such treatment of straw and the like, ammonia has generally been conveyed directly from a container, in which the ammonia is pressurised, to a treatment location which preferably is at the discharge of the chopping apparatus used, or it may be fed by a conveyor leading from the chopping device to a silo or another storage location; or the ammonia may actually also be conveyed directly into the chopping device.However, it has been found that difficulties arise in obtaining a sufficiently uniform treatment of the material because the ammonia, on being introduced, partly evaporates, and the addition of ammonia can therefore not be effectively controlled so that it may become irregular and it becomes impossible fully to utilise the feeding value of the material being treated, which is conditional upon all the material getting into effective contact with the ammonia to liberate the nutritious substances of the material.

According to the present invention there is provided a method of treating chopped straw and similar plant materials with ammonia fed from a pressurised container and fed to the material, the ammonia being relieved of pressure during liberation of ammonia vapour before being conveyed to the location of the treatment. As the ammonia is pressure relieved ammonia it can flow evenly into the space where the treatment is to be carried out, i.e. the location of treatment proper, and therefore it is possible, e.g. in a rotary conveyor often used in connection with a straw chopper, to obtain a very uniform and effective mixing of the ammonia and the straw and thus to obtain a product which is significantly more valuable than that obtainable by the methods used in the past.

The invention also relates to an apparatus for carrying out the method just defined, the apparatus comprising a chamber with a circular cross-section and an upright axis, there being at the upper end of the chamber a tangential inlet opening for ammonia from a pressurised container, and at the bottom of the chamber a discharge opening for pressure relieved liquid ammonia, this discharge opening communicating with a pipe which leads to a location of treatment, and the chamber having a further discharge opening for ammonia vapour. Such a very simple apparatus provides an excellent pressure relief of the ammonia, and the liquid ammonia is conveyed directly to the location of treatment, while the ammonia vapour may be discharged in any appropriate manner.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which: Figure 1 is a diagrammatica vertical section taken along line I-I in Figure 2 of apparatus for treating chopped straw and similar plant material with ammonia, and Figure 2 is a section taken along line Il-Il in Figure 1.

The apparatus shown in the Figures includes a cylindrical chamber 1 having its axis upright and in which there is provided a pipe 2 disposed coaxially with the chamber and extending upwards from the bottom 3 of the chamber to a point adjacent the top 4 of the chamber. A tangential water inlet opening 5 and a tangential ammonia inlet opening 6 are provided at a short distance below the upper end of the pipe 2. The inlet opening 5 communicates with a pipe 7 in which there is a control valve 8 through which the opening 5 may be connected to a water supply. The inlet opening 6 can be placed in communication with a container for pressurised ammonia through a pipe 9 in which there is a control valve 10.

The bottom 3 of the chamber is formed with a discharge opening 11 which communicates directly with the interior of the pipe 2, and outside the pipe 2 a catch plate 12 for the liquid ammonia is provided at the bottom 3. A discharge opening 13 within the catch plate 12 leads directly to the location of treat ment for the chopped straw.

When water and ammonia enter through the two tangential openings 5 and 6, the ammonia partly evaporates, and this ammonia vapour moves up towards the top 4 of the chamber and from there is guided down through the pipe 2 as, normally, there is a slight difference in pressure between the ammonia vapour in the chamber and the location of treatment where the ammonia is to be used. The pressure relieved ammonia is whirled along the wall of the chamber and is mixed there with water from the inlet opening 5. The ammonia thus mixed is caught by the catch plate 12 and is discharged through the opening 13 to the location of treatment.

Since the apparatus is so constructed that the discharge opening for ammonia vapour communicates with a pipe which leads to the location of treatment or a location for subsequent treatment of chopped straw already treated with the liquid ammonia, complete utilisation of the ammonia is provided for, and the ammonia may easily be dosed expediently in relation to the quantity of the material to be treated.

It is particularly expedient that the wall of the chamber is additionally formed with a tangential water inlet opening. This permits the pressure relived ammonia to be suitably diluted, whereafter in liquid form, diluted with the water, the ammonia is conveyed from there to the location of treatment.

Such a dilution of the ammonia has been found expedient for further improvement of uniformity since the greater amount of liquid is easier to distribute, and individual parts of the straw are therefore not subjected to too-strongly concentrated ammonia.

By having the discharge opening for ammonia vapour fitted at the bottom of the chamber and surrounded by a pipe section which is coaxial with the chamber and extends in the chamber upwards from the bottom of the chamber to a point shortly below the top of the chamber, the discharge opening for the pressure relieved liquid ammonia being disposed outside this pipe section (preferably adjacent the wall of the chamber), a particularly effective sep aration between the liquid and gaseous ammonia is obtained.

Claims

1. A method of treating chopped straw and simi lar plant materials with ammonia fed from a pressurised container and fed to the material, the ammonia being relieved of pressure during liberation of ammonia vapour before being conveyed to the location of the treatment.

2. A method as claimed in claim 1, wherein the treatment is effected immediately after the chopping operation.

3. A method of treating chopped straw and similar plant materials with ammonia, substantially as hereinbefore described with reference to the accompanying drawing.

4. Apparatus for carrying out the method as claimed in any one of claims 1 to 3, the apparatus comprising a chamberwith a circular cross-section and an upright axis, there being at the upper end of the chamber a tangential inlet opening for ammonia from a pressurised container, and at the bottom of the chamber a discharge opening for pressure relieved liquid ammonia, this discharge opening communicating with a pipe which leads to a location of treatment, and the chamber having a further discharge opening for ammonia vapour.

5. Apparatus as claimed in claim 4, wherein the chamber is cylindrical.

6. Apparatus as claimed in claim 4 or 5, wherein the further discharge opening that is for ammonia vapour communicates with a pipe which leads to said location of treatment.

7. Apparatus as claimed in claim 4 or 5, wherein the further discharge opening that is for ammonia vapour communicates with a pipe which leads to a location for subsequent treatment of the chopped material already treated with the liquid ammonia.

8. Apparatus as claimed in any one of claims 4 to 7, wherein the wall of the chamber is additionally provided with a tangential water inlet opening.

9. apparatus as claimed in any one of claims 4 to 8, wherein the further discharge opening that is for ammonia vapour is fitted at the bottom of the chamber and is surrounded by a pipe section which is coaxial with the chamber and extends in the chamber, upwards from the bottom of the chamber to a point shortly below the top of the chamber, the first-mentioned discharge opening that is for the pressure relieved liquid ammonia being disposed outside the pipe section.

10. Apparatus as claimed in claim 9, wherein the first-mentioned discharge opening that is for the pressure relieved liquid ammonia is adjacent the wall ofthe chamber.

11. Apparatus for carrying out the method as claimed in claim 1,2 or 3, substantially as hereinbefore described with reference to the accompanying drawing.